Ufuk Ozgen

Phtytochemical Studies and Quantitative HPLC Analysis of Rosmarinic Acid and Luteolin 5- O -β-D-Glucopyranoside on Thymus praecox subsp. grossheimii var. grossheimii

Thymus praecox ssp. grossheimii (RONNIGER) JALAS var. grossheimii (Lamiaceae) is used as an herbal tea for cold, stomachache, cough, and infections in Turkey. There are no phytochemical studies on this species. We performed phytochemical studies and quantitative analysis of rosmarinic acid and luteolin 5-O-β-D-glucopyranoside in the methanol extract of the plant. Several chromatographic methods were used for the isolation of major compounds. HPLC methods were applied for quantitative analysis of rosmarinic acid and luteolin 5-O-β-D-glucopyranoside in the methanol extract. In this study, ursolic acid (1), oleanolic acid (2), methyl rosmarinate (3), ethyl rosmarinate (4), rosmarinic acid (5), luteolin 5-O-β-D-glucopyranoside (6), and thymoquinol 2,5-O-β-diglucopyranoside (7) were isolated from the aerial parts of the plant. The relative contents of rosmarinic acid and luteolin 5-O-β-D-glucopyranoside in the extract were 15.2 and 57.8u2009mg/g of dry weight, respectively. Compounds isolated from this plant and the contents of rosmarinic acid and luteolin 5-O-β-D-glucopyranoside provided reasonable evidence for the traditional usages of this plant.

Quantitative determination of shikonin derivatives with UV-Vis spectrophotometric methods in the roots of Onosma nigricaule

Abstract The genus Onosma is represented by 97 species, 4 varieties, 1 hybrid species in the flora of Turkey. Some Onosma species with roots containing naphthoquinones (alkannin, shikonin and alkannin/shikonin derivatives) are known as “Havaciva” in Turkey. Onosma nigricaule is an endemic species for Turkey. The roots of O. nigricaule are used for wounds and burns in Erzurum (Turkey). In this study, quantitative determination of shikonin derivatives (deoxyshikonin, β,β-dimethylacrylshikonin and acetyl shikonin) isolated from the roots of O. nigricaule was performed using a UV-Vis spectrophotometric method. The isolated shikonin derivatives have shown three maxima at 493 nm, 523 nm and 562 nm. The mean absorption coefficient of the three shikonin derivatives (deoxyshikonin, β,β-dimethylacrylshikonin and acetyl shikonin) was determined at 523 nm and 562 nm as 15.27 l/g cm and 9.39 l/g cm, respectively. The total content of shikonin derivatives were determined as 214.6 mg/100 g root at 523 nm and 220.6 mg/100 g root at 562 nm by using mean absorption coefficient of the three shikonin derivatives (deoxyshikonin, β,β-dimethylacrylshikonin and acetyl shikonin).

Clinopodium vulgare L. subsp. vulgare Ekstresinin Antioksidan, Antimikrobial, Tirozinaz İnhibitor Aktiviteleri ve RP-HPLC ile Fenolik Bileşiklerinin Araştırılması

Clinopodium vulgare L. subsp. vulgare, Clinopodium cinsine ve Lamiaceae familyasina mensup cok yillik aromatik otsu bir bitkidir. Bu cins bitkiler siklikla geleneksel tedavide kullanilmaktadir. Farkli Clinopodium turlerinin farkli ekstrelerinin antioksidan, antimikrobiyal, tirozinaz inhibitor etkilerini ve HPLC ile fenolik bilesenlerinin analizini konu alan calismalar olmasina ragmen, Clinopodium vulgare L. subsp. vulgare ekstresinin bu ozelliklerinin tumunu iceren herhangi bir calisma bulunmamaktadir. Bu calismanin amaci C. vulgarexa0 subsp. vulgare metanol ekstresinin antioksidan, antimikrobiyal, tirozinaz inhibitor aktivitelerini ve HPLC analizi ile fenolik madde icerigini belirlemektir. Ekstrenin fenolik bilesenleri ters faz yuksek performansli sivi kromatografisi (RP- HPLC) ile belirlendi. Antioksidan, tirozinaz inhibitor aktivite spektrofotometrik yontemlerle ve antimikrobiyal aktivite disk difuzyon metodu ile incelendi. Ekstrenin toplam fenolik madde miktari 27.9±0.4 mg gallik asit esdegeri/g numune, 2,2-difenil-1-pikrilhidrazil (DPPH) radikal supurme kapasitesi IC 50 degeri 0.114±0.0004 mg/mL ve ferrik indirgeyici antioksidan guc (FRAP) degeri 1556±3 µM troloks esdegeri/g numune olarak hesaplandi. Tirozinaz inhibisyon calisma sonucuna gore ekstrenin IC 50 degeri kojik asit standardindan yuksek bulundu. HPLC ile analiz sonucunda protokatekuik asit, klorojenik asit, vanilin, sinapik asit ve benzoik asit tespit edildi. Ekstre, asid-hizli bakteri (M. smegmatis), bazi gram pozitif (S. aureus ve B. cereus) ve bazi gram negatif (Y. pseudotuberculosis) bakterilere karsi ilimli antibakteriyal aktivite gosterdi. Ancak C. albicans and S. c erevisiae turlerine karsi hicbir antifungal aktivite gostermedi. Bu calismanin sonuclarina gore, C. vulgare subsp. vulgare yeni farmasotiklerin gelistirilmesinde potansiyel bir kaynak olarak dusunulebilir.

Composition of Volatile Components and Biological Activities of Aethionema diastrophis

Twenty of the 41 Aethionema species in Turkish Flora are endemic to the country [1]. Various new taxa have since been included, including A. alanyae, A. dumanii, A. acarii, and A. karamanicum [2]. The species described in the present paper raises the total of known Turkish Aethionema species to 42. This makes Anatolia an important center for the genus [1]. Until now, the antioxidant and antimicrobial activities, and the volatile components of A.diastrophis have not been studied. The aims of the present study are to evaluate the volatile components, phenolic composition, and antioxidant, antibacterial, and antifungal activities of A. diastrophis, in addition to assessing its potential for use in the food industry and medicine. Samples of A. diastrophis were collected from Artvin, Turkey, in May 2014. A voucher specimen was deposited in the Herbarium of the Faculty of Forestry, Karadeniz Technical University, Trabzon (KATO 17115). Antioxidant capacity was assessed by ferric-reducing antioxidant power (FRAP) [3], cupric-reducing antioxidant capacity (CUPRAC) [4], and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay [5]. In addition to the methanolic extract, the water extract of A. diastrophis was also tested to determine antimicrobial activity. The agar-well diffusion method [6] was employed with modifications [7] for susceptibility screening. The compositions of the essential oils were characterized by SPME and GC-FID/MS. Reverse-phase high-performance liquid chromatography (RP-HPLC) DAD (Diode Array Detector) and UV spectral analysis (200–400 nm) were also applied to the methanolic extracts. Protocatechuic aldehyde (29.4%), chlorogenic acid (14.3%), and benzoic acid (56.3%) were detected by comparison with 16 phenolic acid standards based on retention time and UV spectra. The total phenolic contents of A. diastrophis were 551 2.12 mg GAE/g in methanolic extract and 882 2.48 mg GAE/g in aqueous extract using the Folin–Ciocalteu method. Total antioxidant activities as FRAP values for A. diastrophis were 160 1.15 mol Trolox per gram of sample in methanolic extract and 508 2.02 mol Trolox per gram of sample in aqueous extract. The DPPH scavenging activities of methanolic and aqueous extracts of A. diastrophis, expressed in terms of SC50, were 1.036 0.008 mg/mL and 0.764 0.003, respectively. The radical-scavenging activity of extracts was lower than that of BHT (0.013 0.001 mg/mL), a commonly used synthetic antioxidant in the food industry. The cupric-reducing powers of methanolic and aqueous extracts of A. diastrophis, expressed as TEAC values, were 122.8 1.02 and 223.5 1.25 mol Trolox/g sample, respectively. The methanolic and aqueous extracts were tested for antimicrobial activity against six bacterial and two yeast strains using disc diffusion. The results were assessed on the basis of inhibition zone diameters. Ampicillin, streptomycin, and fluconazole were employed as positive controls. The control drug activity findings were Ampicillin against E. coli: 10 mm, Y. pseudotuberculosis: 10 mm, P. aeruginosa: 18 mm, S. aureus: 10 mm, E. faecalis: 35 mm, B. cereus: 15 mm; streptomycin against M. smegmatis: 35 mm; fluconazole against C. albicans: 25 mm, S. cerevisiae > 25 mm. The methanolic extract exhibited particular efficacy against Mycobacterium smegmatis ATCC®607, Yersinia pseudotuberculosis ATCC®911, and Escherichia coli ATCC®35218, Staphylococcus aureus ATCC 25923, Candida albicans ATCC 60193, and Saccharomyces cerevisiae RSKK 251.

Carbonic Anhydrase and Urease Inhibitory Potential of Various Plant Phenolics Using in vitro and in silico Methods

Plant phenolics are known to display many pharmacological activities. In the current study, eight phenolic compounds, e.g., luteolin 5‐O‐β‐glucoside (1), methyl rosmarinate (2), apigenin (3), vicenin 2 (4), lithospermic acid (5), soyasaponin II (6), rubiadin 3‐O‐β‐primeveroside (7), and 4‐(β‐d‐glucopyranosyloxy)benzyl 3,4‐dihydroxybenzoate (8), isolated from various plant species were tested at 0.2 mm against carbonic anhydrase‐II (CA‐II) and urease using microtiter assays. Urease inhibition rate for compounds 1 – 8 ranged between 5.0 – 41.7%, while only compounds 1, 2, and 4 showed a considerable inhibition over 50% against CA‐II with the IC50 values of 73.5 ± 1.05, 39.5 ± 1.14, and 104.5 ± 2.50 μm, respectively, where IC50 of the reference (acetazolamide) was 21.0 ± 0.12 μm. In silico experiments were also performed through two docking softwares (Autodock Vina and i‐GEMDOCK) in order to find out interactions between the compounds and CA‐II. Actually, compounds 6 (30.0%) and 7 (42.0%) possessed a better binding capability toward the active site of CA‐II. According to our results obtained in this study, among the phenolic compounds screened, particularly 1, 2, and 4 appear to be the promising inhibitors of CA‐II and may be further investigated as possible leads for diuretic, anti‐glaucoma, and antiepileptic agents.