Two novel indole alkaloids, Kopsiyunnanines A and B, from a Yunnan Kopsia

Synthesis of symmetrical and unsymmetrical 3,3-di(indolyl)indolin-2-ones under controlled catalysis of ionic liquids

“…During these investigations, the indolin-2-one (oxindole) moiety has been recognized as a biologically active framework. [27][28][29][30][31] Thus, it is not surprising that access to several members of this class may be the goal of many research laboratories. [27][28][29][30][31] Thus, it is not surprising that access to several members of this class may be the goal of many research laboratories.…”

Kopsiyunnanines F and isocondylocarpines: new tubotaiwine-type alkaloids from Yunnan Kopsia arborea

“…The leaves and fruits of Yunnan K. arborea are used to treat rheumatoid arthritis, dropsy, and tonsillitis [8]. We have previously reported the structure elucidation and semisynthesis of several unusual alkaloids isolated from the crude base of the aerial part of Yunnan K. arborea [9,10]. These alkaloids include kopsiyunnanine A, a new cytotoxic modified corynanthe-aspidospermatan-type bisindolic alkaloid; kopsiyunnanine B, a new D ring rearranged corynanthe-type oxindole alkaloid; and kopsiyunnanines C and D, which are unusual methoxymethyl or ethoxymethyl functionalized indole alkaloids.…”

Total Syntheses of <i>Lycopodium</i> and Monoterpenoid Indole Alkaloids Based on Biosynthesis-Inspired Strategies

“…Strictosidine (45), which is biosynthesized by the condensation of tryptamine (43) and secologanin (44), is the key intermediate for the in vivo elaboration of numerous groups of monoterpenoid indole alkaloids having rich structural di-versity. 31) According to their structural characteristics, monoterpenoid indole alkaloids are classified into four major types (with many subdivisions), i.e., Corynanthe, Strychnos, Aspidosperma, and Iboga.…”

“…31) According to their structural characteristics, monoterpenoid indole alkaloids are classified into four major types (with many subdivisions), i.e., Corynanthe, Strychnos, Aspidosperma, and Iboga. (Chart 12) Biogenetically, the Corynanthe skeleton represented by geissoschizine (46) is the first compound to be formed from strictosidine (45) to be biogenetically derived from geissoschizine (46) by the ring closure between C16 and N 1 . 32,33) Geissoschizine (46) is also supposed to be a common biogenetic intermediate to provide Akuammiline-type alkaloids represented by rhazimal (50) (Chart 13).…”

“…(Chart 12) Biogenetically, the Corynanthe skeleton represented by geissoschizine (46) is the first compound to be formed from strictosidine (45) to be biogenetically derived from geissoschizine (46) by the ring closure between C16 and N 1 . 32,33) Geissoschizine (46) is also supposed to be a common biogenetic intermediate to provide Akuammiline-type alkaloids represented by rhazimal (50) (Chart 13). There are no reports of the total syntheses of C-Mavacurine type natural products by the direct coupling of C16 and N 1 in the Corynanthe skeleton, probably because its highly strained property owing to its pentacyclic framework has made synthesis difficult.…”