Digalloyl Glycoside: A Potential Inhibitor of Trypanosomal PFK from Euphorbia abyssinica J.F. Gmel

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 (IC50 22.09 ± 0.7 µM and 29.96 ± 0.44 µM, respectively) and hyaluronidase enzymes (IC50 49.30 ± 1.57 µM and 62.58 ± 0.92, respectively) that remarkably exceeds the activity of the standard drugs kojic acid (IC50 = 65.21 ± 0.47 µM) and luteolin, (IC50 = 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.

Development of certain aminoquinazoline scaffolds as potential multitarget anticancer agents with apoptotic and anti-proliferative effects: Design, synthesis and biological evaluation

Newly designed 4 - aminoquinazoline derivatives (5a-f, 6a, b, 7, 8, 9, 10a-c, 11a, b, 12a, b and 13a, b) have been synthesized and evaluated for their potential multitarget anticancer activities, apoptotic and anti-proliferative effects. Thereupon, in vitro cytotoxic activities of all the synthesized compounds were screened against NCI 60 human cancer cell lines (nine subpanels) at NCI, USA. Successfully, 2-morpholino-N-(quinazolin-4-yl) acetohydrazide 5e was granted an NSC code, owing to its significant potency and broad spectrum of activity against various cancer cell lines; leukemia K-562, non-small cell lung cancer NCI-H522 cells, colon cancer SW-620, melanoma LOX IMVI, MALME-3M, renal cancer RXF 393, ACHN and breast cancer MDA-MB231/ATCC (GI% = 99.6, 161, 126.03, 90.22, 174.47, 139.7, 191 and 97, respectively). Compound 5e showed the best inhibitory activity (GI₅₀ = 1.3 µM) against melanoma LOX IMVI, when tested at five doses against NCI 60 cell lines. Furthermore, compound 5e showed comparable EGFR and CDK2 inhibitory activity results (IC₅₀ = 0.093 ± 0.006 μM and 0.143 ± 0.008 μM, respectively) to those of lapatinib and ribociclib (IC₅₀ = 0.03 ± 0.002 μM and 0.067 ± 0.004 μM, respectively). Western blotting analysis of compound 5e against melanoma LOX IMVI marked out significant reduced EGFR and CDK2 protein expression percentages, up to 32.97% and 34.09%, respectively, if compared to lapatinib (31.18%) and ribociclib (29.66%). Moreover, compound 5e caused clear cell cycle arrests at S phase of renal UO-31 cells and at G1 phase of both breast cancer MCF7 and ovarian cancer IGROV1, associated with remarkable increase of DNA content of the controls. In accordance, it demonstrated promising anti- proliferative and apoptotic activities, showing a significant increase in total apoptotic percentages of renal cancer UO-31, breast cancer MCF7 and ovarian IGROV1 cancer cell lines, if compared to the control untreated cells (from 1.79% to 46.72%, 2.19% to 39.02% and 1.66 to 42.51%, respectively). Molecular modelling and dynamic simulation study results supported the main objectives of the present work.

Euphocactoside, a New Megastigmane Glycoside from Euphorbia cactus Growing in Saudi Arabia

A phytochemical investigation of the aerial parts of Euphorbia cactus Ehrenb. ex Boiss. revealed a new megastigmane, euphocactoside (5), along with eleven known metabolites. Euphocactoside (5) is the 3-O-glucoside derivative of a polyhydroxylated megastigmane showing unprecedented structural features. The structure of euphocactoside, including stereochemical details, was elucidated by extensive spectroscopic analysis based on 1D and 2D nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HR-ESIMS). The isolated compounds were evaluated for their cytotoxic activity against three different human cancer cell lines, namely, A549 (lung), LoVo (colon), and MCF-7 (breast), using MTT assay, and moderate to marginal activities were observed for compounds 1-3, 8 and 9 against all three cell lines.