1
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Fazekas TJ, Micalizio GC. Progress Toward the Asymmetric De Novo Synthesis of Limonoids. Org Lett 2024; 26:1073-1077. [PMID: 38277646 DOI: 10.1021/acs.orglett.3c04306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2024]
Abstract
Asymmetric de novo construction of limonoids remains a challenging problem in stereoselective synthesis due to the diverse and complex structures associated with this class of natural products. Here, a unique synthetic pathway to an "intact" limonoid system is described. The synthetic route is based on exploiting an oxidative rearrangement reaction of a densely functionalized late-stage intermediate to simultaneously establish the stereodefined C10 quaternary center and an allylic acetate at C12. This is a unique example of a complex rearrangement reaction that proceeds on a system whose presumed intermediate allyl cation is highly hindered and lacks neighboring protons that are otherwise required for cation termination.
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Affiliation(s)
- Timothy J Fazekas
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Glenn C Micalizio
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
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2
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Watanabe Y, Sakata K, Urabe D, Hagiwara K, Inoue M. Formal Total Synthesis of Batrachotoxin Enabled by Radical and Weix Coupling Reactions. J Org Chem 2023. [PMID: 38051654 DOI: 10.1021/acs.joc.3c02290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Batrachotoxin (1), originally isolated from a Columbian poison-dart frog, is a steroidal alkaloid. Its 6/6/6/5-membered carbocycle (ABCD-ring) contains two double bonds, one nitrogen, and five oxygen functionalities. We developed a radical-based convergent strategy and realized the total synthesis of 1 in 28 steps. The AB-ring and D-ring fragments were efficiently synthesized and linked by exploiting a powerful Et3B/O2-mediated radical coupling reaction. Vinyl triflate and vinyl bromide were then utilized for a Pd/Ni-promoted Weix coupling reaction to cyclize the C-ring. A hydroxy group of the C-ring was stereoselectively installed by a decarboxylative hydroxylation reaction to prepare an advanced intermediate of our previous total synthesis of 1.
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Affiliation(s)
- Yuuki Watanabe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Komei Sakata
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Daisuke Urabe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Koichi Hagiwara
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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3
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Song M, Luo HJ, Li ZW, Qiu L, Zhao YX, He CW, Zhang XQ, Ye WC, Lin LG, Zhang QW. Limonoids from the roots of Melia azedarach and their anti-inflammatory activity. PHYTOCHEMISTRY 2023; 216:113869. [PMID: 37739201 DOI: 10.1016/j.phytochem.2023.113869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/01/2023] [Accepted: 09/19/2023] [Indexed: 09/24/2023]
Abstract
Twelve undescribed limonoids, meliazedarines J-U (1-12), along with a known one, were isolated from the roots of Melia azedarach. Their structures were elucidated by extensive spectroscopic investigations, X-ray diffraction analyses, and ECD calculations. Compounds 1-8 were identified as ring intact limonoids, while compounds 9-12 were established as ring C-seco ones. The anti-inflammatory potential of compounds 1-4, 6, 8, 9, and 11-13 was evaluated on macrophages. Compounds 1, 3, 4, 6, and 9 significantly suppressed nitric oxide production in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages, among them compound 3 showed the best inhibitory effect with an IC50 value of 7.07 ± 0.48 μΜ. Furthermore, compound 3 effectively reduced interleukin-1β secretion in LPS plus nigericin-induced THP-1 macrophages by inhibiting NLRP3 inflammasome activation. The results strongly suggested that limonoids from the roots of M. azedarach might be candidates for treating inflammation-related diseases.
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Affiliation(s)
- Min Song
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macao, PR China; NMPA Key Laboratory for Quality Evaluation of TCM, and Guangdong Provincial Engineering Research Center for Modernization of TCM, College of Pharmacy, Jinan University, Guangzhou, 510632, PR China
| | - Hui-Juan Luo
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macao, PR China
| | - Zi-Wei Li
- NMPA Key Laboratory for Quality Evaluation of TCM, and Guangdong Provincial Engineering Research Center for Modernization of TCM, College of Pharmacy, Jinan University, Guangzhou, 510632, PR China
| | - Ling Qiu
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macao, PR China
| | - Yu-Xin Zhao
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macao, PR China
| | - Cheng-Wei He
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macao, PR China
| | - Xiao-Qi Zhang
- NMPA Key Laboratory for Quality Evaluation of TCM, and Guangdong Provincial Engineering Research Center for Modernization of TCM, College of Pharmacy, Jinan University, Guangzhou, 510632, PR China
| | - Wen-Cai Ye
- NMPA Key Laboratory for Quality Evaluation of TCM, and Guangdong Provincial Engineering Research Center for Modernization of TCM, College of Pharmacy, Jinan University, Guangzhou, 510632, PR China
| | - Li-Gen Lin
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macao, PR China.
| | - Qing-Wen Zhang
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macao, PR China.
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4
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Wang S, Kuperman LL, Song Z, Chen Y, Liu K, Xia Z, Xu Y, Yu Q. An overview of limonoid synthetic derivatives as promising bioactive molecules. Eur J Med Chem 2023; 259:115704. [PMID: 37544186 DOI: 10.1016/j.ejmech.2023.115704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 07/07/2023] [Accepted: 07/30/2023] [Indexed: 08/08/2023]
Abstract
Limonoids, a class of abundant natural tetracyclic triterpenoids, present diverse biological activity and provide a versatile platform amenable by chemical modifications for clinical use. Among all of the limonoids isolated from natural sources, obacunone, nomilin, and limonin are the primary hub of limonoid-based chemical modification research. To date, more than 800 limonoids analogs have been synthesized, some of which possess promising biological activities. This review not only discusses the synthesis of limonoid derivatives as promising therapeutic candidates and details the pharmacological studies of their underlying mechanisms from 2002 to 2022, but also proposes a preliminary limonoid synthetic structure-activity relationship (SAR) and provides future direction of limonoid derivatization research.
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Affiliation(s)
- Shaochi Wang
- Otorhinolaryngology Hospital, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China; Translational Medicine Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Laura L Kuperman
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20740, USA
| | - Zhihui Song
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20740, USA
| | - Yutian Chen
- Translational Medicine Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Kun Liu
- Translational Medicine Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Zongping Xia
- Translational Medicine Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Yungen Xu
- Department of Medicinal Chemistry, China Pharmaceutical University, Nanjing, Jiangsu, 210009, China.
| | - Qiuning Yu
- Otorhinolaryngology Hospital, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.
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5
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Watanabe Y, Morozumi H, Mutoh H, Hagiwara K, Inoue M. Total Synthesis of (-)-Batrachotoxin Enabled by a Pd/Ag-Promoted Suzuki-Miyaura Coupling Reaction. Angew Chem Int Ed Engl 2023; 62:e202309688. [PMID: 37582693 DOI: 10.1002/anie.202309688] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 08/11/2023] [Accepted: 08/15/2023] [Indexed: 08/17/2023]
Abstract
Batrachotoxin is an extremely potent cardio- and neurotoxic steroidal alkaloid found in certain species of frogs, birds, and beetles. The steroidal 6/6/6/5-membered carbocycle (ABCD-ring) is U-shaped and functionalized with two double bonds, a six-membered C3-hemiacetal across the AB-ring, a seven-membered oxazepane on the CD-ring, and a dimethylpyrrolecarboxy group at the D-ring carbon chain. These structural features present an unusual and formidable synthetic challenge. Herein we report a total synthesis of batrachotoxin based on a newly devised convergent strategy through a 22-step sequence. Enantiopure AB-ring and D-ring fragments were prepared and subjected to a crucial C(sp2 )-C(sp2 ) coupling reaction. Although both C(sp2 ) centers were sterically encumbered by proximal tetrasubstituted carbon atoms, Ag2 O strongly promoted the Pd(PPh3 )4 -catalyzed Suzuki-Miyaura coupling reaction at room temperature, thereby connecting the two fragments without damaging their preexisting functionalities. Subsequent treatment with t-BuOK induced Dieckmann condensation to cyclize the C-ring. The judiciously optimized functionalizations realized oxazepane formation, carbon chain extension, and pyrrole carboxylic acid condensation to deliver batrachotoxin.
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Affiliation(s)
- Yuuki Watanabe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hisahiro Morozumi
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroyuki Mutoh
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Koichi Hagiwara
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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6
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Wang XY, Yang M, Zhou Y, Zhou J, Hao YJ. A highly efficient metal-free selective 1,4-addition of difluoroenoxysilanes to chromones. Org Biomol Chem 2023; 21:1033-1037. [PMID: 36625240 DOI: 10.1039/d2ob02152h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A highly efficient metal-free selective 1,4-addition reaction of difluoroenoxysilanes to chromones was developed using the low-cost and readily available HOTf as the catalyst, which is a facile and straightforward method to access valuable C2-difluoroalkylated chroman-4-one derivatives. Interestingly, the products could be readily converted to the difluorinated bioisostere of the natural product (S)-2,6-dimethylchroman-4-one and a difluorinated benzo-seven-membered heterocycle via the Schmidt rearrangement reaction. In addition, the in vitro anti-proliferative activities of these synthesized derivatives against human colon carcinoma cells (HCT116) revealed that compound 3g exhibited potent inhibitory effect on HCT116 cancer cells with an IC50 value of 6.37 μM, representing a novel lead compound for further structural optimization and biological evaluation.
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Affiliation(s)
- Xi-Yu Wang
- School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, China.
| | - Min Yang
- School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, China.
| | - Ying Zhou
- School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, China.
| | - Jian Zhou
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, and Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China. .,School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, China.
| | - Yong-Jia Hao
- School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, China.
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7
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Schuppe AW, Liu Y, Gonzalez-Hurtado E, Zhao Y, Jiang X, Ibarraran S, Huang D, Wang E, Lee J, Loria JP, Dixit VD, Li X, Newhouse TR. Unified Total Synthesis of the Limonoid Alkaloids: Strategies for the De Novo Synthesis of Highly Substituted Pyridine Scaffolds. Chem 2022; 8:2856-2887. [PMID: 37396824 PMCID: PMC10311986 DOI: 10.1016/j.chempr.2022.09.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Highly substituted pyridine scaffolds are found in many biologically active natural products and therapeutics. Accordingly, numerous complementary de novo approaches to obtain differentially substituted pyridines have been disclosed. This article delineates the evolution of the synthetic strategies designed to assemble the demanding tetrasubstituted pyridine core present in the limonoid alkaloids isolated from Xylocarpus granatum, including xylogranatopyridine B, granatumine A and related congeners. In addition, NMR calculations suggested structural misassignment of several limonoid alkaloids, and predicted their C3-epimers as the correct structures, which was further validated unequivocally through chemical synthesis. The materials produced in this study were evaluated for cytotoxicity, anti-oxidant effects, anti-inflammatory action, PTP1B and Nlrp3 inflammasome inhibition, which led to compelling anti-inflammatory activity and anti-oxidant effects being discovered.
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Affiliation(s)
- Alexander W. Schuppe
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Yannan Liu
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Elsie Gonzalez-Hurtado
- Department of Pathology, Immunobiology, Comparative Medicine, Yale School of Medicine, 310 Cedar Street, New Haven, Connecticut 06520, United States
| | - Yizhou Zhao
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Xuefeng Jiang
- College of Pharmaceutical Sciences, Zhejiang University, 866 Yuhangtang Rd, Hangzhou 310018, P. R. China
| | - Sebastian Ibarraran
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - David Huang
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Emma Wang
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Jaehoo Lee
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - J. Patrick Loria
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Vishwa Deep Dixit
- Department of Pathology, Immunobiology, Comparative Medicine, Yale School of Medicine, 310 Cedar Street, New Haven, Connecticut 06520, United States
| | - Xin Li
- College of Pharmaceutical Sciences, Zhejiang University, 866 Yuhangtang Rd, Hangzhou 310018, P. R. China
| | - Timothy R. Newhouse
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
- Lead contact
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8
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Abstract
The limonoids have attracted significant attention from the synthetic community owing to their striking structural complexity and medicinal potential. Recent efforts notwithstanding, synthetic access to many intact or ring D-seco limonoids still remains elusive. Here, we report the first de novo synthesis of gedunin, a ring D-seco limonoid with HSP90 inhibitory activity, that proceeds in 13 steps. Two enabling features in our strategy are the application of modern catalytic transformations to set the key quaternary centers in the carbocyclic core and the use of biocatalytic oxidation at C3 to establish a chemical handle to access the A-ring enone motif. The strategy presented herein may provide an entry point to a wider range of oxidized limonoids.
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Affiliation(s)
- Jian Li
- Department of Chemistry, BioScience Research Collaborative, Rice University, Houston, Texas 77005, United States
| | - Fang Chen
- Department of Chemistry, BioScience Research Collaborative, Rice University, Houston, Texas 77005, United States
| | - Hans Renata
- Department of Chemistry, BioScience Research Collaborative, Rice University, Houston, Texas 77005, United States
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9
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Luo J, Sun Y, Li Q, Kong L. Research progress of meliaceous limonoids from 2011 to 2021. Nat Prod Rep 2022; 39:1325-1365. [PMID: 35608367 DOI: 10.1039/d2np00015f] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Covering: July 2010 to December 2021Limonoids, a kind of natural tetranortriterpenoids with diverse skeletons and valuable insecticidal and medicinal bioactivities, are the characteristic metabolites of most plants of the Meliaceae family. The chemistry and bioactivities of meliaceous limonoids are a continuing hot area of natural products research; to date, about 2700 meliaceous limonoids have been identified. In particular, more than 1600, including thirty kinds of novel rearranged skeletons, have been isolated and identified in the past decade due to their wide distribution and abundant content in Meliaceae plants and active biosynthetic pathways. In addition to the discovery of new structures, many positive medicinal bioactivities of meliaceous limonoids have been investigated, and extensive achievements regarding the chemical and biological synthesis have been made. This review summarizes the recent research progress in the discovery of new structures, medicinal and agricultural bioactivities, and chem/biosynthesis of limonoids from the plants of the Meliaceae family during the past decade, with an emphasis on the discovery of limonoids with novel skeletons, the medicinal bioactivities and mechanisms, and chemical synthesis. The structures, origins, and bioactivities of other new limonoids were provided as ESI. Studies published from July 2010 to December 2021 are reviewed, and 482 references are cited.
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Affiliation(s)
- Jun Luo
- Jiangsu Key Laboratory of Bioactive Natural Product Research, State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, People's Republic of China.
| | - Yunpeng Sun
- Jiangsu Key Laboratory of Bioactive Natural Product Research, State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, People's Republic of China.
| | - Qiurong Li
- Jiangsu Key Laboratory of Bioactive Natural Product Research, State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, People's Republic of China.
| | - Lingyi Kong
- Jiangsu Key Laboratory of Bioactive Natural Product Research, State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, People's Republic of China.
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10
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Nicholson JM, Millham AB, Bucknam AR, Markham LE, Sailors XI, Micalizio GC. General Enantioselective and Stereochemically Divergent Four-Stage Approach to Fused Tetracyclic Terpenoid Systems. J Org Chem 2022; 87:3352-3362. [PMID: 35175755 PMCID: PMC9438405 DOI: 10.1021/acs.joc.1c02979] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Tetracyclic terpenoid-derived natural products are a broad class of medically relevant agents that include well-known steroid hormones and related structures, as well as more synthetically challenging congeners such as limonoids, cardenolides, lanostanes, and cucurbitanes, among others. These structurally related compound classes present synthetically disparate challenges based, in part, on the position and stereochemistry of the numerous quaternary carbon centers that are common to their tetracyclic skeletons. While de novo syntheses of such targets have been a topic of great interest for over 50 years, semisynthesis is often how synthetic variants of these natural products are explored as biologically relevant materials and how such agents are further matured as therapeutics. Here, focus was directed at establishing an efficient, stereoselective, and molecularly flexible de novo synthetic approach that could offer what semisynthetic approaches do not. In short, a unified strategy to access common molecular features of these natural product families is described that proceeds in four stages: (1) conversion of epichlorohydrin to stereodefined enynes, (2) metallacycle-mediated annulative cross-coupling to generate highly substituted hydrindanes, (3) tetracycle formation by stereoselective forging of the C9-C10 bond, and (4) group-selective oxidative rearrangement that repositions a quaternary center from C9 to C10. These studies have defined the structural features required for highly stereoselective C9-C10 bond formation and document the generality of this four-stage synthetic strategy to access a range of unique stereodefined systems, many of which bear stereochemistry/substitution/functionality not readily accessible from semisynthesis.
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Affiliation(s)
- Joshua M. Nicholson
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Adam B. Millham
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Andrea R. Bucknam
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Lauren E. Markham
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Xenia Ivanna Sailors
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Glenn C. Micalizio
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
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11
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Liu Y, Schuppe AW, Zhao Y, Lee J, Newhouse TR. Synthesis of (-)-melazolide B, a degraded limonoid, from a natural terpene precursor. TETRAHEDRON CHEM 2022; 1:100011. [PMID: 38606284 PMCID: PMC11008529 DOI: 10.1016/j.tchem.2022.100011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
Degraded limonoids are a subclass of limonoid natural products that derive from ring-intact or ring-rearranged limonoids. Establishment of robust synthetic routes to access them could provide valuable materials to identify the simplest active pharmacophore responsible for the observed biological activities of the parent molecules. This communication delineates the development of a divergent strategy to furnish melazolide B and several other related congeners from a common keto-lactone intermediate, which was rapidly assembled from α-ionone. A chemoselective carbonyl α,β-dehydrogenation and a Wharton reduction were key strategic steps in this synthetic pathway.
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Affiliation(s)
| | | | - Yizhou Zhao
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT, 06520-8107, United States
| | - Jaehoo Lee
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT, 06520-8107, United States
| | - Timothy R. Newhouse
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT, 06520-8107, United States
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12
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Belen’kii LI, Gazieva GA, Evdokimenkova YB, Soboleva NO. The literature of heterocyclic chemistry, Part XX, 2020. ADVANCES IN HETEROCYCLIC CHEMISTRY 2022. [DOI: 10.1016/bs.aihch.2022.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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13
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Kim HW, Wang M, Leber CA, Nothias LF, Reher R, Kang KB, van der Hooft JJJ, Dorrestein PC, Gerwick WH, Cottrell GW. NPClassifier: A Deep Neural Network-Based Structural Classification Tool for Natural Products. JOURNAL OF NATURAL PRODUCTS 2021; 84:2795-2807. [PMID: 34662515 PMCID: PMC8631337 DOI: 10.1021/acs.jnatprod.1c00399] [Citation(s) in RCA: 104] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Indexed: 05/04/2023]
Abstract
Computational approaches such as genome and metabolome mining are becoming essential to natural products (NPs) research. Consequently, a need exists for an automated structure-type classification system to handle the massive amounts of data appearing for NP structures. An ideal semantic ontology for the classification of NPs should go beyond the simple presence/absence of chemical substructures, but also include the taxonomy of the producing organism, the nature of the biosynthetic pathway, and/or their biological properties. Thus, a holistic and automatic NP classification framework could have considerable value to comprehensively navigate the relatedness of NPs, and especially so when analyzing large numbers of NPs. Here, we introduce NPClassifier, a deep-learning tool for the automated structural classification of NPs from their counted Morgan fingerprints. NPClassifier is expected to accelerate and enhance NP discovery by linking NP structures to their underlying properties.
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Affiliation(s)
- Hyun Woo Kim
- Center
for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093, United States
| | - Mingxun Wang
- Skaggs
School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California 92093, United States
- Ometa
Laboratories LLC, San Diego, California 92121, United States
| | - Christopher A. Leber
- Center
for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093, United States
| | - Louis-Félix Nothias
- Skaggs
School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California 92093, United States
| | - Raphael Reher
- Center
for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093, United States
- Institute
of Pharmacy Martin-Luther-University Halle-Wittenberg, Universitätsplatz 10, 06108 Halle (Saale), Germany
| | - Kyo Bin Kang
- Research
Institute of Pharmaceutical Sciences, College of Pharmacy, Sookmyung Women’s University, Seoul 04310, Korea
| | | | - Pieter C. Dorrestein
- Skaggs
School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California 92093, United States
| | - William H. Gerwick
- Center
for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093, United States
- Skaggs
School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California 92093, United States
| | - Garrison W. Cottrell
- Department
of Computer Science and Engineering, University
of California, San Diego, La Jolla, California 92093, United States
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14
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Fejedelem Z, Carney N, Nagorny P. Synthesis of Cardiotonic Steroids Oleandrigenin and Rhodexin B. J Org Chem 2021; 86:10249-10262. [PMID: 34255963 PMCID: PMC8582021 DOI: 10.1021/acs.joc.1c00985] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This article describes a concise synthesis of cardiotonic steroids oleandrigenin (7) and its subsequent elaboration into the natural product rhodexin B (2) from the readily available intermediate (8) that could be derived from the commercially available steroids testosterone or DHEA via three-step sequences. These studies feature an expedient installation of the β16-oxidation based on β14-hydroxyl-directed epoxidation and subsequent epoxide rearrangement. The following singlet oxygen oxidation of the C17 furan moiety provides access to oleandrigenin (7) in 12 steps (LLS) and a 3.1% overall yield from 8. The synthetic oleandrigenin (7) was successfully glycosylated with l-rhamnopyranoside-based donor 28 using a Pd(II)-catalyst, and the subsequent deprotection under acidic conditions provided cytotoxic natural product rhodexin B (2) in a 66% yield (two steps).
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Affiliation(s)
- Zachary Fejedelem
- Chemistry Department, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Nolan Carney
- Chemistry Department, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Pavel Nagorny
- Chemistry Department, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
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15
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Cao DH, Yao JN, Sun P, Ji KL, Li XN, Cai Q, Xiao CF, Hu HB, Yu ZY, Xu YK. Structurally diverse limonoids and bio-active evaluation from Trichilia connaroides. Fitoterapia 2021; 153:105001. [PMID: 34329727 DOI: 10.1016/j.fitote.2021.105001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 10/20/2022]
Abstract
Four new limonoids, named as trichiconlide G (1), 2-hydroxyltrijugin F (2), 23-oxo-21-hydroxyltrijugin F (3), 21-oxo-23-hydroxyltrijugin F (4), along with sixteen known analogues (5-20) were isolated from the leaves and twigs of Trichilia connaroides. Their structures and absolute configurations were determined by spectroscopic analyses, X-ray diffraction analysis, and TD-DFT-ECD calculations. Trichiconlide G (1) is one rare naturally occurring 1,2-seco phragmalin-type limonoid bearing a C-7/28 δ-lactone ring. Additionally, 2-hydroxyltrijugin F (2), 23-oxo-21-hydroxyltrijugin F (3), and 21-oxo-23-hydroxyltrijugin F (4) are three naturally occurring limonoids with a rare C-16/8 δ-lactone ring. All isolates were evaluated for their cytotoxic and anti-inflammatory activities. None of compounds exhibited cytotoxicity against five human cancer cell lines A-549, HepG2, 5-8F, Siha, and SCC-4 at the concentration of 40 μM. Compounds 16 and 17 showed moderate anti-inflammatory activity with IC50 values of 28.45 ± 2.51 and 22.66 ± 2.01 μM, respectively.
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Affiliation(s)
- Dong-Hua Cao
- The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha 410004, PR China; Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, PR China
| | - Jian-Neng Yao
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China
| | - Peng Sun
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, PR China
| | - Kai-Long Ji
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, PR China
| | - Xiao-Nian Li
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China
| | - Qiang Cai
- Department of Hepatobiliary Surgery, The Second People's Hospital of Yunnan Province, Kunming 650021, PR China
| | - Chun-Fen Xiao
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, PR China
| | - Hua-Bin Hu
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, PR China
| | - Zhi-Yong Yu
- Department of Hepatobiliary Surgery, The Second People's Hospital of Yunnan Province, Kunming 650021, PR China.
| | - You-Kai Xu
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, PR China.
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16
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Mutoh H, Nakamura S, Hagiwara K, Inoue M. Construction of Pentacyclic Limonoid Skeletons via Radical Cascade Reactions. J Org Chem 2021; 86:6869-6878. [PMID: 33905252 DOI: 10.1021/acs.joc.1c00212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Limonoids 1 and 2 share a 6/6/6/5-membered ABCD-ring system and a six-membered oxacycle and differ in their C9-stereochemistries. A new radical-based strategy was devised to construct the pentacyclic skeletons of 1 and 2. An oxacycle-fused A-ring and enyne fragments were coupled to produce radical precursors 4a-4c with different C7-oxygen functionalities. The bridgehead tertiary bromide of 4a-4c participated in a radical cascade reaction with the three unsaturated bonds to cyclize the C9-diastereomeric BCD-rings.
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Affiliation(s)
- Hiroyuki Mutoh
- Graduate School of Pharmaceutical Sciences, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Shu Nakamura
- Graduate School of Pharmaceutical Sciences, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Koichi Hagiwara
- Graduate School of Pharmaceutical Sciences, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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17
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Guo L, Tang P. Recent Advance in the Synthesis of Natural Products of Schisandra Triterpenoid. CHINESE J ORG CHEM 2021. [DOI: 10.6023/cjoc202105049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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18
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Shi YS, Zhang Y, Li HT, Wu CH, El-Seedi HR, Ye WK, Wang ZW, Li CB, Zhang XF, Kai GY. Limonoids from Citrus: Chemistry, anti-tumor potential, and other bioactivities. J Funct Foods 2020. [DOI: 10.1016/j.jff.2020.104213] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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19
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Mándi A, Wu J, Kurtán T. TDDFT-ECD and DFT-NMR studies of thaigranatins A–E and granatumin L isolated from Xylocarpus granatum. RSC Adv 2020; 10:32216-32224. [PMID: 35518141 PMCID: PMC9056630 DOI: 10.1039/d0ra03725g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 08/20/2020] [Indexed: 11/21/2022] Open
Abstract
TDDFT-ECD calculations were utilized to explain the mirror image or different ECD spectra of thaigranatins A–E and granatumin L.
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Affiliation(s)
- Attila Mándi
- Department of Organic Chemistry
- University of Debrecen
- 4002 Debrecen
- Hungary
| | - Jun Wu
- School of Pharmaceutical Sciences
- Southern Medical University
- Guangzhou 510515
- P. R. China
| | - Tibor Kurtán
- Department of Organic Chemistry
- University of Debrecen
- 4002 Debrecen
- Hungary
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