Determination of short-chain fatty acids in dietary fiber extracts using ion-exclusion chromatography with suppressed conductivity detection.

A new chromatographic method for the sequential determination of short-chain fatty acids is described. Acetic, propionic and butyric acids were determined in dietary fiber extracts using ion-exclusion chromatography equipped with inverse chemical suppression and conductivity detection. The best optimization of the chromatographic conditions were achieved when a 100 mm x 7.8 mm ion-exclusion column with a solution of 0.5 mmol L(-1) sulfuric acid as eluent in a flow rate of 0.6 mL min(-1) were employed. The organic acids were sequentially separated in less than 10 min with limits of detection ranging from 1 up to 7.5 micromol L(-1) and limits of quantification from 5 up to 25 micromol L(-1). The linearity of the analytical response was studied in the range of 0.005-10 mmol L(-1) for acetic acid and 0.025-10 mmol L(-1) for propionic and butyric acids with coefficients of determination (R(2)) ranging between 0.9985 and 0.9999. The method was tested and proved to be selective, precise, accurate, reproducible and highly sensitive. Finally, the method was applied in the analysis of biological samples.

Safflower oil: an integrated assessment of phytochemistry, antiulcerogenic activity, and rodent and environmental toxicity

Gastric ulcers are a significant medical problem and the development of complications lead to significant mortality rates worldwide. In Brazil, Carthamus tinctorius L., Asteraceae, seeds essential oil, the safflower oil, is currently used as a thermogenic compound and as treatment for problems related to the cardiovascular system. In this study, by Raman spectroscopy, it was shown that oleic and linoleic acids are the compounds present in higher concentrations in the safflower oil. We demonstrated that safflower oil (750 mg/kg, p.o.) decrease the ulcerogenic lesions in mice after the administration of hydrochloric acid-ethanol. The gastric ulcers induced by non-steroidal anti-inflammatory drug (NSAID) in mice treated with cholinomimetics were treated with four different doses of safflower oil, of which, the dose of 187.5 mg/kg (p.o.) showed significant antiulcerogenic properties (**p < 0.01). Moreover, the safflower oil at doses of 187.5 mg/kg (i.d.) increased the pH levels, gastric volume (**p < 0.01) and gastric mucus production (***p < 0.001), and decreased the total gastric acid secretion (***p < 0.001). The acute toxicity tests showed that safflower oil (5.000 mg/kg, p.o.) had no effect on mortality or any other physiological parameter. Ecotoxicological tests performed using Daphnia similis showed an EC50 at 223.17 mg/l, and therefore safflower oil can be considered “non-toxic” based on the directive 93/67/EEC on risk assessment for new notified substances by European legislation. These results indicate that the antiulcer activity of Safflower oil may be due to cytoprotective effects, which serve as support for new scientific studies related to this pathology.

Application of liquid chromatography/electrospray ionization tandem mass spectrometry to the analysis of polyphenolic compounds from an infusion of Byrsonima crassa Niedenzu.

A fast and reliable method, based on high-performance liquid chromatography coupled to electrospray ionization ion trap tandem mass spectrometry (HPLC/ESI-ITMS), was developed to investigate the infusion prepared from the leaves of Byrsonima crassa Niedenzu (Malpighiaceae), a native plant used in Brazil against gastric disorders. The use of on-line reverse-phase HPLC/ESI-ITMS allowed separation of three major classes of compounds and identification of over 20 very polar compounds characterized as galloylquinic acids, proanthocyanidins, and flavonoid glycosides, as well as the dimeric flavonoid amentoflavone and minor amounts of galloyl hexose and galloyl saccharose. This approach provided data that will allow establishment of a method for a future standardization of the infusion.

Ethnopharmacology and the sustainable development of new plant-derived drugs

This paper presents a reflection based on the experience generated by fifteen years of studies on pharmacology and chemistry of medicinal plants, in a underdeveloped country, Brazil. Although the diversity of the Brazilian flora presents a remarkable opportunity towards the development of new medicinal products, there are only small natural products research groups. Strategies for pharmacological and chemical studies of medicinal plants investigated during this time, major difficulties and ways to bypass them are discussed. The ethnopharmacological approach adopted as a general method by our research team has given good results. Details of our experience in the way to develop new plant durgs are reviewed and updated.