Records of Natural Products Articles

A new aliphatic acid named japodic acid (1) with a gem-dimethyl cyclopropane ring has been isolated from the roots of Jatropha podagrica. Its structure was established by 1D and 2D NMR and mass spectrometric data. Two other known compounds, erythrinasinate (2) and fraxidin (3) were also isolated from this plant for the first time. Japodic acid showed mild insect growth inhibition activity against Helicoverpa zea (37% growth reduction at 100 ppm). Fraxidin and erythrinasinate exhibited antibacterial activity against Bacillus subtilis while japodic acid was inactive in the antibacterial assays conducted.

A simple, precise and accurate high-performance thin-layer chromatographic method has been established for quantitative determination of quinine. Conditions were also optimized for best possible extraction of quinine via varying concentrations of diethyl amine in different solvents (n-hexane, chloroform, ethyl acetate and methanol) for maximum recovery of quinine. Methanol modified with 20 % DEA found to be best for highest possible recovery of target analyte quinine. Chromatographic separation of quinine was performed on silica gel 60 F 254 HPTLC plates with ethyl acetate : diethyl amine in the proportion 88 : 12 (v/v), as mobile phase. The determination was carried out using the densitometric absorbance mode at 236 nm. Quinine response was found to be linear over the range 4–24 μg spot −1. The HPTLC method was evaluated in terms of specificity, precision, reproducibility, LOD – LOQ and robustness. Beside these parameters, number of theoretical plates and flow constant were also included as a part of validation.

The antimicrobial activity of the extracts and pure compounds from the sponge Axinella infundibuliformis collected Mombasa , the Kenyan Coast have been reported. The pure compounds were purified and characterized through various chromatographic and spectroscopic techniques. Three triterpenoid compounds were isolated and identified from Axinella infundibuliformis. These were 3β-Hydroxylup-20(29)-ene (1), 3β-Hydroxylup-20(29)-en-28-oic acid (2) and 3-Oxo-lup-20(29)-en-28-oic acid (3). The hexane, dichloromethane and methanol crude extracts (10 mg/ml) of Axinella infundibuliformis showed strong antibacterial activity against methicilin resistant Staphylococcus aureus with inhibition zone diameters of 24.7 ± 0.05, 22.0 ± 0.35 and 12.7 ± 0.09 mm respectively. The MIC values for dichloromethane and hexane extracts were then evaluated as at 6.25 mg/mLand 3.12 mg/mLrespectively. The antifungal tests for Axinella infundibuliformis against Candida albicans by all the three extracts showed mild activity with inhibition zone diameters of 6.7 ± 0.02, 6.0 ± 0.04, and 5.7 ± 0.03 mm respectively. In addition, the dichloromethane and hexane extracts exhibited low activities against Microsporum gypseum (6.3 ± 001 mm) and Cryptococcus neoformans (6.3 ± 0.07mm) respectively. Of the three compounds isolated, 3β-Hydroxylup-20(29)-ene (24.0 ± 0.09 mm diameter) exhibited strong activity against Pseudomonas aeruginosa, while 3β-Hydroxylup-20(29)-en-28-oic acid (7.0 ± 0.06 mm diameter) and 3-Oxo-lup-20(29)-en-28-oic acid (10.7 ± 0.08 mm diameter) showed moderate activity against P. aeruginosa. Gentamycin (Standard drug 10 µg/disc) had an inhibition zone diameter of 16.0 ± 0.01 mm.

The aqueous extract from the shoot of Acacia karroo was evaluated for its acute toxicity by the oral route in mice and for the sub acute effect on haematological, biochemical and histological parameters in rats. In the acute toxicity test, A. karroo extract caused death in animals that received 1600 and 3200 mg/kg doses. Oral treatments in rats with this extract at 800 mg/kg did not cause any significant change in the red blood cell count (RBC), packed cell volume (PCV), haemoglobin concentration (HB), mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC), mean corpuscular haemoglobin (MCH), white blood cells and its differentials. It, however, caused a significance decrease in the levels of platelets. In the biochemical parameters, the extract caused a significant decrease in the levels of total protein, albumin, globulin, aspartate amino transferase (AST), alanine amino transferase (ALT), total and unconjugated bilirubin. Changes were also noted in the body weights but no significant changes were observed in the levels of some electrolytes (sodium, potassium and chloride). Clinico-pathologically, starry hair coat, respiratory distress and mortality were recorded. Lung with multiple abscess, kidney and liver with mild congestion were also observed histopathologically. The study concluded that caution must be exercised in the use of the plant for medicinal purposes .

Hepatoprotective activity of Croton zehntneri Pax & Hoffman (Euphorbiaceae) leaf essential oil (EOCz) was evaluated against single dose of acetaminophen-induced (500 mg/kg, p.o.) acute hepatotoxicity in mice. EOCz significantly protected the hepatotoxicity as evident from the activities of serum glutamate pyruvate transaminase (GPT), serum glutamate oxaloacetate transaminase (GOT) activities, that were significantly (p<0.01) elevated in the acetaminophen alone treated animals. Histopathological examinations of liver tissue corroborated well with the biochemical changes. Hepatic steatosis, hydropic degeneration and necrosis were observed in the acetaminophen treated group, while these were completely absent in the standard and EOCz treated groups. In conclusion, these data suggest that the Croton zehntneri essential oil can prevent hepatic injuries from acetaminophen-induced hepatotoxicity in mice.