Abdulselam Ertaş

Antioxidant and anticholinesterase activity evaluation of ent-kaurane diterpenoids from Sideritis arguta.

The petroleum ether and acetone extracts of the aerial parts of Sideritis arguta afforded two new and six known diterpenoids with the ent-kaurane skeleton. The structures of the new diterpenoids were determined as ent-7alpha,18-diacetoxy-16beta-hydroxykaurane (diacetyldistanol) (1) and ent-7alpha-acetoxy,15alpha,18-dihydroxykaur-16-ene (15-epi-eubol) (2) by spectroscopic data interpretation. Antioxidant potential was investigated for the ent-kauranes and the plant extracts by three methods (beta-carotene bleaching, free-radical scavenging, and superoxide-anion scavenging activity). Acetylcholinesterase and butyrylcholinesterase inhibitory activity were also evaluated, and the ent-kauranes eubol (3), sideroxol (5), and 7-epi-candicandiol (6) exhibited moderate butyrylcholinesterase inhibitory activity.

Chemical Compositions by Using LC-MS/MS and GC-MS and Biological Activities of Sedum sediforme (Jacq.) Pau

In this research, the chemical composition and biological activities of various extracts obtained from whole parts of Sedum sediforme (Jacq.) Pau were compared. The amounts of total phenolic and flavonoid components in crude extracts were determined by expression as pyrocatechol and quercetin equivalents, respectively. All of the extracts (petroleum ether, acetone, methanol, and water) obtained from S. sediforme showed strong antioxidant activity in four tested methods. Particularly, the IC50 values of the methanol extract, which was the richest in terms of total phenolic and flavonoid contents, were found to be lower than those of α-tocopherol and BHT in β-carotene bleaching (9.78 ± 0.06 μg/mL), DPPH free radical scavenging (9.07 ± 0.07 μg/mL), and ABTS cation radical scavenging (5.87 ± 0.03 μg/mL) methods. Furthermore, the methanol extract of S. sediforme showed higher inhibition activity than galanthamine against acetyl- and butyryl-cholinesterase enzymes. Also, acetone and methanol extracts exhibited moderate antimicrobial activity against Candida albicans. The main constituents of fatty acid and essential oil were identified as palmitic acid (C16:0) (28.8%) and α-selinene (20.4%), respectively, by GC-MS. In the methanol extract of S. sediforme, quercetin, rutin, naringenin, and protocatechuic, p-coumaric, caffeic, and chlorogenic acids were detected and quantified by LC-MS/MS. Results of the current study showed that the methanol extract of S. sediforme may also be used as a food supplement.

Complete 13C NMR assignments for ent-kaurane diterpenoids from Sideritis species

In this work, the detailed NMR studies and full 13C NMR assignments for five diterpenoids isolated from Sideritis caesarea and Sideritis athoa are described. The assignments are based on a combination of 1D and 2D NMR techniques including 1H, 13C, 1H1H COSY, gHSQC [1J(C,H)] and gHMBCδC [nJ(C,H) (n = 2 and 3)] and NOESY experiments. Copyright

Elucidation of Phosphodiesterase-1 Inhibitory Effect of Some Selected Natural Polyphenolics Using In Vitro and In Silico Methods

BACKGROUND Polyphenols are organic compounds widely found in plants and possess many diverse biological activities. In the current study, eleven polyphenolic compounds [rutin (1), trans-ferulic acid (2), epigallaocatechin gallate (3), fumaric acid (4), chlorogenic acid (5), gallic acid (6), trans-resveratrol (7), propyl gallate (8), (+)-catechin (9), quercetin (10), and kaempferol-3-O-β-D-galactoside (11)] have been evaluated for their in vitro inhibitory activity against phosphodiesterase- 1 (PDE-1). The active compounds 1, 5, 6, and 7 possessed IC50 values of 173.90 ± 2.58, 36.67 ± 1.60, 325.19 ± 3.62, and 323.81 ± 4.25 μM, respectively. In silico experiments were performed to elucidate the binding patterns of inhibitor molecules with the active sites of the enzymes. RESULT Molecular docking studies have shown that compounds 1 and 5 have better docking results than standard inhibitor (EDTA) against the PDE-1. In conclusion, chlorogenic acid, rutin, gallic acid, and resveratrol could be promising PDE-1 inhibitors and leads to identify new drug candidates against PDE-1-associated disorders.