Comparative analysis of extraction techniques and biological activities of the root of Tribulus terrestris L. grown in Northern Iraq

Abstract

Tribulus terrestris root extracts were used in this study to find the yield percentage, total condensed tannins concentration, anti-microbial and antioxidant activities, as well as to identify and quantify phenolics components. A variety of extraction techniques such as microwave extraction (ME), convection extraction (CE), and accelerated solvent extraction (ASE) were employed, with methanol, ethanol and water used as solvents. The total condensed tannin concentration and antioxidant capacity were evaluated using UV-visible spectroscopy at 580 nm and 517 nm, respectively. Antimicrobial activity was determined by disc diffusion method. The LC-MS/MS was used to identify and quantify phenolic compounds. The ASE technique yielded the highest extraction efficiency (12.06%) when using methanol, while the conventional extraction technique yielded the lowest extraction efficiency (6.60%). The average total condensed tannin concentration in the TT root, measured by triplicate, was 10.83 mg/L. The methanol extract obtained using the ME technique exhibited the largest inhibitory zone (19.33 mm) against Micrococcus luteus LA2971. The ASE technique produced the highest radical scavenging activity (DPPH) with the methanol extract, while the CE technique showed the lowest DPPH scavenging activity in the ethanol extract. The ethanol extract had a greater capacity to scavenge DPPH than BHT. The highest and the lowest amounts of phenolic compounds were identified by using LC-MS/MS as Vanillin (125 µg/g) and chlorogenic acid (1.46 µg/g), respectively. Furthermore, the results demonstrated that hesperidin (10.79 µg/g), and quercetin (0.16 µg/g) had the highest and lowest quantities of flavonoids, respectively.