C. Koch (c + koch)

Distribution by Scientific Domains
Chemistry50%

Selected Abstracts

Antibacterial activities of essential oils and extracts of Turkish Achillea, Satureja and Thymus species against plant pathogenic bacteria

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2010
Recep Kotan
Abstract BACKGROUND: The aims of this study were to examine the chemical composition of the essential oils and hexane extracts of the aerial parts of Satureja spicigera (C. Koch) Boiss., Thymus fallax Fisch. & CA Mey, Achillea biebersteinii Afan, and Achillea millefolium L. by GC and GC,MS, and to test antibacterial efficacy of essential oils and n -hexane, chloroform, acetone and methanol extracts as an antibacterial and seed disinfectant against 25 agricultural plant pathogens. RESULTS: Thymol, carvacrol, p -cymene, thymol methyl ether and ,-terpinene were the main constituents of S. spicigera and T. fallax oils and hexane extracts. The main components of the oil of Achillea millefolium were 1,8-cineole, ,-cadinol and caryophyllene oxide, whereas the hexane extract of this species contained mainly n -hexacosane, n -tricosane and n -heneicosane. The oils and hexane extracts of S. spicigera and T. fallax exhibited potent antibacterial activity over a broad spectrum against 25 phytopathogenic bacterial strains. Carvacrol and thymol, the major constituents of S. spicigera and T. fallax oils, also showed potent antibacterial effect against the bacteria tested. The oils of Achillea species showed weak antibacterial activity. Our results also revealed that the essential oil of S. spicigera, thymol and carvacrol could be used as potential disinfection agents against seed-borne bacteria. CONCLUSION: Our results demonstrate that S. spicigera, T. fallax oils, carvacrol and thymol could become potentials for controlling certain important agricultural plant pathogenic bacteria and seed disinfectant. Copyright © 2009 Society of Chemical Industry [source]

Microsatellite diversity associated with ecological factors in Hordeum spontaneum populations in Israel

MOLECULAR ECOLOGY, Issue 6 2001
Timo Turpeinen
Abstract Microsatellite diversity at 18 loci was analysed in 94 individual plants of 10 wild barley, Hordeum spontaneum (C. Koch) Thell., populations sampled from Israel across a southward transect of increasing aridity. Allelic distribution in populations was not distributed randomly. Estimates of mean gene diversity were highest in stressful arid-hot environments. Sixty-four per cent of the genetic variation was partitioned within populations and 36% between populations. Associations between ecogeographical variables and gene diversity, He, were established in nine microsatellite loci. By employing principle component analysis we reduced the number of ecogeographical variables to three principal components including water factors, temperature and geography. At three loci, stepwise multiple regression analysis explained significantly the gene diversity by a single principal component (water factors). Based on these observations it is suggested that simple sequence repeats are not necessarily biologically neutral. [source]

Antioxidant activities of some Lamiaceae plant extracts

PHYTOTHERAPY RESEARCH, Issue 1 2006
Nurgun Erdemoglu
Abstract The antioxidant activities of four Lamiaceae plants, Salvia viridis L., Salvia multicaulis Vahl, Stachys byzantina C. Koch and Eremostachys laciniata (L.) Bunge have been determined by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) as well as by flow injection analysis-luminol chemiluminescence (FIA-CL). All extracts were shown to possess a significant scavenger activity against DPPH free radical and an inhibitory effect on H2O2 - or HOCl-luminol chemiluminescence. The extracts scavenged 50% of DPPH radical ranging in the following descending order: Salvia viridis > Stachys byzantina > Salvia multicaulis > Eremostachys laciniata. The most potent extract on H2O2 -induced peak chemiluminescence was that of Salvia viridis and on HOCl-induced peak chemiluminescence was that of Stachys byzantina. The results concluded that the extracts have a potential source of antioxidants of natural origin. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Compositions of Essential Oils and Trichomes of Teucrium chamaedrys L. subsp.

CHEMISTRY & BIODIVERSITY, Issue 1 2009
subsp. syspirense (C. Koch) Rech. fil., trapezunticumRech. fil.
Abstract Teucrium chamaedrys L. is a member of the Lamiaceae family and is represented in the Flora of Turkey by six subspecies. The aerial organs of T. chamaedrys L. subsp. trapezunticumRech. fil. and subsp. syspirense (C. Koch) Rech. fil. bears numerous eglandular and glandular trichomes. Eglandular trichomes are simple, long-multicellular with cuticular micropapillae, and glandular hairs are of peltate and capitate types. The peltate hairs consist of a basal cell, a short unicellular stalk, and multicellular secretory head, and the capitate ones possess 1,2 stalk cells and one glandular head cell. The aerial parts were subjected to microdistillation for the isolation of volatiles. The analysis was simultaneously performed by using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The major components were characterized as , -caryophyllene (18%), nonacosane (12%), germacrene D (11%), caryophyllene oxide (7%), and ,- pinene (7%) for subsp. trapezunticum, and caryophyllene oxide (23%), ,- pinene (11%), and caryophyllenol II (5%) for subsp. syspirense. [source]