1
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Hoenke S, Serbian I, Csuk R. A Malaprade cleavage, a McMurry ring closure and an intramolecular aldol contraction of maslinic acid’s ring A. RESULTS IN CHEMISTRY 2022. [DOI: 10.1016/j.rechem.2022.100547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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2
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Liao JX, Sun JS, Hu ZN, Liu H. Advances in the Semi-Synthesis of Triterpenoids. SYNTHESIS-STUTTGART 2021. [DOI: 10.1055/a-1543-9719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
AbstractRecent achievements in triterpenoid semi-synthesis are discussed in this short review, which is divided into three parts according to the type of synthetic strategy being employed. These strategies include functionalization, modification of the carbon skeleton, and glycosylation. In the section on functionalization strategies, both functional group interconversions and new functional group installations on triterpenoid starting materials are described. The section on modification of the carbon skeleton is divided into three parts according to the tactic being applied, and incorporates rearrangement of the carbon skeleton, ring scission, and introduction of an additional heterocyclic ring. Meanwhile, in the section on glycosylation, notable achievements in the semi-synthesis of both natural and artificial triterpene saponins are discussed. Overall, the pivotal transformations that have brought about striking chemical structure variations of triterpenoid starting materials are highlighted herein, and it is hoped that this short review will provide inspiration to both established and new investigators engaged in this field of research. 1 Introduction2 Semi-Synthesis of Triterpenoids via Functionalization Strategies2.1 Functionalization of Rings with Functional Groups2.2 Functionalization of a Side Chain2.3 Functionalization of Rings without Existing Functional Groups 2.4 Functionalization of Angular Methyl Groups2.5 Functionalization of Angular Methyl Groups and Functional-Group-Free Rings2.6 Multisite Modifications3 Semi-Synthesis of Triterpenoids via C-Skeleton Modification Strategies3.1 Rearrangement Tactics3.2 Ring-Opening Tactics3.3 Additional Ring Introduction Tactics4 emi-Synthesis of Triterpenoids via a Glycosylation Strategy5 Conclusions and Outlook
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3
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Quílez Del Moral JF, Pérez Á, Herrador MDM, Barrero AF. Access to Natural Valparanes and Daucanes: Enantioselective Synthesis of (-)-Valpara-2,15-diene and (+)-Isodaucene. JOURNAL OF NATURAL PRODUCTS 2019; 82:9-15. [PMID: 30601659 DOI: 10.1021/acs.jnatprod.8b00129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The first total synthesis of a natural diterpene valparane, (-)-valpara-2,15-diene (1), has been achieved from all -trans-geranylgeraniol (9), a natural renewable compound. The key steps involve a Ti(III)-mediated radical cyclization of the chiral monoepoxypolyene (14 R,15 R)-14,15-epoxy,16- tert-butyldimethylsilyloxygeranyllinalyl acetate (8) to give the 6,6,7-tricyclic intermediate 7 with stereocontrolled formation of six stereocenters; a stereo- and regio-directed contraction of the A ring in 7 to produce a cyclopentane ring; and the ready generation of the target isopropenyl group. This research provides access to structurally related natural products such as the sesquiterpene (+)-isodaucene (3), the synthesis of which is also reported herein.
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Affiliation(s)
- José F Quílez Del Moral
- Department of Organic Chemistry, Institute of Biotechnology , University of Granada , Campus Fuentenueva , 18071 Granada , Spain
| | - Álvaro Pérez
- Department of Organic Chemistry, Institute of Biotechnology , University of Granada , Campus Fuentenueva , 18071 Granada , Spain
| | - María Del Mar Herrador
- Department of Organic Chemistry, Institute of Biotechnology , University of Granada , Campus Fuentenueva , 18071 Granada , Spain
| | - Alejandro F Barrero
- Department of Organic Chemistry, Institute of Biotechnology , University of Granada , Campus Fuentenueva , 18071 Granada , Spain
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4
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Qiao Z, Liu H, Sui JJ, Liao JX, Tu YH, Schmidt RR, Sun JS. Diversity-Oriented Synthesis of Steviol Glycosides. J Org Chem 2018; 83:11480-11492. [PMID: 30183288 DOI: 10.1021/acs.joc.8b01274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
With cheap and easily available mixtures of steviol glycosides as starting materials, a practical method for steviol acquisition has been developed, on the basis of which a facile, diversity-oriented, and economic protocol for the synthesis of structurally defined steviol glycosides was established. The novel approach is featured by the highly efficient glycosylation of sterically hindered and acid-sensitive steviol via orchestrated application of Yu glycosylation, Schmidt glycosylation, and PTC glycosylation. Hence, these high-intensity sweeteners and potential lead compounds for drug development are now readily accessible.
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Affiliation(s)
- Zhi Qiao
- The National Research Centre for Carbohydrate Synthesis , Jiangxi Normal University 99 Ziyang Avenue , Nanchang 330022 , China
| | - Hui Liu
- The National Research Centre for Carbohydrate Synthesis , Jiangxi Normal University 99 Ziyang Avenue , Nanchang 330022 , China
| | - Jing-Jing Sui
- The National Research Centre for Carbohydrate Synthesis , Jiangxi Normal University 99 Ziyang Avenue , Nanchang 330022 , China
| | - Jin-Xi Liao
- The National Research Centre for Carbohydrate Synthesis , Jiangxi Normal University 99 Ziyang Avenue , Nanchang 330022 , China
| | - Yuan-Hong Tu
- The National Research Centre for Carbohydrate Synthesis , Jiangxi Normal University 99 Ziyang Avenue , Nanchang 330022 , China
| | - Richard R Schmidt
- The National Research Centre for Carbohydrate Synthesis , Jiangxi Normal University 99 Ziyang Avenue , Nanchang 330022 , China.,Department of Chemistry , University of Konstanz , D-78457 , Konstanz , Germany
| | - Jian-Song Sun
- The National Research Centre for Carbohydrate Synthesis , Jiangxi Normal University 99 Ziyang Avenue , Nanchang 330022 , China
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5
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Haut FL, Speck K, Wildermuth R, Möller K, Mayer P, Magauer T. A Negishi cross-coupling reaction enables the total synthesis of (+)-stachyflin. Tetrahedron 2018. [DOI: 10.1016/j.tet.2018.02.048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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6
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Sommerwerk S, Heller L, Kuhfs J, Csuk R. Urea derivates of ursolic, oleanolic and maslinic acid induce apoptosis and are selective cytotoxic for several human tumor cell lines. Eur J Med Chem 2016; 119:1-16. [PMID: 27149037 DOI: 10.1016/j.ejmech.2016.04.051] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/19/2016] [Accepted: 04/20/2016] [Indexed: 01/01/2023]
Abstract
2,3-Di-O-acetyl-maslinic acid benzylamide (5) has previously been shown to possess high cytotoxicity for a variety of human tumor cell lines while being of low cytotoxicity to non-malignant cells. Structural modifications performed on 5 revealed that the presence of these acetyl groups in 5 and the presence of (2β,3β)-configurated centers seems necessary for obtaining high cytotoxicity combined with best selectivity between malignant cells and non-malignant mouse fibroblasts. Compounds carrying an ursane skeleton showed weaker cytotoxicity than their oleanane derived analogs. In addition, the benzylamide function in compound 5 should be replaced by a phenylurea moiety to gain better cytotoxicity while retaining and improving the selectivity. Thus, maslinic acid derived N-[2β,3β-di-O-acetyl-17β-amino-28-norolean-12-en-17-yl]phenylurea (45) gave best results showing EC50 = 0.9 μM (for A2780 ovarian cancer cells) with EC50 > 120 μM for fibroblasts (NIH 3T3) and triggered apoptosis while caspase-3 was not activated by this compound.
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Affiliation(s)
- Sven Sommerwerk
- Martin-Luther-University Halle-Wittenberg, Organic Chemistry, Kurt-Mothes-Str.2, D-06120, Halle, Saale, Germany
| | - Lucie Heller
- Martin-Luther-University Halle-Wittenberg, Organic Chemistry, Kurt-Mothes-Str.2, D-06120, Halle, Saale, Germany
| | - Julia Kuhfs
- Martin-Luther-University Halle-Wittenberg, Organic Chemistry, Kurt-Mothes-Str.2, D-06120, Halle, Saale, Germany
| | - René Csuk
- Martin-Luther-University Halle-Wittenberg, Organic Chemistry, Kurt-Mothes-Str.2, D-06120, Halle, Saale, Germany.
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7
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Zhang W, Zhu XL, Ding W, Shi XX. A novel stereoselective synthesis of (−)-quinic acid starting from the naturally abundant (−)-shikimic acid. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.tetasy.2015.10.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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8
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Triterpenoids with a Five-Membered a-Ring: Distribution in Nature, Transformations, Synthesis, and Biological Activity. Chem Nat Compd 2015. [DOI: 10.1007/s10600-015-1193-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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9
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Kvasnica M, Urban M, Dickinson NJ, Sarek J. Pentacyclic triterpenoids with nitrogen- and sulfur-containing heterocycles: synthesis and medicinal significance. Nat Prod Rep 2015; 32:1303-30. [DOI: 10.1039/c5np00015g] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Triterpenoids are natural compounds which are usually produced by plants as secondary metabolites. Triterpenic heterocycles are compounds with a variety of interesting biological activities.
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Affiliation(s)
- Miroslav Kvasnica
- Laboratory of Growth Regulators
- Centre of the Region Hana for Biotechnological and Agricultural Research
- Institute of Experimental Botany ASCR & Palacky University
- 78371 Olomouc
- Czech Republic
| | - Milan Urban
- Institute of Molecular and Translational Medicine
- Faculty of Medicine and Dentistry
- Palacky University
- 77900 Olomouc
- Czech Republic
| | - Niall J. Dickinson
- Department of Organic Chemistry
- Faculty of Science
- Palacky University
- Olomouc
- Czech Republic
| | - Jan Sarek
- Institute of Molecular and Translational Medicine
- Faculty of Medicine and Dentistry
- Palacky University
- 77900 Olomouc
- Czech Republic
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Rousseau G, Lebeuf R, Schenk K, Castet F, Robert F, Landais Y. Base-catalyzed intramolecular hydroamination of cyclohexa-2,5-dienes: insights into the mechanism through DFT calculations and application to the total synthesis of epi-elwesine. Chemistry 2014; 20:14771-82. [PMID: 25223607 DOI: 10.1002/chem.201403662] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 07/10/2014] [Indexed: 11/08/2022]
Abstract
The base-catalyzed intramolecular hydroamination of 1-ethylaminocyclohexa-2,5-dienes is described. The transformation proceeds through isomerization of the cyclohexa-1,4-dienyl fragment into the corresponding conjugated 1,3-diene prior to the hydroamination step. Attaching a chiral glycinol ether auxiliary on the amino group allows the protonation to occur with complete diastereocontrol. The resulting lithium amide then adds onto the 1,3-dienyl moiety, affording the desired fused pyrrolidine ring along with the corresponding lithium allylic anion. Protonation of the latter then proceeds with high regiocontrol to favor the resulting allylic amines. In contrast, when the reaction was performed on primary amines, fused pyrrolidines bearing a homoallylic amino group were obtained. The stereochemical course of the process and determination of the reaction pathways were established based on calculations performed at the DFT level. Finally, application of the methodology to the enantioselective synthesis of (+)-epi-elwesine, a crinane alkaloid, is described.
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Affiliation(s)
- Géraldine Rousseau
- ISM, UMR 5255, University of Bordeaux and CNRS, 351, Cours de la liberation, 33400 Talence Cedex (France)
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11
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Bednarczyk–Cwynar B, Zaprutko L. C-Lactam Derivatives of Oleanolic Acid. Hydrolysis and Further Acylation of Methyl Acetyloleanolate C-Lactam and C-Thiolactam. Nat Prod Commun 2014. [DOI: 10.1177/1934578x1400900325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Acetyl methyl oleanolate was transformed into a seven-membered C-lactam derivative (2) using Beckmann rearrangement of the corresponding C-oxime during the last step of the synthesis. The C=O group of the lactam system was transformed into a C=S group by Lavesson's reagent. The resulting acetylthiolactam 3 and initial acetyllactam 2 were subjected to alkaline hydrolysis to obtain lactam 4 and thiolactam 5 with an unsubstituted C-3 hydroxyl group. Subsequently, compounds 4 and 5 were acylated with either succinic or acetic anhydride in pyridine. Various acylating conditions were tested for hydroxythiolactam 5. The structures of the newly obtained compounds were supported by spectral and mass spectrometric data.
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Affiliation(s)
- Barbara Bednarczyk–Cwynar
- Department of Organic Chemistry, Poznan University of Medical Sciences, Grunwaldzka Str. 6, 60 – 780 Poznan, Poland
| | - Lucjusz Zaprutko
- Department of Organic Chemistry, Poznan University of Medical Sciences, Grunwaldzka Str. 6, 60 – 780 Poznan, Poland
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12
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Trant JF, Hudlicky T. Ring-opening of hindered cyclic epoxides with potassium carboxylates in the presence of conjugate acids. CAN J CHEM 2013. [DOI: 10.1139/cjc-2013-0386] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During attempts to ring-open a highly hindered epoxide, traditional methods were found to be ineffective. An alternative strategy for opening epoxides was implemented that employed a potassium carboxylate in the presence of its conjugate acid in a solvent mixture containing polar and potassium-sequestering components. A systematic analysis of the components of the reaction mixture indicated that the addition of the conjugate acid was the most important feature for providing good conversion. This reaction appears to be general for most classes of carboxylic acids including cinnamic, aromatic, and highly hindered carboxylic acids (30%–79% yield) and only fails with weak carboxylate nucleophiles. Three highly substituted and hindered cyclohexene oxide derivatives were examined for reactivity and the reaction conditions appear to tolerate a variety of functional groups to provide the ring-opened species. This pH-moderate system proved useful for hindered cyclic epoxides when all other techniques failed and should prove general to a wide spectrum of epoxide and carboxylic acid partners in those cases where the use of a strong Lewis or protic acid catalyst, or a strong basic nucleophile, is inappropriate.
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Affiliation(s)
- John F. Trant
- Department of Chemistry and Centre for Biotechnology, Brock University, 500 Glenridge Avenue, St. Catharines, ON L2S 3A1, Canada
| | - Tomas Hudlicky
- Department of Chemistry and Centre for Biotechnology, Brock University, 500 Glenridge Avenue, St. Catharines, ON L2S 3A1, Canada
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14
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Sánchez-Tena S, Reyes-Zurita FJ, Díaz-Moralli S, Vinardell MP, Reed M, García-García F, Dopazo J, Lupiáñez JA, Günther U, Cascante M. Maslinic acid-enriched diet decreases intestinal tumorigenesis in Apc(Min/+) mice through transcriptomic and metabolomic reprogramming. PLoS One 2013; 8:e59392. [PMID: 23527181 PMCID: PMC3601079 DOI: 10.1371/journal.pone.0059392] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 02/14/2013] [Indexed: 12/22/2022] Open
Abstract
Chemoprevention is a pragmatic approach to reduce the risk of colorectal cancer, one of the leading causes of cancer-related death in western countries. In this regard, maslinic acid (MA), a pentacyclic triterpene extracted from wax-like coatings of olives, is known to inhibit proliferation and induce apoptosis in colon cancer cell lines without affecting normal intestinal cells. The present study evaluated the chemopreventive efficacy and associated mechanisms of maslinic acid treatment on spontaneous intestinal tumorigenesis in ApcMin/+ mice. Twenty-two mice were randomized into 2 groups: control group and MA group, fed with a maslinic acid–supplemented diet for six weeks. MA treatment reduced total intestinal polyp formation by 45% (P<0.01). Putative molecular mechanisms associated with suppressing intestinal polyposis in ApcMin/+ mice were investigated by comparing microarray expression profiles of MA-treated and control mice and by analyzing the serum metabolic profile using NMR techniques. The different expression phenotype induced by MA suggested that it exerts its chemopreventive action mainly by inhibiting cell-survival signaling and inflammation. These changes eventually induce G1-phase cell cycle arrest and apoptosis. Moreover, the metabolic changes induced by MA treatment were associated with a protective profile against intestinal tumorigenesis. These results show the efficacy and underlying mechanisms of MA against intestinal tumor development in the ApcMin/+ mice model, suggesting its chemopreventive potential against colorectal cancer.
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Affiliation(s)
- Susana Sánchez-Tena
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
- Institute of Biomedicine, Universitat de Barcelona and CSIC-Associated Unit, Barcelona, Spain
| | | | - Santiago Díaz-Moralli
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
- Institute of Biomedicine, Universitat de Barcelona and CSIC-Associated Unit, Barcelona, Spain
| | - Maria Pilar Vinardell
- Department of Physiology, Faculty of Pharmacy, University of Barcelona, Barcelona, Spain
| | - Michelle Reed
- Henry Wellcome Building for Biomolecular NMR Spectroscopy, CR UK Institute for Cancer Studies, University of Birmingham, Birmingham, United Kingdom
| | - Francisco García-García
- Functional Genomics Node, National Institute of Bioinformatics, Centro de Investigación Pricipe Felipe, Valencia, Spain
- Department of Bioinformatics, Centro de Investigación Pricipe Felipe, Valencia, Spain
- Centro de Investigación Biomédica En Red de Enfermedades Raras, Valencia, Spain
| | - Joaquín Dopazo
- Functional Genomics Node, National Institute of Bioinformatics, Centro de Investigación Pricipe Felipe, Valencia, Spain
- Department of Bioinformatics, Centro de Investigación Pricipe Felipe, Valencia, Spain
- Centro de Investigación Biomédica En Red de Enfermedades Raras, Valencia, Spain
| | - José A. Lupiáñez
- Department of Biochemistry and Molecular Biology, University of Granada, Granada, Spain
| | - Ulrich Günther
- Henry Wellcome Building for Biomolecular NMR Spectroscopy, CR UK Institute for Cancer Studies, University of Birmingham, Birmingham, United Kingdom
| | - Marta Cascante
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
- Institute of Biomedicine, Universitat de Barcelona and CSIC-Associated Unit, Barcelona, Spain
- * E-mail:
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Kazakova OB, Yamansarov EY, Kukovinets OS, Medvedeva NI. Transformation of triterpene ketoximes into lactams by the action of ozone. Chem Nat Compd 2011. [DOI: 10.1007/s10600-011-0049-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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16
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C-Lactam Derivatives of Oleanolic Acid. The Synthesis of C-lactam by Beckmann Rearrangement of C-oxime. Nat Prod Commun 2011. [DOI: 10.1177/1934578x1100601206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Oleanolic acid, one of the most known triterpenes, was subjected to different chemical transformations within C-3 β-hydroxyl group, a double bond between C-12 and C-13, and a carboxyl function at C-17 in order to obtain new derivatives. The key compound consists of four six-membered rings (A, B, D, E) and one enlarged ring (C ring) containing a nitrogen atom and a carbonyl function – lactam. This type of derivative can be obtained by Beckmann rearrangement of the appropriate oxime. The lactam can be transformed into thiolactam with the use of Lavesson's reagent. The method is also presented for new derivatives synthesis, as well as their structure elucidation by spectroscopic means.
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17
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Parra A, Rivas F, Martin-Fonseca S, Garcia-Granados A, Martinez A. Maslinic acid derivatives induce significant apoptosis in b16f10 murine melanoma cells. Eur J Med Chem 2011; 46:5991-6001. [DOI: 10.1016/j.ejmech.2011.10.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 09/29/2011] [Accepted: 10/04/2011] [Indexed: 01/11/2023]
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18
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Dobado JA, Gómez-Tamayo JC, Calvo-Flores FG, Martínez-García H, Cardona W, Weiss-López B, Ramírez-Rodríguez O, Pessoa-Mahana H, Araya-Maturana R. NMR assignment in regioisomeric hydroquinones. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2011; 49:358-365. [PMID: 21452342 DOI: 10.1002/mrc.2745] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 01/26/2011] [Accepted: 01/31/2011] [Indexed: 05/30/2023]
Abstract
A set of regioisomeric pairs of tricyclic hydroquinones, analogues of antitumor 9,10-dihydroxy-4,4-dimethyl-5,8-dihydroanthracen-1(4H)-one (1) and other derivatives, were synthesized and their regiochemistry and NMR spectra assigned by using (1)H-detected one-bond (C-H) HMQC and long-range C-H HMBC, in good agreement with theoretical O3LYP/Alhrichs-pVTZ calculations. The 5-hydroxymethyl derivatives (11, 15, 19) showed a (3)J(H, H) coupling constant of methylene protons evidencing the presence of a seven-membered intramolecular hydrogen bonded ring, not observed for the 8-hydroxymethyl isomers.
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Affiliation(s)
- Jose A Dobado
- Grupo de Modelización y Diseño Molecular, Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
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19
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Synthesis and crystal structures of ring A modified glycyrrhetinic acid derivatives derived from 2,3-oxirane and 2,3-thiirane intermediates. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.03.098] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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20
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Fleck M, Bach T. Total Synthesis of Punctaporonin C by a Regio- and Stereoselective [2+2]-Photocycloaddition. Chemistry 2010; 16:6015-32. [PMID: 20411543 DOI: 10.1002/chem.201000036] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Martin Fleck
- Lehrstuhl für Organische Chemie 1, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
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21
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Parra A, Lopez PE, Garcia-Granados A. Different pathways for the deoxygenation of the A-ring of natural triterpene compounds. Nat Prod Res 2010; 24:177-96. [DOI: 10.1080/14786410903172098] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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22
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Tafazzoli M, Ghiasi M. Structure and conformation of α-, β- and γ-cyclodextrin in solution: Theoretical approaches and experimental validation. Carbohydr Polym 2009. [DOI: 10.1016/j.carbpol.2009.02.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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23
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Parra A, Rivas F, Lopez PE, Garcia-Granados A, Martinez A, Albericio F, Marquez N, Muñoz E. Solution- and solid-phase synthesis and anti-HIV activity of maslinic acid derivatives containing amino acids and peptides. Bioorg Med Chem 2009; 17:1139-45. [DOI: 10.1016/j.bmc.2008.12.041] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Revised: 12/15/2008] [Accepted: 12/16/2008] [Indexed: 10/21/2022]
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24
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Lannang AM, Louh GN, Lontsi D, Specht S, Sarite SR, Flörke U, Hussain H, Hoerauf A, Krohn K. Antimalarial compounds from the root bark of Garcinia polyantha Olv. J Antibiot (Tokyo) 2008; 61:518-23. [PMID: 18997392 DOI: 10.1038/ja.2008.70] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Eight compounds were isolated from the roots of Garcinia polyantha, and identified. Two of them, the xanthone garciniaxanthone I (1), and the triterpene, named garcinane (2), are reported as new natural products. The structures of the new compounds were elucidated on the basis of 1D and 2D NMR spectroscopic studies. The structure of compound 1 was confirmed by X-ray crystallography. Among the remaining six known compounds, three were known xanthones [smeathxanthone A (3), smeathxanthone B (4), and chefouxanthone (5)], one benzophenone [isoxanthochymol (6)], one triterpene [magnificol], and one sterol [beta-sitosterol]. The in vitro antimalarial activity of isoxanthochymol (6) against Plasmodium falciparum shows strong chemosuppression of parasitic growth.
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Cerda-García-Rojas CM, Catalán CAN, Muro AC, Joseph-Nathan P. Vibrational circular dichroism of Africanane and lippifoliane sesquiterpenes from Lippia integrifolia. JOURNAL OF NATURAL PRODUCTS 2008; 71:967-971. [PMID: 18500843 DOI: 10.1021/np8000927] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The agreement between theoretical and experimental vibrational circular dichroism curves of (4R,9R,10R)-(+)-african-1(5)-ene-2,6-dione (1) and (4R,9S,10R)-lippifoli-1(6)-en-5-one (2), isolated from the widely used plant Lippia integrifolia, allowed the determination of the conformation and absolute configuration of 1 and confirmed both structural features for 2. Molecular modeling of 1 and 2 was carried out by means of a systematic and a Monte Carlo search protocol followed by geometry optimization employing density functional theory calculations with the B3LYP/6-31G(d), B3LYP/DGDZVP, and/or B3PW91/DGDZVP2 functionals/basis sets. Validation of the minimum energy conformations for both tricyclic substances was achieved by comparison of the experimental and theoretical vicinal (1)H-(1)H NMR coupling constants obtained by DFT-GIAO calculations.
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Affiliation(s)
- Carlos M Cerda-García-Rojas
- Departamento de Química, Centro de InVestigación y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado 14-740, México, D. F., 07000 México.
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García-Granados A, López PE, Melguizo E, Parra A, Simeó Y. Remote Hydroxylation of Methyl Groups by Regioselective Cyclopalladation. Partial Synthesis of Hyptatic Acid-A. J Org Chem 2007; 72:3500-9. [PMID: 17402787 DOI: 10.1021/jo070116e] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hyptatic acid-A (32), a 2alpha,3beta,24-trihydroxyolean-12-en-28-oic acid, previously isolated from Hyptis capitata, was obtained from maslinic acid (2). The regioselective cyclopalladation of the axial methyl group on C-4 of maslinic acid afforded the C-24 hydroxymethylene group due to the presence of a C-2-OR substituent. Nevertheless, hederagenin (7) (23-hydroxy derivative) was formed when this oxygenated group was not present.
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Affiliation(s)
- Andrés García-Granados
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Granada, 18071, Granada, Spain
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Zhao Y, Truhlar DG. How Well Can New-Generation Density Functionals Describe Protonated Epoxides Where Older Functionals Fail? J Org Chem 2006; 72:295-8. [PMID: 17194116 DOI: 10.1021/jo061863z] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In a recent article, Carlier et al. (J. Org. Chem. 2006, 71, 1592) examined the prediction of several DFT functionals and showed that the most popular density functional, B3LYP, and 15 others fail badly for the prediction of the structure of protonated 2-methyl-1,2-epoxypropane. In this note, we compare the performance of several recently developed density functionals for the calculation of structures and energetics of protonated cyclic ethers, including epoxides. We found that several of the newly developed DFT methods perform better than B3LYP or any of the other 17 functionals examined by Carlier. We conclude that a recently published functional, M05-2X, has greatly improved performance for an unsymmetrical protonated epoxide, and we recommend this functional for studies that involve protonated epoxides and protonated ethers.
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Affiliation(s)
- Yan Zhao
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, USA
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28
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Yang HJ, Li BG, Cai XH, Qi HY, Luo YG, Zhang GL. Chiral decalins: preparation from oleanolic acid and application in the synthesis of (-)-9-epi-ambrox. JOURNAL OF NATURAL PRODUCTS 2006; 69:1531-8. [PMID: 17125216 DOI: 10.1021/np060159a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
A novel and versatile process was developed to prepare the trans-decalins Delta9(11)-3beta-acetoxysclareolide (2) and Delta9(11)-3beta-acetoxy-8-epi-sclareolide (3), respectively, with 4a-methoxycarbonyl-2,7,7-trimethyl-1-oxo-cis-decalin-2-ene (4) and its C-3 hydroxyl derivative 5 from oleanolic acid (3beta-hydroxyolean-12-en-28-oic acid, 1). Three key steps were (a) introduction of the AcO-12 group and the C-9,C-11 double bond at ring C of methyl 3beta-acetoxyolean-12-en-28-oate (8) to afford the diene, methyl 3,12-diacetoxyolean-9(11),12-dien-28-oate (11); (b) photolytic cleavage of the C-8,C-14 bond in the diene to give an acetoxy-substituted triene 14; and (c) oxidative cleavage of the triene or its hydrolyzed alpha,beta-unsaturated ketone product with m-CPBA/TsOH to give the cis- and trans-decalins 2-5. Delata9(11)-3beta-Acetoxysclareolide (2) was stereospecifically reduced to give 3beta-acetoxy-9-epi-sclareolide (23), from which (-)-9-epi-ambrox (7) was synthesized.
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Affiliation(s)
- Hai-Jun Yang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
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Garcia‐Granados A, López PE, Melguizo E, Parra A, Simeó Y. Reactivity of Chiral Sesquiterpene Synthons Obtained by the Degradation of Maslinic Acid from Olive‐Pressing Residues. SYNTHETIC COMMUN 2006. [DOI: 10.1080/00397910600773858] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Zaprutko L, Partyka D, Bednarczyk-Cwynar B. Triterpenoids. Part 21: Oleanolic acid azaderivatives as percutaneous transport promoters. Bioorg Med Chem Lett 2004; 14:4723-6. [PMID: 15324895 DOI: 10.1016/j.bmcl.2004.06.087] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2004] [Revised: 06/17/2004] [Accepted: 06/25/2004] [Indexed: 10/26/2022]
Abstract
Some new oleanolic acid derivatives with lactame and thiolactame structures in the A- or C-ring were prepared and tested as percutaneous transport promoters in vitro. Their activity was comparable with activity of N-dodecylcaprolactame (Azone). A-Thiolactame derivative of methyl oleanolate (13) was the most effective compound.
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Affiliation(s)
- Lucjusz Zaprutko
- Department of Organic Chemistry, Pharmaceutical Faculty, Poznan University of Medical Sciences, Poznań, Poland
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Dhavale DD, Markad SD, Karanjule NS, PrakashaReddy J. Asymmetric Dihydroxylation of d-Glucose Derived α,β-Unsaturated Ester: Synthesis of Azepane and Nojirimycin Analogues. J Org Chem 2004; 69:4760-6. [PMID: 15230599 DOI: 10.1021/jo049509t] [Citation(s) in RCA: 66] [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
The asymmetric dihydroxylation of a d-glucose derived alpha,beta-unsaturated ester 3 afforded syn vicinal diols in good to high diastereoselectivity. The conversion of these vicinal diols to the corresponding cyclic sulfate, regio-, stereoselective nucleophilic ring opening by sodium azide, and LAH reduction afforded amino heptitols 7a,b that were converted to azepane 1c,d and nojirimycin analogues 2c,d.
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Affiliation(s)
- Dilip D Dhavale
- Department of Chemistry, Garware Research Centre, University of Pune, Pune-411 007, India.
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Oxidation of several triterpenic diene and triene systems. Oxidative cleavage to obtain chiral intermediates for drimane and phenanthrene semi-synthesis. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.03.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Dobado JA, Benkadour N, Melchor S, Portal D. Structure and theoretical NMR chemical shifts of modified cyclodextrins†. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.theochem.2003.11.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Garcı́a-Granados A, López PE, Melguizo E, Parra A, Simeó Y. Partial synthesis of C-ring derivatives from oleanolic and maslinic acids. Formation of several triene systems by chemical and photochemical isomerization processes. Tetrahedron 2004. [DOI: 10.1016/j.tet.2003.12.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Degradation of triterpenic compounds from olive-pressing residues. Synthesis of trans-decalin type chiral synthons. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(03)01634-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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