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Wang JZ, Cheng B, Kato A, Kise M, Shimadate Y, Jia YM, Li YX, Fleet GW, Yu CY. Design, synthesis and glycosidase inhibition of C-4 branched LAB and DAB derivatives. Eur J Med Chem 2022; 233:114230. [DOI: 10.1016/j.ejmech.2022.114230] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 02/11/2022] [Accepted: 02/22/2022] [Indexed: 12/17/2022]
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2
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Wu QK, Kinami K, Kato A, Li YX, Fleet GWJ, Yu CY, Jia YM. Synthesis and Glycosidase Inhibition of Broussonetine M and Its Analogues. Molecules 2019; 24:molecules24203712. [PMID: 31619020 PMCID: PMC6832352 DOI: 10.3390/molecules24203712] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/10/2019] [Accepted: 10/14/2019] [Indexed: 01/13/2023] Open
Abstract
Cross-metathesis (CM) and Keck asymmetric allylation, which allows access to defined stereochemistry of a remote side chain hydroxyl group, are the key steps in a versatile synthesis of broussonetine M (3) from the d-arabinose-derived cyclic nitrone 14. By a similar strategy, ent-broussonetine M (ent-3) and six other stereoisomers have been synthesized, respectively, starting from l-arabino-nitrone (ent-14), l-lyxo-nitrone (ent-3-epi-14), and l-xylo-nitrone (2-epi-14) in five steps, in 26%–31% overall yield. The natural product broussonetine M (3) and 10’-epi-3 were potent inhibitors of β-glucosidase (IC50 = 6.3 μM and 0.8 μM, respectively) and β-galactosidase (IC50 = 2.3 μM and 0.2 μM, respectively); while their enantiomers, ent-3 and ent-10’-epi-3, were selective and potent inhibitors of rice α-glucosidase (IC50 = 1.2 μM and 1.3 μM, respectively) and rat intestinal maltase (IC50 = 0.29 μM and 18 μM, respectively). Both the configuration of the polyhydroxylated pyrrolidine ring and C-10’ hydroxyl on the alkyl side chain affect the specificity and potency of glycosidase inhibition.
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Affiliation(s)
- Qing-Kun Wu
- Beijing National Laboratory for Molecular Science (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Kyoko Kinami
- Department of Hospital Pharmacy, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
| | - Atsushi Kato
- Department of Hospital Pharmacy, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
| | - Yi-Xian Li
- Beijing National Laboratory for Molecular Science (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - George W J Fleet
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, OX13TA Oxford, UK.
- National Engineering Research Center for Carbohydrate Synthesis, Jiangxi Normal University, Nanchang 330022, China.
| | - Chu-Yi Yu
- Beijing National Laboratory for Molecular Science (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
- National Engineering Research Center for Carbohydrate Synthesis, Jiangxi Normal University, Nanchang 330022, China.
| | - Yue-Mei Jia
- Beijing National Laboratory for Molecular Science (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
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Huang Y, Gao Y, He W, Wang Z, Li W, Lin A, Xu J, Tanabe G, Muraoka O, Wu X, Xie W. Practical Route to Neokotalanol and Its Natural Analogues: Sulfonium Sugars with Antidiabetic Activities. Angew Chem Int Ed Engl 2019; 58:6400-6404. [PMID: 30815962 DOI: 10.1002/anie.201900761] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 02/22/2019] [Indexed: 11/09/2022]
Abstract
An efficient and divergent approach toward the synthesis of all four de-O-sulfonated sulfonium type α-glucosidase inhibitors, originally isolated from plants of genus Salacia, is reported for the first time. The key strategy features a coupling reaction between thiol derivatives and a diiodide counterpart. The newly designed thiol coupling partner presents high chemical stability, while the diiodide partner could be easily obtained with increased overall yields compared with conventional routes. The intermolecular nucleophilic substitution reaction followed by a diastereoselective intramolecular cyclization provided the target five-member sulfonium salt structure, which was connected in an α-orientation to a polyhydroxylated side-chain moiety.
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Affiliation(s)
- Yuhao Huang
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, P. R. China
| | - Yunlong Gao
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, P. R. China
| | - Weigang He
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, P. R. China
| | - Zihao Wang
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, P. R. China
| | - Wei Li
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, P. R. China
| | - Aijun Lin
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, P. R. China
| | - Jinyi Xu
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, P. R. China
| | - Genzoh Tanabe
- Faculty of Pharmacy, Kinki University, 3-4-1 Kowakae, Higashi-osaka, 577-8502, Osaka, Japan
| | - Osamu Muraoka
- Faculty of Pharmacy, Kinki University, 3-4-1 Kowakae, Higashi-osaka, 577-8502, Osaka, Japan
| | - Xiaoming Wu
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, P. R. China
| | - Weijia Xie
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, P. R. China
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Huang Y, Gao Y, He W, Wang Z, Li W, Lin A, Xu J, Tanabe G, Muraoka O, Wu X, Xie W. Practical Route to Neokotalanol and Its Natural Analogues: Sulfonium Sugars with Antidiabetic Activities. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201900761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Yuhao Huang
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal ChemistrySchool of PharmacyChina Pharmaceutical University Nanjing 210009 P. R. China
| | - Yunlong Gao
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal ChemistrySchool of PharmacyChina Pharmaceutical University Nanjing 210009 P. R. China
| | - Weigang He
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal ChemistrySchool of PharmacyChina Pharmaceutical University Nanjing 210009 P. R. China
| | - Zihao Wang
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal ChemistrySchool of PharmacyChina Pharmaceutical University Nanjing 210009 P. R. China
| | - Wei Li
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal ChemistrySchool of PharmacyChina Pharmaceutical University Nanjing 210009 P. R. China
| | - Aijun Lin
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal ChemistrySchool of PharmacyChina Pharmaceutical University Nanjing 210009 P. R. China
| | - Jinyi Xu
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal ChemistrySchool of PharmacyChina Pharmaceutical University Nanjing 210009 P. R. China
| | - Genzoh Tanabe
- Faculty of PharmacyKinki University 3-4-1 Kowakae, Higashi-osaka 577-8502 Osaka Japan
| | - Osamu Muraoka
- Faculty of PharmacyKinki University 3-4-1 Kowakae, Higashi-osaka 577-8502 Osaka Japan
| | - Xiaoming Wu
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal ChemistrySchool of PharmacyChina Pharmaceutical University Nanjing 210009 P. R. China
| | - Weijia Xie
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal ChemistrySchool of PharmacyChina Pharmaceutical University Nanjing 210009 P. R. China
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Rajashree R, Patil R, Khlokute SD, Goudar SS. Effect of Salacia reticulata W. and Clitoria ternatea L. on the cognitive and behavioral changes in the streptozotocin-induced young diabetic rats. J Basic Clin Physiol Pharmacol 2017; 28:107-114. [PMID: 28132032 DOI: 10.1515/jbcpp-2016-0024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 10/21/2016] [Indexed: 11/15/2022]
Abstract
BACKGROUND Diabetes mellitus (DM) of juvenile onset affects both the peripheral and central nervous systems (CNS). However, central effects are less documented and studied than peripheral deficits. Currently, the only feasible treatment available for type 1 DM (T1DM) is insulin which has its own limitations. Hence, an alternative therapy, especially a newer herbal formulation is very much the need of the time. The present study aimed to determine the effects of the alcoholic extracts of roots of the Salacia reticulata W. (SR) and Clitoria ternatea L. (CT) on cognitive and behavioral changes in juvenile diabetic rats. METHODS Diabetes was induced in 25-day-old Wistar rats by streptozotocin (50 mg/kg bw, IP). Animals were divided into seven groups (n=6). Rats were treated with root extracts of SR and CT (100 mg/kg BW each) for 30 days, from day 1 and day 20 of diabetes confirmation. Then, rats were tested in elevated plus maze (EPM) and Morris water maze (MWM). RESULTS A statistically significant (p<0.05) difference was observed between the SRCT group and diabetic groups of rats. Apart from decreasing FBS, the combined therapy also proved beneficial as nootropic agent in rats with early-onset diabetes. However, significant improvement is observed only in the learning and memory among preventive group, but not in the curative group. CONCLUSIONS SRCT, a herbal formula, when used in combination, has a more potent effect in preventing the deleterious effects of juvenile diabetes on cognitive and behavioral changes.
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Bagri P, Chester K, Khan W, Ahmad S. Aspects of extraction and biological evaluation of naturally occurring sugar-mimicking sulfonium-ion and their synthetic analogues as potent α-glucosidase inhibitors from Salacia: a review. RSC Adv 2017. [DOI: 10.1039/c7ra02955a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
A review of the selective inhibitory activities of sulfonium compounds ofSalaciaagainst intestinal α-glucosidases, structural features important for effective inhibition and the toggling approach for controlling starch digestion and glucose release.
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Affiliation(s)
- Priyanka Bagri
- School of Pharmaceutical Education and Research
- Bioactive Natural Product Laboratory
- Department of Pharmacognosy and Phytochemistry
- Jamia Hamdard
- New Delhi
| | | | - Washim Khan
- School of Pharmaceutical Education and Research
- Bioactive Natural Product Laboratory
- Department of Pharmacognosy and Phytochemistry
- Jamia Hamdard
- New Delhi
| | - Sayeed Ahmad
- School of Pharmaceutical Education and Research
- Bioactive Natural Product Laboratory
- Department of Pharmacognosy and Phytochemistry
- Jamia Hamdard
- New Delhi
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7
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Al-Asri J, Gyémánt G, Fazekas E, Lehoczki G, Melzig MF, Wolber G, Mortier J. α-Amylase Modulation: Discovery of Inhibitors Using a Multi-Pharmacophore Approach for Virtual Screening. ChemMedChem 2016; 11:2372-2377. [PMID: 27726310 DOI: 10.1002/cmdc.201600427] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Indexed: 11/07/2022]
Abstract
Better control of postprandial hyperglycemia can be achieved by delaying the absorption of glucose resulting from carbohydrate digestion. Because α-amylase initiates the hydrolysis of polysaccharides, the design of α-amylase inhibitors can lead to the development of new treatments for metabolic disorders such as type II diabetes and obesity. In this study, a rational computer-aided approach was developed to identify novel α-amylase inhibitors. Three-dimensional pharmacophores were developed based on the binding mode analysis of six different families of compounds that bind to this enzyme. In a stepwise virtual screening workflow, seven molecules were selected from a library of 1.4 million. Five out of seven biologically tested compounds showed α-amylase inhibition, and the two most potent compounds inhibited α-amylase with IC50 values of 17 and 27 μm. The scaffold benzylideneacetohydrazide was shared by four of the discovered inhibitors, emerging as a novel drug-like non-carbohydrate fragment and constituting a promising lead scaffold for α-amylase inhibition.
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Affiliation(s)
- Jamil Al-Asri
- Institute of Pharmacy, Department of Pharmaceutical & Medicinal Chemistry, Freie Universität Berlin, Königin-Luise Str. 2-4, 14195, Berlin, Germany
| | - Gyöngyi Gyémánt
- Department of Inorganic & Analytical Chemistry, University of Debrecen, Egyetem ter 1, PO Box 21, 4032, Debrecen, Hungary
| | - Erika Fazekas
- Department of Inorganic & Analytical Chemistry, University of Debrecen, Egyetem ter 1, PO Box 21, 4032, Debrecen, Hungary
| | - Gábor Lehoczki
- Department of Inorganic & Analytical Chemistry, University of Debrecen, Egyetem ter 1, PO Box 21, 4032, Debrecen, Hungary
| | - Matthias F Melzig
- Institute of Pharmacy, Department of Pharmaceutical & Medicinal Chemistry, Freie Universität Berlin, Königin-Luise Str. 2-4, 14195, Berlin, Germany
| | - Gerhard Wolber
- Institute of Pharmacy, Department of Pharmaceutical & Medicinal Chemistry, Freie Universität Berlin, Königin-Luise Str. 2-4, 14195, Berlin, Germany
| | - Jérémie Mortier
- Institute of Pharmacy, Department of Pharmaceutical & Medicinal Chemistry, Freie Universität Berlin, Königin-Luise Str. 2-4, 14195, Berlin, Germany
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8
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Mohan S, Jayakanthan K, Nasi R, Kuntz DA, Rose DR, Pinto BM. Synthesis and Biological Evaluation of Heteroanalogues of Kotalanol and De-O-Sulfonated Kotalanol. Org Lett 2010; 12:1088-91. [DOI: 10.1021/ol100080m] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sankar Mohan
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6, Department of Medical Biophysics, University of Toronto and Division of Molecular and Structural Biology, Ontario Cancer Institute, Toronto, ON, Canada M5G 2M9, and Department of Biology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
| | - Kumarasamy Jayakanthan
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6, Department of Medical Biophysics, University of Toronto and Division of Molecular and Structural Biology, Ontario Cancer Institute, Toronto, ON, Canada M5G 2M9, and Department of Biology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
| | - Ravindranath Nasi
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6, Department of Medical Biophysics, University of Toronto and Division of Molecular and Structural Biology, Ontario Cancer Institute, Toronto, ON, Canada M5G 2M9, and Department of Biology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
| | - Douglas A. Kuntz
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6, Department of Medical Biophysics, University of Toronto and Division of Molecular and Structural Biology, Ontario Cancer Institute, Toronto, ON, Canada M5G 2M9, and Department of Biology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
| | - David R. Rose
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6, Department of Medical Biophysics, University of Toronto and Division of Molecular and Structural Biology, Ontario Cancer Institute, Toronto, ON, Canada M5G 2M9, and Department of Biology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
| | - B. Mario Pinto
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6, Department of Medical Biophysics, University of Toronto and Division of Molecular and Structural Biology, Ontario Cancer Institute, Toronto, ON, Canada M5G 2M9, and Department of Biology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
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9
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Gloster TM, Davies GJ. Glycosidase inhibition: assessing mimicry of the transition state. Org Biomol Chem 2010; 8:305-20. [PMID: 20066263 PMCID: PMC2822703 DOI: 10.1039/b915870g] [Citation(s) in RCA: 191] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Accepted: 09/30/2009] [Indexed: 12/15/2022]
Abstract
Glycoside hydrolases, the enzymes responsible for hydrolysis of the glycosidic bond in di-, oligo- and polysaccharides, and glycoconjugates, are ubiquitous in Nature and fundamental to existence. The extreme stability of the glycosidic bond has meant these enzymes have evolved into highly proficient catalysts, with an estimated 10(17) fold rate enhancement over the uncatalysed reaction. Such rate enhancements mean that enzymes bind the substrate at the transition state with extraordinary affinity; the dissociation constant for the transition state is predicted to be 10(-22) M. Inhibition of glycoside hydrolases has widespread application in the treatment of viral infections, such as influenza and HIV, lysosomal storage disorders, cancer and diabetes. If inhibitors are designed to mimic the transition state, it should be possible to harness some of the transition state affinity, resulting in highly potent and specific drugs. Here we examine a number of glycosidase inhibitors which have been developed over the past half century, either by Nature or synthetically by man. A number of criteria have been proposed to ascertain which of these inhibitors are true transition state mimics, but these features have only be critically investigated in a very few cases.
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Affiliation(s)
- Tracey M. Gloster
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5YW, UK. ; ; Fax: +44 1904 328266; Tel: +44 1904 328260
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Gideon J. Davies
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5YW, UK. ; ; Fax: +44 1904 328266; Tel: +44 1904 328260
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10
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Wardrop DJ, Waidyarachchi SL. Synthesis and biological activity of naturally occurring α-glucosidase inhibitors. Nat Prod Rep 2010; 27:1431-68. [DOI: 10.1039/b914958a] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Muraoka O, Tanabe G, Hatanaka T, Minematsu T, Matsuda H, Yoshikawa M. Syntheses and Evaluation as Glycosidase Inhibitor of 1,5-Dideoxy-1,5-imino-D-glucitol Analogs of Salacinol, a Potent α-Glucosidase Inhibitor Isolated from Ayurvedic Medicine, Salacia reticulata. HETEROCYCLES 2009. [DOI: 10.3987/com-08-s(d)61] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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12
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Oben JE, Ngondi JL, Momo CN, Agbor GA, Sobgui CSM. The use of a Cissus quadrangularis/Irvingia gabonensis combination in the management of weight loss: a double-blind placebo-controlled study. Lipids Health Dis 2008; 7:12. [PMID: 18377661 PMCID: PMC2330043 DOI: 10.1186/1476-511x-7-12] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2008] [Accepted: 03/31/2008] [Indexed: 11/22/2022] Open
Abstract
AIM To evaluate the effects of two formulations, Cissus quadrangularis-only and a Cissus quadrangularis/Irvingia gabonensis combination, on weight loss in overweight and obese human subjects. METHODS The study was a 10 week randomized, double-blind, placebo-controlled design involving 72 obese or overweight participants (45.8% male; 54.2% female; ages 21-44; mean age = 29.3). The participants were randomly divided into three equal (n = 24) groups: placebo, Cissus quadrangularis-only, and Cissus quadrangularis/Irvingia gabonensis combination. Capsules containing the placebo or active formulations were administered twice daily before meals; no major dietary changes nor exercises were suggested during the study. A total of six anthropomorphic and serological measurements (body weight, body fat, waist size; total plasma cholesterol, LDL cholesterol, fasting blood glucose level) were taken at baseline and at 4, 8 and 10 weeks. RESULTS Compared to the placebo group, the two active groups showed a statistically significant difference on all six variables by week 10. The magnitude of the differences was noticeable by week 4 and continued to increase over the trial period. CONCLUSION Although the Cissus quadrangularis-only group showed significant reductions on all variables compared to the placebo group, the Cissus quadrangularis/Irvingia gabonensis combination resulted in even larger reductions. This apparently synergistic formulation should prove helpful in the management of obesity and its related complications.
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Affiliation(s)
- Julius E Oben
- Laboratory of Nutrition and Nutritional Biochemistry, Department of Biochemistry, B.P. 812, University of Yaoundé 1, Yaoundé, Cameroon
| | - Judith L Ngondi
- Laboratory of Nutrition and Nutritional Biochemistry, Department of Biochemistry, B.P. 812, University of Yaoundé 1, Yaoundé, Cameroon
| | - Claudia N Momo
- Laboratory of Nutrition and Nutritional Biochemistry, Department of Biochemistry, B.P. 812, University of Yaoundé 1, Yaoundé, Cameroon
| | - Gabriel A Agbor
- Laboratory of Nutrition and Nutritional Biochemistry, Department of Biochemistry, B.P. 812, University of Yaoundé 1, Yaoundé, Cameroon
- CRPMT, Institute of Medicinal Plants Studies, Yaoundé, Cameroon
| | - Caroline S Makamto Sobgui
- Laboratory of Nutrition and Nutritional Biochemistry, Department of Biochemistry, B.P. 812, University of Yaoundé 1, Yaoundé, Cameroon
- CRPMT, Institute of Medicinal Plants Studies, Yaoundé, Cameroon
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Chen W, Pinto BM. Synthesis of aza- and thia-spiroheterocycles and attempted synthesis of spiro sulfonium compounds related to salacinol. Carbohydr Res 2007; 342:2163-72. [PMID: 17669386 DOI: 10.1016/j.carres.2007.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2007] [Revised: 07/01/2007] [Accepted: 07/03/2007] [Indexed: 11/16/2022]
Abstract
The synthesis of aza- and thia-spiroheterocycles and the attempted synthesis of spiro sulfonium compounds related to salacinol are described. The binding of the nanomolar inhibitor swainsonine to Drosophila Golgi alpha-mannosidase II (dGMII) involves a large contribution of interactions between the six-membered ring of the inhibitor and the hydrophobic pocket within the enzyme active site. Salacinol, a naturally occurring sulfonium ion, is one of the active principles in the aqueous extracts of Salacia reticulata that are traditionally used in Sri Lanka and India for the treatment of diabetes. Spiro aza- and thia-heterocycles and a spiro analogue of salacinol were designed with the expectation that the hydrocarbon portions would make hydrophobic contributions to binding. The former sets of compounds were synthesized successfully but the salacinol analogue proved to be elusive. The stereochemistry of the final compounds was determined by means of 1D-NOESY experiments. The aza- and thia-heterocycles were not effective inhibitors of Golgi alpha-mannosidase II or human maltase glucoamylase.
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Affiliation(s)
- Wang Chen
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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14
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Flammang AM, Erexson GL, Mirwald JM, Henwood SM. Toxicological and cytogenetic assessment of a Salacia oblonga extract in a rat subchronic study. Food Chem Toxicol 2007; 45:1954-62. [PMID: 17566623 DOI: 10.1016/j.fct.2007.04.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2006] [Revised: 03/23/2007] [Accepted: 04/20/2007] [Indexed: 12/18/2022]
Abstract
Salacia oblonga holds potential as a natural method to mitigate the blood glucose response for people with diabetes by inhibiting the activity of intestinal alpha-glucosidases. As part of a safety evaluation of novel ingredients for use in blood glucose control, the toxicity of a S. oblonga root extract (SOE) was evaluated in a subchronic 90-day feeding study in rats. An in vivo-in vitro rat peripheral blood lymphocyte chromosomal aberrations assay was added at termination of the subchronic rat study to examine cultured lymphocytes for possible chromosomal aberration induction. This was conducted due to a previous weak; although reproducible, positive chromosomal aberrations response in cultured peripheral blood human lymphocytes after acute in vitro treatment with SOE. The present study results indicate that SOE was negative for the induction of chromosomal aberrations in cultured rat peripheral blood lymphocytes after 90 consecutive days of treatment with SOE. The no observable adverse effect level (NOAEL) was determined to be 2,500 mg/kg/day following daily subchronic oral gavage administrations to rats.
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Affiliation(s)
- A M Flammang
- Abbott Nutrition, 625 Cleveland Ave, Columbus, OH 43215-1724, USA.
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15
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Bhat RG, Kumar NS, Pinto BM. Synthesis of phosphate derivatives related to the glycosidase inhibitor salacinol. Carbohydr Res 2007; 342:1934-42. [PMID: 17572396 DOI: 10.1016/j.carres.2007.05.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Revised: 05/23/2007] [Accepted: 05/25/2007] [Indexed: 10/23/2022]
Abstract
The syntheses of polyhydroxylated imino- and anhydro thio-alditol compounds related to the naturally occurring glycosidase inhibitor, salacinol, containing a phosphate group in the side chain are described. The compounds lack hydroxyl groups on the acyclic side chain and are prototypes of the exact salacinol analogue. The synthetic strategy relies on the Mitsunobu reaction of N- and S-hydroxyalkyl derivatives of 2,3,5-tri-O-benzyl-1,4-dideoxy-1,4-imino-D-arabinitol and 1,4-anhydro-2,3,5-tri-O-benzyl-1-thio-D-arabinitol with dibenzyl phosphate to yield the corresponding protected heteroalditol phosphates. Screening of these compounds against recombinant human maltase glucoamylase (MGA), a critical intestinal glucosidase involved in the processing of oligosaccharides of glucose into glucose itself, shows that they are not effective inhibitors of MGA and demonstrates the importance of the hydroxyl and/or sulfate substituents present on the side chain for effective inhibition. The attempted synthesis of the exact analogue of salacinol by opening of cyclic phosphates is also described.
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Affiliation(s)
- Ramakrishna G Bhat
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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16
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Chen W, Sim L, Rose DR, Pinto BM. Synthesis of analogues of salacinol containing a carboxylate inner salt and their inhibitory activities against human maltase glucoamylase. Carbohydr Res 2007; 342:1661-7. [PMID: 17597595 DOI: 10.1016/j.carres.2007.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2007] [Revised: 06/02/2007] [Accepted: 06/02/2007] [Indexed: 10/23/2022]
Abstract
The syntheses of analogues of the naturally occurring glycosidase inhibitor, salacinol, containing a carboxylate inner salt are described. Salacinol is a sulfonium ion with an internal sulfate counterion. The synthetic strategy relies on the nucleophilic attack of 1,4-anhydro-2,3,5-tri-O-benzyl-4-thio-D- or L-arabinitol at the least hindered carbon of 4,5-anhydro-2,3-O-isopropylidene-D-ribonic acid benzyl ester to yield coupled adducts. Deprotection of the coupled products gives the target compounds. The compound derived from D-arabinitol inhibits recombinant human maltase glucoamylase, one of the key intestinal enzymes involved in the breakdown of glucose oligosaccharides in the small intestine, with a Ki value of 10+/-1 microM.
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Affiliation(s)
- Wang Chen
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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17
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Mohan S, Pinto BM. Zwitterionic glycosidase inhibitors: salacinol and related analogues. Carbohydr Res 2007; 342:1551-80. [PMID: 17559821 DOI: 10.1016/j.carres.2007.05.014] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2007] [Revised: 05/01/2007] [Accepted: 05/08/2007] [Indexed: 11/24/2022]
Abstract
Natural products with interesting biological properties and structural diversity have often served as valuable lead drug candidates for the treatment of human diseases. Salacinol, a naturally occurring alpha-glucosidase inhibitor, was shown to be one of the active principles of the aqueous extract of a medicinal plant that has been prescribed traditionally as an Ayurvedic treatment for type II diabetes. Salacinol contains an intriguing zwitterionic sulfonium-sulfate structure that comprises a 1,4-anhydro-4-thio-D-arabinitol core and a polyhydroxylated acyclic chain. Due to the unique structural features and its potential to become a lead drug candidate in the treatment of type II diabetes, a great deal of attention has been focused on salacinol and its analogues. Since the isolation of salacinol, several papers describing various synthetic routes to salacinol and its analogues have appeared in the literature. This review is aimed at highlighting the synthetic aspects of salacinol and related compounds as well as their structure-activity relationship studies.
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Affiliation(s)
- Sankar Mohan
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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18
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Liu H, Nasi R, Jayakanthan K, Sim L, Heipel H, Rose DR, Pinto BM. New Synthetic Routes to Chain-Extended Selenium, Sulfur, and Nitrogen Analogues of the Naturally Occurring Glucosidase Inhibitor Salacinol and their Inhibitory Activities against Recombinant Human Maltase Glucoamylase. J Org Chem 2007; 72:6562-72. [PMID: 17658854 DOI: 10.1021/jo071045m] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Six heteroanalogues (X = S, Se, NH) of the naturally occurring glucosidase inhibitor salacinol, containing polyhydroxylated, acyclic chains of 6-carbons, were synthesized for structure-activity studies with different glycosidase enzymes. The target zwitterionic compounds were synthesized by means of nucleophilic attack of the PMB-protected 1,4-anhydro-4-seleno-, 1,4-anhydro-4-thio-, and 1,4-anhydro-4-imino-D-arabinitols at the least hindered carbon atom of 1,3-cyclic sulfates. These 1,3-cyclic sulfates were derived from D-glucose and D-galactose, and significantly, they utilized butane diacetal as the protecting groups for the trans 2,3-diequatorial positions. Deprotection of the coupled products proceeded smoothly, unlike in previous attempts with different protecting groups, and afforded the target selenonium, sulfonium, and ammonium sulfates with different stereochemistry at the stereogenic centers. The four new heterosubstituted compounds (X = Se, NH) inhibited recombinant human maltase glucoamylase (MGA), one of the key intestinal enzymes involved in the breakdown of glucose oligosaccharides in the small intestine. The two selenium derivatives each had Ki values of 0.10 microM, giving the most active compounds to date in this general series of zwitterionic glycosidase inhibitors. The two nitrogen compounds also inhibited MGA but were less active, with Ki values of 0.8 and 35 microM. The compounds in which X = S showed Ki values of 0.25 and 0.17 microM. Comparison of these data with those reported previously for related compounds reinforces the requirements for an effective inhibitor of MGA. With respect to chain extension, the configurations at C-2' and C-4' are critical for activity, the configuration at C-3', bearing the sulfate moiety, being unimportant. It would also appear that the configuration at C-5' is important but the relationship is dependent on the heteroatom.
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Affiliation(s)
- Hui Liu
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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19
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Mohan S, Sim L, Rose DR, Pinto BM. Synthesis of S-alkylated sulfonium-ions and their glucosidase inhibitory activities against recombinant human maltase glucoamylase. Carbohydr Res 2007; 342:901-12. [PMID: 17316580 DOI: 10.1016/j.carres.2007.01.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Revised: 01/16/2007] [Accepted: 01/31/2007] [Indexed: 11/22/2022]
Abstract
The syntheses of nine S-alkylated, cyclic sulfonium-ions with varying alkyl chain lengths, as mimics of N-alkylated imino sugars, and their glucosidase inhibitory activities are described. The target compounds were synthesized by alkylation of 2,3,5-tri-O-benzyl-1,4-anhydro-4-thio-d-arabinitol at the ring sulfur atom using various alkyl halides, followed by deprotection using boron trichloride. Enzyme inhibitory assays against recombinant human maltase glucoamylase (MGA), a critical enzyme in the small intestine involved in the breakdown of glucose oligosaccharides into glucose itself, shows that they are effective inhibitors of MGA with K(i) values ranging from 6 to 75 microM.
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Affiliation(s)
- Sankar Mohan
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
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20
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Nasi R, Sim L, Rose DR, Pinto BM. New Chain-Extended Analogues of Salacinol and Blintol and Their Glycosidase Inhibitory Activities. Mapping the Active-Site Requirements of Human Maltase Glucoamylase. J Org Chem 2006; 72:180-6. [PMID: 17194097 DOI: 10.1021/jo061944v] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of new chain-extended sulfonium and selenonium salts of 1,4-anhydro-4-thio-(or 4-seleno)-d-arabinitol, analogues of the naturally occurring glycosidase inhibitor salacinol, is described. Nucleophilic attack at the least hindered carbon atom of 4,6-O-benzylidene-2,5-di-O-p-methoxybenzyl-d-mannitol-1,3-cyclic sulfate by 2,3,5-tri-O-p-methoxybenzyl-1,4-anhydro-4-thio-(or 4-seleno)-d-arabinitol gave the sulfonium and selenonium sulfates, respectively. Subsequent deprotection with trifluoroacetic acid yielded the target compounds. In these analogues, an extended polyhydroxylated aliphatic side chain has been incorporated while maintaining the stereochemistry of C-2' and C-3' of salacinol or blintol. These compounds were designed to probe the premise that they would bind with higher affinity to glucosidases than salacinol because the extra hydroxyl groups in the acyclic chain would make favorable polar contacts within the active site. Both target compounds inhibited recombinant human maltase glucoamylase, one of the key intestinal enzymes involved in the breakdown of glucose oligosaccharides in the small intestine, with Ki values in the low micromolar range. Comparison of these values to those of related compounds synthesized in previous studies has provided a better understanding of structure-activity relationships and the optimal stereochemistry at the different stereogenic centers required of an inhibitor of this enzyme. With respect to chain extension, the configurations at C-2' and C-4' are critical for activity, the configuration at C-3', bearing the sulfate moiety, being unimportant. The desired configuration at C-5' is also specified. However, comparison of the activities of the chain-extended analogues with those of salacinol and blintol indicates that there is no particular advantage of the chain-extension relative to salacinol or blintol. These results are similar to those reported earlier for kotalanol, a 7-carbon-extended derivative, versus salacinol against rat intestinal maltase, sucrase, and isomaltase.
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Affiliation(s)
- Ravindranath Nasi
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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21
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Chen W, Kuntz DA, Hamlet T, Sim L, Rose DR, Mario Pinto B. Synthesis, enzymatic activity, and X-ray crystallography of an unusual class of amino acids. Bioorg Med Chem 2006; 14:8332-40. [PMID: 17010621 DOI: 10.1016/j.bmc.2006.09.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Revised: 08/28/2006] [Accepted: 09/07/2006] [Indexed: 11/23/2022]
Abstract
The synthesis of two novel amino acids, nitrogen analogues of the naturally occurring glycosidase inhibitor, salacinol, containing a carboxylate inner salt are described, along with the crystal structure of one of these analogues in the active site of Drosophila melanogaster Golgi mannosidase II (dGMII). Salacinol, a naturally occurring sulfonium ion, is one of the active principals in the aqueous extracts of Salacia reticulata that are traditionally used in Sri Lanka and India for the treatment of diabetes. The synthetic strategy relies on the nucleophilic attack of 2,3,5-tri-O-benzyl-1,4-dideoxy-1,4-imino l- or d-arabinitol at the least hindered carbon of 5,6-anhydro-2,3-di-O-benzyl-l-ascorbic acid to yield coupled adducts. Deprotection, stereoselective catalytic reduction, and hydrolysis of the coupled products give the target compounds. The compound derived from d-arabinitol inhibits dGMII, one of the critical enzymes in the glycoprotein processing pathway, with an IC(50) of 0.3mM. Inhibition of GMII has been identified as a target for control of metastatic cancer. An X-ray crystal structure of the complex of this compound with dGMII provides insight into the requirements for an effective inhibitor. The same compound inhibits recombinant human maltase glucoamylase, one of the key intestinal enzymes involved in the breakdown of glucose oligosaccharides in the small intestine, with a K(i) value of 21microM.
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Affiliation(s)
- Wang Chen
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
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22
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Flammang AM, Erexson GL, Mecchi MS, Murli H. Genotoxicity testing of a Salacia oblonga extract. Food Chem Toxicol 2006; 44:1868-74. [PMID: 16901601 DOI: 10.1016/j.fct.2006.06.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2005] [Revised: 05/23/2006] [Accepted: 06/06/2006] [Indexed: 12/18/2022]
Abstract
Salacia oblonga has been used for thousands of years in Ayurvedic medicine for the oral treatment of diabetes. The root extract has been shown to inhibit the activity of intestinal alpha-glucosidases, therefore S. oblonga holds potential as a natural method to mitigate the blood glucose response for people with diabetes. As part of a safety evaluation of novel ingredients for use in blood glucose control, the potential genotoxicity of a S. oblonga root extract (SOE) was evaluated using the standard battery of tests (reverse mutation assay; chromosomal aberrations assay; mouse micronucleus assay) recommended by US Food and Drug Administration (FDA) for food ingredients. SOE was determined not to be genotoxic under the conditions of the reverse mutation assay and mouse micronucleus assay, and weakly positive for the chromosomal aberrations assay. A reproducible, although weak, positive chromosomal aberrations response in human lymphocytes is of concern and further toxicity research is recommended. Use of SOE is presently expected to be safe, as anticipated intake is small compared to the doses administered in the genotoxicity assays and may, after further toxicity research, may prove be a useful ingredient in foodstuffs.
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Affiliation(s)
- A M Flammang
- Ross Products Division Abbott Laboratories, 3300 Stelzer Road, 625 Cleveland Avenue, Columbus, OH 43215-1724, USA.
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23
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Nasi R, Pinto BM. Synthesis of new analogues of salacinol containing a pendant hydroxymethyl group as potential glycosidase inhibitors. Carbohydr Res 2006; 341:2305-11. [PMID: 16854397 DOI: 10.1016/j.carres.2006.06.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Revised: 06/20/2006] [Accepted: 06/28/2006] [Indexed: 11/23/2022]
Abstract
The synthesis of new analogues of the naturally occurring glycosidase inhibitor, salacinol, and its ammonium analogue, ghavamiol is described. These analogues contain an additional hydroxymethyl group at C-1, which was intended to form additional polar contacts within the active site of glycosidase enzymes. The target zwitterionic compounds were synthesized by means of nucleophilic attack at the least hindered carbon atom of 2,4-O-benzylidene-l (or d)-erythritol 1,3-cyclic sulfate by 2,5-anhydro-1,3:4,6-di-O-benzylidene-2,5-dideoxy-5-thio (or 1,5-imino)-l-iditol.
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Affiliation(s)
- Ravindranath Nasi
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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24
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Liu H, Pinto BM. Design and synthesis of selenonium and sulfonium ions related to the naturally occurring glucosidase inhibitor salacinol. CAN J CHEM 2006. [DOI: 10.1139/v06-100] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Four series of analogues of the naturally occurring glucosidase inhibitor salacinol were synthesized for structure–activity studies with different glycosidase enzymes. The target zwitterionic compounds were synthesized by means of nucleophilic attack at the least-hindered carbon atom of the 1,3-cyclic sulfates derived from D-glucose and D-mannose by the isopropylidene-protected 1,4-anhydro-4-thio- and seleno-D-allitols and the 4-thio- and seleno-L-allitols. Deprotection of the coupled products afforded the novel sulfonium and selenonium ions containing polyhy droxylated acyclic chains of four and six carbons, with different stereochemistry at the stereogenic centers and with 1,4-anhydro-4-seleno or 4-thio-D- or L- alditol heterocyclic rings. The compounds showed no significant activity against recombinant human maltase glucoamylase (MGA), a critical intestinal glucosidase involved in the processing of oligosaccharides of glucose into glucose itself.Key words: glycosidase inhibitors, zwitterionic, selenonium salts, sulfonium salts, cyclic sulfates, L-ascorbic acid, D-gulonic-γ-lactone.
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25
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26
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Rossi EJ, Sim L, Kuntz DA, Hahn D, Johnston BD, Ghavami A, Szczepina MG, Kumar NS, Sterchi EE, Nichols BL, Pinto BM, Rose DR. Inhibition of recombinant human maltase glucoamylase by salacinol and derivatives. FEBS J 2006; 273:2673-83. [PMID: 16817895 DOI: 10.1111/j.1742-4658.2006.05283.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Inhibitors targeting pancreatic alpha-amylase and intestinal alpha-glucosidases delay glucose production following digestion and are currently used in the treatment of Type II diabetes. Maltase-glucoamylase (MGA), a family 31 glycoside hydrolase, is an alpha-glucosidase anchored in the membrane of small intestinal epithelial cells responsible for the final step of mammalian starch digestion leading to the release of glucose. This paper reports the production and purification of active human recombinant MGA amino terminal catalytic domain (MGAnt) from two different eukaryotic cell culture systems. MGAnt overexpressed in Drosophila cells was of quality and quantity suitable for kinetic and inhibition studies as well as future structural studies. Inhibition of MGAnt was tested with a group of prospective alpha-glucosidase inhibitors modeled after salacinol, a naturally occurring alpha-glucosidase inhibitor, and acarbose, a currently prescribed antidiabetic agent. Four synthetic inhibitors that bind and inhibit MGAnt activity better than acarbose, and at comparable levels to salacinol, were found. The inhibitors are derivatives of salacinol that contain either a selenium atom in place of sulfur in the five-membered ring, or a longer polyhydroxylated, sulfated chain than salacinol. Six-membered ring derivatives of salacinol and compounds modeled after miglitol were much less effective as MGAnt inhibitors. These results provide information on the inhibitory profile of MGAnt that will guide the development of new compounds having antidiabetic activity.
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Affiliation(s)
- Elena J Rossi
- Department of Medical Biophysics, University of Toronto, Canada
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27
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Choubdar N, Pinto BM. Attempted Synthesis of 2-Acetamido and 2-Amino Derivatives of Salacinol. Ring Opening Reactions. J Org Chem 2006; 71:4671-4. [PMID: 16749804 DOI: 10.1021/jo060167w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The attempted synthesis of the 2-acetamido and 2-amino derivatives of salacinol, a naturally occurring glycosidase inhibitor, is described. Reaction of the protected acetamidothioarabinitol unit with the cyclic sulfate derived from L-erythritol gave the corresponding sulfonium sulfate, which underwent ring opening to give an acyclic amido sulfate. The corresponding reaction of the protected azidothioarabinitol unit with the cyclic sulfate proceeded to give the sulfonium sulfate. However, upon reduction of the azido function to an amine it formed an acyclic ammonium sulfate.
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Affiliation(s)
- Niloufar Choubdar
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
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28
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Liu H, Pinto BM. Synthesis of zwitterionic selenonium and sulfonium sulfates from D-mannose as potential glycosidase inhibitors. CAN J CHEM 2006. [DOI: 10.1139/v06-027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Four chain-extended analogues of the naturally occurring glycosidase inhibitor salacinol were synthesized for structureactivity studies with different glycosidase enzymes. The syntheses involved the reaction of isopropylidene-protected 1,4-thio- and 1,4-seleno-D-talitols and 1,5-thio- and 1,5-seleno-L-gulitols, derived from D-mannose, with a benzylidene- and isopropylidene-protected 1,3-cyclic sulfate, also derived from D-mannose. Deprotection of the products afforded the novel selenonium and sulfonium sulfates composed of heterocyclic five- and six-membered ring core structures with pendant polyhydroxylated, acyclic chains of six carbon atoms.Key words: glycosidase inhibitors, zwitterionic selenonium and sulfonium sulfates, cyclic sulfate
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29
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Liu H, Sim L, Rose DR, Pinto BM. A New Class of Glucosidase Inhibitor: Analogues of the Naturally Occurring Glucosidase Inhibitor Salacinol with Different Ring Heteroatom Substituents and Acyclic Chain Extension. J Org Chem 2006; 71:3007-13. [PMID: 16599595 DOI: 10.1021/jo052539r] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Six chain-extended analogues of the naturally occurring glycosidase inhibitor salacinol, with ring-heteroatom variation, were synthesized for structure-activity studies with different glycosidase enzymes. The syntheses involved the reaction of PMB-protected D- and L- seleno-, thio-, and iminoarabinitol with a benzylidene- and isopropylidene-protected 1,3-cyclic sulfate, derived from commercially available D-sorbitol, in 1,1,1,3,3,3-hexafluoro-2-propanol containing potassium carbonate. Deprotection of the products afforded the novel selenonium, sulfonium, and iminium analogues of salacinol containing polyhydroxylated, monosulfated, extended acyclic chains of 6-carbons, differing in stereochemistry at the stereogenic centers and ring-heteroatom constitution. Four of these compounds inhibit recombinant human maltase glucoamylase, one of the key intestinal enzymes involved in the breakdown of glucose oligosaccharides in the small intestine, with Ki values in the micromolar range, thus providing lead candidates for the treatment of Type 2 diabetes.
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Affiliation(s)
- Hui Liu
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
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30
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Johnston BD, Jensen HH, Pinto BM. Synthesis of Sulfonium Sulfate Analogues of Disaccharides and Their Conversion to Chain-Extended Homologues of Salacinol: New Glycosidase Inhibitors. J Org Chem 2006; 71:1111-8. [PMID: 16438529 DOI: 10.1021/jo052252u] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Four chain extended homologues of salacinol, a naturally occurring glycosidase inhibitor, were prepared for evaluation as inhibitors of glucosidase enzymes involved in the breakdown of carbohydrates. The syntheses involved the reactions of 1,4-anhydro-2,3,5-tri-O-benzyl-4-thio-D-arabinitol with cyclic sulfate derivatives of different monosaccharides. Debenzylation of the products afforded the novel sulfonium sulfate derivatives of D-glucose, D-galactose, D-arabinose, and D-xylose that are of interest in their own right as glycosidase inhibitors. Reduction to the corresponding alditols then afforded the homologues of salacinol containing polyhydroxylated, acyclic chains of 5- and 6-carbons, differing in stereochemistry at the stereogenic centers. Three of the chain-extended homologues inhibited recombinant human maltase glucoamylase, one of the key intestinal enzymes involved in the breakdown of glucose oligosaccharides in the small intestine, with Ki values in the low micromolar range, of approximately the same magnitude as salacinol, thus providing lead candidates for the treatment of Type 2 diabetes.
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Affiliation(s)
- Blair D Johnston
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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31
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Gallienne E, Gefflaut T, Bolte J, Lemaire M. Synthesis of New Nitrogen Analogues of Salacinol and Deoxynojirimycin and Their Evaluation as Glycosidase Inhibitors. J Org Chem 2006; 71:894-902. [PMID: 16438498 DOI: 10.1021/jo0517388] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of two enantiomerically pure iminosugars, analogues of 1-L-deoxynojirimycin (l-DNJ) and 1-D-deoxymannojirimycin (DMJ), was achieved using cyclic sulfate substituted isoxazoline derivatives. The piperidine ring was formed via the reduction of an isoxazoline into an amine which underwent a spontaneous intramolecular cyclization by reaction with the cyclic sulfate moiety. The nucleophilic attack of these two trisubstituted piperidines and morpholine on L- and D-erythritol-1,3-cyclic sulfates gave six new nitrogen analogues of salacinol. The inhibitory properties of the synthesized salacinol analogues were evaluated on several commercial glycosidases.
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Affiliation(s)
- Estelle Gallienne
- Laboratoire SEESIB, UMR 6504 CNRS, Université Blaise Pascal, 24 avenue des Landais, 63177 Aubière Cedex, France
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32
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Muraoka O, Yoshikai K, Takahashi H, Minematsu T, Lu G, Tanabe G, Wang T, Matsuda H, Yoshikawa M. Synthesis and biological evaluation of deoxy salacinols, the role of polar substituents in the side chain on the α-glucosidase inhibitory activity. Bioorg Med Chem 2006; 14:500-9. [PMID: 16198577 DOI: 10.1016/j.bmc.2005.08.040] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Revised: 08/13/2005] [Accepted: 08/16/2005] [Indexed: 10/25/2022]
Abstract
Three analogs (5, 6, and 7) lacking polar substituents in the side chain of a naturally occurring alpha-glucosidase inhibitor, salacinol (1a), were synthesized by the coupling reaction of a thiosugar, 1,4-dideoxy-1,4-epithio-D-arabinitol (3), with cyclic sulfates (8, 9, and 10), and their alpha-glucosidase inhibitory activities were examined. All these simpler analogs (5, 6, and 7) showed less inhibitory activity compared to 1a, and proved the importance of cooperative role of the polar substituents for the alpha-glucosidase inhibitory activity. A practical synthetic route to 3 starting from D-xylose is also described.
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Affiliation(s)
- Osamu Muraoka
- School of Pharmaceutical Sciences, Kinki University, 3-4-1 Kowakae, Higashi-osaka, Osaka 577-8502, Japan.
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33
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Kumar NS, Pinto BM. Synthesis of d-lyxitol and d-ribitol analogues of the naturally occurring glycosidase inhibitor salacinol. Carbohydr Res 2005; 340:2612-9. [PMID: 16198322 DOI: 10.1016/j.carres.2005.09.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2005] [Revised: 09/04/2005] [Accepted: 09/05/2005] [Indexed: 11/16/2022]
Abstract
The synthesis of analogues of the naturally occurring glycosidase inhibitor, salacinol, in which the D-arabinitol ring has been replaced by D-lyxitol or D-ribitol, is described. Salacinol is one of the active principles in the aqueous extracts of Salacia reticulata, which are traditionally used in India and Sri Lanka for the treatment of Type II diabetes. The synthetic strategy relies on the nucleophilic attack of 1,4-anhydro-2,3,5-tri-O-p-methoxybenzyl-4-thio-D-lyxitol or 1,4-anhydro-2,3,5-tri-O-p-methoxybenzyl-4-thio-D-ribitol at the least hindered carbon of the benzylidene-protected L-cyclic sulfate derived from L-erythritol. Screening of these compounds against recombinant human maltase glucoamylase (MGA), a critical intestinal glucosidase involved in the processing of oligosaccharides of glucose into glucose itself, shows that they are not effective inhibitors of MGA and demonstrates the importance of the d-arabinitol configuration in the heterocyclic ring for effective inhibition.
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Affiliation(s)
- Nag S Kumar
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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Gallienne E, Benazza M, Demailly G, Bolte J, Lemaire M. Short synthesis of new salacinol analogues and their evaluation as glycosidase inhibitors. Tetrahedron 2005. [DOI: 10.1016/j.tet.2005.03.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Crystallographic analysis of the interactions of Drosophila melanogaster Golgi α-mannosidase II with the naturally occurring glycomimetic salacinol and its analogues. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.tetasy.2004.11.057] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Liu H, Pinto BM. Efficient Synthesis of the Glucosidase Inhibitor Blintol, the Selenium Analogue of the Naturally Occurring Glycosidase Inhibitor Salacinol. J Org Chem 2005; 70:753-5. [PMID: 15651838 DOI: 10.1021/jo048058+] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An efficient synthesis of blintol, the selenium congener of the naturally occurring glycosidase inhibitor salacinol, and a potent glucosidase inhibitor itself, is described. Unlike our previously reported synthesis, this improved route makes use of p-methoxybenzyl ether protecting groups in the synthesis of one of the two key intermediates, 2,3,5-tri-O-p-methoxybenzyl-1,4-anhydro-4-seleno-D-arabinitol, from L-xylose. The other key intermediate, 2,4-O-benzylidene-L-erythritol-1,3-cyclic sulfate, was successfully prepared from D-glucose instead of the expensive L-glucose. All protecting groups in the resulting adducts were removed with trifluoroacetic acid to yield a mixture of stereoisomers, thereby obviating the problematic deprotection of benzyl ethers by hydrogenolysis. The major stereoisomer, blintol, was then obtained by fractional crystallization.
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Affiliation(s)
- Hui Liu
- Department of Chemistry, Simon Fraser University, Burnaby, B.C., Canada V5A 1S6
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Szczepina MG, Johnston BD, Yuan Y, Svensson B, Pinto BM. Synthesis of Alkylated Deoxynojirimycin and 1,5-Dideoxy-1,5-iminoxylitol Analogues: Polar Side-Chain Modification, Sulfonium and Selenonium Heteroatom Variants, Conformational Analysis, and Evaluation as Glycosidase Inhibitors. J Am Chem Soc 2004; 126:12458-69. [PMID: 15453780 DOI: 10.1021/ja0482076] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The syntheses of N-alkylated deoxynojirimycin and 1,5-dideoxy-1,5-iminoxylitol derivatives having either a D- or an L-erythritol-3-sulfate functionalized N-substituent are reported. The alkylating agent used was a cyclic sulfate derivative, whereby selective attack of the nitrogen atom at the least hindered primary center afforded the desired ammonium salt. In aqueous solution, these salts were configurationally labile at the ammonium center. Sulfonium and/or selenonium analogues of the ammonium salts were prepared by analogous reactions. The chalcogen salts were obtained as mixtures of diastereomers, separable in some cases, differing only in the stereochemistry at the configurationally stable sulfur or selenium atoms. Proof of configuration and conformation of each compound was obtained by detailed NMR experiments. The compounds are six-membered ring analogues of salacinol, a known sulfonium-salt glucosidase inhibitor. Evaluation of the target compounds for enzyme inhibition of the glucosidase enzyme glucoamylase G2 indicated that these compounds were either inactive or, at best, only weak inhibitors of maltose hydrolysis.
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Affiliation(s)
- Monica G Szczepina
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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Veerapen N, Yuan Y, Sanders DAR, Pinto BM. Synthesis of novel ammonium and selenonium ions and their evaluation as inhibitors of UDP-galactopyranose mutase. Carbohydr Res 2004; 339:2205-17. [PMID: 15337448 DOI: 10.1016/j.carres.2004.07.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2004] [Accepted: 07/12/2004] [Indexed: 11/26/2022]
Abstract
The syntheses of two ammonium salts of 1,4-dideoxy-1,4-imino-d-galactitol containing erythritol sulfate side chains are described. The parent compound is a known inhibitor of the enzyme UDP-galactopyranose mutase (UDP-galactopyranose furanomutase, E.C. 5.4.99.9), which is responsible for the conversion of UDP-galactopyranose into UDP-galactofuranose and is presumably protonated in its active form. The side chain was chosen because it is present in a known sulfonium ion alpha-glucosidase inhibitor, salacinol. The syntheses of the selenonium analogues derived from 1,4-dideoxy-1,4-seleno-d-galactitol are also described. The synthetic strategy in the syntheses of all four salts involved the nucleophilic attack of a protected derivative of the alditol at the least hindered carbon of 2,4-O-benzylidene d- or l-erythritol-1,3-cyclic sulfate to give adducts that were subsequently deprotected. The importance of different protecting groups used in the various syntheses is also highlighted. Enzyme inhibition assays carried out on these compounds, and the corresponding sulfonium ions synthesized previously, show that they are poor inhibitors of UDP-galactopyranose mutase.
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Affiliation(s)
- Natacha Veerapen
- Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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Li Y, Scott CR, Chamoles NA, Ghavami A, Pinto BM, Turecek F, Gelb MH. Direct multiplex assay of lysosomal enzymes in dried blood spots for newborn screening. Clin Chem 2004; 50:1785-96. [PMID: 15292070 PMCID: PMC3428798 DOI: 10.1373/clinchem.2004.035907] [Citation(s) in RCA: 250] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Newborn screening for deficiency in the lysosomal enzymes that cause Fabry, Gaucher, Krabbe, Niemann-Pick A/B, and Pompe diseases is warranted because treatment for these syndromes is now available or anticipated in the near feature. We describe a multiplex screening method for all five lysosomal enzymes that uses newborn-screening cards containing dried blood spots as the enzyme source. METHODS We used a cassette of substrates and internal standards to directly quantify the enzymatic activities, and tandem mass spectrometry for enzymatic product detection. Rehydrated dried blood spots were incubated with the enzyme substrates. We used liquid-liquid extraction followed by solid-phase extraction with silica gel to remove buffer components. Acarbose served as inhibitor of an interfering acid alpha-glucosidase present in neutrophils, which allowed the lysosomal enzyme implicated in Pompe disease to be selectively analyzed. RESULTS We analyzed dried blood spots from 5 patients with Gaucher, 5 with Niemann-Pick A/B, 11 with Pompe, 5 with Fabry, and 12 with Krabbe disease, and in all cases the enzyme activities were below the minimum activities measured in a collection of heterozygous carriers and healthy noncarrier individuals. The enzyme activities measured in 5-9 heterozygous carriers were approximately one-half those measured with 15-32 healthy individuals, but there was partial overlap of each condition between the data sets for carriers and healthy individuals. CONCLUSION For all five diseases, the affected individuals were detected. The assay can be readily automated, and the anticipated reagent and supply costs are well within the budget limits of newborn-screening centers.
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Affiliation(s)
- Yijun Li
- Department of Chemistry, University of Washington, Seattle, WA
| | - C. Ronald Scott
- Department of Pediatrics, University of Washington, Seattle, WA
| | | | - Ahmad Ghavami
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - B. Mario Pinto
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | | | - Michael H. Gelb
- Department of Chemistry, University of Washington, Seattle, WA
- Department of Biochemistry, University of Washington, Seattle, WA
- Address correspondence to this author at: Department of Chemistry, Campus Box 351700, University of Washington, Seattle, WA 98195. Fax 206-685-8665;
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Ghavami A, Chen JJW, Mario Pinto B. Synthesis of a novel class of sulfonium ions as potential inhibitors of UDP-galactopyranose mutase. Carbohydr Res 2004; 339:401-7. [PMID: 14698899 DOI: 10.1016/j.carres.2003.09.036] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Two sulfonium salts of 1,4-anhydro-4-thio-D-galactitol, with structures related to the known sulfonium salt glycosidase inhibitor, salacinol, have been synthesized as potential inhibitors of UDP-galactopyranose mutase. The synthetic strategy relies on the alkylation reaction of 1,4-anhydro-2,3,5,6-tetra-O-benzyl-4-thio-D-galactitol at the sulfur atom with 2,4-O-benzylidene-D- or -L-erythritol-1,3-cyclic sulfate. In each case, the reaction proceeded stereoselectively to yield only one stereoisomer at the stereogenic sulfur atom. The effect of the polar solvent, 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), in promoting high-yielding reactions is highlighted. The target compounds are then obtained by hydrogenolysis.
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Affiliation(s)
- Ahmad Ghavami
- Department of Chemistry, Simon Fraser University, British Columbia, V5A 1S6, Burnaby, Canada
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Fragoso-Serrano M, Guillén-Jaramillo G, Pereda-Miranda R, Cerda-García-Rojas CM. Conformational analysis of sulfur-containing 6-deoxy-l-hexose derivatives by molecular modeling and NMR spectroscopy. A theoretical study and experimental evidence of intramolecular nonbonded interactions between sulfur and oxygen. J Org Chem 2003; 68:7167-75. [PMID: 12968866 DOI: 10.1021/jo034492k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
6-Deoxy-l-mannose diphenyldithioacetal (1) unexpectedly gave the rearranged products phenyl 3,4-di-O-acetyl-2-S-phenyl-1,2-dithio-6-deoxy-beta-l-glucopyranoside (9) and 3,4-di-O-acetyl-2,5-anhydro-6-deoxy-l-glucose diphenyldithioacetal (10) upon treatment with acetyl chloride, while 6-deoxy-l-mannose ethylenedithioacetal (3) yielded (4aR,6S,7S,8R,8aS)-7,8-diacetyloxy-6-methylhexahydro-4aH-[1,4]dithiino[2,3b]pyran (11), whose structure was further confirmed by X-ray diffraction, and 3,4-di-O-acetyl-2,5-anhydro-l-rhamnose ethylenedithioacetal (12). The geometry of the four rearranged products as well as that of 1-thio-6-deoxy-l-mannopyranosides 5 and 7 and their acetyl derivatives 6 and 8 was studied by density functional theory (B3LYP/6-31G) molecular models, in combination with a Karplus-type analysis of the NMR vicinal coupling constants, revealing that the six-membered ring of pyranosides 5-9 and 11 exists in a slightly distorted chair conformation (6-13% distortion) and that the conformational behavior of the 2,5-anhydro-6-deoxy-l-glucose dithioacetals 10 and 12 is strongly influenced by the presence of stabilizing intramolecular nonbonded sulfur-oxygen 1,4- and 1,5-interactions. Compounds 9-12 were formed by a molecular rearrangement via sulfonium ion intermediates followed by stereoselective intramolecular cyclizations as formulated by the quantum chemical calculations performed in the present study.
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Affiliation(s)
- Mabel Fragoso-Serrano
- Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado 14-740, Mexico City 07000, Mexico
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Johnson MA, Jensen MT, Svensson B, Pinto BM. Selection of a high-energy bioactive conformation of a sulfonium-ion glycosidase inhibitor by the enzyme glucoamylase G2. J Am Chem Soc 2003; 125:5663-70. [PMID: 12733904 DOI: 10.1021/ja0212617] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Transferred nuclear Overhauser effect and rotating-frame Overhauser enhancement NMR spectroscopies are used to probe the conformation of a bicyclic sulfonium ion, which is an analogue of the naturally occurring glycosidase inhibitor castanospermine, bound to the enzyme glucoamylase G2. Enzyme inhibition assays indicate that the bicyclic sulfonium ion is a slightly better inhibitor (K(i) = 1.32 mM) of glucoamylase G2 than the naturally occurring sulfonium-ion glycosidase inhibitor, salacinol, with a K(i) value of 1.7 mM. The NMR results are interpreted in terms of the selection by the enzyme of a high-energy conformation of the ligand that is already represented in the ensemble of free-ligand conformations.
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Affiliation(s)
- Margaret A Johnson
- Department of Chemistry, Simon Fraser University, Burnaby, B.C., Canada, V5A 1S6
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Ulgar V, López Ó, Maya I, Fernández-Bolaños JG, Bols M. Synthesis of furan 4′-thio-C-nucleosides, their methylsulfonium and sulfoxide derivatives. Evaluation as glycosidase inhibitors. Tetrahedron 2003. [DOI: 10.1016/s0040-4020(03)00339-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
The three-dimensional structure of glycosidases and of their complexes and the study of transition-state mimics reveal structural details that correlate with mechanism. Of particular interest are the transition-state conformations harnessed by individual enzymes and the substrate distortion observed in enzyme-ligand complexes. 3D-structure in synergy with transition-state mimicry opens the way for mechanistic interpretation of enzyme inhibition and for the development of therapeutic agents.
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Affiliation(s)
- Andrea Vasella
- Laboratorium für Organische Chemie, ETH Hönggerberg, HCI H317, CH-8093 Zürich, Switzerland
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Ghavami A, Johnston BD, Maddess MD, Chinapoo SM, Jensen MT, Svensson B, Pinto BM. Synthesis of 1,4-anhydro-D-xylitol heteroanalogues of the naturally occurring glycosidase inhibitor salacinol and their evaluation as glycosidase inhibitors. CAN J CHEM 2002. [DOI: 10.1139/v02-078] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The syntheses of two 1,4-anhydro-D-xylitol heteroanalogues (8 and 9) of the naturally occurring sulfonium ion, salacinol (3), containing a sulfur or nitrogen atom in the ring are described. Salacinol (3) is one of the active principles in the aqueous extracts of Salacia reticulata that are traditionally used in Sri Lanka and India for the treatment of Type 2 diabetes. The synthetic strategy relies on the nucleophilic attack of sulfur or nitrogen analogues of 1,4-anhydro-D-xylitol at the least-hindered carbon of 2,4-O-benzylidene-L-erythritol-1,3-cyclic sulfate. The sulfonium ion 8 inhibited barley-α-amylase (AMY1) and porcine pancreatic-α-amylase (PPA), with Ki values of 109 ± 11 and 55 ± 5 µM, respectively. In contrast, the ammonium ion 9 showed no significant inhibition of either AMY1 or PPA. Compounds 8 and 9 also showed no significant inhibition of glucoamylase.Key Words: glycosidase inhibitors, salacinol analogues, anhydro-D-xylitol heteroanalogues, enzyme inhibition.
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Johnston BD, Ghavami A, Jensen MT, Svensson B, Pinto BM. Synthesis of selenium analogues of the naturally occurring glycosidase inhibitor salacinol and their evaluation as glycosidase inhibitors. J Am Chem Soc 2002; 124:8245-50. [PMID: 12105902 DOI: 10.1021/ja020299g] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The syntheses of two selenium analogues (10 and 11) of the naturally occurring sulfonium ion, salacinol (3), are described. Salacinol is one of the active principles in the aqueous extracts of Salacia reticulata that are traditionally used in Sri Lanka and India for the treatment of diabetes. The synthetic strategy relies on the nucleophilic attack of a 2,3,5-tri-O-benzyl-1,4-anhydro-4-seleno-D-arabinitol at the least hindered carbon of benzyl- or benzylidene-protected D- or L-erythritol-1,3-cyclic sulfate. The use of 1,1,1,3,3,3-hexafluoro-2-propanol as a solvent in the coupling reaction proves to be beneficial. Enzyme inhibition assays indicate that 10 is a better inhibitor (K(i) = 0.72 mM) of glucoamylase than 3, which has a K(i) value of 1.7 mM. In contrast, 11 showed no significant inhibition of glucoamylase. Compounds 10 and 11 showed no significant inhibition of barley-alpha-amylase or porcine pancreatic-alpha-amylase.
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Affiliation(s)
- Blair D Johnston
- Department of Chemistry, Simon Fraser University, Burnaby, B.C., Canada V5A 1S6
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Muraoka O, Ying S, Yoshikai K, Matsuura Y, Yamada E, Minematsu T, Tanabe G, Matsuda H, Yoshikawa M. Synthesis of a nitrogen analogue of salacinol and its alpha-glucosidase inhibitory activity. Chem Pharm Bull (Tokyo) 2001; 49:1503-5. [PMID: 11724251 DOI: 10.1248/cpb.49.1503] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A nitrogen analogue 4 of the naturally occurring sulfonium ion salacinol (1), a potent alpha-glucosidase inhibitor isolated from the Ayruvedic medicine Salacia reticulata, was synthesized and its inhibitory activity against alpha-glucosidase tested. Substitution of the sulfur atom in 1 with a nitrogen reduced the activity considerably. The solid-state stereostructure of the related compound (5) was determined on the basis of single crystal X-ray measurement.
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Affiliation(s)
- O Muraoka
- School of Pharmaceutical Sciences, Kinki University, Osaka, Japan. muraoka@phar,kindai.ac.jp
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