ZINC CHLORIDE CATALYZED SYNTHESIS OF BETA-SITOSTEROL FROM DRIED LEAVES OF ACACIA AURICULIFORMIS

ABSTRACT This study deals with the Zinc chloride-catalyzed synthesis of β-sitosterol from Acacia auriculiformis leaves. The leaves were analyzed by evaluating the effects of temperature and catalyst concentration on product yield, with characterization carried out using Gas Chromatography-Mass Spectrometry (GC-MS). The samples were divided into three groups: A (A1–A5, with 0.5% catalyst loading), B (B1–B2, with 1.0% catalyst loading), and C (C1–C5, with 1.5% catalyst loading), each processed at different temperatures (40°C–90°C). The findings revealed a decrease in dried sample weight with increasing temperature due to moisture loss, with the lowest recorded at 70°C for A3 (1.56 g), 80°C for A4 (1.49 g), 80°C for B2 (1.31 g), and 80°C for C4 (1.21 g), indicating significant thermal decomposition. The β-sitosterol yield was significantly affected by both temperature and catalyst concentration, with GC-MS analysis showing that the highest yield of 21.11% (980.36 mg/g) was obtained in A3 (70°C, 0.5% catalyst loading), followed by 9.56% (469.33 mg/g) in B1 (40°C, 1.0% loading), and 9.11% (441.32 mg/g) in A2 (60°C, 0.5% loading). Conversely, lower β-sitosterol content was observed at higher temperatures and catalyst variations, with C5 (90°C, 1.5% loading) recording the lowest yield of 1.63% (79.82 mg/g), and B2 (80°C, 1.0% loading) showing 2.87% (140.56 mg/g). Other significant yields included C3 (70°C, 1.5% loading) at 5.32% (260.78 mg/g) and A5 (90°C, 0.5% loading) at 3.78% (183.23 mg/g). These variations indicate that moderate temperatures (60–70°C) and a balanced catalyst concentration (0.5%) provide optimal conditions for β-sitosterol synthesis, while excessive heating and high catalyst loadings negatively impact yield. The results highlight the importance of precise reaction optimization to maximize β-sitosterol extraction from Acacia auriculiformis leaves.