Solid-state 13C NMR and molecular modeling studies of acetyl aleuritolic acid obtained from Croton cajucara Benth

Antioxidant capacity, antimicrobial activity and triterpenes isolated from Jatropha isabellei Müll Arg

Jatropha isabellei Müll Arg. belongs to the family Euphorbiaceae. The antioxidant capacity of this plant was evaluated by the DPPH method and inhibition of thiobarbituric acid reactive substances (TBARS). Ethyl acetate fraction demonstrated the best antioxidant capacity against the DPPH free radical and its profile was similar to ascorbic acid. This fraction also presented the best results of phenolics, flavonoids and condensed tannins, showing a positive relation between the phenolic content and antioxidant activity. All fractions and the crude extract were able to inhibit significantly the TBARS production induced by Fe(II) for the two tested concentrations, reaching the basal levels. In this test, ethyl acetate and dichloromethane fraction showed good values for inhibitory concentration. The dichloromethane fraction showed the best results against the fungi Sporothrix schenckii and Fusarium proliferatum and the bacterium of Micrococcus genus. This fraction allowed the isolation of acetil aleuritolic acid and a mixture of sitosterol 3-O-β-D-glucoside and stigmasterol, described for the first time in this species.

Anti-inflammatory diterpene from Thyrsanthera suborbicularis

Bioactivity-guided isolation on a n-hexane-soluble fraction of Thyrsanthera suborbicularis led to the isolation of a new rosane-type diterpene, 19-hydroxy-1(10), 15-rosadiene (1), along with three known compounds, taraxerol, acetyl aleuritolic acid, and spathulenol. The structures of isolated compounds were determined by interpretation of NMR spectroscopic data and mass spectrometry. Compound 1 demonstrated significantly inhibitory activity on nitric oxide production in RAW264.7 lipopolysaccharide (LPS)-activated mouse macrophages with an IC(50) value of 2.91 µg/ml via the suppression of inducible nitric oxide synthase (iNOS) mRNA expression.

Involvement of glutathione, sulfhydryl compounds, nitric oxide, vasoactive intestinal peptide, and heat-shock protein-70 in the gastroprotective mechanism of Croton cajucara Benth. (Euphorbiaceae) essential oil

This study aimed to evaluate the gastroprotective mechanism of action of the essential oil of Croton cajucara Benth. (Euphorbiaceae) stem bark in ethanol-induced gastric ulcers and its in vitro anti-Helicobacter pylori activity. The involvement of heat-shock protein-70, vasoactive intestinal peptide, glutathione, nitric oxide, and nonprotein sulfhydryl compounds in the gastroprotective effect was determined in male Wistar rats. The minimum inhibitory concentration against H. pylori was determined in vitro. The results were analyzed by analysis of variance followed by the Dunnett test, and a P value less than 0.05 was considered to represent a statistically significant difference. C. cajucara decreased ethanol-induced ulcer area in 100% of ulcers and decreased the histologic lesions. In the C. cajucara group, the area marked by heat-shock protein-70 was significantly higher than the area in the control group; this finding was not seen for vasoactive intestinal peptide. C. cajucara could not maintain glutathione levels close to those in the sham group. The gastric ulcer area of rats treated with the sulfhydryl compound blocker was decreased, but the ulcer area of rats treated with nitric oxide synthase inhibitor showed no alteration. The minimum inhibitory concentration obtained for C. cajucara was 125 μg/mL. These findings suggest that sulfhydryl compounds and heat-shock protein-70, but not nitric oxide, glutathione, or vasoactive intestinal peptide, are involved in the C. cajucara gastroprotective effect against ethanol-induced gastric ulcers.