Journal of Analytical & Bioanalytical Techniques
Open Access

Abstract

In 2010, Chen et al . discovered a red-shift ed chlorophyll in a methanolic extract of Shark Bay stromatolites, and was named Chl f . In 2011, Ohkubo et al . found Chl f -like pigment in a unicellular cyanobacterium newly isolated from Lake Biwa, but the pigment was detected only when it was cultivated under near infrared light. In this work, we have determined the molecular structure of this pigment by HPLC, absorption, CD, mass and NMR measurements. Th e absorption spectrum of the pigment in methanol was completely diff erent from that of Chl a , but similar to the reported spectrum of Chl f . Th e Soret and Q Y bands were red-shift ed, compared to Chl a and Chl d . Th e Soret band of this pigment was well split in diethyl ether and benzene, while Chl d showed such a split not in those solvents but in methanol. Th e Soret/Q Y -band ratio of this pigment in methanol was ca. 0.9, diff erent from the reported value of ca. 1.9. Th e pigment was easily separated from Chls a , b and d in our normal-phase HPLC; Chl f eluted between Chl a and Chl b (or d ). CD spectral analysis showed that the pigment is not prime- type but normal-type. Mass analysis exhibited that molecular formula of this pigment is C 52 H 72 O 6 N 4 Mg, same as that of Chls b and f . Th e transformation of a methyl moiety of Chl a to a formyl one yielding Chl f was revealed by NMR analysis; the pigment has been identifi ed to be 2-formyl-Chl a , namely, Chl f .

Biography

M. Kobayashi has completed his Ph.D from University of Tokyo. He has published more than 100 papers mainly in the fi eld of chlorophylls.