Abstract

This study estimated the fatty acid, proximate and quantitative phytochemical compositions of Costus afer matured stem collected from Choba campus of University of Port Harcourt, in Choba community, Rivers State. This was carried out using standard procedures of analysis (fatty acid and proximate) as well as gas chromatographic method (quantitative phytochemical analysis). The fatty acid analysis of the plant stem revealed high contents of linolenic acid (32.26%), linoleic acid (25.89%) and palmitic acid (25.48%) and moderate levels of oleic acid (7.11%) and stearic acid (6.36%) while myristic acid, palmitoleic acid, arachidonic acid, behenic acid and lignoceric acid was low and caprylic acid, capric acid, lauric acid, margaric acid, arachidonic acid, erucic acid were absent. The results of the proximate composition of the stem of Costus afer indicated that total carbohydrate composition of Costus afer stem was the highest (54.98%) while crude fat had the lowest value of 1.15%. The moisture content had a moderate value of 22.15% while total ash (4.60%), crude protein (7.72%) and crude fibre (9.40%) values were low. The gas chromatographic analysis of the stem indicated that the total alkaloid composition was 70.59mg/100g with high compositions of papaverine (44.72%), methyl morphine (23.24%), morphine (17.92%) and narcotine (14.11%). The total flavonoids concentration was 28.29mg/100g. Myricetin (69.79%) had the highest value with moderate levels of quercetin (14.88%) and kaempferol (9.78%). The total composition of saponin was 2.87mg/100g. The sapogenin content of the stem (39.20%) was the highest with moderate levels of diosgenin (26.13%), saponine (22.12%) and tigonine (9.76%) while gitogenin value (2.28%) was observed to be low. The analysis of the plant stem showed the presence of glycosides (22.35mg/100mg) made up mainly of costugenin (65.60%), digitoxin (18.73%), digoxin (6.28%), salicin (4.76%) and low levels of ouabain (1.95%) and kaemferol-3-rhamnoside (1.08%). The study has shown that matured stems of Costus afer can contribute greatly towards meeting human nutritional requirements and suggest the possibility of its use in folklore medicine.

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