Prokaryotic triterpenoids. (22R,32R)-34,35-Dinorbacteriohopane-32,33-diols from Acetobacter aceti ssp. xylinum: new bacteriohopane derivatives with shortened side-chain

Abstract

Five new C₃₃-pentacyclic triterpenoids, members of the hopanoid family, differ from all known biohopanoids in that their shortened side-chain bears only two vicinal hydroxy groups. They were isolated from Acetobacter aceti ssp, xylinum and were identified by spectroscopic methods. The absolute configuration at C-32 was shown to be (32R) by comparison of an appropriate derivative of the bacterial hopanoids with the diacetates of (22R,32R)-11(22R,32S)-34,35-dinorbacteriohopane-32,33-diol 12, respectively prepared by asymmetric hemisynthesis.