Some Major Steps in the Understanding of the Chemistry and Biochemistry of Chl - Chlorophyll Biosynthesis and Technological Applications - page 9

1.2.4 Smith, 1948
In 1948, on the basis of the correspondence of the newly published absorbance
spectrum of MV Pchlide a (mistaken for MV Pchl a ), and the action spectrum of
MV Chl a formation, smith proposed that MV Pchl a (in fact, MV Pchlide a ) is the
immediate precursor of MV Chl a (Smith 1948 ). That dogma was dropped later on
(see below).
1.2.5 Muir and Neuberger, and Wittenberg
and Shemin, 1949
In1949, Muir and Neuberger and Wittenberg and Shemin showed that one carbon
atom and the nitrogen atom of each pyrrole ring of protoheme is derived from the
alpha-atom and the associated nitrogen atom of glycine (Muir and Neuberger 1949 ).
1.2.6 Granick, 1950
In 1950 Granick demonstrated the accumulation of monovinyl (MV) Pchlide a in
Chlorella mutants inhibited in their capability to form Chl, and proposed that in
plants, Pchlide a is the immediate precursor of Pchlide a phytyl ester (i.e. Pchl a ).
Then Granick organized DV Proto, DV Mg-Proto, MV Pchlide a , MV Pchlide
a phytyl ester, and MV Chl a by order of increasing chemical complexity into a
paper chemistry, single branched, Chl a biosynthetic pathway that originated in DV
Proto and ended in the formation of MV Chl a (Granick 1950 ).
1.2.7 Muir and Neuberger and Wittenberg and Shemin, 1950
In 1950, Muir and Neuberger and Wittenberg and Shemin showed that each of the
four methine bridge carbon atoms of protoheme is derived from the alpha-carbon of
glycine. Wittenberg and Shemin used chromic acid oxidation, a technique devel-
oped by Willstatter and Ashina in 1909 (see above).
1.2.8 Shemin and Wittenberg, 1951
In 1951, Shemin and Wittenberg concluded that all four pyrrole rings of protoheme
arise from a common pyrrole precursor (Shemin and Wittenberg 1951 ).