Gülderen Yilmaz

Acetylcholinesterase, butyrylcholinesterase, and tyrosinase inhibition studies and antioxidant activities of 33 Scutellaria L. taxa from Turkey

The members of Scutellaria L. (Lamiaceae) is known to be rich particularly in flavonoids and among them, S. baicalensis has been recorded to be used for memory-enhancing purpose. Therefore, we initiated a study to screen the methanol extracts prepared from the aerial parts of 33 Turkish Scutellaria species for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities, which are the key enzymes taking place in pathogenesis of Alzheimers disease. Besides, the methanol extracts were tested in vitro against another enzyme, tyrosinase, which is associated with melanin hyperpigmentation. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenger effect, ferrous ion-chelating ability, and ferric-reducing antioxidant power (FRAP) of the ethyl acetate and methanol extracts were also determined. AChE, BChE, and tyrosinase inhibition of the extracts were performed on ELISA microplate reader by spectrophotometric method. The extracts showed weak inhibition against AChE and BChE, while the best tyrosinase inhibition was caused by the methanol extract of S. brevibracteata subsp. subvelutina. The extracts had a very high DDPH radical scavenging effect and moderate antioxidant activity in ferrous ion-chelating and FRAP tests.

Composition of the Essential Oils of Subspecies of Scutellaria albida L. From Turkey

Abstract The essential oil obtained by hydrodistillation from subspecies of Scutellaria albida L. (Lamiaceae): S. albida L. subsp. albida, S. albida L. subsp. colchica (Rech.f.) J.R.Edm., S. albida L. subsp. condensata (Rech.f.) J.R.Edm., and S. albida L. subsp. velenovskyi (Rech.f.) Greuter et Burdet from Turkey were analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS), simultaneously. Linalool (20% and 29%) was identified as major component in the oils of S. albida subsp. albida and S. albida subsp. condensata oil, respectively. In the oil of S. albida subsp. colchica, hexadecanoic acid (13%) was found as major component. β-Caryophyllene (20%) was the main component of the oil of S. albida subsp. velenovskyi.

Antimicrobiological Studies on Turkish Cistus. Species

ABSTRACT The genus Cistus. L., mainly growing in the Mediterranean region, is represented by five species in Turkey: C. creticus. L., C. laurifolius. L., C. monspeliensis. L., C. parviflorus. Lam., and C. salviifolius. L. In this study, in vitro. antimicrobial activity of water, methanol, chloroform, ethyl acetate, and buthanol extracts, prepared from dried and powdered leaves and the fruits of the five Cistus. species, were investigated by the disk diffusion method against the following microorganisms: Staphylococcus aureus. (ATCC 29213 and ATCC 25923), Streptococcus faecalis. (ATCC 29212), Bacillus subtilis. (ATCC 6633), Bacillus cereus. (RSKK 1122), Pseudomonas aeruginosa. (ATCC 27853), Escherichia coli. (ATCC 25922), and Candida albicans. (ATCC 10231). Chloroform, ethyl acetate, butanol, and the remaining aqueous extracts, obtained from the fractionation of methanol extract, were also tested. All of the extracts showed some activity against B. subtilis. and B. cereus.. Lyophylized extracts showed the highest activity against Staphylococcus aureus. 25923 and 29213. Buthanol extracts of the leaves and fruits of C. creticus. showed the highest activity. Extracts of all Cistus. species did not show any activity against Pseudomonas aeruginosa. and Candida albicans..

Essential oil composition of three species of Scutellaria from Turkey

The chemical compositions of the essential oils obtained by hydrodistillation from the aerial parts of Scutellaria diffusa, Scutellaria heterophylla and Scutellaria salviifolia were separately identified simultaneously by gas chromatography and gas chromatography–mass spectrometry. The main components were determined as hexadecanoic acid (30%) and caryophyllene oxide (9%) in the oil of S. diffusa. Germacrene D (21%), hexadecanoic acid (16%) and β-caryophyllene (13%) were found as major components in the oil of S. heterophylla. The main components of the oil of S. salviifolia were germacrene D (40%), bicyclogermacrene (14%) and β-caryophyllene (11%). Overall, individually 63, 68 and 43 constituents were identified in the aerial parts of S. diffusa, S. heterophylla and S. salviifolia essential oils representing 92.1%, 89.9% and 90% of the total, respectively.

Antiepileptic activity of four selected Skullcap (Scutellaria) species on mice

Epilepsy is a brain disorder which is characterized with spontaneous seizures invoked by neurotransmitter system complex. It is among the most common neurological diseases in the world which affects about 50 million people (1). Although there are surgical interventions and chip implants for the treatment, current chemical treatment relies on prevention of convulsions with antiepileptic drugs. However some of the patients still have convulsions during this drug administration. In addition in almost 20% of the cases, insufficient drug activity, serious side effects and chronic toxicities are reported (2). Therefore search for new molecules continues in this disorder. Plants have various metabolites which are subject of new drug candidates (3). Some plants have potent impact on GABA receptors and voltage-gated ABSTRACT

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.

Composition of the fruit essential oils of four Heptaptera species growing in Turkey

0009-3130/09/4503-0431 ©2009 Springer Science+Business Media, Inc. 1) Ankara University, Faculty of Pharmacy, Department of Pharmaceutical Botany, 06100 Tandogan, Ankara, Turkey; 2) Anadolu University, Faculty of Pharmacy, Department of Pharmacognosy, 26470 Eskisehir, Turkey, e-mail: betuldemirci@gmail.com. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 364–365, May–June, 2009. Original article submitted October 4, 2007. Chemistry of Natural Compounds, Vol. 45, No. 3, 2009

ANKARA’ DA AKTARLARDA “ADAÇAYI” ADI ALTINDA SATILAN DROGLARIN MORFOLOJİK VE ANATOMİK OLARAK İNCELENMESİ

Sage is defined as the drog obtained from fresh or dried leaves of Salvia officinalis L. (Lamiaceae, Labiatae) in Pharmacopoeias and monographs. However, in our country, mostly 2 genera belonging to Labiatae family (Salvia L. and Sideritis L.) and species of these genera are known as sage. 88 Salvia and 44 Sideritis species grow naturally in Turkey. In this study, we aimed to identify the herbal drugs sold under the name of sage in Ankara, and also to determine their morphological and anatomical properties and determining whether they conform to European Pharmacopoeia or not. 9 samples which sold under the name sage were taken from 5 different herbalists located in different parts of Ankara. The samples were numbered and identified according to their morphological properties and their morphological photographs were taken. Preparations of 9 different samples were examined under the microscope and their characteristic features were determined, the differences between these species were put forward by means of drawings and photographs. As a result of study, it was determined that species that are sold in herbalist under the name sage actually belonged to 4 different taxa belonging to 2 genera (Sideritis congesta P.H.Davis & Hub.Mor., Sideritis caesarea H.Duman, Aytaç & Başer, Salvia fruticosa Miller and Salvia sp.). The anatomical properties specific to Labiatae family were seen in these species as characteristic features.

In vitro antiviral assessment against DNA and RNA viruses as well as antibacterial and antifungal profiles of selected Turkish species of the Salvia genus

The present study was undertaken to evaluate antibacterial, antifungal, and antiviral properties of the chloroform and methanol extracts from the aerial parts of fourteen Turkish Salvia species (Lamiaceae) including S. albimaculata Hedge & Hub., S. aucheri var canescens Boiss. et Heldr., S. candidissima ssp. occidentalis Vahl., S. ceratophylla L., S. cryptantha Montbret et Aucher ex. Benth., S. cyanescens Boiss. et Bal., S. frigida Boiss., S. forskahlei L., S. halophila Hedge, S. microstegia Boiss. & Bal., S. multicaulis Vahl., S. sclarea L., S. syriaca L., and S. verticillata L. ssp. amasiaca (Freyn, & Bornm.) against Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacer baumannii, Staphylococcus aureus, Bacillus subtilis, Enterococcus faecalis, and Candida albicans by microdilution method. Both Herpes simplex (DNA) and Parainfluenza-3 viruses (RNA) were used for the determination of antiviral activity of the abovementioned Salvia extracts by using Madin-Darby bovine kidney (MDBK) and Vero cell lines. The methanol extracts were found to be quite active against S. aureus and E. faecalis (2 and 4µg/mL, respectively), while the chloroform extracts were more active against S. aureus, B. subtilis, and E. faecalis (1, 2, and 2µg/mL, respectively). All of the extracts displayed the antifungal activity having the MIC value at 8µg/mL. Maximum cytopathogenic effect (CPE) concentrations as the indicator of antiviral activities of the extracts were determined and the chloroform extracts belonging to S. albimaculata, S. cyanescens, and S. microstegia (1–64µg/mL) along with the methanol extracts of S. ceratophylla, S. halophila, and S. sclarea (16–32µg/mL) showed reasonable antiviral effect. The cytotoxicity of the extracts was also expressed as the maximum non-toxic concentrations (MNTC), ranging between 16–128µg/mL.