摘要

A key intermediate in the biosynthetic pathway by which C-24 bile acids are formed from cholesterol has long been considered to be varanic acid. (24 xi,25 xi)-3 alpha,7 alpha,12 alpha-24-tetrahydroxy-5 beta-cholestan-27-oic acid. The (24R,25R)-epimer of this tetrahydroxy bile acid, in the form of its taurine N-acyl amidate, was thought to be the major biliary bile acid in lizards of the family Varanidae. We report here that a major biliary bile acid of three lizard species - the Komodo dragon (Varanus komodoensis), Gray%26apos;s monitor (Varanus olivaceus), and the Gila monster (Heloderma suspectum) - is a novel epimer of varanic acid. The epimer was shown to be (24R,25S)-3 alpha,7 alpha,12 alpha,24-tetrahydroxy-5 beta-cholestan-27-oic acid (present in bile as its taurine conjugate). The structure was established by mass spectroscopy and by H-1 and C-13 nuclear magnetic spectroscopy, as well as by synthesis of the compound.

  • 出版日期2012-11