Biosynthesis of porphyrins and related macrocycles. Part 22. Vitamin B12: studies on the chlorin, Faktor-I, and the detection of 3-epi-Faktor-I
Abstract
The chlorin, Faktor-I, is prepared in greater quantity than previously by enzymic methylation of uro'gen-III using a cell-free preparation from Clostridium tetanomorphum. Circular dichroism and 1H n.m.r. spectra are determined on the octamethyl ester of Faktor-I and all the important signals in the n.m.r. spectrum are assigned. An isomeric chlorin is detected in the products from the enzymic runs having properties in accord with its being 3-epi-Faktor-I.