A xanthonoid is a chemical natural phenolic compound formed from the

xanthone Xanthone is an organic compound with the molecular formula O 6H4sub>2CO. It is a white solid. In 1939, xanthone was introduced as an insecticide and it currently finds uses as ovicide for codling moth eggs and as a larvicide. Xanthone is also ...

backbone. Many members of the

Clusiaceae The Clusiaceae or Guttiferae Juss. (1789) (''nom. alt. et cons.'' = alternative and valid name) are a family (biology), family of plants including 13 genera and ca 750 species. Several former members of Clusiacae are now placed in Calophyllaceae ...

contain xanthonoids. Xanthonoid biosynthesis in cell cultures of ''

Hypericum androsaemum ''Hypericum androsaemum'', also referred to as Tutsan, Shrubby St. John's Wort, or sweet-amber, is a flowering plant in the family Hypericaceae. It is a perennial shrub reaching up to 70 cm in height, native to open woods and hillsides in E ...

'' involves the presence of a

benzophenone synthase In enzymology, a benzophenone synthase () is an enzyme that catalyzes the chemical reaction :3 malonyl-CoA + 3-hydroxybenzoyl-CoA \rightleftharpoons 4 CoA + 2,3',4,6-tetrahydroxybenzophenone + 3 CO2 Thus, the two substrates of this enzyme are m ...

condensing a molecule of

benzoyl-CoA Benzoyl-CoA is a molecule implied in the activity of the different enzymes 4-hydroxybenzoyl-CoA reductase, benzoyl-CoA reductase, benzoyl-CoA 3-monooxygenase, benzoate-CoA ligase, 2alpha-hydroxytaxane 2-O-benzoyltransferase, anthranilate N-be ...

with three malonyl-CoA yielding to 2,4,6-trihydroxybenzophenone. This intermediate is subsequently converted by a

benzophenone 3′-hydroxylase Benzophenone is the organic compound with the formula (C6H5)2CO, generally abbreviated Ph2CO. It is a white solid that is soluble in organic solvents. Benzophenone is a widely used building block in organic chemistry, being the parent diarylket ...

, a cytochrome P450 monooxygenase, leading to the formation of 2,3′,4,6-tetrahydroxybenzophenone. Some examples are tomentonone, zeyloxanthonone and calozeyloxanthone isolated from the bark of ''

Calophyllum tomentosum ''Calophyllum tomentosum'' is a species of flowering plant in the family Calophyllaceae, commonly known as bintangur. It is found in Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, � ...

'', apetalinone A, B, C and D from '' Calophyllum apetalum'', gaudichaudione A, B, C, D, E, F, G, H, gaudichaudiic acid A, B, C, D, E, morellic acid and forbesione from '' Garcinia gaudichaudii'', methylswertianin and bellidifolin from '' Swertia punicea'' or psorospermin obtained from '' Psorospermum febrifugum''. Cassiaxanthone can be found in ''

Cassia reticulata ''Senna reticulata'', the ''mangerioba grande'' or ''maria mole'' in Portuguese, is a pioneer tree species found on highly fertile floodplains in South America. It has some medicinal uses, but is regarded by farmers as a noxious weed, named ''mat ...

''. Cytotoxic xanthones ( gambogin, morellin dimethyl acetal, isomoreollin B, moreollic acid, gambogenic acid, gambogenin, isogambogenin, desoxygambogenin, gambogenin dimethyl acetal, gambogellic acid, gambogic acid, isomorellin, morellic acid, desoxymorellin and hanburin) can be isolated from the dry latex of ''

Garcinia hanburyi ''Garcinia hanburyi'' is a plant species in the genus ''Garcinia'', native to Indochina; it is one of the gamboge producing trees. Cytotoxic xanthonoid A xanthonoid is a chemical natural phenolic compound formed from the xanthone backbone. Ma ...

'' (gamboge tree).Cytotoxic xanthones from Garcinia hanburyi. Jun Asano, Kazuhiro Chiba, Masahiro Tada and Takao Yoshii, Phytochemistry, Volume 41, Issue 3, February 1996, Pages 815-820,

References

{{xanthonoid Xanthonoids Secondary metabolites