Steroidal and Terpenoid Alkaloids

Steroidal and Terpenoid Alkaloids.—Following upon earlier work on the biosynthesis of steroidal alkaloids it has been shown that (255)-5a -cholestan-3/8,26-diol (159), but not the corresponding furostan derivative (160), is a precursor for tomatidine (162) in Lycopersicon pimpinellifolium [This contrasts with the observation that the (255)-sapogenin, neotigogenin (163), was labelled by both precursors in these experiments.] If these results are taken together with the observation that 

Tschesche, Euchetn Conference on Chemistry and Biosynthesis of Steroids and Terpenoids , La 

Arigoni, 9th lUPAC Symposium of Natural Products , Ottawa, 1974, quoted in ref. 166. J. R. Hanson and R. Nyfelcr, J.C.S. Chem. Comm., 1975,171 ibid., 824. 

A new natural imino-alcohol, 3,4-dihydroxy-2,5-dihydroxymethylpyrrolidine (1) has been isolated from the roots and leaves of Derris elliptica. Its structure and configuration have been settled principally by n.m.r. and mass spectrometry. It appears to be the first example of the occurrence of an iminopolyol in the vegetable kingdom. Trichostachine (2) has been found in the fruit of Piper guineense Schum, 

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