LISIANTHUS FLAVONOID PIGMENTS AND FACTORS INFLUENCING THEIR EXPRESSION IN FLOWER COLOR

NMR, MS and analytical data are cited in support of the newly defined complete structures of the major flavonoid pigments and copigments in lisianthus flowers. The copigments newly characterized and found in fl owers of all colours are ylgalactopyranoside]-7-O-alpha-L-rhamnopyrano side, its Z-isomer and by analogy, the lesser isorhamnetin and myricet in equivalents. Purple flower pigments with newly defined structures a re: a-D-[6-O-alpha-L-rhamnopyranosylgalactopyranoside] 5-O-beta-D-[6-E -p-coumaroylglucopyranoside], its Z-isomer, and by analogy the lesser cyanidin equivalent, together with oside-5-O-beta-D-[6-E-p-coumaroylgl ucopyranoside], its Z-isomer, and by analogy the lesser cyanidin equiv alent. Different pigment/copigment compositions are shown to account f or the basic colour differences between white, cream, pink, mauve and purple flowers, but other factors involved in stabilizing and fine-tun ing the colours are pigment concentration, copigmentation and pH contr ol.