Xanthone

About: Xanthone is a research topic. Over the lifetime, 1639 publications have been published within this topic receiving 25870 citations. The topic is also known as: 9-oxo-xanthene & Diphenyline ketone oxide.

Acetic acid acts as an elicitor exerting a chitosan-like effect on xanthone biosynthesis in Hypericum perforatum L. root cultures.

Abstract: Acetic acid acts as a signal molecule, strongly enhancing xanthone biosynthesis in Hypericum perforatum root cultures. This activity is specific, as demonstrated by the comparison with other short-chain monocarboxylic acids. We have recently demonstrated that Hypericum perforatum root cultures constitutively produce xanthones at higher levels than the root of the plant and that they respond to chitosan (CHIT) elicitation with a noteworthy increase in xanthone production. In the present study, CHIT was administered to H. perforatum root cultures using three different elicitation protocols, and the increase in xanthone production was evaluated. The best results (550 % xanthone increase) were obtained by subjecting the roots to a single elicitation with 200 mg l−1 CHIT and maintaining the elicitor in the culture medium for 7 days. To discriminate the effect of CHIT from that of the solvent, control experiments were performed by administering AcOH alone at the same concentration used for CHIT solubilization. Unexpectedly, AcOH caused an increase in xanthone production comparable to that observed in response to CHIT. Feeding experiments with 13C-labeled AcOH demonstrated that this compound was not incorporated into the xanthone skeleton. Other short-chain monocarboxylic acids (i.e., propionic and butyric acid) have little or no effect on the production of xanthones. These results indicate that AcOH acts as a specific signal molecule, able to greatly enhance xanthone biosynthesis in H. perforatum root cultures.

Two New Xanthones Isolated from the Stem Bark of Garcinia lancilimba

Abstract: Two new xanthones, 1,5,6-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':3,4)-2-(3-methylbut-2-enyl)xanthone (1) and 1,6,7-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':3,2)-4-(3-methylbut-2-enyl)xanthone (2), have been isolated from the stem bark of Garcinia lancilimba (Guttiferae), together with six known xanthones. Their structures were identified on the basis of extensive spectral evidence including detailed 2D NMR and HR-MS data. Two new compounds showed moderate inhibitory effect on human breast cancer MDA-MB-435S cell line.

Anti-inflammatory and antioxidant activities of phenolic compounds from Desmodium caudatum leaves and stems

Abstract: Four flavanonols (1–4), one xanthone (5), and three flavonoid glycosides (6–8), were isolated from the leaves and stems of Desmodium caudatum. Their structures were elucidated by comparing spectroscopic data with reported values. The anti-inflammatory activity of the isolated compounds was investigated in lipopolysaccharide (LPS)-stimulated bone marrow-derived dendritic cells. Among them, compounds 1 and 2 exhibited inhibitory effects on LPS-induced IL-6, IL-12 p40, and TNF-α production with IC50 values ranging from 6.0 to 29.4 μM. Compound 5 exhibited 1,1-diphenyl-2-picrylhydrazyl radical and intracellular reactive oxygen species scavenging activity in human HaCaT keratinocytes. These results warrant further studies of the potential anti-inflammatory and antioxidant benefits of compounds from D.caudatum.