#soxhlet

Retama raetam is an important source of biologically active compounds, especially Piperidine and Quinolizidine alkaloids as it has been traditionally used in the treatment of many diseases. Our study aims to evaluate the extraction of alkaloids from different plant organs in different ways and to estimate DPPH free radical scavenging of total alkaloids and ethanolic extract from fruits. Alkaloids of R. raetam from Algerian Sahara was extracted using three different methods. Four parts of this plant were subjected to these extraction methods. The evaluation of the antioxidant activity was measured by using the free radical DPPH test. The highest stock of alkaloids was found in the stems followed by the roots and the lowest content was found in the fruits. Soxhlet extraction was the most efficient method to extract alkaloids from R. raetam. The extracts showed very interesting antioxidant activity. The percentages of DPPH inhibition are IC50= 0.087mg/ml and 0.097mg/ml respectively. Stem part of R. raetam was found to be the richer part in alkaloids. Fruit extract exhibited very interesting antioxidant activity

Ridomil® (Metalaxyl 4% + Mancozeb 64%) is one of the most extensively used fungicide to manage late blight globally. The overuse of the chemical has recently raised human health and environmental concerns. The objective of the study was to determine the effect of Ridomil® application regime on yield and Metalaxyl residue in potato tubers. A field experiment was conducted where Ridomil® was applied at 7, 14 and 21 day spray intervals using manufacturer’s recomended dosage of 2.5g L-1. Fresh tuber samples were also randomly collected from Limuru and Wakulima markets in Kiambu and Nairobi counties respectively. Data on disease severity (RAUDPC), incidence and yield were collected and analyzed using SAS software. Assay of metalaxyl residue was extracted using Soxhlet method and quantified by Gas Chromatography Mass Spectrometer. Higher tuber yield and lower disease score were obtained in plots sprayed at 7 day interval compared to unprotected plots. Samples collected from Limuru market and plots sprayed at 7 and 14 day spray interval had 0.09, 1.69 and 0.08 mgkg-1 respectively. Metalaxyl residues observed in samples from Wakulima market and plots sprayed at 21 day spray interval were below the limit of detection. The results indicate that potato consumed in most parts of Kenya could be unsafe following the application of Ridomil® at weekly or biweekly spray intervals.)