Methyl chlorophyllide a as a probable intermediate in the chlorophyll a pathway.

Although the enzyme chlorophyllase has been long known (13) only recently has evidence been presented for its probable function in chlorophyll a (chl a) biogenesis, namely, the demonstration that methyl chlorophyllide a (me chlide a) was transesterified with phytol in the presence of chlorophyllase yielding chl a (2). However, no evidence has been presented that wouild indicate the presence of me chlide a in green plants, a finding that would strongly support the above as the function of clhlorophyllase in chl a biosynthesis. This report describes the isolation and partial characterization of minor quantities of me chlide a from extracts of expanding wheat (Triticumiii aestivum) or passion flower leaves (Passiflora X alatocaerulea). This finding together with that described above suggests that the final steps in chl a biogenesis are