In Vitro and In Silico Evaluation of ACE2 and LOX Inhibitory Activity of Origanum Essential Oils and Carvacrol

Origanum spp. are used both for culinary purposes and for their biological activities. In this study, commercial Origanum majorana, Origanum minutiflorum, Origanum vulgare, and Origanum onites essential oils and their prominent constituent carvacrol were evaluated for their in vitro and in silico angiotensin-converting enzyme 2 and lipoxygenase enzyme inhibitory potentials. The essential oils were analysed by gas chromatography-flame ionisation detection and gas chromatography-mass spectrometry, where carvacrol was identified as the major component (62 - 81%), confirming the quality. In vitro enzyme inhibition assays were conducted both with the essential oils (20 µg/mL) and with carvacrol (5 µg/mL). The comparative values of angiotensin-converting enzyme 2 percent inhibition for O. majorana, O. minutiflorum, O. vulgare, and O. onites essential oils were determined as 85.5, 79.1, 74.3, and 42.8%, respectively. As a result of the enzyme assays, carvacrol showed 90.7% in vitro angiotensin-converting enzyme 2 inhibitory activity. The in vitro lipoxygenase inhibition of the essential oils (in the same order) was 89.4, 78.9, 81.1, and 73.5%, respectively, where carvacrol showed 74.8% inhibition. In addition, protein-ligand docking and interaction profiling was used to gain structural and mechanistic insights into the angiotensin-converting enzyme 2 and lipoxygenase inhibitory potentials of major Origanum essential oil constituents. The in silico findings agreed with the significant enzyme inhibition activity observed in vitro. Further in vivo studies are suggested to confirm the safety and efficacy of the oils.

In vitro and in silico Evaluation of ACE2 and LOX Inhibitory Activity of Eucalyptus Essential Oils, 1,8-Cineole, and Citronellal

Eucalyptus essential oils are well-known and used especially in upper respiratory tract pathologies or diseases as herbal drug preparations. In the present study, the in vitro angiotensin-converting enzyme 2 (ACE2) and lipoxygenase (LOX) enzyme inhibitory potentials of commercial Eucalyptus globulus Labill. and Eucalyptus citriodora Hook. essential oils were evaluated for their potential anti-coronavirus disease 2019 (COVID-19), and anti-inflammatory effects. In addition, the major components, 1,8-cineole and citronellal, were evaluated for their ability to bind at the active site of either human ACE2 or human 5-LOX using an in silico setting. Before activity evaluation, Eucalyptus globulus and E citriodora essential oils were analysed by GC/FID and GC/MS, where 1,8-cineole (30%), and citronellal (80%) were identified as the major components, respectively. The in vitro ACE2 inhibition was calculated as 94.9% for E globulus, and that of E citriodora essential oil as 83.4%. In vitro LOX inhibition experiments for essential oils in the same order showed inhibitions of 71.3 and 91.4%, respectively, at 20 µg/mL test concentrations in microplate-based fluorometric assays. In addition, protein–ligand docking, and interaction profiling was used to gain structural and mechanistic insights into the in silico ACE2 and LOX inhibitory potentials of the major Eucalyptus essential oil constituents, 1,8-cineole as well as citronellal. The resulting data supported the in vitro findings; however, further in vivo studies are needed to confirm the activity.

Review of Studies on Phlomis and Eremostachys Species (Lamiaceae) with Emphasis on Iridoids, Phenylethanoid Glycosides, and Essential Oils

As the sixth-largest Angiosperm family, Lamiaceae contains more than 245 genera and 7886 species that are distributed worldwide. It is also the third-largest family based on the number of taxa in Turkey where it is represented by 46 genera and 782 taxa with a high endemism ratio (44%). Besides, Lamiaceae are rich in plants with economic and medicinal value containing volatile and nonvolatile compounds. Many aromatic plants of Lamiaceae such as Salvia, Sideritis, Stachys, Phlomis, and Teucrium species are used in traditional herbal medicine throughout Turkey as well as in other Mediterranean countries. Salvia (Sage tea "Adaçayı"), Sideritis (Mountain tea "Dağçayı"), Stachys (Hairy Tea "Tüylü Çay"), and Phlomis (Turkish sage "Çalba or Şalba") are the largest genera that are used as herbal teas. This review focuses on the volatile and nonvolatile compounds of Lamiaceae from the genera Phlomis and Eremostachys of the subfamily Lamioideae with emphasis on iridoids, phenylethanoid glycosides, and essential oils.

In vitro Anti-Leishmanial Activity of Essential Oils Extracted from Plants Growing in Northern Cyprus Against Leishmania tropica

OBJECTIVE

Natural plant products are considered as a source of novel and effective compounds for the treatment of leishmaniasis. In this study, the in vitro activities of essential oils obtained from Origanum dubium (OD), Origanum majorana (OM), Salvia fruticosa (SF) and Laurus nobilis (LN) plants in Northern Cyprus were investigated against Leishmania tropica.

METHODS

Leishmania tropica strain (MHOM/TR/2012/CBCL-LT) was obtained. RPMI-1640 was added to 96-well plates in 100 μL aliquots, 100 μg/mL essential oil was added to the first well of each row and serial 2-fold dilutions were performed. A promastigote suspension was pipetted into all wells, and the plates were incubated. The promastigotes were enumerated using a haemocytometer.

RESULTS

OD essential oil was effective at killing all promastigotes at a minimum inhibitor height (MIC)=0.2 μg/mL and had high activity at the lowest concentrations. Both SF and LN oils had MIC=1.56 μg/mL and LD₅₀=0.78 μg/mL. SF was observed to impair promastigote morphology at the lowest concentrations, while LN did not exert any effect at concentrations <0.2 μg/mL. OM essential oil was found to have a MIC=3.13 μg/mL and a LD₅₀=1.56 μg/mL.

CONCLUSION

All tested essential oils inhibited promastigotes of Leishmania tropica. OD essential oil demonstrated the highest anti-leishmanial activity.

AMAÇ

Bitkilerden elde edilen doğal ürünlerin leishmaniasis tedavisi için yeni ve etkili bileşiklerin üretilmesine öncülük edeceği düşünülmektedir. Çalışmamızda, Kuzey Kıbrıs’ta yetişen Origanum dubium (OD), Origanum majorana (OM), Salvia fruticosa (SF) ve Laurus nobilis (LN) bitkilerinden elde edilen uçucu yağların Leishmania tropica’ya karşı in vitro etkinlikleri araştırılmıştır.

YÖNTEMLER

Çalışmamızda, Leishmania tropica suşu (MHOM/TR/2012/CBCL-LT) kullanıldı. Düz tabanlı 96’lık plaklarda, tüm kuyucuklara 100 μL RPMI-1640 ve ilk kuyucuklara 100 μg/mL uçucu yağlar eklenerek, seri dilüsyonları yapıldı. Ardından tüm kuyucuklara Leishmania tropica promastigot süspansiyonundan pipetlendi ve inkübe edildi. Hemositometre yöntemiyle promastigotların sayısı incelendi.

BULGULAR

OD yağının minimum inhibitör konsantrasyonu (MİK)=0,2 μg/mL’de tüm promastigotları öldürürken, en düşük konsantrasyonlarda bile etkili olduğu görülmüştür. SF ve LN uçucu yağlarının ikisinde de MİK=1,56 μg/mL, LD₅₀=0,78 μg/mL olarak saptanmıştır. SF’nin en düşük konsantrasyonlarının bile promastigot morfolojisini bozduğu görülürken, Laurus nobilis’in ise 0,2 μg/mL’den sonraki konsantrasyonlarda etkisini kaybettiği belirlenmiştir. OM uçucu yağının MİK=3,13 μg/mL, LD₅₀=1,56 μg/mL olduğu görülmüştür.

SONUÇ

Kullanılan tüm uçucu yağların Leishmania tropica promastigotlarını inhibe ettiği görülürken, en yüksek anti-leishmanial etkinlik Origanum dubium uçucu yağında bulunmuştur.

Microbial Biotransformation of α-ionol

Ionols are important flavour and fragrance compounds both in natural and synthetic aroma blends that are used in many daily products. α-Ionol has been converted for the first time to 3-oxo-α-ionone by microbial biotransformation using the plant pathogenic fungi Aspergillus niger NRRL 326 and Fusarium culmorum (freshly isolated) over 7 d at 25°C at 6.6 and 15.3% yield, respectively. The structure of the metabolite, which was purified by column chromatography, was elucidated by FTIR, GC-MS and NMR studies.

Fungal Biotransformation of Cyclademol and Antimicrobial Activities of Its Metabolites

Cyclademol (1) was converted for the first time to 1-(4-hydroxy-3,3-dimethylcyclohexyl) ethanone (2) and 4-(1-hydroxyethyl)-2,2-dimethylcyclohexanol (3) with 31.2 and 15.1% yields by Aspergillus niger and Neurospora crassa, respectively. The resulting metabolite structures were established by FT-IR, MS and NMR spectroscopic studies, respectively. In addition, the in vitro antimicrobial activities of the substrates and metabolites were evaluated comparatively both by using agar dilution and microdilution methods. The minimum inhibitory concentrations (MIC) of the tested compounds against a panel of pathogenic bacterial strains ranged from 1000 - 4000 μg/mL, whereas the MIC values against fungal strains were between 500 −1000 μg/mL.

Investigation of Galatella villosa and G. tatarica for Antioxidant, α-Amylase, Tyrosinase, Lipoxygenase and Xanthine Oxidase Inhibitory Activities

In the present work two Galatella species, Galatella villosa Rchb.f. and Galatella tatarica (Less.) Novopokr collected from Kazakhstan were subjected to hydrodistillation to yield essential oils (EOs), and to maceration in methanol to yield extracts (MEs). The EOs and MEs were evaluated for antioxidant and in vitro inhibitory activities against α-amylase, tyrosinase, lipoxygenase and xanthine oxidase enzymes. The EOs of G. villosa and G. tatarica were investigated for chemical composition using GC-FID and GC/MS techniques. The composition of MEs was investigated with LC-MS/MS technique. Monoterpenes, β-pinene (23.6 %) and α-pinene (14.4 %) were the main constituents of G. tatarica essential oil, while the oil of G. villosa was characterized not only with monoterpene α-pinene (9.0 %), but also fatty acid, hexadecanoic acid (10.2%). 3-, 5-, 1,5- and 3,4-caffeoylquinic acids, 3-, 4- and 5-feruloylquinic acids, quercetin and its different glycosides were detected in MEs according to mass spectral data. G. tatarica (IC50=74.3 μg/mL) and G. villosa (IC50=78.5 μg/mL) extracts showed significant antioxidant activity. In the β-carotene bleaching test, the extracts demonstrated noteworthy activity (%Inh 44.46 and 41.14). The extracts scavenged ABTS radical as 1.85 mM and 1.27 mM of Trolox. In a concentration of 0.5 mg/mL, the oils showed 89% and 85% inhibition of α-amylase, while the extracts showed 86% and 78% inhibition at 2 mg/mL concentration, respectively. The EOs demonstrated noteworthy potent LOX enzyme inhibition ranging between 45% and 57%. In xanthine-xanthine oxidase model system, the extracts demonstrated the highest inhibitory potency ranging between 43% and 39%. The present work is the first contribution to the chemistry and biological activities of G. tatarica and G. villosa.

Rose Mentioned in the Works of Scientists of the Medieval East and Implications in Modern Science

Fragrant roses (e.g., Rosa damascena, R.gallica, R. centifolia) have been mentioned in ancient texts written by scientists of the Medieval East such as Al-Kindi (9th CE), Al-Dinawari (9th CE), Rhazes (9th CE), Az-Zahrawi (10th CE), Ibn Sina (11th CE), Al-Mizza (14th CE), and Ad-Dimasqi (14th CE). The great physician Ibn Sina emphasized the beneficial effects of rose fragrance on the heart and the brain. He praised rose water's effects on mind and spirit, and its beneficial effects on brain function and cognitive power. Modern studies have provided scientific evidence for this information.

Inhibition of Human Neutrophil Responses by the Essential Oil of Artemisia kotuchovii and Its Constituents

Essential oils were obtained by hydrodistillation of the flowers+leaves and stems of Artemisia kotuchovii Kupr. (AKEO(f+l) and AKEO(stm), respectively) and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The primary components of the oils were estragole, (E)- and (Z)-β-ocimenes, methyleugenol, limonene, spathulenol, β-pinene, myrcene, and (E)-methyl cinnamate. Seventy-four constituents were present at concentrations from 0.1 to 1.0%, and 34 compounds were identified in trace (<0.1%) amounts in one or both plant components. Screening of the essential oils for biological activity showed that AKEO(stm), but not AKEOf+l, inhibited N-formyl-Met-Leu-Phe (fMLF)-stimulated Ca(2+) flux and chemotaxis and phorbol-12-myristate-13-acetate (PMA)-induced reactive oxygen species (ROS) production in human neutrophils. Selected pure constituents, representing >96% of the AKEO(stm) composition, were also tested in human neutrophils and HL-60 cells transfected with N-formyl peptide receptor 1 (FPR1). One component, 6-methyl-3,5-heptadien-2-one (MHDO), inhibited fMLF- and interleukin 8 (IL-8)-stimulated Ca(2+) flux, fMLF-induced chemotaxis, and PMA-induced ROS production in human neutrophils. MHDO also inhibited fMLF-induced Ca(2+) flux in FPR1-HL60 cells. These results suggest that MHDO may be effective in modulating some innate immune responses, possibly by inhibition of neutrophil migration and ROS production.

The Bioactive Essential Oil of Heracleum sphondylium L. subsp. ternatum (Velen.) Brummitt

The essential oil of Heracleum sphondylium L. subsp. ternatum (Velen.) Brummit (Umbelliferae) was isolated from crushed seeds by means of hydrodistillation and analyzed by GC and GC/MS. Major components were identified as 1-octanol (50.3%), octyl butyrate (24.6%), and octyl acetate (7.3%). Furthermore, antimicrobial activity of the oil was evaluated using microdilution broth and agar diffusion methods. The bioactive constituent of the essential oil was determined as 1-octanol by using a bioautography assay.

The Microbial Oxidation of (–)-β-Pinene by Botrytis cinerea

(-)-β-pinene, a flavor and fragrance monoterpene is an important constituent of essential oils of many aromatic plants. It was oxidized by a plant-pathogenic fungus, Botrytis cinerea to afford four metabolites characterized as (-)-6α-hydroxy-β-pinene, (-)-4β,5β-dihydroxy- β-pinene, (-)-2β,3β-dihydroxypinane, and (-)-4β-hydroxy-β-pinene-6-one by detailed spectroscopic studies along with other known metabolites.

In vitro antioxidant properties and anthocyanin compositions of elderberry extracts

In this study, dried elderberry fruits growing wild in Turkey were macerated using different solvents and an infusion was prepared according to traditional methods. All extracts were investigated for their total phenolic content, total monomeric anthocyanins, qualitative-quantitative determination of cyanidin-3-glucoside (by HPLC-UV analysis), anthocyanin compositions (by LC/MS-MS), free radical scavenging activity (DPPH and ABTS) and inhibition of β-carotene/linoleic acid co-oxidation. An extract with 70% ethanol was found to be richer in cyanidin-3-glucoside when compared to the other extracts. The infusion was found to be as rich as the 70% ethanol extract. Ethanol and acetone extracts (both 70%) were found to be more active in the free radical activity and β-carotene bleaching assays. Water extract showed good ABTS radical scavenging activity when compared with ascorbic acid.

Phoenix dactylifera L. spathe essential oil: chemical composition and repellent activity against the yellow fever mosquito

Date palm, Phoenix dactylifera L. (Arecaceae), grows commonly in the Arabian Peninsula and is traditionally used to treat various diseases. The aim of the present study was to identify chemical composition of the essential oil and to investigate the repellent activity. The essential oil of P. dactylifera was obtained by hydrodistillation from the spathe, a specialized leaf structure that surrounds the pollinating organs of the palm. The oil was subsequently analyzed by GC-FID and GC-MS. The oil showed promising repellent activity against yellow fever mosquito - Aedes aegypti. Sixteen components were characterized, constituting 99% of the oil. The main components were 3,4-dimethoxytoluene (73.5%), 2,4-dimethoxytoluene (9.5%), β-caryophyllene (5.5%), p-cresyl methyl ether (3.8%), and caryophyllene oxide (2.4%). The minimum effective dosage (MED) for repellency for the P. dactylifera oil was 0.051mg/cm(2), which had moderately lower potency compared to reference standard N,N-diethyl-3-methylbenzamide, DEET (0.018mg/cm(2)) in the "cloth patch assay". The five major compounds were individually assayed for repellency to determine to what extent each is responsible for repellency from the oil. 3,4-Dimethoxytoluene and 2,4-dimethoxytoluene showed the best repellent activity with the same MED value of 0.063mg/cm(2), respectively. The results indicate that these two constituents which comprise a large proportion of the P. dactylifera oil (83%) are likely responsible for the observed repellent activity. In this aspect, the P. dactylifera spathe oil is a sustainable, promising new source of natural repellents.

Natural product studies of U.S. endangered plants: volatile components of Lindera melissifolia (Lauraceae) repel mosquitoes and ticks

The number of endangered plant species in the U.S. is significant, yet studies aimed towards utilizing these plants are limited. Ticks and mosquitoes are vectors of significant pathogenic diseases of humans. Repellents are critical means of personal protection against biting arthropods and disease transmission. The essential oil and solvent extracts from Lindera melissifolia (Walt.) Blume (Lauraceae) (pondberry) drupes were gathered and analyzed by GC and GC-MS. The essential oil obtained from this endangered plant showed a significant dose dependent repellency of ticks and a moderate mosquito repellent effect while the subsequent hexanes extract was completely ineffective. Fractional freezing enriched the tick repellent components of the essential oil. Several known tick repellent components were recognized by the GC-MS comparison of the resulting fractions and β-caryophyllene, α-humulene, germacrene D and β-elemene warrant evaluations for tick repellency. Identifying pondberry as a potential renewable source for a broad spectrum repellent supports efforts to conserve similar U.S. endangered or threatened plant species.

Anticandidal activity of the essential oil of Nepeta transcaucasica Grossh

Hydrodistallation of the aerial parts of Nepeta transcaucasica Grossh. (Lamiaceae), collected in Ağrı, Doğubayazıt Province, afforded an essential oil that was characterized by GC and GC/MS analyses. Twenty-seven compounds, representing 97.69% of the total oil composition, were identified, and 4aα,7α,7aβ-nepetalactone (1; 39%), 4aα,7α,7aα-nepetalactone (2; 28%), and germacrene D (3; 15%) constituted the major components. The anticandidal effects of the oil were evaluated against seven Candida strains by using the broth microdilution method. The oil showed good inhibitory effects against C. glabrata and C. tropicalis at minimal inhibitory concentrations (MICs) of 0.09 and 0.375 mg/ml, respectively.

In vitro antioxidant properties and phenolic composition of Salvia halophila Hedge from Turkey

An endemic plant of Turkey Salvia halophila Hedge (Lamiaceae) was examined for its antioxidant activity and phenolic compositions. The aerial part of S. halophila was extracted with different solvents in an order of increasing polarity such as hexane, ethyl acetate, methanol, and 50% methanol using a Soxhlet apparatus. Water extract was also prepared from S. halophila by reflux. All solvent fractions were investigated for their total phenolic contents, flavonoids, flavonols, qualitative-quantitative compositions, iron(III) reductive activities, free radical scavenging activities and the effect upon linoleic acid peroxidation activities. The peroxidation level was also determined by the TBA method. The results of activity tests given as IC₅₀ values were estimated from non-linear algorithm and compared with standards via BHT, ascorbic acid, gallic acid. Polar fractions were found more active among the others in free radical activity system whereas non-polar fractions protected the peroxidation of linoleic acid. Rosmarinic acid was the most abundant component, in the extracts.

Salvia Officinalis L.: Composition and Antioxidant-related Activities of a Crude Extract and Selected Sub-fractions

The composition and antioxidant properties of a methanol: acetic acid (99:1, v/v) soluble crude extract isolated from S. officinalis L. leaves through maceration and selected fractions isolated thereof are presented in this study. The total phenol content was estimated as gallic acid equivalents, whilst qualitative-quantitative phenolic content was determined using high performance liquid chromatography with photodiode array detection. Antioxidant evaluation consisted of ferric reductive capacity and 1,1-diphenyl-2-picrylhydrazyl and hydroxyl free radical scavenging determinations. The crude extract contained hydroxybenzoic acids, hydroxycinnamic acids, flavonoids and diterpenoids, whilst caffeic acid, carnosic acid, luteolin, luteolin-7- O-glucoside and rosmarinic acid were identified from their chromatographic and spectral characteristics and quantified from their respective calibration curves. The crude extract and sub-fractions demonstrated varying degrees of efficacy in the antioxidant-related assays used, except the n-hexane fraction, which was unable to reduce iron(III) at reasonable concentrations. Although the positive controls, ascorbic acid, BHA and BHT, were more potent than the S. officinalis samples, two fractions were significantly ( p < 0.05) more potent iron(III) reducing agents than pycnogenol, a proanthocyanidin-rich commercial preparation.

Salvia officinalis L.: composition and antioxidant-related activities of a crude extract and selected sub-fractions

The composition and antioxidant properties of a methanol: acetic acid (99:1, v/v) soluble crude extract isolated from S. officinalis L. leaves through maceration and selected fractions isolated thereof are presented in this study. The total phenol content was estimated as gallic acid equivalents, whilst qualitative-quantitative phenolic content was determined using high performance liquid chromatography with photodiode array detection. Antioxidant evaluation consisted of ferric reductive capacity and 1,1-diphenyl-2-picrylhydrazyl and hydroxyl free radical scavenging determinations. The crude extract contained hydroxybenzoic acids, hydroxycinnamic acids, flavonoids and diterpenoids, whilst caffeic acid, carnosic acid, luteolin, luteolin-7-O-glucoside and rosmarinic acid were identified from their chromatographic and spectral characteristics and quantified from their respective calibration curves. The crude extract and sub-fractions demonstrated varying degrees of efficacy in the antioxidant-related assays used, except the n-hexane fraction, which was unable to reduce iron(III) at reasonable concentrations. Although the positive controls, ascorbic acid, BHA and BHT, were more potent than the S. officinalis samples, two fractions were significantly (p < 0.05) more potent iron(III) reducing agents than pycnogenol, a proanthocyanidin-rich commercial preparation.

Biotransformation of α-Cedrol and Caryophyllene Oxide by the Fungus Neurospora crassa

Incubation of α-cedrol and caryophyllene oxide with Neurospora crassa afforded 12β-hydroxy cedrol, 10α-hydroxy cedrol, and 3β-hydroxy cedrol, and 12β-hydroxy caryophyllene oxide as major metabolites, respectively. The antibacterial and radical scavenging activities of the metabolites were evaluated in vitro using broth microdilution and bioauthographic techniques. However, no significant antibacterial and antioxidant activities were observed when compared with those of standard substances.

Characterization of Szovitsia callicarpa Volatile Constituents Obtained by Micro- and Hydrodistillation

The volatile constituents of Szovitsia callicarpa Fisch. & C. A. Mey. were obtained from the fruits by microdistillation, due to the limited plant material availability. Initial GC-MS analyses of the obtained material showed an unidentified major constituent with a molecular ion peak at M+ 280. After hydrodistillation of the plant material, the resulting essential oil was also analyzed by GC and GC-MS, simultaneously. In total, twenty-two compounds, representing 98.6% of the microdistilled sample, were identified, whereas seventeen components were detected in the hydrodistilled oil, representing 98.5% of the total. The GC-MS analyses showed that the samples contained an unidentified major constituent, which was further purified from the hydrodistilled essential oil by micro-column chromatography. The structure was elucidated as α-kessyl acetate using 1H- and 13C-NMR spectroscopic and mass spectroscopic techniques. Other major constituents in the analytes were determined as longipinene, longicyclene and kessane. In addition, both samples, as well as the major compound α-kessyl acetate, were tested at 1 mg/mL concentration against the pathogen Candida tropicalis and for its free radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH•) by TLC-bioauthographic techniques. Both preliminary assays at the tested concentration showed no activity.

Characterization of Szovitsia callicarpa volatile constituents obtained by micro- and hydrodistillation

The volatile constituents of Szovitsia callicarpa Fisch. & C. A. Mey. were obtained from the fruits by microdistillation, due to the limited plant material availability. Initial GC-MS analyses of the obtained material showed an unidentified major constituent with a molecular ion peak at M+ 280. After hydrodistillation of the plant material, the resulting essential oil was also analyzed by GC and GC-MS, simultaneously. In total, twenty-two compounds, representing 98.6% of the microdistilled sample, were identified, whereas seventeen components were detected in the hydrodistilled oil, representing 98.5% of the total. The GC-MS analyses showed that the samples contained an unidentified major constituent, which was further purified from the hydrodistilled essential oil by micro-column chromatography. The structure was elucidated as alpha-kessyl acetate using 1H- and 13C-NMR spectroscopic and mass spectroscopic techniques. Other major constituents in the analytes were determined as longipinene, longicyclene and kessane. In addition, both samples, as well as the major compound alpha-kessyl acetate, were tested at 1 mg/mL concentration against the pathogen Candida tropicalis and for its free radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH*) by TLC-bioauthographic techniques. Both preliminary assays at the tested concentration showed no activity.

Biological activities of Bellis perennis volatiles and extracts

Different parts of Bellis perennis were subjected to hydrodistillation and the products were subsequently analyzed by GC and GC/MS. Aqueous and methanol extracts were prepared from the aerial parts. Antioxidant [1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging, reducing activity, total antioxidant] and antimicrobial activity of the plant materials were studied. The aqueous extracts showed higher DPPH scavenging activity (85.8% at 102.5 microg/mL) than the methanol extract. Reducing power was also observed for both tested extracts, where the formation of linoleic acid peroxides was more for the aqueous extract than the methanol extract. Antimicrobial activities of all plant materials were evaluated at varying concentrations against a panel of pathogens, but without pronounced inhibitory effect.

Essential oil compositions and antioxidant properties of the roots of twelve Anatolian Paeonia taxa with special reference to chromosome counts

Essential oil compositions and antioxidant potentials of fourteen ethanol (75%) root extracts prepared from twelve taxa of the genus Paeonia (Paeoniaceae), including P. arietina Anders., P. daurica Andrews, P. xkayae N. Ozhatay, P. kesrouanensis Thiéb., P. mascula (L.) Miller subsp. arasicola G. Kaynak, ö. Yilmaz & R. Daşkin, P. mascula (L.) Miller subsp. bodurii N. Ozhatay, P. cf. mascula L. (Mill.) subsp. mascula (two samples from central and northeastern Anatolia), P. cf. officinalis Retz., P. peregrina Miller (two samples from western and northwestern Anatolia), P. tenuifolia L., P. turcica Davis & Cullen, and P. wittmanniana Hartwiss ex Lindl. were assessed. The chromosome numbers of the root tips of the species were examined using chromosome staining technique with Shiff's reagent under Leitz microscope. The essential oils of the roots of the Paeonia species were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) and the major components were identified as salicylaldehyde (10%-94.4%), cis-myrtanal (5.5%-59.7%), and methyl salicylate (2%-52.2%). Antioxidant potentials were tested against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and nitric oxide (NO) radicals using propyl gallate and rutin as the references. Total phenolic contents of the ethanol extracts were determined using Folin-Ciocalteau's method. The extracts exerted moderate NO scavenger effect and displayed insignificant DPPH radical scavenger activity at 500 microg mL(-1). On the other hand, P. daurica, P. tenuifolia and P. cf. mascula subsp. mascula are diploids with 2n = 10, while other nine taxa are tetraploids with 2n = 20.

Biological Activities of Bellis perennis Volatiles and Extracts

Different parts of Bellis perennis were subjected to hydrodistillation and the products were subsequently analyzed by GC and GC/MS. Aqueous and methanol extracts were prepared from the aerial parts. Antioxidant [1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging, reducing activity, total antioxidant] and antimicrobial activity of the plant materials were studied. The aqueous extracts showed higher DPPH scavenging activity (85.8% at 102.5 μg/mL) than the methanol extract. Reducing power was also observed for both tested extracts, where the formation of linoleic acid peroxides was more for the aqueous extract than the methanol extract. Antimicrobial activities of all plant materials were evaluated at varying concentrations against a panel of pathogens, but without pronounced inhibitory effect.

Chemical composition and antimicrobial activity of the essential oils of Lavandula stoechas L. ssp. stoechas growing wild in Turkey

The chemical compositions of the essential oils obtained by hydrodistillation from the dried leaves and flowers of Lavandula stoechas L. ssp. stoechas were separately identified by GC-FID and GC-MS analyses. The main components were alpha-fenchone (41.9 +/- 1.2%), 1,8-cineole (15.6 +/- 0.8%), camphor (12.1 +/- 0.5%), and viridiflorol (4.1 +/- 0.4%) in the leaves; and alpha-fenchone (39.2 +/- 0.9%), myrtenyl acetate (9.5 +/- 0.4%), alpha-pinene (6.1 +/- 0.09%), camphor (5.9 +/- 0.05%) and 1,8-cineole (3.8 +/- 0.1%) in the flowers. Overall, 55 and 66 constituents were identified in the leaf and flower essential oils representing more than 90% and 94% of the total, respectively. In addition, the essential oils were evaluated for their antibacterial and anticandidal activities by broth microdilution. The flower essential oil was found to be relatively more active than the leaf oil towards the tested pathogenic microorganisms. Methicillin-resistant Staphylococcus aureus was more susceptible to the flower oil (MIC = 31.2 microg/mL). The oils, evaluated for their free radical scavenging activity using a TLC-DPPH assay, were inactive at a concentration of 2 mg/mL.

Chemical Composition and Antimicrobial Activity of the Essential Oils of Lavandula Stoechas L. Ssp. Stoechas Growing Wild in Turkey

The chemical compositions of the essential oils obtained by hydrodistillation from the dried leaves and flowers of Lavandula stoechas L. ssp. stoechas were separately identified by GC-FID and GCMS analyses. The main components were α-fenchone (41.9±1.2%), 1,8-cineole (15.6±0.8%), camphor (12.1±0.5%), and viridiflorol (4.1±0.4%) in the leaves; and α-fenchone (39.2±0.9%), myrtenyl acetate (9.5±0.4%), α-pinene (6.1±0.09%), camphor (5.9±0.05%) and 1,8-cineole (3.8±0.1%) in the flowers. Overall, 55 and 66 constituents were identified in the leaf and flower essential oils representing more than 90% and 94% of the total, respectively. In addition, the essential oils were evaluated for their antibacterial and anticandidal activities by broth microdilution. The flower essential oil was found to be relatively more active than the leaf oil towards the tested pathogenic microorganisms. Methicillin-resistant Staphylococcus aureus was more susceptible to the flower oil (MIC= 31.2 μg/mL). The oils, evaluated for their free radical scavenging activity using a TLC-DPPH assay, were inactive at a concentration of 2 mg/mL.

Effects of Origanum onites on endothelial function and serum biochemical markers in hyperlipidaemic patients

The effects of Origanum onites on endothelial function and antioxidative status were investigated in 48 patients with mild hyperlipidaemia who required no drug therapy. All participants were given lifestyle and low-fat dietary advice, however 32 of the patients (study group) were also prescribed 25 ml of aqueous distillate of Origanum onites to be taken after each meal for 3 months. The remaining 16 patients were the control group. Various biochemical markers and endothelial function parameters were measured at baseline and after 3 months. A significantly greater increase in high density lipoprotein-cholesterol and significantly greater decreases in low density lipoprotein-cholesterol, apolipoprotein B, lipoprotein(a) and high sensitivity C-reactive protein occurred in the study group compared with the control group over the 3-month study period. Paraoxonase and arylesterase activities, and flow- and nitroglycerine-mediated dilatation of the brachial artery showed significantly greater increases in the study group compared with the changes in the control group. In conclusion, consumption of Origanum onites distillate had beneficial effects on lipid profiles, antioxidant status and endothelial function in patients with mild hyperlipidaemia.

In vitro antioxidant properties and phenolic composition of Salvia virgata Jacq. from Turkey

Antioxidant activities and phenolic compositions of the active fractions of Salvia virgata Jacq. (Lamiaceae) from Turkey were examined. The aerial part of S. virgata was extracted with different solvents in an order of increasing polarity such as hexane, ethyl acetate, methanol, and 50% aqueous methanol using a Soxhlet apparatus. Water extract was also prepared from S. virgata by reflux. All solvent fractions were investigated for their total phenolic contents, total flavonoids, flavonols, qualitative-quantitative compositions (by HPLC-PDA analysis), iron(III) reductive activities, free radical scavenging activities (using DPPH*), and effect upon linoleic acid peroxidation activities; also, the peroxidation level was determined by the TBA method. The results of activity tests given as IC50 values were estimated from nonlinear algorithm and compared with standards, viz., butylated hydroxytoluene, ascorbic acid, and gallic acid. Polar fractions were found to be more active for free radical activity whereas nonpolar fractions protected the peroxidation of linoleic acid. Rosmarinic acid was the most abundant component in the extracts, followed by caffeic acid and lutelin-7- O-glycoside.

Effect of maturation on the composition and biological activity of the essential oil of a commercially important Satureja species from Turkey: Satureja cuneifolia Ten. (Lamiaceae)

The essential oil obtained by hydrodistillation from aerial parts of Satureja cuneifolia Ten., collected in three different maturation stages such as preflowering, flowering, and postflowering, were analyzed simultaneously by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Thymol (42.5-45.2%), p-cymene (19.4-24.3%), and carvacrol (8.5-13.2%) were identified as the main constituent in all stages. At the same time, the essential oils and main components were evaluated for their antimicrobial activity using a microdilution assay resulting in the inhibition of a number of common human pathogenic bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and the yeasts Candida albicans and Candida tropicalis. The minimum inhibitory concentrations (MIC) varied between 62.5 and 250 microg/mL within a moderate antimicrobial activity range. Furthermore, the antioxidant capacity of the essential oils and major components thymol and carvacrol were examined in vitro. The essential oils obtained from S. cuneifolia in three different stages and its main components were interacted with 1,1-diphenyl-2-picrylhydrazyl (DPPH (*)) as a nitrogen-centered stable radical, resulting in IC 50 = 1.6-2.1 mg/mL. In addition, the effects on inhibition of lipid peroxidation of the essential oils were assayed using the beta-carotene bleaching method. All of the tested oils inhibited the linoleic acid peroxidation at almost the same level as butylated hydroxytoluene (BHT) (93.54-94.65%). BHT and ascorbic acid were used as positive controls in the antioxidant assays.