Identification of anti-nociceptive constituents from the pollen of Typha angustifolia L. using effect-directed fractionation.

The pollen of T. angustifolia, also known as Pu huang in Chinese, has been used for treatment of stranguria, hematuria, dysmenorrhea, metrorrhagia and injuries in China for a long time. Extensive efforts have been directed toward its phytochemical and biological aspects. However, little is known about its anti-nociceptive implication and material basis. This work presented the investigation of the anti-nociceptive effect of Typhae Pollen using an effect-directed fractionation strategy, thereby leading to identification of isorhamnetin-3-O-neohesperidin (1) and typhaneoside (2), together with other minor flavonoid glycoside congeners, as the main anti-nociceptive constituents. This work not only unveils the anti-nociceptive potential of Typhae Pollen, but also establishes a method to enrich and identify the anti-nociceptive constitutes of Typhae Pollen. Moreover, this work is a successful example of effect-directed fractionation strategy, which represents a powerful tool in TCM-based drug discovery and development.