Four Alkaloids from Alstonia scholaris with Antitumor Activity via Disturbing Glutathione Homeostasis

The Journal of Organic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Янв. 9, 2025

Alstoschoquinolines A–D (1–4) representing three unprecedented scaffolds were isolated from the leaves of Alstonia scholaris through direct separation by LC/MS detection. 1 and 2 consisted a 5/6/5-coupled quinoline architecture containing six consecutive chiral carbons, while 3 4 possessed bridged ring featuring 6/6/6/6 6/6/8/6 skeletons, respectively. They might be derived corynantheine-type indole alkaloid via sequential oxidation rearrangement. Compound exhibited significant inhibitory effect on colon carcinoma cells disturbing glutathione circulation.

Язык: Английский

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Recent Advances in the Synthesis of β-Carboline Alkaloids

Molecules, Год журнала: 2021, Номер 26(3), С. 663 - 663

Опубликована: Янв. 27, 2021

β-Carboline alkaloids are a remarkable family of natural and synthetic indole-containing heterocyclic compounds they widely distributed in nature. Recently, these have been the focus interest, thanks to their diverse biological activities. Their pharmacological activity makes them desirable as sedative, anxiolytic, hypnotic, anticonvulsant, antitumor, antiviral, antiparasitic or antimicrobial drug candidates. The growing potential inherent encourages many researchers address challenges synthesis products containing complex β-carboline frameworks. In this review, we describe recent developments closely related derivatives through selected examples from last 5 years. is on key steps with improved procedures approaches. Furthermore also highlighted.

Язык: Английский

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Modular Synthesis of Polycyclic Alkaloid Scaffolds via an Enantioselective Dearomative Cascade

Organic Letters, Год журнала: 2020, Номер 22(3), С. 1175 - 1181

Опубликована: Янв. 15, 2020

The polycyclic core of the akuammiline alkaloids can be synthesized from simple tryptamine and tryptophol derivatives via a Ag(I)-catalyzed enantioselective dearomative cyclization cascade sequence. complex tetracyclic scaffolds are prepared rapid, versatile, three-step modular synthesis commercially available indole in high yields enantiomeric excess (up to 99% yield >99% ee).

Язык: Английский

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Enantioselective Total Synthesis of Cymoside through a Bioinspired Oxidative Cyclization of a Strictosidine Derivative

Angewandte Chemie International Edition, Год журнала: 2019, Номер 59(4), С. 1527 - 1531

Опубликована: Дек. 4, 2019

Abstract The first total synthesis of the caged monoterpene indole alkaloid cymoside is reported. This natural product displays a unique hexacyclic‐fused skeleton whose biosynthesis implies an early oxidative cyclization strictosidine. Our approach to furo[3,2‐ b ]indoline framework relied on unprecedented biomimetic sequence which started by diastereoselective oxidation ring into hydroxyindolenine triggered addition enol ether and was followed trapping oxocarbenium intermediate.

Язык: Английский

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Total Syntheses of Pleiocarpamine, Normavacurine, and C-Mavacurine

Organic Letters, Год журнала: 2019, Номер 21(9), С. 3342 - 3345

Опубликована: Апрель 18, 2019

The total syntheses of C-mavacurine-type indole alkaloids, (±)-pleiocarpamine, (±)-normavacurine, and (±)- C-mavacurine, were accomplished. key step in the was cyclization between metal carbenoid at C16 N1 position a Corynanthe-type compound that equipped with diazo function. For this cyclization, N4 modification substrate using an amine-borane complex indispensable to fix molecular conformation.

Язык: Английский

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Bioinspired Oxidative Cyclization of the Geissoschizine Skeleton for Enantioselective Total Synthesis of Mavacuran Alkaloids

Angewandte Chemie International Edition, Год журнала: 2019, Номер 58(29), С. 9861 - 9865

Опубликована: Май 13, 2019

Reported is the enantioselective total syntheses of mavacuran alkaloids, (+)-taberdivarine H, (+)-16-hydroxymethyl-pleiocarpamine, and (+)-16-epi-pleiocarpamine, their postulated biosynthetic precursor 16-formyl-pleiocarpamine. This family monoterpene indole alkaloids a target choice since some its members are subunits intricate bisindole such as bipleiophylline. Inspired by hypothesis, an oxidative coupling approach from geissoschizine framework to form N1-C16 bond was explored. Quaternization aliphatic nitrogen center key achieving induced KHMDS/I2 it masks nucleophilicity locks in required cis conformation.

Язык: Английский

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The chemistry of mavacurane alkaloids: a rich source of bis-indole alkaloids

Natural Product Reports, Год журнала: 2021, Номер 38(10), С. 1852 - 1886

Опубликована: Янв. 1, 2021

This review presents the chemistry of mavacuranes, a subfamily monoterpene indole alkaloids, from their isolation, biosynthesis, total synthesis to tendency assemble with other partners form intricate bis-indole alkaloids.

Язык: Английский

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Bisindole Alkaloids from the Alstonia Species: Recent Isolation, Bioactivity, Biosynthesis, and Synthesis

Molecules, Год журнала: 2021, Номер 26(11), С. 3459 - 3459

Опубликована: Июнь 7, 2021

Bisindoles are structurally complex dimers and intriguing targets for partial total synthesis. They exhibit stronger biological activity than their corresponding monomeric units. Alkaloids, including those containing C-19 methyl-substitution in units, synthetic derivatives, mismatched pairs can be attractive synthesis may unlock better drug targets. We herein discuss the isolation of bisindoles from various Alstonia species, bioactivity, putative biosynthesis, The macralstonidine, macralstonine, O-acetylmacralstonine, dispegatrine, as well alstonisidine, villalstonine, macrocarpamine also discussed this review. completion pleiocarpamine by Sato et al. completes formal latter two bisindoles.

Язык: Английский

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Catalytic Asymmetric Alkynylation of 3,4‐Dihydro‐β‐carbolinium Ions Enables Collective Total Syntheses of Indole Alkaloids

Angewandte Chemie International Edition, Год журнала: 2021, Номер 60(47), С. 25135 - 25142

Опубликована: Сен. 28, 2021

Chiral tetrahydro-β-carboline (THβC) is not only a prevailing structural feature of many natural alkaloids but also versatile synthetic precursor for vast array monoterpenoid indole alkaloids. Asymmetric synthesis C1-alkynyl THβCs remains rarely explored and challenging. Herein, we describe the development two complementary approaches catalytic asymmetric alkynylation 3,4-dihydro-β-carbolinium ions with up to 96 % yield 99 ee. The utility chiral was demonstrated by collective total syntheses seven alkaloids: harmicine, eburnamonine, desethyleburnamonine, larutensine, geissoschizol, geissochizine, akuammicine.

Язык: Английский

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Total Syntheses of (+)‐Villocarine A, (−)‐Apogeissoschizine, and (+)‐Geissoschizine

Chemistry - A European Journal, Год журнала: 2023, Номер 29(18)

Опубликована: Янв. 21, 2023

Total syntheses of geissoschizine-type monoterpenoid indole alkaloids (MTIAs) are reported. An intramolecular Pictet-Spengler cyclization was developed for the selective construction 3R stereocenter. The first total synthesis (+)-villocarine A then achieved. Furthermore, highly strained (-)-apogeissoschizine also accomplished in an aza-Michael cyclization/E1cB elimination/stereoselective olefin isomerization sequence. Finally, (+)-geissoschizine, a common biosynthetic intermediate MTIAs, obtained from apogeissoschizine through ring-opening along with release ring strain.

Язык: Английский

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