Atalay Sokmen

Antioxidant and antimicrobial activity of the essential oil and methanol extracts of Achillea millefolium subsp. millefolium Afan. (Asteraceae)

The in vitro antimicrobial and antioxidant activities of the essential oil and methanol extracts of Achillea millefolium subsp. millefolium Afan. (Asteraceae) were investigated. GC-MS analysis of the essential oil resulted in the identification of 36 compounds constituting 90.8% of the total oil. Eucalyptol, camphor, alpha-terpineol, beta-pinene, and borneol were the principal components comprising 60.7% of the oil. The oil strongly reduced the diphenylpicrylhydrazyl radical (IC(50)=1.56 micro g/ml) and exhibited hydroxyl radical scavenging effect in the Fe(3+)-EDTA-H(2)O(2) deoxyribose system (IC(50)=2.7 micro g/ml). It also inhibited the nonenzymatic lipid peroxidation of rat liver homogenate (IC(50)=13.5 micro g/ml). The polar phase of the extract showed antioxidant activity. The oil showed antimicrobial activity against Streptococcus pneumoniae, Clostridium perfringens, Candida albicans, Mycobacterium smegmatis, Acinetobacter lwoffii and Candida krusei while water-insoluble parts of the methanolic extracts exhibited slight or no activity. This study confirms that the essential oil of Achillea millefolium possesses antioxidant and antimicrobial properties in vitro.

ANTIMICROBIAL AND ANTIOXIDATIVE ACTIVITIES OF THE ESSENTIAL OILS AND METHANOL EXTRACTS OF SALVIA CRYPTANTHA (MONTBRET ET AUCHER EX BENTH.) AND SALVIA MULTICAULIS (VAHL)

Abstract The essential oils and methanolic extracts of Salvia cryptantha and Salvia multicaulis were examined for their potential antimicrobial and radical scavenging activities. No, or slight, activity was observed when the polar and non-polar subfractions of the extracts were tested, whereas essential oils exhibited antimicrobial activity. The essential oils isolated from S. cryptantha and S. multicaulis were analysed by GC–MS and 53 and 47 constituents were identified, respectively. Antioxidant activities of the polar subfraction and the essential oil were examined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical-scavenging and lipid peroxidation assays. The essential oils, in particular, and the non-polar subfractions of methanol extracts, showed antioxidant activity. In conclusion, the results indicate that the oils of S. cryptantha and S. multicaulis have the capacity to scavenge free radicals and to inhibit the growth of pathogenic microorganisms. Therefore they could be suitable for using as antimicrobial and antioxidative agents in the food industry.

The in vitro antibacterial activity of Turkish medicinal plants

A total of 76 extracts from 35 plants available in the Turkish flora were assayed for their in vitro antibacterial activities against five pathogenic bacteria and a yeast. Sixteen crude extracts from eight plant species were found to possess an activity against at least one or more test microorganisms. Bioassay-guided fractionation of the most active crude extracts was also carried out with the most active extracts. Activity against Staphylococcus aureus, Bacillus cereus, Branhamella catarrhalis, Escherichia coli, Clostridium perfringens and Candida albicans (yeast) is discussed.

Compositions and the in vitro antimicrobial activities of the essential oils of Achillea setacea and Achillea teretifolia (Compositae)

GC-MS analysis of the isolated essential oils from air-dried aerial parts of Achillea setacea and Achillea teretifolia, an endemic taxon, resulted in the identification of 51 constituents (79.8% of the total oil) and 42 constituents (87.1% of the total oil), respectively. Eucalyptol (1,8-cineole) was the major constituent of both oils studied (18.5 and 19.9%, respectively). The antimicrobial activities of the essential oils were individually evaluated against 14 microorganisms. Both oils exhibited inhibitory effects on Clostridium perfringens, Acinetobacter lwoffii and Candida albicans with a range of minimum inhibitory concentration values extended from 0.28 to 2.25 mg/ml. Camphor and their derivatives, borneol, terpinen-4-ol and eucalyptol (1,8-cineol) can be considered as the main antimicrobial constituents of the oils studied.

Antimicrobial activity of extracts from the cell cultures of some Turkish medicinal plants.

Twenty‐four callus, and eleven cell suspension, cultures were established from Turkish medicinal plants, and crude extracts prepared from them tested against microorganisms to assess their antimicrobial activities in vitro. Of the extracts tested, those belonging to the cell cultures of five of the plant species showed antibacterial activity against mainly three bacteria and a yeast. No activity was observed against herpes simplex viruses, HSV‐I and II, but an extract from Hypericum capitatum showed a slight antiretroviral activity against HIV‐I. Copyright

Production and optimisation of rosmarinic acid by Satureja hortensis L. callus cultures

In this study, production and optimisation of rosmarinic acid, a phenolic acid and an economically important metabolite, was investigated in the callus cultures established from the mature seeds of Satureja hortensis L. (summer savory) plant. Gamborgs B5 basal medium, supplemented with indol butyric acid (IBA) (1.00 mg L−1), N6-benzyl aminopurine (6-BA) (1.00 mg L−1) and sucrose (2.5%, w/v), was employed for the establishment and maintenance of the callus cultures. Applications were individually prepared by preparing the media containing different IBA/6-BA combinations and sucrose concentrations. All of the applications were carried out in the continuous dark. In the applications, where the effects of IBA/6-BA combinations on the growth and rosmarinic acid accumulation were assayed (1–15 applications), the highest biomass yield was obtained from the medium supplemented with 1.00 mg L−1 IBA and 5.00 mg L−1 6-BA. In the case of the rosmarinic acid accumulation, an opposite relationship was determined between the growth and rosmarinic acid production. While the highest biomass yield was obtained from the medium containing 1.00 mg L−1 IBA and 5.00 mg L−1 6-BA, the highest rosmarinic acid accumulation was obtained from the medium supported with 1.00 mg L−1 IBA and 1.00 mg L−1 6-BA. In the applications where the effects of sucrose concentrations on the growth and rosmarinic acid accumulation were examined, the highest biomass yield was obtained from the medium which is supplemented with 5.0% (w/v) sucrose. In this category, the highest rosmarinic acid accumulation was obtained from the medium which is supported with 3.0% (w/v) sucrose. According to the experiments carried out with the wild S. hortensis, it is found to have 25.02 ± 1.21 mg g−1 rosmarinic acid. No differentiation was observed in any callus during the course of this study.

Phenolic Contents and Antioxidant Potential of Crataegus Fruits Grown in Tunisia as Determined by DPPH, FRAP, and β-Carotene/Linoleic Acid Assay

Crataegus fruit is one of most important fruits in Tunisian flora. Some fruits of this genus are edible. This study was undertaken in order to examine the benefits of these fruits in human health and their composition of antioxidants including total polyphenol, flavonoids, proanthocyanidins content, and total anthocyanins. The antioxidative properties of the ultrasonic methanolic extract were assessed by different in vitro methods such as the FRAP, DPPH, and β-carotene/linoleic acid assay. We concluded that peel fraction of red fruits possessed relatively high antioxidant activity and might be a rich source of natural antioxidants in comparison with the pulp and seed fruit extract. The results also showed that hawthorn yellow fruit presents lower amounts of phenolic content, absence of anthocyanins, and less antioxidant capacity. Most of peel and seed fractions were stronger than the pulp fractions in antioxidant activity based on their DPPH IC50, FRAP values, and results of β-carotene/linoleic acid. The total phenolic compounds contents were also highly correlated with the DPPH method and the FRAP assay.

Phenolic acid contents, essential oil compositions and antioxidant activities of two varieties of Salvia euphratica from Turkey.

This study was designed to evaluate the in vitro antioxidant activities of n-hexane (Hex), dichloromethane (DCM), methanol (MeOH) and essential oils (EO) extracts obtained from Salvia euphratica var. euphratica and Salvia euphratica var. leiocalycina and to determine their essential oil and phenolic acid compositions. The samples were screened for their antioxidant activity by using DPPH and β-carotene/linoleic acid assays. Methanol extracts of both varieties exhibited strong antioxidant activities. Our results showed that rosmarinic acid was dominant phenolic acid of MeOH extracts (39.4 and 55.8 µg mg−1, respectively). The chemical compositions of essential oils of two varieties were analysed and their main components were determined as eucalyptol (18.4%) and trans-pinocarvyl acetate (24.9%), respectively. It can be said that these varieties could be used as natural antioxidant

Biological Activities of Extracts and Essential Oil of Thymus transcaucasicus Ronniger

Abstract Hexane, chloroform, water extracts and essential oil obtained from flowering aerial parts of Thymus transcaucasicus Ronniger were screened for potential in vitro antioxidant, antimicrobial and antiviral activities. Chemical composition of essential oil was determined by employing GC-MS analysis; thymol being the main component in 55%. The essential oil and extracts were screened for their possible antioxidant activities by two complementary test systems, namely DPPH free radical scavenging and β-Carotene color bleaching test-a spectrophotometric method. The highest free radical scavenging activity was observed in the essential oil (IC50: 20 μg/ml) whilst, in β-Carotene color bleaching test, hexane extract showed superiority, with an inhibition rate at 72.3%. Antibacterial and antifungal activities of the extracts were also evaluated and among which the essential oil exerted better activity against all microorganisms tested except for Pseudomonas aeruginosa. Nevertheless, none was effective against test viruses, namely HSV and Influenza.

Synthesis and antimicrobial activity of new phthalocyanine complexes and electrochemical and spectroelectrochemical behaviour of cobaltphthalocyanine

A novel phthalocyanine bearing oxygen donor atoms on the peripheral positions has been synthesised by cyclotetramerisation of (E)-4-(4-cinnamoylphenoxy) phthalonitrile and its nickel, zinc, cobalt, copper and lead derivatives prepared. The thermal stabilities of the phthalocyanine compounds have been determined and their possible biological activities (antibacterial, anticandidal and antifungal) studied. The effects of substituent on the electrochemical and in situ spectroelectrochemical behaviour of cobaltphthalocyanine have been investigated and an in situ electrocolorimetric method was applied to investigate the colour of the electrogenerated anionic and cationic forms of the complex.