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Munir R, Zahoor AF, Nazeer U, Saeed MA, Mansha A, Irfan A, Tariq MU. Gilman reagent toward the synthesis of natural products. RSC Adv 2023; 13:35172-35208. [PMID: 38053693 PMCID: PMC10694855 DOI: 10.1039/d3ra07359a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 11/19/2023] [Indexed: 12/07/2023] Open
Abstract
With the ever-increasing scope of organocuprates, a well-established Gilman reagent has been considered as an unprecedented synthetic tool in modern organic chemistry. The broad research profile of the Gilman reagent (R2CuLi in THF or Et2O) is owing to its propensity to carry out three kinds of reactions, i.e., epoxide ring opening reactions, 1,4-conjugate addition reactions, and SN2 reactions in a regioselective manner. This review examines the applications of Gilman reagent in the total synthesis of both abundant and scarce natural products of remarkable synthetic pharmaceutical profile reported since 2011. The presented insights will be of a vital roadmap to general organic synthesis and it will contribute to the development of new natural products and their analogues in future drug discovery.
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Affiliation(s)
- Ramsha Munir
- Department of Chemistry, Government College University Faisalabad 38000-Faisalabad Pakistan
| | - Ameer Fawad Zahoor
- Department of Chemistry, Government College University Faisalabad 38000-Faisalabad Pakistan
| | - Usman Nazeer
- Department of Chemistry, University of Houston 3585 Cullen Boulevard Texas 77204-5003 USA
| | - Muhammad Athar Saeed
- Department of Chemistry, Government College University Faisalabad 38000-Faisalabad Pakistan
| | - Asim Mansha
- Department of Chemistry, Government College University Faisalabad 38000-Faisalabad Pakistan
| | - Ahmad Irfan
- Department of Chemistry, King Khalid University P.O. Box 9004 Abha 61413 Saudi Arabia
| | - Muhammad Umair Tariq
- Department of Chemistry, Faculty of Natural Sciences, Forman Christian College University Lahore 54600 Pakistan
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2
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Chua RW, Song KP, Ting ASY. Comparative analysis of antimicrobial compounds from endophytic Buergenerula spartinae from orchid. Antonie Van Leeuwenhoek 2023; 116:1057-1072. [PMID: 37597137 DOI: 10.1007/s10482-023-01870-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/08/2023] [Indexed: 08/21/2023]
Abstract
A rare fungal endophyte, identified as Buergenerula spartinae (C28), was isolated from the roots of Cymbidium orchids and was characterised and evaluated for its antimicrobial activities. Bio-guided fractionation revealed 4 fractions from B. spartinae (C28) having antibacterial activities against at least one bacterial pathogen tested (Bacillus cereus and Staphylococcus aureus). However, inhibitory activities were absent against pathogenic fungi (Ganoderma boninense, Pythium ultimum and Fusarium solani). Fraction 2 and fraction 4 of B. spartinae (C28) exhibited potent antibacterial activities against S. aureus (MIC: 0.078 mg/mL) and B. cereus (MIC: 0.313 mg/mL), respectively. LCMS analysis revealed the presence of antibacterial agents and antibiotics in fraction 2 (benoxinate, pyropheophorbide A, (-)-ormosanine and N-undecylbenzenesulfonic acid) and fraction 4 (kaempferol 3-p-coumarate, 6-methoxy naphthalene acetic acid, levofuraltadone, hinokitiol glucoside, 3-α(S)-strictosidine, pyropheophorbide A, 5'-hydroxystreptomycin, kanzonol N and 3-butylidene-7-hydroxyphthalide), which may be responsible for the antibacterial activities observed. Most of the bioactive compounds profiled from the antibacterial fractions were discovered for the first time from endophytic isolates (i.e. from B. spartinae (C28)). Buergenerula spartinae (C28) from Cymbidium sp. is therefore, an untapped resource of bioactive compounds for potential applications in healthcare and commercial industries.
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Affiliation(s)
- Ru Wei Chua
- School of Science, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Keang Peng Song
- School of Science, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Adeline Su Yien Ting
- School of Science, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia.
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3
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Zhang HH, Zhang XK, Si RR, Shen SC, Liang TT, Fan TT, Chen W, Xu LH, Han BN. Chemical and Biological Study of Novel Aplysiatoxin Derivatives from the Marine Cyanobacterium Lyngbya sp. Toxins (Basel) 2020; 12:E733. [PMID: 33238397 PMCID: PMC7700248 DOI: 10.3390/toxins12110733] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/05/2020] [Accepted: 11/20/2020] [Indexed: 12/03/2022] Open
Abstract
Since 1970s, aplysiatoxins (ATXs), a class of biologically active dermatoxins, were identified from the marine mollusk Stylocheilus longicauda, whilst further research indicated that ATXs were originally metabolized by cyanobacteria. So far, there have been 45 aplysiatoxin derivatives discovered from marine cyanobacteria with various geographies. Recently, we isolated two neo-debromoaplysiatoxins, neo-debromoaplysiatoxin G (1) and neo-debromoaplysiatoxin H (2) from the cyanobacterium Lyngbya sp. collected from the South China Sea. The freeze-dried cyanobacterium was extracted with liquid-liquid extraction of organic solvents, and then was subjected to multiple chromatographies to yield neo-debromoaplysiatoxin G (1) (3.6 mg) and neo-debromoaplysiatoxin H (2) (4.3 mg). They were elucidated with spectroscopic methods. Moreover, the brine shrimp toxicity of the aplysiatoxin derivatives representing differential structural classifications indicated that the debromoaplysiatoxin was the most toxic compound (half inhibitory concentration (IC50) value = 0.34 ± 0.036 µM). While neo-aplysiatoxins (neo-ATXs) did not exhibit apparent brine shrimp toxicity, but showed potent blocking action against potassium channel Kv1.5, likewise, compounds 1 and 2 with IC50 values of 1.79 ± 0.22 µM and 1.46 ± 0.14 µM, respectively. Therefore, much of the current knowledge suggests the ATXs with different structure modifications may modulate multiple cellular signaling processes in animal systems leading to the harmful effects on public health.
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Affiliation(s)
- Hui-Hui Zhang
- Department of Development Technology of Marine Resources, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (H.-H.Z.); (X.-K.Z.); (S.-C.S.); (T.-T.F.); (W.C.)
| | - Xin-Kai Zhang
- Department of Development Technology of Marine Resources, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (H.-H.Z.); (X.-K.Z.); (S.-C.S.); (T.-T.F.); (W.C.)
| | - Ran-Ran Si
- School of Materials Science and Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China;
| | - Si-Cheng Shen
- Department of Development Technology of Marine Resources, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (H.-H.Z.); (X.-K.Z.); (S.-C.S.); (T.-T.F.); (W.C.)
| | - Ting-Ting Liang
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, China;
| | - Ting-Ting Fan
- Department of Development Technology of Marine Resources, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (H.-H.Z.); (X.-K.Z.); (S.-C.S.); (T.-T.F.); (W.C.)
| | - Wei Chen
- Department of Development Technology of Marine Resources, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (H.-H.Z.); (X.-K.Z.); (S.-C.S.); (T.-T.F.); (W.C.)
| | - Lian-Hua Xu
- Department of Development Technology of Marine Resources, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (H.-H.Z.); (X.-K.Z.); (S.-C.S.); (T.-T.F.); (W.C.)
| | - Bing-Nan Han
- Department of Development Technology of Marine Resources, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (H.-H.Z.); (X.-K.Z.); (S.-C.S.); (T.-T.F.); (W.C.)
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4
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Feuillastre S, Raffier L, Pelotier B, Piva O. Formal enantioselective synthesis of nhatrangin A. Org Biomol Chem 2020; 18:1949-1956. [PMID: 32101216 DOI: 10.1039/c9ob02639h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A new and straightforward synthesis of the C1-C7 core fragment of nhatrangin A was achieved in 14 steps from achiral 3-hydroxybenzaldehyde, without the need of chiral reagents or enzymatic resolution to introduce the chiral centers. The key asymmetric steps include in particular a highly enantioselective organocatalyzed Michael addition on an aryl vinyl ketone, a Sharpless asymmetric epoxidation and a subsequent regioselective ring opening of the resulting chiral epoxide. This work represents the first formal enantioselective synthesis of nhatrangin A.
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Affiliation(s)
- Sophie Feuillastre
- Université de Lyon - Université Claude Bernard Lyon 1 - CNRS - INSA Lyon - CPE Lyon, Institut de Chimie et Biochimie Moléculaires et Supramoléculaires - UMR 5246, équipe SURCOOF, Campus Lyon-Tech-La Doua, bât. Raulin, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France.
| | - Ludovic Raffier
- Université de Lyon - Université Claude Bernard Lyon 1 - CNRS - INSA Lyon - CPE Lyon, Institut de Chimie et Biochimie Moléculaires et Supramoléculaires - UMR 5246, équipe SURCOOF, Campus Lyon-Tech-La Doua, bât. Raulin, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France.
| | - Béatrice Pelotier
- Université de Lyon - Université Claude Bernard Lyon 1 - CNRS - INSA Lyon - CPE Lyon, Institut de Chimie et Biochimie Moléculaires et Supramoléculaires - UMR 5246, équipe SURCOOF, Campus Lyon-Tech-La Doua, bât. Raulin, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France.
| | - Olivier Piva
- Université de Lyon - Université Claude Bernard Lyon 1 - CNRS - INSA Lyon - CPE Lyon, Institut de Chimie et Biochimie Moléculaires et Supramoléculaires - UMR 5246, équipe SURCOOF, Campus Lyon-Tech-La Doua, bât. Raulin, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France.
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5
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Fan TT, Zhang HH, Tang YH, Zhang FZ, Han BN. Two New Neo-debromoaplysiatoxins-A Pair of Stereoisomers Exhibiting Potent Kv1.5 Ion Channel Inhibition Activities. Mar Drugs 2019; 17:E652. [PMID: 31766406 PMCID: PMC6950415 DOI: 10.3390/md17120652] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/15/2019] [Accepted: 11/16/2019] [Indexed: 11/17/2022] Open
Abstract
A pair of stereoisomers possessing novel structures with 6/6/5 fused-ring systems, neo-debromoaplysiatoxin E (1) and neo-debromoaplysiatoxin F (2), were isolated from the marine cyanobacterium Lyngbya sp. Their structures were elucidated using various spectroscopic techniques including high resolution electrospray ionization mass spectroscopy (HRESIMS) and nuclear magnetic resonance (NMR). The absolute stereochemistry was determined by calculated electronic circular dichroism (ECD) and gauge-independent atomic orbital (GIAO) NMR shift calculation followed by DP4+ analysis. Significantly, this is the first report on aplysiatoxin derivatives with different absolute configurations at C9-C12 (1: 9S, 10R, 11S, 12S; 2: 9R, 10S, 11R, 12R). Compounds 1 and 2 exhibited potent blocking activities against Kv1.5 with IC50 values of 1.22 ± 0.22 μM and 2.85 ± 0.29 μM, respectively.
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Affiliation(s)
- Ting-Ting Fan
- Department of Development Technology of Marine Resources, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (T.-T.F.); (H.-H.Z.); (F.-Z.Z.)
| | - Hui-Hui Zhang
- Department of Development Technology of Marine Resources, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (T.-T.F.); (H.-H.Z.); (F.-Z.Z.)
| | - Yang-Hua Tang
- Department of Pharmacy, Graduate School, Hunan University of Chinese Medicine, Changsha 410208, China;
| | - Fan-Zhong Zhang
- Department of Development Technology of Marine Resources, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (T.-T.F.); (H.-H.Z.); (F.-Z.Z.)
| | - Bing-Nan Han
- Department of Development Technology of Marine Resources, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (T.-T.F.); (H.-H.Z.); (F.-Z.Z.)
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6
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Tang YH, Wu J, Fan TT, Zhang HH, Gong XX, Cao ZY, Zhang J, Lin HW, Han BN. Chemical and biological study of aplysiatoxin derivatives showing inhibition of potassium channel Kv1.5. RSC Adv 2019; 9:7594-7600. [PMID: 35521179 PMCID: PMC9061199 DOI: 10.1039/c9ra00965e] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 02/25/2019] [Indexed: 11/21/2022] Open
Abstract
Three new aplysiatoxins, neo-debromoaplysiatoxin D (1), oscillatoxin E (2) and oscillatoxin F (3), accompanied by four known analogues (4–7), were identified from the marine cyanobacterium Lyngbya sp. Structural frames differ amongst these metabolites, and therefore we classified compounds 1 and 4–6 as aplysiatoxins as they possess 6/12/6 and 6/10/6 tricyclic ring systems featuring a macrolactone ring, and compounds 2, 3 and 7 as oscillatoxins that feature a hexane-tetrahydropyran in a spirobicyclic system. Bioactivity experiments showed that compounds 1 and 4–6 presented significant expression of phosphor-PKCδ whereas compounds 2, 5 and 7 showed the most potent blocking activity against potassium channel Kv1.5 with IC50 values of 0.79 ± 0.032 μM, 1.28 ± 0.080 μM and 1.47 ± 0.138 μM, respectively. Molecular docking analysis supplementing the binding interaction of oscillatoxin E (2) and oscillatoxin F (3) with Kv1.5 showed oscillatoxin E (2) with a strong binding affinity of −37.645 kcal mol−1 and oscillatoxin F (3) with a weaker affinity of −32.217 kcal mol−1, further supporting the experimental data. New aplysiatoxin derivative (oscillatoxin E) exhibiting potent blocking activity against potassium channel Kv1.5 is consistent with molecular docking analysis.![]()
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Affiliation(s)
- Yang-Hua Tang
- Research Center of Marine Biology and Natural Products
- College of Life Sciences and Medicine
- Zhejiang Sci-Tech University
- Hangzhou 310018
- China
| | - Jing Wu
- Department of Pathophysiology
- Shanghai Jiaotong University
- School of Medicine
- Shanghai 200025
- China
| | - Ting-Ting Fan
- Research Center of Marine Biology and Natural Products
- College of Life Sciences and Medicine
- Zhejiang Sci-Tech University
- Hangzhou 310018
- China
| | - Hui-Hui Zhang
- Research Center of Marine Biology and Natural Products
- College of Life Sciences and Medicine
- Zhejiang Sci-Tech University
- Hangzhou 310018
- China
| | - Xiao-Xia Gong
- Research Center of Marine Biology and Natural Products
- College of Life Sciences and Medicine
- Zhejiang Sci-Tech University
- Hangzhou 310018
- China
| | - Zheng-Yu Cao
- Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development
- China Pharmaceutical University
- Nanjing
- China
| | - Jian Zhang
- Department of Pathophysiology
- Shanghai Jiaotong University
- School of Medicine
- Shanghai 200025
- China
| | - Hou-Wen Lin
- Research Center for Marine Drugs
- State Key Laboratory of Oncogenes and Related Genes
- Department of Pharmacy
- Ren Ji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine
- Shanghai 200127
| | - Bing-Nan Han
- Research Center of Marine Biology and Natural Products
- College of Life Sciences and Medicine
- Zhejiang Sci-Tech University
- Hangzhou 310018
- China
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7
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Quercetin Suppresses CYR61-Mediated Multidrug Resistance in Human Gastric Adenocarcinoma AGS Cells. Molecules 2018; 23:molecules23020209. [PMID: 29364834 PMCID: PMC6017870 DOI: 10.3390/molecules23020209] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 01/20/2018] [Accepted: 01/24/2018] [Indexed: 01/23/2023] Open
Abstract
Cysteine-rich angiogenic inducer 61 (CYR61) is an extracellular matrix-associated protein involved in survival, tumorigenesis, and drug resistance. Therefore, we examined the effects of flavones against CYR61-overexpressing human gastric adenocarcinoma AGS (AGS-cyr61) cells, which show remarkable resistance to 5-fluorouracil (5-FU), adriamycin (ADR), tamoxifen (TAM), paclitaxel (PAC), and docetaxel (DOC). Among the tested flavones, quercetin had the lowest 50% inhibitory concentration (IC50) and significantly reduced the viability of AGS-cyr61 cells compared with AGS cells. Quercetin: (1) reduced multidrug resistance-associated protein 1 and nuclear factor (NF)-kappa B p65 subunit levels; (2) reversed multidrug resistance (MDR); (3) inhibited colony formation and induced caspase-dependent apoptosis; and (4) suppressed migration and down-regulated epithelial-mesenchymal transition-related proteins in AGS-cyr61. Moreover, AGS-cyr61 cells treated with quercetin concentrations close to the IC50 and simultaneously treated with 5-FU or ADR in the sub-lethal range showed strong synergism between quercetin and these two drugs. These findings indicate that CYR61 is a potential regulator of drug resistance and that quercetin may be a novel agent for improving the efficacy of anticancer drugs in AGS-cyr61 cells.
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Han BN, Liang TT, Keen LJ, Fan TT, Zhang XD, Xu L, Zhao Q, Wang SP, Lin HW. Two Marine Cyanobacterial Aplysiatoxin Polyketides, Neo-debromoaplysiatoxin A and B, with K+ Channel Inhibition Activity. Org Lett 2018; 20:578-581. [DOI: 10.1021/acs.orglett.7b03672] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Bing-Nan Han
- Department
of Development Technology of Marine Resources, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
- Research
Center for Marine Drugs, State Key Laboratory of Oncogenes and Related
Genes, Department of Pharmacy, Ren Ji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Ting-Ting Liang
- School
of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, China
| | - Lawrence Jordan Keen
- Department
of Development Technology of Marine Resources, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Ting-Ting Fan
- Department
of Development Technology of Marine Resources, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Xiao-Dan Zhang
- Department
of Development Technology of Marine Resources, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Lin Xu
- Department
of Development Technology of Marine Resources, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Qi Zhao
- Faculty
of Health Sciences, University of Macau, Macau, China
| | - Shu-Ping Wang
- Research
Center for Marine Drugs, State Key Laboratory of Oncogenes and Related
Genes, Department of Pharmacy, Ren Ji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Hou-Wen Lin
- Research
Center for Marine Drugs, State Key Laboratory of Oncogenes and Related
Genes, Department of Pharmacy, Ren Ji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
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Structure Related Inhibition of Enzyme Systems in Cholinesterases and BACE1 In Vitro by Naturally Occurring Naphthopyrone and Its Glycosides Isolated from Cassia obtusifolia. Molecules 2017; 23:molecules23010069. [PMID: 29283428 PMCID: PMC6017707 DOI: 10.3390/molecules23010069] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 12/26/2017] [Accepted: 12/27/2017] [Indexed: 11/23/2022] Open
Abstract
Cassia obtusifolia Linn. have been used to improve vision, inflammatory diseases, and as hepatoprotective agents and to promote urination from ancient times. In the present study, we investigated the influence of glycosylation of components of C. obtusifolia and structure-activity relationships (SARs) with respect to the inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1), which are related to Alzheimer’s disease (AD). All six C. obtusifolia-derived compounds, rubrofusarin (1), rubrofusarin 6-O-β-d-glucopyranoside (2), rubrofusarin 6-O-β-d-gentiobioside (3), nor-rubrofusarin 6-O-β-d-glucoside (4), isorubrofusarin 10-O-β-d-gentiobioside (5), and rubrofusarin 6-O-β-d-triglucoside (6) showed promising inhibitory activity against AChE/BACE1. Compounds 3 and 4 showed most significant inhibition against AChE and BACE1, respectively. The SARs results emphasized the importance of gentiobiosyl moiety in the rubrofusarin for AChE inhibition, whereas the presence of hydroxyl group at C-8 and the glucosyl moiety at the C-6 position in the nor-rubrofusarin appeared to largely determine BACE1 inhibition. Kinetics and docking studies showed the lowest binding energy and highest affinity for mixed-type inhibitors, 3 and 4. Hydrophobic bonds interactions and the number of hydrogen bonds determined the strength of the protein-inhibitor interaction. These results suggest that C. obtusifolia and its constituents have therapeutic potential, and that the SARs of its active components are further explored with a view towards developing a treatment for AD.
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Loss of the Phenolic Hydroxyl Group and Aromaticity from the Side Chain of Anti-Proliferative 10-Methyl-aplog-1, a Simplified Analog of Aplysiatoxin, Enhances Its Tumor-Promoting and Proinflammatory Activities. Molecules 2017; 22:molecules22040631. [PMID: 28406454 PMCID: PMC6153940 DOI: 10.3390/molecules22040631] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 04/05/2017] [Accepted: 04/11/2017] [Indexed: 01/29/2023] Open
Abstract
Aplysiatoxin (ATX) is a protein kinase C (PKC) activator with potent tumor-promoting activity. In contrast, 10-methyl-aplog-1 (1), a simplified analog of ATX, was anti-proliferative towards several cancer cell lines without significant tumor-promoting and proinflammatory activities. To determine the effects of the phenolic group on the biological activities of 1, we synthesized new derivatives (2, 3) that lack the phenolic hydroxyl group and/or the aromatic ring. Compound 2, like 1, showed potent anti-proliferative activity against several cancer cell lines, but little with respect to tumor-promoting and proinflammatory activities. In contrast, 3 exhibited weaker growth inhibitory activity, and promoted inflammation and tumorigenesis. The binding affinity of 3 for PKCδ, which is involved in growth inhibition and apoptosis, was several times lower than those of 1 and 2, possibly due to the absence of the hydrogen bond and CH/π interaction between its side chain and either Met-239 or Pro-241 in the PKCδ-C1B domain. These results suggest that both the aromatic ring and phenolic hydroxyl group can suppress the proinflammatory and tumor-promoting activities of 1 and, therefore, at least the aromatic ring in the side chain of 1 is indispensable for developing anti-cancer leads with potent anti-proliferative activity and limited side effects. In accordance with the binding affinity, the concentration of 3 necessary to induce PKCδ-GFP translocation to the plasma membrane and perinuclear regions in HEK293 cells was higher than that of 1 and 2. However, the translocation profiles for PKCδ-GFP due to induction by 1–3 were similar.
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Kikumori M, Yanagita RC, Tokuda H, Suenaga K, Nagai H, Irie K. Structural optimization of 10-methyl-aplog-1, a simplified analog of debromoaplysiatoxin, as an anticancer lead. Biosci Biotechnol Biochem 2015; 80:221-31. [PMID: 26452398 DOI: 10.1080/09168451.2015.1091718] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Aplog-1 is a simplified analog of debromoaplysiatoxin (DAT) with potent tumor-promoting and proinflammatory activities. Aplog-1 and DAT exhibited anti-proliferative activities against several human cancer cell lines, whereas aplog-1 did not have tumor-promoting nor proinflammatory activities. We have recently found 10-methyl-aplog-1 (1) to have strong anti-proliferative activity compared with aplog-1. To further investigate the structural factors involved in the tumor-promoting, proinflammatory, and anti-proliferative activities, two dimethyl derivatives of aplog-1 (2, 3) were synthesized, where two methyl groups were installed at positions 4 and 10 or 10 and 12. 10,12-Dimethyl-aplog-1 (2) had stronger inhibitory effects on the growth of several human cancer cell lines than 1 and DAT, but exhibited no tumor-promoting and proinflammatory activities. In contrast, 4,10-dimethyl-aplog-1 (3) displayed weak tumor-promoting and proinflammatory activities along with anti-proliferative activity similar to that of 1 and DAT. Compound 2 would be the optimized seed for anticancer drugs among the simplified analogs of DAT.
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Affiliation(s)
- Masayuki Kikumori
- a Division of Food Science and Biotechnology , Graduate School of Agriculture, Kyoto University , Kyoto , Japan
| | - Ryo C Yanagita
- b Faculty of Agriculture, Department of Applied Biological Science , Kagawa University , Miki , Japan
| | - Harukuni Tokuda
- c Department of Complementary and Alternative Medicine, Clinical R&D , Graduate School of Medical Science, Kanazawa University , Kanazawa , Japan
| | - Kiyotake Suenaga
- d Faculty of Science and Technology , Keio University , Yokohama , Japan
| | - Hiroshi Nagai
- e Department of Ocean Sciences , Tokyo University of Marine Science and Technology , Tokyo , Japan
| | - Kazuhiro Irie
- a Division of Food Science and Biotechnology , Graduate School of Agriculture, Kyoto University , Kyoto , Japan
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12
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Irie K, Yanagita RC. Synthesis and Biological Activities of Simplified Analogs of the Natural PKC Ligands, Bryostatin-1 and Aplysiatoxin. CHEM REC 2014; 14:251-67. [DOI: 10.1002/tcr.201300036] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Kazuhiro Irie
- Division of Food Science and Biotechnology; Graduate School of Agriculture; Kyoto University; Kyoto 606-8502 Japan
| | - Ryo C. Yanagita
- Department of Applied Biological Science; Faculty of Agriculture, Kagawa University; Kagawa 761-0795 Japan
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Anti-Chikungunya viral activities of aplysiatoxin-related compounds from the marine cyanobacterium Trichodesmium erythraeum. Mar Drugs 2014; 12:115-27. [PMID: 24394406 PMCID: PMC3917264 DOI: 10.3390/md12010115] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 11/25/2013] [Accepted: 12/12/2013] [Indexed: 11/21/2022] Open
Abstract
Tropical filamentous marine cyanobacteria have emerged as a viable source of novel bioactive natural products for drug discovery and development. In the present study, aplysiatoxin (1), debromoaplysiatoxin (2) and anhydrodebromoaplysiatoxin (3), as well as two new analogues, 3-methoxyaplysiatoxin (4) and 3-methoxydebromoaplysiatoxin (5), are reported for the first time from the marine cyanobacterium Trichodesmium erythraeum. The identification of the bloom-forming cyanobacterial strain was confirmed based on phylogenetic analysis of its 16S rRNA sequences. Structural determination of the new analogues was achieved by extensive NMR spectroscopic analysis and comparison with NMR spectral data of known compounds. In addition, the antiviral activities of these marine toxins were assessed using Chikungunya virus (CHIKV)-infected cells. Post-treatment experiments using the debrominated analogues, namely compounds 2, 3 and 5, displayed dose-dependent inhibition of CHIKV when tested at concentrations ranging from 0.1 µM to 10.0 µM. Furthermore, debromoaplysiatoxin (2) and 3-methoxydebromoaplysiatoxin (5) exhibited significant anti-CHIKV activities with EC50 values of 1.3 μM and 2.7 μM, respectively, and selectivity indices of 10.9 and 9.2, respectively.
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