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PubMedDate not supplied

Antineoplastic agents from higher plants: application of tandem mass spectrometry to xanthones from Psorospermum febrifugum.

Psorospermum febrifugum was examined using tandem ms for the presence of 3',4'-deoxypsorospermin-4'-chloro-3'-ol and psorospermin. Collision-induced dissociation at both high and low energy is used to bring about fragmentation. Daughter spectra were interpreted to reveal characteristic fragmentations for both compounds. Examination of the authentic compounds, various extracts of the plant root, and the plant root material itself established that psorospermin occurs naturally in the plant. The data also suggest the presence of the chlorohydrin in the root, as well as establishing its presence in the root extracts. The detection of neutral compounds in complex mixtures by tandem ms is facilitated if comparisons can be made between spectra resulting from different methods of ionization and excitation.

Antineoplastic Agents, Phytogenic↗
PubMed2000

New prenylated anthraquinones and xanthones from Vismia guineensis.

From the roots of Vismia guineensis 23 structurally related compounds were isolated and identified. Ten of them are new constituents, namely 3-O-(2-hydroxy-3-methylbut-3-enyl)-emodin (1); 3-O-(2-methoxy-3-methylbut-3-enyl)-emodin (2); 1, 8-dihydroxy-3-(2-methoxy-3-methylbut-3-enyloxy)-6-methylx anthone (3); 1,8-dihydroxy-3-geranyloxy-6-methylxanthone (4); 1, 8-dihydroxy-3-isoprenyloxy-6-methylxanthone (5); 1,8-dihydroxy-3-(3, 7-dimethyl-7-methoxyoct-2-enyloxy)-6-methylxanthone (6); 3-O-(E-3-hydroxymethylbut-2-enyl)-emodin (7); 3-O-(3-hydroxymethyl-4-hydroxybut-2-enyl)-emodin (8); 1, 8-dihydroxy-3-(E-3-hydroxymethylbut-2-enyloxy)-6-methylxa nthone (9); and 1, 8-dihydroxy-3-(3-hydroxymethyl-4-hydroxybut-2-enyloxy)-6- methylxantho ne (10). Their structures were established by means of EIMS and a combination of homonuclear and heteronuclear 2D NMR techniques. Furthermore, an in vitro preliminary screening of antimitotic activity of all the isolated compounds was also evaluated.

Anthraquinones↗
PubMed2005

Cytotoxicities of xanthones and cinnamate esters from Hypericum hookerianum.

5-Hydroxy-2-methoxyxanthone (1), 2-hydroxy-3-methoxyxanthone (2), trans-kielcorin (3), 4-hydroxy-3-methoxyphenyl ferulate (4) and 3beta-O-caffeoylbetulinic acid (5) were isolated from Hypericum hookerianum. Compounds 1-5 were tested against the growth of three human tumor cell lines, MCF-7, NCI-H460 and SF-268. Compounds 4 and 5 exhibited significant inhibitory activity effects against all three; GI50 values for 4 were 15.1 +/- 1.6, 18.7 +/- 2.3 and 15.9 +/- 2.7 and for 5 12.2 +/- 2.4, 19.6 +/- 2.3 and 24.3 +/- 2.5. Compound 3 was less active with GI50 values of 55.1 +/- 2.3, 49.7 +/- 3.0 and 40.5 +/- 1.5, while 1 and 2 exhibited only weak effects. Compounds 4 and 5 were moderately effective in influencing the mitogenic response to human lymphocytes to hemoagglutinin, with IC values of 26.1 +/- 3.6 and 40.8 +/- 4.9, respectively.

Antineoplastic Agents, Phytogenic↗
PubMed2006

Benzopyrans, biphenyls and xanthones from the root of Garcinia linii and their activity against Mycobacterium tuberculosis.

A new benzopyran, (S)-3-hydroxygarcibenzopyran, and three new biphenyls, garcibiphenyl C, garcibiphenyl D, garcibiphenyl E, together with thirteen known compounds have been additionally isolated from the root of Garcinia linii. The structures of these new compounds were determined through spectral analyses. Among the isolates, 1,7-dihydroxy-3-methoxyxanthone and 1,5-dihydroxy-3-methoxyxanthone showed antitubercular activities with MICs of 3.1 +/- 0.5 and 6.3 +/- 1.0 microg/mL against Mycobacterium tuberculosis 90-221,387 in vitro, respectively.

Anti-Bacterial Agents↗
PubMed2001

Antidiabetic activity of a xanthone compound, mangiferin.

Mangiferin (MF) isolated from Anemarrhena asphodeloides Bunge rhizome, was tested for antidiabetic activity in KK-Ay mice, an animal model of type-2 diabetes. MF lowered the blood glucose level of KK-Ay mice 3 weeks after oral administration (p < 0.01). However, no effect on the blood glucose level in normal mice was seen, indicating that MF could be useful in treating type-2 diabetes. In addition, MF improved hyperinsulinemia and, on insulin tolerance test, reduced blood glucose levels of KK-Ay mice. From these findings, it seems likely that MF exerts its antidiabetic activity by decreasing insulin resistance.

Administration, Oral↗
PubMed2006

Cytoprotective effects of 5 benzophenones and a xanthone from Hypericum annulatum in models of epirubicin-induced cytotoxicity: SAR-analysis and mechanistic investigations.

A new benzophenone O-glucoside neoannulatophenonoside (1) together with the known pinocembrin-7-O-glucoside were isolated from the aerial parts of Hyperium annulatum Moris (Guttiferae). The former was identified as 3',5',6-trihydroxy-4-methoxybenzophenone-2-O-beta-D-glucopyranoside by means of chemical and physical evidence. The cytoprotective effects of the new compound together with the previously isolated from this species hypericophenonoside (2), annulatophenone (3), annulatophenonoside (4), acetylannulatophenonoside (5) and 1,3,7-trihydroxyxanthone (6) were evaluated in a model of epirubicin-induced cellular toxicity in K-562 cells. While the benzophenone O-glycosides 1, 2, 4 and 5 exerted substantial cytoprotective effects against the epirubicin cytotoxicity in K-562 cells the aglycones 3 and 6 lacked any significant cytoprotective activity. Biochemical investigations aimed at evaluating the free-radical scavenging activity of the tested compounds as well as their effects on the cellular glutathione stores were carried out as well, aiming at unravelling the mechanisms of cytoprotection. Finally, the ability of 1, 4 and 5 to ameliorate epirubicin-induced anticlonogenic effects on bone marrow cells colony forming units, in vitro were also evaluated. Taken together, the experimental data indicate that the benzophenone glycosides isolated from H. annulatum have a substantial cytoprotective potential against the toxic effects induced by epirubicin and necessitates further detailed pharmacological evaluation of these compounds as possible chemoprotective/radioprotective agents.

Animals↗
PubMed1998

[Mechanism of Canscora lucidissima xanthones against arrhythmia induced by myocardial ischemia-reperfusion in rats].

OBJECTIVE: To study the protective effect of 1,8-dihydroxy-3,5- dimethoxyxanthone (Xan-I) 1-hydroxy-5-dimethoxyxanthone(Xam-II) and 1-hydroxy-3,7,8-trimethoxyanthone (Xan-III) on arrhythmia induced by myocardial ischemia-reperfusion injury and their mechanism. METHOD: A rat model was used. The experimental result shows that. RESULT: An intravenous injection of Xan-I, Xan-II and Xan-III 1 mg/kg given 3 min before left coronary artery ligation reduces significantly the incidence of ventricular arrhythmia and its duration, diminishes the release of glutamic oxaloacetic transaminase and lactate dehydrogenase, elevates the activity of superoxide dismutase and reduces the amount of malondialdehyde. The potency of the above effect among 3 Xans is Xan-I > Xan-III > Xan-II. CONCLUSION: It follows that the protective effect of Xans on myocardial ischemia reperfusion induced by arrhythmia might be associated with the reduction of myocardial lipid peroxidation and the enhancement of SOD activity, and the amount and site of-OH(hydroxy) and -OCH3 (methoxy) on the benzenoid structure may be related to the affinity of Xan.

Animals↗
PubMed2004

The influence of some aminoalkanolic xanthone derivatives on central nervous and cardiovascular systems in rodents.

A series of appropriate aminoalkanolic derivatives 2- or 4-methylxanthone was synthesized and evaluated for anticonvulsant activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole seizure threshold (scPtz) assays, and for neurotoxicity (TOX). The most interesting result was the anticonvulsant activity of (R,S)-2N-(6-chloro-2-xanthonemethyl-2N-methylamino-1-propanol hydrochloride (II, which displayed anti-MES and anti-scPtz activity. Some of the obtained compounds (I - IV and V - VII) were also tested for their effect on the circulatory system (the effect on normal electrocardiogram, protection against adrenaline-, barium-, calcium- and/or strophanthine-induced arrhythmias, the effect on the arterial blood pressure and respiratory movements) and acute toxicity.

Animals↗
PubMed1982

Antiallergic action of disodium cromoglycate and xanthone RS 7540.

Disodium cromoglycate (DSCG) and RS 7540 both inhibited the rat PCA reaction mediated by mouse IgE; RS 7540 was more potent. RS 7540 showed self- and cross-tachyphylaxis with DSCG and failed to protect rat mast cells against desensitization induced by antigen. In the guinea pig ileum test, DSCG reduced stimulation by various spasmogens, whereas RS 7540 even at high doses was inactive. These differences suggest that RS 7540 has major deficiencies as a potential alternative to DSCG in the treatment of bronchial asthma.

Animals↗