S-substituted cysteine derivatives and thiosulfinate formation in Petiveria alliacea -: part II

Three cysteine derivatives, (R)-S-(2-hydroxyethyl)cysteine, together with (RSRC)- and (SSRC)-S-(2-hydroxyethyl)cysteine sulfoxides, have been isolated from the roots of Petiveria alliacea. Furthermore, three additional amino acids, S-methyl-, S-ethyl-, and S-propyleysteine derivatives, were detected. They were present only in trace amounts ( < 3 mug g(-1) fr. wt), precluding determination of their absolute configurations and oxidation states. In addition, four thiosulfinates, S-(2-hydroxyethyl) (2-hydroxyethane)-, S-(2-hydroxyethyl) phenylmethane-, S-benzyl (2-hydroxyethane)- and S-benzyl phenylmethanethiosulfinates, have been found in a homogenate of the roots. The formation pathways of various benzyl/phenyl-containing compounds previously found in the plant were also discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.