PHYTOCHEMICAL SCREENING AND ANTIOXIDANT ACTIVITY OF LEAF EXTRACT PREPARED BY SOXHLET EXTRACTION OF SELECTED MEMBERS OF APOCYNACEAE

The present study aimed to understand, phytochemistry and antioxidant property of five members belonging to Apocynaceae, Catharanthus roseus (L) G. Don; Plumeria alba L.; Pentalinon luteum (L) B. F. Hanson & Wunderlin; Rauvolfia tetraphylla L and Nerium oleander L. The preliminary phytochemical analysis was carried out using the methanolic extract for protein, carbohydrate, alkaloids, phenol, tannin flavonoids, and saponin. They were quantified using spectrophotometer using different standards and methods like the Bradford method using BSA as standard for protein, phenol-sulphuric acid method using glucose as standard for carbohydrates, Folin-Ciocalteau method by Sidduraju and Becker for phenol using catechol as standard, tannins using Folin-Ciocalteu method using tannic acid as standard, Zhishen et al., modified method for flavonoids using quercetin as standard. Total alkaloids were estimated using the dry weight method. Antioxidant properties were studied using the ability of the Soxhlet extracts of the plant samples to scavenge the DPPH radicals using Blois method with modifications. The highest concentration for protein was found in Rauvolfia tetraphylla, and the lowest concentration was found in Nerium oleander. The highest concentration of carbohydrate and tannin was found in Catharanthus roseus and the lowest in Nerium oleander. The highest alkaloid, phenol, and flavonoid content were found among in Catharanthus roseus, Plumeria alba and the lowest in Nerium oleander. Nerium oleander exhibited the highest scavenging properties for two of the Soxhlet concentrations out of three (the highest antioxidant activity for 200 µg/mL, 100 µg/mL).