Microchemical Investigation on the Distribution of Pollen Flavonoid Components

Abstract

A part of the micro-amount components of natural honey was thought to originate in the component of occluded pollens and the present series of experiments was carried out as a part of studies on pollens. Chemistry of pollens has increased interest from pure chemical and pharmaceutical standpoint and the components detected are numerous. However, analytical work in this country is small due probably to the difficulty in collecting pollens. Analyses have been made on limited number of pollens, mostly on those in the honey collected by bees and on those especially of interest from allergic considerations.Microchemical examinations were made on the flavonoids, whose physiological action is of interest in medicopharmacological field, among the many kinds of pigment contained in pollen grains, in their distribution and properties with 17 genera (37 kinds) of anemophilous plants and 51 genera (95 kinds) of entomophilous plants. Presence of carotenoids was found less in the pollens of anemophilous plants and more in the entomophilous plants, and the pollens which contain a large amount of carotenoids have less flavonoids. Many of the anemophilous plants contain isorhamnetin but not in entomophilous plants. Quercetin, one of the most widely distributed flavonoids in nature, is also found in numerous pollens. Past workers indicated that only one kind of a flavonoid is found in the pollens of one flower but the present series of experiments have shown that two or three kinds of flavonoid are present in one kind of a pollen. It was also found that pollens of some plants have different kind of flavonoids in the wild and horticultural species.