Xanthone, tetrahydroxy

Tetrahydroxy-8- isoprenylxanthone (xanthone) Tovomila krukovii (Clusiaceae) Candida albicans secreted aspartic protease (46 pM) [36]... 

Swertifrancheside (= 1,5,8-Trihydroxy-3-methoxy-7-(5, 7, 3", 4"-tetrahydroxy-6 -C-(3-D-glucopyranosyl-4 -oxy-8 -flavyl )-xanthone) Flavone-xanthone C-glycoside)... 

A marine fungal isolate, identified as Wardomyces anomalus, was cultivated and found to produce two new xanthone derivatives, 2, 3, 6, 8-tetrahydroxy-l-methylxanthone 333 and 2, 3, 4, 6,... 

Scheme 3 l,3,5,6-Tetrahydroxy-4-(3-methyl-2-butenyl)-xanthone ugaxanthone (10)... 

Hyperxanthone C 2,3,6,8-tetrahydroxy-l-(2-hydroxy-3-methyl-3-butenyl)xanthone H. scabrum [84]... 

Figure (13) shows two examples of xanthones produced by hypericum plants. Metabolite 1, calycinoxanthon D (1,3,5,6-tetrahydroxy-4-lavandulylxanthone), isolated from II. calycinum and II. roeperanum [72], and compound 2, roeperanone (1,3,5,6-tetrahydroxy-4-trans-sesquilavandulylxanthone), identified in the roots of H. roeperanum, represent xanthones bearing a terpene alkyl moiety. 

To the best of our knowledge, the occurrence in vivo of this chemical class of compounds is low in St. Jonh s Wort. In fact, only kielcorin (0.01%) and the 1,3,6,7-tetrahydroxy-xanthone (trace amounts) have been so far isolated from its roots and its leaves and stems, respectively [9]. 

In 1995, a new xanthone paxanthone B (30) was isolated with garcinone (31) and l,3,6,7-tetrahydroxy-8-(3-methyl-2-butenyl)-9/f-xanthen-9-one (32) from the cell suspension cultures in the callus tissue cultures of Hypericum patulum (Figure 7a) [23],... 

Jackson B, Locksley HD, Scheinmann F 1969 The isolation of 6-desoxyjacareubin,2-(3,3-dimeth-ylallyl)-l,3,5,6-tetrahydroxy-xanthone and jacareubin from Callophyllum inophyllum. Phytochemistry 8 927... 

Norathyriol (1,3,6,7-Tetrahydroxy- xanthone) Athyrium mesosorum Makino ( = Rhachidosorus mesosorus Ching) CiaHgOs >320 102... 

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