01812nas a2200169   4500008004100000022001400041245011800055210006900173260011000242300001400352490000700366520106400373100001901437700002101456700003701477856012801514       2013                        eng d  a1463-926200aBiocatalysis: fungi mediated novel and selective 12 beta- or 17 beta-hydroxylation on the basic limonoid skeleton0 aBiocatalysis fungi mediated novel and selective 12 beta or 17 be  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR  a1311-13170 v153 a<p>Basic limonoids carrying a 4,4,8-trimethyl-17-furanylsteroid skeleton are a class of triterpenoids and well-known for their insecticidal as well as a vast array of pharmacological activities. Rare and synthetically challenging 12 beta- and 17 beta-hydroxylation was achieved on the basic limonoid skeleton to produce a novel series of hydroxylated limonoids using fungi-mediated biocatalysis. The fungal system belonging to the genera of Mucor efficiently converted azadiradione, epoxyazadiradione, gedunin and their derivatives into corresponding 12 beta- and/or 17 beta-hydroxy derivatives. The position and stereochemistry of hydroxylation was determined by rigorous spectroscopic and crystallographic studies. This fungi-mediated stereo- and regio-selective hydroxylation process was highly efficient and mild enough to sustain chemically sensitive functional groups around the basic limonoid skeleton. Modifications of specific functional groups and variation in biocatalyst were shown to bring selectivity among 12 beta- or 17 beta-hydroxylation.</p>1 aHaldar, Saikat1 aKolet, Swati, P.1 aThulasiram, Hirekodathakallu, V.  uhttps://library.ncl.res.in/content/biocatalysis-fungi-mediated-novel-and-selective-12-beta-or-17-beta-hydroxylation-basic-0