Flavonoid variation and evolution inAsplenium normale and related species (Aspleniaceae)

Flavonoid profiles of 132 populations (472 individuals) ofAsplenium normale, and related species,A. boreale, A. shimurae, andA. oligophlebium var.oligophlebium and var.iezimaense in Japan were surveyed by HPLC and 2D-PC. Of the five taxa, each ofAsplenium boreale, A. shimurae andA. oligophlebium including var.iezimaense had consistent flavonoid composition: apigenin 7, 4′-di-O-rhamnoside (9) inAsplenium boreale, 7-O-glucosyirhamnosides of apigenin and luteolin (6 and 7) inA. shimurae and genkwanin 4′-O-glucosyl-rhamnoside (5) in twoA. oligophlebium varieties. On the other hand,Asplenium normale was divided into seven chemotypes A-G: A-type has 7-O-dirhamnosides of apigenin and luteolin (1 and 2) and genkwanin 4′-O-glucosylrhamnoside (5); B-type, 5 alone; C-type, apigenin 7-O-rhamnoside-4′-O-glucosylrhamnoside (8); D-type, 1 and 2; E-type, 1,2 and 8; F-type, 1, 2, 5 and 8; and G-type, 5 and 8. Among them, the most frequent types were A, B and C, and A-type was mainly distributed in inland of Honshu, Shikoku and Kyushu, while B- and C-types extended their distribution areas southwards in general and occur along the Pacific coast with several exception. Chemical and evolutionary relationships amongAsplenium boreale, A. shimurae, A. oligophlebium, and the chemotypes ofA. normale were discussed on the basis of general biosynthetic pathway.