ABSTRACT
Three new sesquiterpene pyridine alkaloids, tripfordines A-C (1-3), were isolated from an ethanolic extract of the roots of Tripterygium wilfordii, along with eight known pyridine alkaloids, and tested for in vitro cytotoxic and anti-HIV activity. The structures of the new compounds were established on the basis of spectroscopic data interpretation. Anti-HIV structure-activity relationships (SAR) for this compound type are proposed on the basis of the screening results from the newly isolated compounds and prior data of known sesquiterpene pyridine alkaloids. The position of a carboxyalkyl chain on the pyridine moiety was not critical since both 2'- and 4'-substituted compounds exhibited high anti-HIV activity (EC(50) 0.1 microg/mL). In contrast, a hydroxy group at C-8' (carboxypropyl side chain) or C-9' (carboxybutyl side chain) was found to affect anti-HIV activity.
Subject(s)
Alkaloids , Anti-HIV Agents , Drugs, Chinese Herbal , Plants, Medicinal/chemistry , Pyridines , Sesquiterpenes , Tripterygium/chemistry , Alkaloids/chemistry , Alkaloids/isolation & purification , Alkaloids/pharmacology , Anti-HIV Agents/chemistry , Anti-HIV Agents/isolation & purification , Anti-HIV Agents/pharmacology , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/isolation & purification , Drugs, Chinese Herbal/pharmacology , Molecular Structure , Plant Bark/chemistry , Plant Roots/chemistry , Pyridines/chemistry , Pyridines/isolation & purification , Pyridines/pharmacology , Sesquiterpenes/chemistry , Sesquiterpenes/isolation & purification , Sesquiterpenes/pharmacology , Structure-Activity RelationshipABSTRACT
Two new taxane diterpenes, dantaxusin C (1) and dantaxusin D (2), were isolated from an ethanol extract of the aerial parts of Taxus yunnanensis along with 14 known taxoids. All structures were established on the basis of 1D and 2D NMR and HREIMS spectroscopic methods.
