Abstract
We compared the hypotensive effects of fractions with molecular weights of 500 to 1, 000 obtained from hot water extracts from twelve kinds of citrus peel. Intravenous administration of fractions from mandarine orange, lemon, grapefruit, yuzu, orange, iyokan, narutokan and sudachi showed marked falls of blood pressure in SHR and SHRSP. Furthermore, we fractionated the fraction from lemon peel by HPLC, and isolated a compound which is considered to be a fravonoid.