COO·C_{20}H_{39} / becomes Phæophytin _b_, C_{32}H_{30}O_{2}N_{4} \ COO·CH_{3} Similarly, Isochlorophyllin _a_, becomes Phytochlorin _e_, Chlorophyllin _a_, becomes Phytochlorin _f_, and _g_, COOH / C_{32}H_{32}ON_{4} \ COOH Isochlorophyllin _b_, becomes Phytorhodin _g_ Chlorophyllin _b_, becomes Phytorhodin _i_ and _k_, COOH / C_{32}H_{30}O_{2}N_{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}; ætiophyllin, MgC_{31}H_{34}N_{4}, becomes ætioporphyrin, 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 ætioporphyrin. =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 Hæmatinic acid imide By reduction, there have been obtained from the chlorophylls and the various porphyrins, three isomeric pyrrole derivatives having the following formulas,