Novel steroids from Trichilia hirta as identified by nanoprobe INADEQUATE 2D-NMR spectroscopy.

Two novel steroids, 3-hydroxypregnane-2,16-dione [I] and 2-hydroxyandrosta-1,4-diene-3,16 dione [2], were isolated from ethanolic extracts of the wood and bark of Trichilia hirta. The structure of 1 was rigorously determined from 2D-INADEQUATE NMR data that was: 1) acquired with a new higher-sensitivity C-13 probe called a Nano nmr probe, and; 2) processed with a new NMR-analysis program called FRED, which automatically generated the complete carbon structure (as shown). In this first known application of both a Nanoprobe and FRED software to an unknown compound the complete carbon skeleton was easily determined using only Il mg (30 mu moles) of sample. Copyright (C) 1996 Elsevier Science Ltd