Four new chromenones, kielmeyerones A−D (1− 4), were obtained from the roots of Kielmeyera reticulata. Their structures were elucidated based on spectroscopic data (NMR and HRESIMS) interpretation. The pharmacological activity of kielmeyerone A (1), the major compound, was evaluated using in vitro and in vivo inflammation and pain models. During in vitro screening, 1, at noncytotoxic concentrations (0.097−1.56 μM), inhibited NO production by J774 macrophages stimulated with LPS and IFN-γ. In the complete Freund's adjuvant-induced inflammation model in mice, 1 (12.5−50 mg/kg) inhibited paw edema, demonstrating an anti-inflammatory effect. Additionally, 1 (12.5−50 mg/kg) induced a dose-dependent antinociceptive effect in the late phase of the formalin test, a profile similar to those of nonsteroidal anti-inflammatory drugs. Mice treated with 1 (100 mg/kg) did not show motor performance alterations using a rotarod test. Thus, the present study has characterized new chromenones from Kielmeyera reticulata and has provided evidence of the anti-inflammatory and antinociceptive properties of one of these, kielmeyerone A (1).
The objective of this study was to evaluate the physicochemical changes in crude palm oil during a real case of deep-frying of akara, cowpea-paste balls, fried and sold in the streets of Brazil. Discontinuous frying over five consecutive days, using 5-h frying a day, was performed according to traditional practices. The formation of polar compounds was evaluated by the IUPAC official method and by quick tests based on measures of physical properties, Testo 270 and Fri-check. In addition, 1H-NMR spectroscopy was applied to evaluate physicochemical changes. The results showed that after 15-h frying the total content of polar compounds (TPC) exceeded the limit of 25% established in most of the recommendations and regulations on heated oils. Such a level was reached quickly due to the high content of hydrolytic compounds present in the fresh oil and to the inappropriate use of blends of fresh and used oil in the oil replenishment. The two quick tests presented significantly lower values for TPC than the official method, probably due to the elevated hydrolysis of the fresh oil. In contrast, 1H-NMR results exhibited changes in the fatty acid composition which were similar to those provided by the common GC analysis. The use of crude palm oils of better initial quality and replenishment with fresh oil only are recommended to improve the quality of the oil absorbed by akara.
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