Organic components of moxa.

Moxa was soaked in a mixed solvent of chloroform, methanol and water (5:5:1) at room temperature for 7 days, and the supernatant solution was separated into two layers by the addition of water. Heptatriacontane (C37H76), confirmed by measurements of 1H and 13C-NMR spectra and melting point, was obtained from the chloroform layer, while condensed tannins having catechol derivatives were found in the methanol-water layer. Each ratio of C37H76 in several kinds of moxas to the total weight of the moxa was similar in both high-class and low-class moxas, but that of the tannins was much less in the former than the latter. Comparing the burning-temperature curve to the time between the moxa after the extraction and before, the time for the rise of the burning-temperature from 25 degrees C to the highest temperature was longer in the treated moxa. Removal of C37H76 from the original moxa seems to decelerate the burning of moxa.