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Starch isolated from white yam (Dioscorea rotundata) was subjected to hydroxypropylation under different conditions. Corresponding increases were observed between the molar substitution (MS) and the volume of propylene oxide added to the reaction mixture. After hydroxypropylation, a slight reduction in the intensity of the peak at 2y = 19.67 was observed and the doublet peak at 23.87, which was present in native starch, was no longer seen. Hydroxypropylation enhanced the free swelling capacity (FSC) and solubility. Setback and retrogradation of native starch declined after hydroxypropylation. Turbidity of native starch paste and syneresis were higher with storage time. The results also indicate that enzymatic digestibility improved as the MS increased, while the reverse was observed for starch paste turbidity, syneresis, setback and retrogradation. This study presents relevant information that could strategically position D. rotundata starch and its hydroxypropylated derivatives for industrial applications.

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Antimalarial principles of Spathodeu cumpunulafu stem bark extract were isolated and characterized. The antimalarial principles in the stem bark were 3P-hydroxyurs-12-en-28-oic acid (ursolic acid) and two of its derivatives; 3~hydroxyurs-12,19-dien-28-oic acid (tomentosolic acid) and 3~,2O~-dihydroxyurs-12-en-28 oic acid. This is the first report of the isolation of ursolic acid and its derivatives as antimalarial compounds.