Isolation, structural characterization and molecular docking of β-sitosterol from Trewia polycarpa root bark: a potential source of bioactive compounds

Trewia polycarpa, a member of the Euphorbiaceae family, is widely found in South and Southeast Asia, particularly in India, Sri Lanka, Malaysia, Indonesia, and the suburbs areas of Dhaka, Bangladesh. The present study investigated the n-hexane extraction of 137 mg (TPH-F-7), focusing on the isolation and structural characterization of β-sitosterol using chromatographic techniques, FTIR, 1H-NMR, 13C-NMR, and DEPT-135 analyses. The FTIR spectrum revealed absorption peaks at 3444 cm−1 (O-H stretching), 2953 cm−1, 2924 cm−1, 2870.1 cm−1 (aliphatic C-H stretching), 1640 cm−1 (C=C), 1458 cm−1 (CH2 bending), 1377 cm−1 (OH deformation), 1100 cm−1 (cycloalkane), and 797 cm−1. The 1H-NMR spectrum confirmed the presence of functional groups such as hydroxyl (-OH), methyl (-CH3), methylene (-CH2), and methine (-CH) groups, with notable singlets at δ 0.71 and 1.03 ppm and an olefinic proton triplet at δ 5.37 ppm. The 13C-NMR analysis identified 29 carbon atoms, including a hydroxyl-bearing carbon (δ 71.8 ppm), double bonds (δ 140.8 and 121.7 ppm), and methyl carbons (δ 11.86 and 18.78 ppm), with a γ-gauche interaction influencing C18’s chemical shift. DEPT-135 analysis revealed six methyl, eleven methylene, nine methine, and three quaternary carbons. The isolated compound was identified as β-sitosterol based on its structural features, steroidal properties, and melting point (134–136 °C). Furthermore, the notable interaction profile of a compound isolated from T. polycarpa against specific targeted receptors in a molecular docking study significantly substantiated the advancement of potential therapeutics that could be utilized in the treatment of a broad spectrum of health complications, to illustrate, cancer, diabetes, pain, and diarrhea. This study confirms that Trewia polycarpa is a potential source of β-sitosterol, a compound that significantly contributes to the plant’s pharmacological properties, including its anti-inflammatory, antioxidant, and antimicrobial activities, as well as its potential benefits for bone health and regenerative medicine, highlighting its multifaceted therapeutic potential.