Triterpenes, heterocyclic

Nakamura, S., Sugimoto, S., Matsuda, H., and Yoshikawa, M. (2007a). Structures of dammarane-type triterpene triglycosides from the flower buds of Panax ginseng. Heterocycles 71, 577-588. 

Shirota 0,Sekita S, Satake M, Morita H, Takeya K, Itokawa H. Nine regioisomeric and stereoisomeric triterpene dimers from Maytenus chuchuhuasca. Chem. Pharm. Bull. 2004 52 739-746. Shirota O, Sekita S, Satake M, Morita H, Takeya K, Itokawa H. Two new sesquiterpene pyridine alkaloids from Maytenus chuchuhuasca. Heterocycle 2004 63 1891-1896. 

Hisashi M, Toshio M, Hiroki U, Masayuki Y (2001) Medicinal foodstuffs. XXVI. Inhibitors of aldose reductase and new triterpene and its oligoglycoside, centellasapogenol A and centellasaponin A, from Centella asiatica (Gotu Kola). Heterocycles 55 1499-1504... 

In the course of these changes (Scheme 1), the triterpene side chain is first oxidised, eventually to a -substituted furan ring. The usual definition of a limonoid is that it is a triterpene derivative in which the side chain has become a furan ring by the loss of four carbon atoms, hence an alternative name, tetranortriterpenoids, for the limonoids. In a few compounds which are obviously related a fifth carbon atom has been lost by decarboxylation at C-4, and in a few the furan ring is replaced by a different five membered heterocyclic ring. Some of these last derivatives appear to be oxidation products of the limonoids 40) others may be intermediates in the production of the furan ring 64). 

Stelletta Acetylenic fatty acids, triterpenes (malabaricane), bipyridyl derivatives, S/N heterocycles, nitrogen-containing terpenes and meroterpenes. 

Chalinidae 300-320 300-320 Adocia, Chalinula, Haliclona, Reniera Acetylenic derivatives, macro-heterocycles, triterpenes, sulfated meroterpenes, isonitriles, aromatic carotenoids, atypical sterols, long-chain phenols, pyridine derivatives, S/N heterocycles, cyclic peptides, sulfated derivatives... 

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