Antioxidant and Anti-Aging Phytoconstituents from Faucaria tuberculosa : In Vitro and In Silico Studies.

Research targeting natural cosmeceuticals is now increasing due to the safety and/or limited side effects of natural products that are highly valued in cosmetology. Within a research program exploring botanical sources for valuable skincare antioxidant components, the current study investigated the phytochemical content and the biological potential of Faucaria tuberculosa . Phytochemical investigation of F. tuberculosa extract resulted in purification and characterization of six phytoconstituents, including a new one. The structure of the new constituent was elucidated as (-) catechin-(2→1',4→2')-phloroglucinol ( 4 ). The structural identity of all isolated compounds were confirmed on the basis of extensive physical and spectral (1D, 2D-NMR and HRESIMS) investigations. The ethanolic extract exhibits a rich content of total phenolics (TPC) and total flavonoids (TFC), estimated as 32 ± 0.034 mg GAE/g and 43 ± 0.004 mg RE/g, respectively. In addition, the antioxidant (ABTS and FRAP), antihyaluronidase and antityrosinase activities of all purified phytoconstituents were evaluated. The results noted (-) catechin-(2→1',4→2') phloroglucinol ( 4 ) and phloroglucinol ( 1 ) for their remarkable antioxidant activity, while isorhamnetin 3- O -rutinoside ( 3 ) and 3,5-dihydroxyphenyl β -D-glucopyranoside ( 2 ) achieved the most potent inhibitory activity against tyrosinase (IC 50 22.09 ± 0.7 µM and 29.96 ± 0.44 µM, respectively) and hyaluronidase enzymes (IC 50 49.30 ± 1.57 µM and 62.58 ± 0.92, respectively) that remarkably exceeds the activity of the standard drugs kojic acid (IC 50 = 65.21 ± 0.47 µM) and luteolin, (IC 50 = 116.16 ± 1.69 µM), respectively. A molecular docking study of the two active compounds ( 3 and 2 ) highlighted their high potential to bind to the active sites of the two enzymes involved in the study.