Mehmet Boğa

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.

Antioxidant and anticholinesterase activities of eleven edible plants

Context: Consumers have become more interested in beneficial effects of vegetables, fruits, and tea to protect their health. Objective: The antioxidant potential and anticholinesterase activity of eleven edible plants were investigated. Material and methods: The dichloromethane, ethanol and water extracts prepared from celery [Apium graveolens L. (Umbelliferae)], Jerusalem artichoke [Helianthus tuberosus L. (Compositae)], spinach [Spinacia oleracea L. (Chenopodiaceae)], chard [Beta vulgaris L. var. cicla (Chenopodiaceae)], purslane [Portulaca oleracea L. (Portulacaceae)], ispit, or borage [Trachystemon orientale (L.) G. Don (Boraginaceae)], garden rocket [Eruca sativa Mill. (Brassicaceae)], red cabbage [Brassica oleracea L. var. capitata f. rubra DC. (Cruciferae)], lime flower [Tilia tomentosa Moench (Tiliaceae)], cinnamon [Cinnamomum cassia Presl. (Lauraceae)], and rosehip [Rosa canina L. (Rosaceae)], were tested to determine their antioxidant and anticholinesterase activities by using CUPRAC (cupric reducing antioxidant capacity) and Ellman methods, respectively, for the first time. Results: As a result, the dichloromethane, ethanol and water extracts of cinnamon showed the best antioxidant effect among the extracts of the tested plants. The ethanol extract of cinnamon exhibited 63.02% inhibition against acetylcholinesterase and 85.11% inhibition against butyrylcholinesterase (BChE) at 200 µg/mL concentration while the dichloromethane extract of garden rocket possessed the highest inhibition (91.27%) against BChE among all the tested extracts. Discussion and conclusion: This study indicated that the ethanol extract of cinnamon may be a new potential resource of natural antioxidant and anticholinesterase compounds.

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.

Chemical constituents and biological activities of Cirsium leucopsis, C. sipyleum, and C. eriophorum.

Abstract Two endemic Cirsium species, C. leucopsis DC. and C. sipyleum O. Schwarz, and C. eriophorum (L.) Scop. growing in Turkey were investigated to establish their secondary metabolites, fatty acid compositions, and antioxidant and anticholinesterase potentials. Spectroscopic methods were used to elucidate the structures of thirteen known compounds (p-hydroxy-benzoic acid, vanillic acid, cisepoxyconiferyl alcohol, syringin, balanophonin, 1′-O-methyl-balanophonin, apigenin, kaempferol-3- O-β-D-glucopyranoside, kaempferol-3-O-α-L-rhamnopyranoside, taraxasterol, taraxasterol acetate, β-sitosterol, β-sitosterol-3-O-β-D-glucopyranoside). cis-Epoxyconiferyl alcohol and 1′-O-methylbalanophonin were isolated for the first time from Cirsium species. Palmitic acid (47:1%) was found to be the main fatty acid of C. leucopsis, linoleic acid in both C. sipyleum (42:1%) and C. eriophorum (37:8%). Assays of b-carotene bleaching, scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals, 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium (ABTS) cation radicals, and superoxide anion radicals, as well as cupric reducing antioxidant capacity (CUPRAC) were used to determine the antioxidant activities of the extracts and isolated compounds. Vanillic acid, balanophonin, and kaempferol-3-O-α-L-rhamnopyranoside exhibited strong antioxidant activity. Taraxasterol was a potent inhibitor of acetyl- and butyrylcholinesterase activity, respectively.