AbstractTwo digalactosyldiacylglycerols (DGDG), galactosyl(α1 → 6)‐galactosyl (β1 → 3′)‐diacylglycerol (A isomer) and galactosyl(β1 → 6)‐galactosyl(β1 → 3′)‐diacylglycerol (B isomer), were found to be commonly distributed in some leguminous seeds. B isomer DGDG was detected in the range 1·9–32·5% of the whole DGDG from four varieties of kidney bean, five varieties of soya bean and adzuki bean, and one variety of pea, broad bean and scarlet runner bean. In kidney bean, the principal molecular species of diacylglycerol moieties in B isomer DGDG were dilinolenin (LnLn), linoleoyllinolenin (LLn) and oleoyllinolenin (OLn), whereas those in A isomer were LnLn, OLn and LLn. The major molecular species of B isomer DGDG from broad bean were predominantly dilinolenin (LL) and LLn which were found to be significantly differen