S-ETHENYL CYSTEINE - AN AMINO-ACID FROM OLAX-PHYLLANTHI

Ethanolic extracts of the root hemiparasitic shrub Olax phyllanthi con tain significant fractions of their amino N as S-ethenyl cysteine, a n ew naturally occurring compound. This amino acid was present in all pl ant parts, including seeds and seedlings which had.not yet established haustorial connections with surrounding hosts. It was freely mobile i n the xylem of O. phyllanthi but was not encountered in any of the 45 species of hosts which it was parasitizing in native habitat. The iden tity of the compound was established from HPLC, GC-MS and NMR characte ristics of the purified compound against authentic S-ethenyl-L-cystein e.