The present invention involves a purified bioactive compound of the formula: ##STR1## wherein at least one of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are H or an acyl having less than about five carbon atoms. More specifically the preferred purified bioactive compound is (1R, 1R, 3R, 7S, 7aR)-3-hydroxymethyl-1,2,7-trihydroxypyrrolizidine.Board of Regents, University of Texas Syste
