Newly detected specific hydrogenation of the conjugated double bond of unsaturated alkaloid lactones by Aspergillus sp.

A new isolate of Aspergillus sp. hydrogenated the gamma,delta-double bond of securinine (143 mg l(-1)) to give 14,15-dihydrosecurinine at over 98% (w/w) yield after 8 h. It also hydrogenated the C11(13) double bond of 3-hydroxy-1(10),3,11(13)-guaiatriene-12,6-olide-2-one (HGT) (200 mg l(-1)) to give 3-hydroxy-1(10),3-guaiadiene-12,6-olide-2-one with over 98% (w/w) conversion after 24 h.