Hilal Özbek

β-Hydroxydihydrochalcone and flavonoid glycosides along with triterpene saponin and sesquiterpene from the herbs of Pimpinella rhodantha Boiss.

A new β-hydroxydihydrochalcone glycoside named ziganin (1) and a new acylated flavonol glycoside named isorhamnetin-3-O-α-L-(2″,3″-di-O-trans-coumaroyl)-rhamnopyranoside) (2), along with two known flavonoid glycosides, a β-hydroxydihydrochalcone glycoside, a hydroxybenzoic acid derivative, a trinorguaiane type sesquiterpenoid, a triterpenic saponin and a polyol were isolated from the herbs of Pimpinella rhodantha Boiss. Their structures were elucidated on the basis of spectroscopic analyses including 1D-and 2D-NMR, UV, IR, CD, ESI-MS, APCI-MS, HR-ESI-MS techniques. The isolated compounds were evaluated for their antioxidant capacity through the DPPH free-radical scavenging assay and ferrous ion-chelating power test.

α-Amylase and α-glucosidase inhibitory activities of the herbs of Artemisia dracunculus L. and its active constituents

A new phenylpropanoid named 4-(1′,1′,2′,2′-tetramethylpropyl)-1,2-benzenediol (1) with a known phenylpropanoid: 3-(p-methoxyphenyl)-1,2-propanediol (2), a coumarin: herniarin (3), and a flavonol glycoside: rutin (4) were isolated from the aerial parts of Artemisia dracunculus L. Their structures were elucidated by detailed analyses of 1D and 2D nuclear magnetic resonance, IR, ESI–MS and HR–ESI–MS data. Methanol extract of aerial parts of the plant, different polarity fractions of methanol extract and the isolated compounds from these fractions were evaluated for their alpha amylase and alpha glucosidase inhibitory effects. Phenylpropanoids containing fraction had a significantly higher α-glucosidase inhibitory activity (90.4%) when compared with the standart compound acarbose (26.0%) at 1 mg/mL. However none of the tested extracts or compounds were found to be active on α-amylase inhibition.

Two antigenotoxic chalcone glycosides from Mentha longifolia subsp. longifolia.

Abstract Context: Mentha L. (Labiatae) species (mint) with their flavoring properties have been used in food industries for centuries. Besides they have a great importance in drug development and medicinal applications due to various bioactive compounds of several members of the genus. Objective: The aim of this study was to isolate bioactive compounds with antimutagenic potential by bio-guided fractionation and determine their structures by spectroscopic methods. Materials and methods: The structural elucidation of the isolated compounds was done based on spectroscopic methods, including MALDI-MS, UV, IR, and 2D NMR experiments, and the bio-guided fractionation process was done by using the Ames/Salmonella test system. Henceforth, solely genotoxic and antigenotoxic potential of the new compounds were also confirmed up to 2 µM/plate by using the same test system. Results: Two new chalcone glycosides: (βR)-β,3,2′,6′-tetrahydroxy-4-methoxy-4′-O-rutinosyldihydrochalcone and (βR)-β,4,2′,6′-tetrahydroxy-4′-O-rutinosyldihydrochalcone, were isolated from Mentha longifolia (L.) Hudson subsp. longifolia, together with known six flavonoid glycosides and one phenolic acid: apigenin-7-O-glucoside, luteolin-7-O-glucoside, apigenin-7-O-rutinoside, luteolin-7-O-rutinoside, apigenin-7-O-glucuronide, luteolin-7-O-glucuronide, rosmarinic acid. According to the antimutagenicity results, both new test compounds significantly inhibited the mutagenic activity of 9-aminoacridine in a dose-dependent manner at the tested concentrations from 0.8 to 2 µM/plate. (βR)-β,4,2′,6′-Tetrahydroxy-4′-O-rutinosyldihydrochalcone showed the maximum inhibition rate as 75.94% at 2 µM/plate concentration. Conclusions: This is the first report that two new chalcone glycosides were isolated from Mentha longifolia subsp. longifolia and their antimutagenic potentials by using mutant bacterial tester strains. In conclusion, the two new chalcone glycosides showed a significant antigenotoxic effect on 9-aminoacridine-induced mutagenesis at tested concentrations.

The α-amylase and α-glucosidase inhibitory activities of the dichloromethane extracts and constituents of Ferulago bracteata roots

Abstract Context: Ferulago (Apiaceae) species have been used since ancient times for the treatment of intestinal worms, hemorrhoids, and as a tonic, digestive, aphrodisiac, or sedative, as well as in salads or as a spice due to their special odors. Objectives: This study reports the α-amylase and α-glucosidase inhibitory activities of dichloromethane extract and bioactive compounds isolated from Ferulago bracteata Boiss. & Hausskn. roots. Materials and methods: The isolated compounds obtained from dichloromethane extract of Ferulago bracteata roots through bioassay-guided fractionation and isolation process were evaluated for their in vitro α-amylase and α-glucosidase inhibitory activities at 5000–400 µg/mL concentrations. Compound structures were elucidated by detailed analyses (NMR and MS). Results: A new coumarin, peucedanol-2′-benzoate (1), along with nine known ones, osthole (2), imperatorin (3), bergapten (4), prantschimgin (5), grandivitinol (6), suberosin (7), xanthotoxin (8), felamidin (9), umbelliferone (10), and a sterol mixture consisted of stigmasterol (11), β-sitosterol (12) was isolated from the roots of F. bracteata. Felamidin and suberosin showed significant α-glucosidase inhibitory activity (IC50 0.42 and 0.89 mg/mL, respectively) when compared to the reference standard acarbose (IC50 4.95 mg/mL). However, none of the tested extracts were found to be active on α-amylase inhibition. Discussion and conclusions: The present study demonstrated that among the compounds isolated from CH2Cl2 fraction of F. bracteata roots, coumarins were determined as the main chemical constituents of this fraction. This is the first report on isolation and characterization of the bioactive compounds from root extracts of F. bracteata and on their α-amylase and α-glucosidase inhibitory activities.

In vitro anticholinesterase activity and molecular docking studies of coumarin derivatives isolated from roots of Heptaptera cilicica

The chloroform extract of the roots of Heptaptera cilicica (Boiss. & Bal.) Tutin (Apiaceae) was investigated in terms of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory effects by Ellman method. Afterwards, a new furocoumarin: trichoclin angelate with five known coumarin derivatives: umbelliprenin, badrakemone, badrakemin, badrakemin acetate and prunate were isolated from this extract. Their structures were identified by means of spectroscopic methods (1D, 2D-NMR and HRESIMS). The next step of our study was determining AChE and BuChE inhibitory activities of the compounds by molecular docking and in vitro methods. According to the results, prunate was found to be the most potent compound, which exhibited significant inhibitory potency against acetylcholinesterase (IC50 = 1.76 ± 0.003 µM) and butyrylcholinesterase (IC50 = 0.21 ± 0.002 μM) as compared with the reference compound, galantamine hydrobromide.

Chemical constituents of Lonicera etrusca

0009-3130/12/4804-0693 2012 Springer Science+Business Media, Inc. 6931) Ataturk University, Faculty of Pharmacy, Department of Pharmacognosy, TR-25240, Erzurum, Turkey, e-mail:guvenalp@atauni.edu.tr; 2) Hacettepe University, Faculty of Pharmacy, Department of Pharmacognosy, TR-06100, Ankara,Turkey; 3) Ataturk University, Faculty of Sciences, Department of Chemistry, TR-25240, Erzurum, Turkey. Published in