4}
\
COOH

And bodies known as "porphyrins" are similarly derived from all the other
known phyllins.

For example: cyanophyllin, MgC_{31}H_{32}N_{4}(COOH)_{2}, becomes
cyanoporphyrin, C_{31}H_{34}N_{4}(COOH)_{2}; aetiophyllin,
MgC_{31}H_{34}N_{4}, becomes aetioporphyrin, C_{31}H_{36}N_{4}, etc.

Phytochlorin _e_ and phytorhodin _g_ are the chief products of the
decomposition by acids of the chlorophylls. Indeed, it was the production
of these compounds which led to the discovery of the existence of the two
chlorophylls. When treated with alkalies, they lose their carboxyl groups
and become aetioporphyrin.

=Decomposition of the Chlorophylls by Oxidation and Reduction.=--When acted
upon by oxidizing agents, such as chromic acid, the porphyrins yield two
chief oxidation products, which are pyrrole derivatives having the
following formulas,

CH_{3}-C-CO CH_{3}-C-CO
| \ | \
| NH | NH
| / | /
CH_{3}-CH_{2}-C-CO HOOC-CH_{2}-CH_{2}-C-CO

Methylethylmalein imide Haematinic acid imide

By reduction, there have been obtained from the chlorophylls and the
various porphyrins, three isomeric pyrrole derivatives having the following
formulas,

CH_{3} H CH_{3}
| | |
C_{2}H_{5}-C=C C_{2}H_{5}-C=C C_{2}H_{5}-C=C
| \ | \ | \
| NH | NH | NH
| / | / | /
CH_{3}-C=C CH_{3}-C=C CH_{3}-C=C
| | |
CH_{3} CH_{3} H

Phyllopyrrole Haemopyrrole Isohaemopyrrole

As a result of the study of these decomposition units, Willstaetter has
suggested the following formulas for the structural arrangement of
aetiophyllin and aetioporphyrin, the compounds which result from the removal
of all of the acid groups and finally of the magnes