Susumu Kitanaka

Phlegmacins and anhydrophlegmacinquinones: Dimeric hydroanthracenes from seedlings of Cassia torosa☆

Abstract From seedlings of Cassia torosa four dimeric hydroanthracenes have been isolated. Two, a pair of atropisomeric dimers consisting of two molecules o

Dimeric hydroanthracenes from the unripe seeds of Cassia torosa

Abstract From the unripe seeds of Cassia torosa three new dimeric hydroanthracene derivatives were isolated along with stigmasterol, sitosterol, campesterol, physcion-9-anthrone, torosachyrsone and the phlegmacins A 2 and B 2 . The structures of the new derivatives were established as physcion-10, 10′-bianthrone, anhydrophlegmacin B 2 [2-(6′-methoxy-3′-methyl-3′, 8′, 9′-trihydroxy-1′-oxo-1′, 2′, 3′, 4′-tetrahydroanthracene-10′-yl)-1, 8-dihydroxy-3-methoxy-6-methyl-9-oxo-9, 10-dihydroanthracene] and torosanin [2-(6′-methoxy-3′-methyl-3′, 8′,9′-trihydroxy-1′-oxo-1′, 2′, 3′,4′-tetrahydroanthracene-5′-yl)-1, 8-dihydroxy-3-methoxy-6-methyl-9-oxo-9, 10-dihydroanthracene], respectively.

Studies on the constituents of the seeds of Cassia obtusifolia: The structures of two new lactones, isotoralactone and cassialactone

Abstract Torosachrysone and two new naphthalenic lactones, isotoralactone and cassialactone, were isolated from the seeds of Cassia obtusifolia. Their structures were established as 9,10-dihydroxy-7-methoxy-3-methylene-1H-naphtho(2,3-c)dihydropyrone-1-one and 8-methoxy-4-methyl-1-oxo-4,10,11-trihydroxy-naphtho(2,3-c)oxepin, respectively.

Germitorosone and methylgermitorosone, two hydroanthracene derivatives from seedlings of Cassia torosa

Abstract Two new yellow pigments, germitosone and methylgermitorosone, were isolated from the seedling of Cassia torosa . The structures of these substances were established as 3,7 dimethyl - 6 - methoxy - 1 - oxo - 2,3,8,9 - tetrahydroxy - 1,2,3,4 - tetrahydroanthracene and 6,9 dimethoxy - 3,7 - dimethyl - 1 - oxo - 2,3,8 - trihydroxy - 1,2,3,4 - tetrahydroanthracene respectively.