Shimekit Tadele (PI), Applied Biology Program and Solomon Girmay

Abstract

Vegetable soybean (Glycine max) is well established legume in the human diet in all overthe world. D-Pinitol is a natural product belonging to groups of Cyclitols. D-pinitol playstremendous medicinal roles. The aim of this work is to quantify the bioactive constituentD-Pinitol from seeds, seed pods and leaves of soybean. D-Pinitol extraction of soybeanwas processed with methanolic extraction followed by quantification using a UVspectrophotometer in comparisons with the Caro pinitol®. The maximum wavlength andabsorbance of the standard dissolved in laboratory reagent water were 193 nm and 0.904respectively. The best-fit line, R2, was found to be greater than 0.9983, indicating the Dpinitol’sconcentration has significant effect on D-pinitol’s absorbance over aconcentration range of 31.25 – 1000.0 μg/mL. The mean recovery of the method was 94.3± 8.06 %. The absorbance of the serially diluted standard of 31.25μg/nL, 62.5μg/mL,125μg/mL, 250μg/mL, 500μg/L and 1000μg/mL at 193 nm is 0.032, 0.042, 0.096, 0.205,0.375, and 0.714, respectively. The absorbance of the samples Nyala seed (so), Nyalaseed (mz), Nova seed (so), Nova seed (mz), Nyala seed pod (so), Nova seed pod (so),Nyala leaf (so) and Nova leaf (so) at 193nm were 0.237, 0.267, 0.307, 0.204, 0.213,0.276, 0.24 and 0.263, respectively. The quantity (gm) of D-pinitol within 25gm crudeextract of Nyala seed (so), nyala seed (mz), nova seed (so), nova seed (mz), nyala seedpod (so), nova seed pod (so), nyala leaf (so) and nova leaf (so) were 16.2, 18.4, 21.3,13.9, 14.5, 19, 16.5 and 18.1, respectively. The quantitative values of all varieties arecloser to each other and this may be attributed to the similarity between the samplingareas, South Omo and Metekel zone. Generally, the Ethiopian soybean has high D-pinitolcontent. The pairwise comparison using the Student’s t-test shows no significantdifference, p> 0.05, between the content of D-pinitol in seed, seed pod and leaf.