Synthesis and antifungal activity of functionalized 2,3-spirostane isomers
作者:Sunil Kumar Upadhyay、Clinton C. Creech、Katharine L. Bowdy、Edwin D. Stevens、Branko S. Jursic、Donna M. Neumann
DOI:10.1016/j.bmcl.2011.03.092
日期:2011.5
widely used antifungals, making the development of novel antifungal agents essential. Many naturally occurring products have been found to be effective antimicrobial agents. In particular, saponins with spirostane glycosidic moieties—isolated from plant or marine species—have been shown to possess a range of antimicrobial properties. In this report, we outline a novel approach to the synthesis of a number
Furans are versatile synthons in organic chemistry. Described is a general method for transforming furans into alkynes by dual C-C double-bond cleavage. The reaction is proposed to proceed by sequential [4+2] cycloaddition between furan and singlet oxygen and a formal retro-(3+2) fragmentation of the endoperoxide intermediate. A wide array of furans, including those derived from sapogenins, are amenable
(25R)-5a-Spirostan-2a,3b-diol (gitogenin) 3β-O-[2-O-(α-l-rhamnopyranosyl)-β-d-galactopyranoside] (1), a cytotoxic spirostan saponin isolated from the underground parts of Hosta longipes (Liliaceae), was concisely synthesized. In this context, its congeners 2-4 were also prepared. All four compounds showed comparable potency to dioscin in inhibition against the growth of tumor cells.