Abstract:
Two new isocoumarins named xyridin A and B were isolated from the chloroform extract of the flowering heads of Xyris indica Linn. (Xyridaceae). Their structures have been established as 3-n-propyl-6,7-(methytlenedioxy)-1H-2-benzopyran-1-one and 3-(1-oxopropyl)-6,7-(methytlenedioxy)-1H-2- benzopyran-1-one by means of spectroscopic analyses. Additionally, 3-hy-droxy-chrysazin (1,3,8-trihydroxy-9,10-anthracenedione), a new plant constituent has been isolated along with chrysazin (1,8-dihydroxy-9,10-anthracenedione) and 3-methoxy-chrysazin (1,8-dihydroxy-3-methoxy-9,10-anthracenedione) and two know phytosterols, α - spinasterol and stigmasterol. A possible biogenetic pathway for the formation of the xyridins has been proposed.