Kopsia

Alkaloid Lapidilectine A (21) has a basically similar carbon chain. A series has been isolated from the wood and leaves of Kopsia lapidilecta. (92TL2493, 93JNP1134). 

Kam T-S, Subramaniam G, Lim T (2001) Mersinines A and B and mersiloscine, novel quinolnic alkaloids from Kopsia. Tetrahedron Lett 42 5977-5980... 

Kam T, Subramaniam G (2004) Mersilongine, a novel tetracyclic quinolinic alkaloid from Kopsia. Tetrahedron Lett 45 3521-3524... 

Zhu, J., Guggisberg, A. and Hesse, M. 1986. Indole alkaloids from Kopsia haina-nensis. Planta Medica, 52 63-64. 

Rhazinilam 3 is an axially chiral phenyl-pyrrole compound which was first isolated from Melodinus australis (F. Muell.) Pierre [53]. It has also been found in other Apocynaceae such as Rhazya stricta Decaisne [54,55], Aspidosperma quebracho-bianco Schlecht. [56,57], Leuconitis eugenifolia A. DC [58,59] and Kopsia singapurensis [60]. More recently, (-)-rhazinilam was isolated from intergeneric somatic hybrid cell cultures of two Apocynaceae, Rauvolfia serpentina Benth. Ex Kurz and Rhazia stricta Decaisne [61]. 

Rhazinilam was found to be an oxidative artefact derived from the unstable natural 5,21-dihydrorhazinilam 25 [58,59,60]. Other compounds of the (-)-rhazinilam series have been isolated from various Apocynaceae. (-)-3-Oxorhazinilam 26, also called rhazinicine, was founded in Kopsia dasyrachis Ridl. [63] and in hybrid plant cell cultures [64]. 

In the plant, the unstable dihydrorhazinilam 25 is most certainly the direct biogenetic precursor of rhazinilam, which is an isolation artefact. Indeed, 25 was isolated together with 3 from the Apocynaceae Leuconotis eugenifolia and Leuconotis griffithii [58,59] and Kopsia singapurensis [60]. The question whether (+)-l,2-didehydroaspidospermidine 46 is the actual biogenetic precursor of 25 is still open. 

DIPLORRHYNC US, KOPSIA, OCHROSIA, PLEIOCARPA, AND RELATED GENERA... 

The basic fraction of the ethanolic leaf extract of the Malaysian plant Kopsia griffithii exhibits a strong antileishmania activity. One of the two novel alkaloids isolated from this plant in 1998 was the indolizidino[8,7-fo]indole harmicine [17]. Synthetic approaches to harmicine became attractive owing to its pharmacological potential [18,19]. We applied our three-step pyrrolidine annulation strategy to the synthesis of harmicine (Scheme 15.5) [19]. 

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