Alstoscholactine and Alstolaxepine, Monoterpenoid Indole Alkaloids with γ‑Lactone-Bridged Cycloheptane and Oxepane Moieties from Alstonia scholaris

Two new monoterpenoid indole alkaloids, alstoscholactine (1) and alstolaxepine (2), were isolated from Alstonia scholaris. Compound 1 represents a rearranged stemmadenine alkaloid with an unprecedented C-6–C-19 connectivity, whereas compound 2 represents a 6,7-seco-angustilobine B-type alkaloid inco...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Organic letters 2018-12, Vol.20 (24), p.8014-8018
Hauptverfasser: Krishnan, Premanand, Lee, Fong-Kai, Chong, Kam-Weng, Mai, Chun-Wai, Muhamad, Azira, Lim, Siew-Huah, Low, Yun-Yee, Ting, Kang-Nee, Lim, Kuan-Hon
Format: Artikel
Sprache:eng
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Two new monoterpenoid indole alkaloids, alstoscholactine (1) and alstolaxepine (2), were isolated from Alstonia scholaris. Compound 1 represents a rearranged stemmadenine alkaloid with an unprecedented C-6–C-19 connectivity, whereas compound 2 represents a 6,7-seco-angustilobine B-type alkaloid incorporating a rare γ-lactone-bridged oxepane ring system. Their structures and absolute configurations were determined by spectroscopic analyses. Compound 1 was successfully semisynthesized from 19E-vallesamine. Compound 2 induced marked vasorelaxation in rat isolated aortic rings precontracted with phenylephrine.
ISSN:1523-7060
1523-7052
DOI:10.1021/acs.orglett.8b03592