1
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Gillard RM, Zhang J, Steel R, Wang J, Strull JL, Cai B, Chakraborty N, Boger DL. Aryl Annulation: A Powerful Simplifying Retrosynthetic Disconnection. SYNTHESIS-STUTTGART 2024; 56:118-133. [PMID: 38144170 PMCID: PMC10745204 DOI: 10.1055/a-1959-2088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Retrosynthetic deconstruction of a core aromatic ring is an especially simplifying retrosynthetic step, reducing the complexity of the precursor synthetic target. Moreover, when implemented to provide a penultimate intermediate, it enables late-stage divergent aryl introductions, permitting deep-seated core aryl modifications ordinarily accessible only by independent synthesis. Herein, we highlight the use of a ketone carbonyl group as the functionality to direct such late-stage divergent aryl introductions onto a penultimate intermediate with a projected application in the total synthesis of vinblastine and its presently inaccessible analogs containing indole replacements. Although the studies highlight this presently unconventional strategy with an especially challenging target in mind, the increase in molecular complexity (intricacy) established by the synthetic implementation of the powerful retrosynthetic disconnection, the use of a ketone as the precursor enabling functionality, and with adoption of either conventional or new wave (hetero)aromatic annulations combine to define a general and powerful strategy suited for wide-spread implementation with near limitless scope in target diversification.
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Affiliation(s)
- Rachel M. Gillard
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Jianjun Zhang
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Richard Steel
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Jocelyn Wang
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Jessica L. Strull
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Bin Cai
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Nilanjana Chakraborty
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Dale L. Boger
- Department of Chemistry and the Skaggs Institute for Chemical Biology, the Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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2
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Sofi FA, Tabassum N. Natural product inspired leads in the discovery of anticancer agents: an update. J Biomol Struct Dyn 2023; 41:8605-8628. [PMID: 36255181 DOI: 10.1080/07391102.2022.2134212] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 10/03/2022] [Indexed: 10/24/2022]
Abstract
Natural products have emerged as major leads for the discovery and development of new anti-cancer drugs. The plant-derived anti-cancer drugs account for approximately 60% and the quest for new anti-cancer agents is in progress. Anti-cancer leads have been isolated from plants, animals, marine organisms, and microorganisms from time immemorial. The process of semisynthetic modifications of the parent lead has led to the generation of new anti-cancer agents with improved therapeutic efficacy and minimal side effects. The various chemo-informatics tools, bioinformatics, high-throughput screening, and combinatorial synthesis are able to deliver the new natural product lead molecules. Plant-derived anticancer agents in either late preclinical development or early clinical trials include taxol, vincristine, vinblastine, topotecan, irinotecan, etoposide, paclitaxel, and docetaxel. Similarly, anti-cancer agents from microbial sources include dactinomycin, bleomycin, mitomycin C, and doxorubicin. In this review, we highlighted the importance of natural products leads in the discovery and development of novel anti-cancer agents. The semisynthetic modifications of the parent lead to the new anti-cancer agent are also presented. Further, the leads in the preclinical settings with the potential to become effective anticancer agents are also reviewed.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Firdoos Ahmad Sofi
- Department of Pharmaceutical Sciences, School of Applied Sciences and Technology, University of Kashmir, Srinagar, Jammu & Kashmir, India
| | - Nahida Tabassum
- Department of Pharmaceutical Sciences, School of Applied Sciences and Technology, University of Kashmir, Srinagar, Jammu & Kashmir, India
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3
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Zhang J, Paladugu SR, Gillard RM, Sarkar A, Boger DL. Tris(4-bromophenyl)aminium Hexachloroantimonate-Mediated Intermolecular C(sp 2)-C(sp 3) Free Radical Coupling of Vindoline with β-Ketoesters and Related Compounds. J Am Chem Soc 2022; 144:495-502. [PMID: 34963278 PMCID: PMC8758398 DOI: 10.1021/jacs.1c10971] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
A powerful tris(4-bromophenyl)aminium hexachloroantimonate (BAHA) mediated regioselective intermolecular coupling reaction of vindoline with a wide range of substrates that include β-ketoesters, β-diketones, β-ketoaldehydes, β-ketonitriles, β-ketolactones, β-ketolactams, β-cyanoesters, and malononitriles is detailed. The BAHA-promoted intermolecular sp3/sp2 coupling, representing a special class of selective C-H functionalization reactions with direct carbon-carbon bond formation, proceeds with generation of a quaternary center bound to the aryl C15 center of vindoline capable of accommodating of the vinblastine C16' methyl ester and functionalized for subsequent divergent heterocycle introduction. A comprehensive examination of the reaction scope, optimization of subtle reaction parameters, and key insights into the reaction mechanism are described. Contrary to what might be prevailing expectations, studies suggest the plausible mechanism entails initial single-electron oxidation of the substrate enolate, not vindoline, and subsequent regiospecific addition of the resulting electrophilic radical to vindoline. As such and beyond the new arylation reaction with vindoline, the studies define a host of new, previously unrecognized, applications of BAHA and related triarylaminium radical cations that arises from their ability to generate stabilized electrophilic radicals from β-ketoesters and related substrates under nonreducing and metal-free conditions. Those exemplified herein include mediating stabilized enolate free radical arylation, dimerization, allylation, alkene addition, and α-oxidation reactions.
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Affiliation(s)
| | | | - Rachel M. Gillard
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037, USA
| | - Anindya Sarkar
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037, USA
| | - Dale L. Boger
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037, USA
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4
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Beeck S, Ahles S, Wegner HA. Orthogonal Catalysis for an Enantioselective Domino Inverse-Electron Demand Diels-Alder/Substitution Reaction. Chemistry 2021; 28:e202104085. [PMID: 34813113 PMCID: PMC9299787 DOI: 10.1002/chem.202104085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Indexed: 11/13/2022]
Abstract
An enantioselective domino process for the synthesis of substituted 1,2‐dihydronaphthalenes has been developed by the combination of chiral amines and a bidentate Lewis acid in an orthogonal catalysis. This new method is based on an inverse electron‐demand Diels−Alder and a subsequent group exchange reaction. An enamine is generated in situ from an aldehyde and a chiral secondary amine catalyst that reacts with phthalazine, activated by the coordination to a bidentate Lewis acid catalyst. The absolute configuration of the product is controlled by chiral information provided by the amine. The formed ortho‐quinodimethane intermediate is then transformed via a group exchange reaction with thiols. The new method shows a broad scope and tolerates a wide range of functional groups with enantiomeric ratios up to 91 : 9. All‐in‐all, this enantioselective synthesis tool provides an easy access to complex 1,2‐dihydronaphthalenes starting from readily available phthalazine, aldehydes and thiols in a combinatorial way.
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Affiliation(s)
- Sebastian Beeck
- Justus Liebig University Giessen, Institute of Organic Chemistry, Heinrich-Buff-Ring 17, 35392, Giessen, Germany
| | - Sebastian Ahles
- Justus Liebig University Giessen, Institute of Organic Chemistry, Heinrich-Buff-Ring 17, 35392, Giessen, Germany
| | - Hermann A Wegner
- Justus Liebig University Giessen, Institute of Organic Chemistry, Heinrich-Buff-Ring 17, 35392, Giessen, Germany.,Justus Liebig University Giessen, Center for Materials Research (LaMa), Heinrich-Buff-Ring 16, 35392, Giessen, Germany
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5
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Strauss MA, Kohrs D, Ruhl J, Wegner HA. Mechanistic Study of Domino Processes Involving the Bidentate Lewis Acid Catalyzed Inverse Electron‐Demand Diels−Alder Reaction. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100486] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Marcel A. Strauss
- Institute of Organic Chemistry Justus Liebig University Giessen Heinrich-Buff-Ring 17 35392 Giessen Germany
- Center for Materials Research (LaMa) Justus Liebig University Giessen Heinrich-Buff-Ring 16 35392 Giessen Germany
| | - Daniel Kohrs
- Institute of Organic Chemistry Justus Liebig University Giessen Heinrich-Buff-Ring 17 35392 Giessen Germany
- Center for Materials Research (LaMa) Justus Liebig University Giessen Heinrich-Buff-Ring 16 35392 Giessen Germany
| | - Julia Ruhl
- Institute of Organic Chemistry Justus Liebig University Giessen Heinrich-Buff-Ring 17 35392 Giessen Germany
- Center for Materials Research (LaMa) Justus Liebig University Giessen Heinrich-Buff-Ring 16 35392 Giessen Germany
| | - Hermann A. Wegner
- Institute of Organic Chemistry Justus Liebig University Giessen Heinrich-Buff-Ring 17 35392 Giessen Germany
- Center for Materials Research (LaMa) Justus Liebig University Giessen Heinrich-Buff-Ring 16 35392 Giessen Germany
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6
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Boon BA, Yu YY, Boger DL. Total synthesis of (-)-4-desacetoxy-1-oxovindoline: Single atom exchange of an embedded core heteroatom in vindoline. Tetrahedron 2021; 87:132117. [PMID: 33994597 PMCID: PMC8117404 DOI: 10.1016/j.tet.2021.132117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A concise total synthesis of (-)-4-desacetoxy-1-oxovindoline is disclosed, bearing a single heteroatom exchange in the core structure of the natural product 4-desacetoxyvindoline. Central to the synthesis is powerful oxadiazole intramolecular [4+2]/[3+2] cycloaddition cascade that formed four C-C bonds, created three new rings, and established five contiguous stereocenters about the new formed central 6-membered ring.
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Affiliation(s)
- Byron A. Boon
- Department of Chemistry and The Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037
| | - Yi-Yun Yu
- Department of Chemistry and The Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037
| | - Dale L. Boger
- Department of Chemistry and The Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037
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7
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Zhang J, Shukla V, Boger DL. Inverse Electron Demand Diels-Alder Reactions of Heterocyclic Azadienes, 1-Aza-1,3-Butadienes, Cyclopropenone Ketals, and Related Systems. A Retrospective. J Org Chem 2019; 84:9397-9445. [PMID: 31062977 DOI: 10.1021/acs.joc.9b00834] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A summary of the investigation and applications of the inverse electron demand Diels-Alder reaction is provided that have been conducted in our laboratory over a period that now spans more than 35 years. The work, which continues to provide solutions to complex synthetic challenges, is presented in the context of more than 70 natural product total syntheses in which the reactions served as a key strategic step in the approach. The studies include the development and use of the cycloaddition reactions of heterocyclic azadienes (1,2,4,5-tetrazines; 1,2,4-, 1,3,5-, and 1,2,3-triazines; 1,2-diazines; and 1,3,4-oxadiazoles), 1-aza-1,3-butadienes, α-pyrones, and cyclopropenone ketals. Their applications illustrate the power of the methodology, often provided concise and nonobvious total syntheses of the targeted natural products, typically were extended to the synthesis of analogues that contain deep-seated structural changes in more comprehensive studies to explore or optimize their biological properties, and highlight a wealth of opportunities not yet tapped.
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Affiliation(s)
- Jiajun Zhang
- Department of Chemistry and The Skaggs Institute for Chemical Biology , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - Vyom Shukla
- Department of Chemistry and The Skaggs Institute for Chemical Biology , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - Dale L Boger
- Department of Chemistry and The Skaggs Institute for Chemical Biology , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
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8
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Saya JM, Ruijter E, Orru RVA. Total Synthesis of
Aspidosperma
and
Strychnos
Alkaloids through Indole Dearomatization. Chemistry 2019; 25:8916-8935. [DOI: 10.1002/chem.201901130] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Indexed: 01/07/2023]
Affiliation(s)
- Jordy M. Saya
- Department of Chemistry & Pharmaceutical Sciences, Amsterdam Institute for Molecules, Medicines & SystemsVrije Universiteit Amsterdam De Boelelaan 1108 1081 HZ Amsterdam The Netherlands
| | - Eelco Ruijter
- Department of Chemistry & Pharmaceutical Sciences, Amsterdam Institute for Molecules, Medicines & SystemsVrije Universiteit Amsterdam De Boelelaan 1108 1081 HZ Amsterdam The Netherlands
| | - Romano V. A. Orru
- Department of Chemistry & Pharmaceutical Sciences, Amsterdam Institute for Molecules, Medicines & SystemsVrije Universiteit Amsterdam De Boelelaan 1108 1081 HZ Amsterdam The Netherlands
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9
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Radakovic A, Boger DL. Ultra-potent vinblastine analogues improve on-target activity of the parent microtubulin-targeting compound. Bioorg Med Chem Lett 2019; 29:1370-1374. [PMID: 30952593 DOI: 10.1016/j.bmcl.2019.03.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 03/21/2019] [Accepted: 03/25/2019] [Indexed: 10/27/2022]
Abstract
In recent efforts, several C20' urea vinblastine analogues were discovered that displayed remarkable potency against vinblastine-sensitive tumor cell lines (IC50 50-75 pM), being roughly 100-fold more potent than vinblastine, and that exhibited decreased susceptibility to Pgp efflux-derived resistance in a vinblastine-resistant cell line. Their extraordinary activity indicate that it is not likely or even possible that their cellular functional activity is derived from stoichiometric occupancy of the intracellular tubulin binding sites. Rather, their potency indicates sub-stoichiometric or even catalytic occupancy of candidate binding sites may be sufficient to disrupt tubulin dynamics or microtubule assembly during mitosis. We detail efforts to delineate the underlying behavior responsible for the increased potency and show that the ultra-potent extended C20' ureas retain the mechanistic behavior of vinblastine, display enhanced affinity for tubulin and on-target activity approximately 100-fold both in vitro and in HeLa cells, but do not show evidence of catalytic disassembly of microtubulin. We also use the analogues to show that, in live interphase cells, the effects of the vinblastine class of drugs do not display a catastrophic effect on the microtubule skeleton, but rather a subtler insult to its dynamicity, acting as sub-stoichiometric drugs that inhibit normal microtubulin maturation and dynamics.
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Affiliation(s)
- Aleksandar Radakovic
- Department of Chemistry and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Dale L Boger
- Department of Chemistry and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA.
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10
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Martino E, Casamassima G, Castiglione S, Cellupica E, Pantalone S, Papagni F, Rui M, Siciliano AM, Collina S. Vinca alkaloids and analogues as anti-cancer agents: Looking back, peering ahead. Bioorg Med Chem Lett 2018; 28:2816-2826. [PMID: 30122223 DOI: 10.1016/j.bmcl.2018.06.044] [Citation(s) in RCA: 153] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 06/21/2018] [Accepted: 06/22/2018] [Indexed: 12/31/2022]
Abstract
Cancer still represents a "nightmare" worldwide, causing annually millions of victims. Several antiproliferative molecules are currently used as drugs market and offer a pharmaceutical opportunity for attenuating and treating tumor manifestations. In this context, natural sources have a relevant role, since they provide the 60% of currently-used anticancer agents. Among the numerous natural products, acting via different mechanisms of action, microtubule-targeting agents (MTAs) have a high therapeutic potential, since they disrupt the abnormal cancer cell growth, interfering with the continuous mitotic division. Vinca alkaloids (VAs) are the earliest developed MTAs and approved for clinical use (Vincristine, Vinblastine, Vinorelbine, Vindesine, and Vinflunine) as agents in the treatment of hematological and lymphatic neoplasms. Here, we review the state-of-art of VAs, discussing their mechanism of action and pharmacokinetic properties and highlighting their therapeutic relevance and toxicological profile. Additionally, we briefly disclosed the technological approaches faced so far to ameliorate the pharmacological properties, as well as to avoid the drug resistance. Lastly, we introduced the recent advances in the discovery of new derivatives.
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Affiliation(s)
- Emanuela Martino
- Department of Earth and Environmental Sciences, University of Pavia, Via S. Epifanio 14, 27100 Pavia, Italy
| | - Giuseppe Casamassima
- Department of Drug Sciences, Medicinal Chemistry Section, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Sonia Castiglione
- Department of Drug Sciences, Medicinal Chemistry Section, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Edoardo Cellupica
- Department of Drug Sciences, Medicinal Chemistry Section, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Serena Pantalone
- Department of Drug Sciences, Medicinal Chemistry Section, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Francesca Papagni
- Department of Drug Sciences, Medicinal Chemistry Section, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Marta Rui
- Department of Drug Sciences, Medicinal Chemistry Section, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Angela Marika Siciliano
- Department of Drug Sciences, Medicinal Chemistry Section, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Simona Collina
- Department of Drug Sciences, Medicinal Chemistry Section, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy.
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11
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12
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High expression of class III β-tubulin has no impact on functional cancer cell growth inhibition of a series of key vinblastine analogs. Bioorg Med Chem Lett 2018; 28:863-865. [PMID: 29439899 DOI: 10.1016/j.bmcl.2018.02.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/03/2018] [Accepted: 02/05/2018] [Indexed: 11/22/2022]
Abstract
Clinical association studies have implicated high expression of class III β-tubulin as a predictive factor for lower response rates and reduced overall survival in patients receiving tubulin binding drugs, most notably the taxanes. Because of the implications, we examined a series of key vinblastine analogs that emerged from our studies in functional cell growth inhibition assays for their sensitivity to high expression of class III β-tubulin (human non-small cell lung cancer cell line A549 vs taxol-resistant A549-T24). Unlike taxol, vinblastine and a set of key analogs 3-10 did not exhibit any loss in sensitivity toward A549-T24. The results suggest that vinblastine and related analogs are not likely prone to resistance derived from high expression of class III β-tubulin unlike the taxanes. Most significant are the results with 4-6, a subset of 20' amide vinblastine analogs. They match or exceed the potency of vinblastine and they display more potent activity against taxol-resistant A549-T24 than even wild type A549 cells (1.2-2-fold), complementing our prior observations that they also display no sensitivity to overexpression of Pgp (HCT116/VM46 vs HCT116) and are not subject to resistance derived from Pgp efflux.
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13
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Boger DL. The Difference a Single Atom Can Make: Synthesis and Design at the Chemistry-Biology Interface. J Org Chem 2017; 82:11961-11980. [PMID: 28945374 PMCID: PMC5712263 DOI: 10.1021/acs.joc.7b02088] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Indexed: 01/24/2023]
Abstract
A Perspective of work in our laboratory on the examination of biologically active compounds, especially natural products, is presented. In the context of individual programs and along with a summary of our work, selected cases are presented that illustrate the impact single atom changes can have on the biological properties of the compounds. The examples were chosen to highlight single heavy atom changes that improve activity, rather than those that involve informative alterations that reduce or abolish activity. The examples were also chosen to illustrate that the impact of such single-atom changes can originate from steric, electronic, conformational, or H-bonding effects, from changes in functional reactivity, from fundamental intermolecular interactions with a biological target, from introduction of a new or altered functionalization site, or from features as simple as improvements in stability or physical properties. Nearly all the examples highlighted represent not only unusual instances of productive deep-seated natural product modifications and were introduced through total synthesis but are also remarkable in that they are derived from only a single heavy atom change in the structure.
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Affiliation(s)
- Dale L. Boger
- Department of Chemistry and
The Skaggs Research Institute, The Scripps
Research Institute, 10550
North Torrey Pines Road, La Jolla, California 92037, United States
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14
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Lukesh JC, Carney DW, Dong H, Cross RM, Shukla V, Duncan KK, Yang S, Brody DM, Brütsch MM, Radakovic A, Boger DL. Vinblastine 20' Amides: Synthetic Analogues That Maintain or Improve Potency and Simultaneously Overcome Pgp-Derived Efflux and Resistance. J Med Chem 2017; 60:7591-7604. [PMID: 28857558 DOI: 10.1021/acs.jmedchem.7b00958] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of 180 vinblastine 20' amides were prepared in three steps from commercially available starting materials, systematically exploring a typically inaccessible site in the molecule enlisting a powerful functionalization strategy. Clear structure-activity relationships and a structural model were developed in the studies which provided many such 20' amides that exhibit substantial and some even remarkable enhancements in potency, many that exhibit further improvements in activity against a Pgp overexpressing resistant cancer cell line, and an important subset of the vinblastine analogues that display little or no differential in activity against a matched pair of vinblastine sensitive and resistant (Pgp overexpressing) cell lines. The improvements in potency directly correlated with target tubulin binding affinity, and the reduction in differential functional activity against the sensitive and Pgp overexpressing resistant cell lines was found to correlate directly with an impact on Pgp-derived efflux.
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Affiliation(s)
- John C Lukesh
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Daniel W Carney
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Huijun Dong
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - R Matthew Cross
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Vyom Shukla
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Katharine K Duncan
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Shouliang Yang
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Daniel M Brody
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Manuela M Brütsch
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Aleksandar Radakovic
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Dale L Boger
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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15
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Reddy RR, Adlak K, Ghorai P. Catalyst-free Synthesis of 6-Hydroxy Indoles via the Condensation of Carboxymethyl Cyclohexadienones and Amines. J Org Chem 2017; 82:8426-8437. [PMID: 28714691 DOI: 10.1021/acs.joc.7b01136] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An efficient catalyst-free synthesis of 6-hydroxy indoles from carboxymethyl cyclohexadienones and primary amines has been developed. The aza-Michael addition of the in situ formed enamine, generated through the condensation of carboxymethyl unit of the substrates with an external amine, to cyclohexadienone moiety followed by rearomatization reaction to provide such indoles. Anilines, aliphatic amines, α-chiral aliphatic amines, or even ammonia were used as amine counterpart. Some of the cyclohexadienones gave 6-amino indoles instead of 6-hydroxy indoles using the Re2O7 catalyst. Various post methodological transformations were performed to explore the synthetic utility of the synthesized hydroxy indoles.
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Affiliation(s)
- Reddy Rajasekhar Reddy
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal , Bhauri, Bhopal 462066, India
| | - Komalkant Adlak
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal , Bhauri, Bhopal 462066, India
| | - Prasanta Ghorai
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal , Bhauri, Bhopal 462066, India
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Allemann O, Cross RM, Brütsch MM, Radakovic A, Boger DL. Key analogs of a uniquely potent synthetic vinblastine that contain modifications of the C20' ethyl substituent. Bioorg Med Chem Lett 2017; 27:3055-3059. [PMID: 28551101 PMCID: PMC5538265 DOI: 10.1016/j.bmcl.2017.05.058] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 05/16/2017] [Accepted: 05/18/2017] [Indexed: 11/27/2022]
Abstract
A key series of vinblastine analogs 7-13, which contain modifications to the C20' ethyl group, was prepared with use of two distinct synthetic approaches that provide modifications of the C20' side chain containing linear and cyclized alkyl groups or added functionalized substituents. Their examination revealed the unique nature of the improved properties of the synthetic vinblastine 6, offers insights into the origins of its increased tubulin binding affinity and 10-fold improved cell growth inhibition potency, and served to probe a small hydrophobic pocket anchoring the binding of vinblastine with tubulin. Especially noteworthy were the trends observed with substitution of the terminal carbon of the ethyl group that, with the exception of 9 (R=F vs H, equipotent), led to remarkably substantial reductions in activity (>10-fold): R=F (equipotent with H)>N3, CN (10-fold)>Me (50-fold)>Et (100-fold)>OH (inactive). This is in sharp contrast to the maintained (7) or enhanced activity (6) observed with its incorporation into a cyclic C20'/C15'-fused six-membered ring.
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Affiliation(s)
- Oliver Allemann
- Department of Chemistry and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States
| | - R Matthew Cross
- Department of Chemistry and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States
| | - Manuela M Brütsch
- Department of Chemistry and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States
| | - Aleksandar Radakovic
- Department of Chemistry and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States
| | - Dale L Boger
- Department of Chemistry and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States.
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