Chemotype

The genus Ocimum (Labiatae) comprises 30 species found in tropical and subtropical regions of the planet, of which species O. basilicum L. and O. gratissimum are widely used in food and traditional medicine. Phytochemical studies on Ocimum have revealed a number of essential oil chemotypes, for example, eugenol, methyl chavicol, linalool, and methyl cinnamate. Since essential oils are commercially assessed according to their content, the aim of this study was to develop a simple and precise method for their qualitative and quantitative analysis using NMR spectroscopy combined with chemometrics. Seven essential oils from different species of Ocimum, an unknown sample, and a commercial sample were evaluated and the results compared to those from established and precise GC-MS and GC-FID methods. Chemometric evaluation from both 1H NMR and GC-MS data revealed three chemotypes: eugenol for O. gratissimum, O. micranthum, and O. tenuiflorum; estragole for O. basilicum, O. basilicum var. pu...

Leaf-cutting ants are pests of great economic importance due to the damage they cause to agricultural and forest crops. The use of organosynthetic insecticides is the main form of control of these insects. In order to develop safer technology, the objective of this work was to evaluate the formicidal activity of the essential oils of two Hyptis pectinata genotypes (chemotypes) and their major compounds on the leaf-cutting ants Acromyrmex balzani Emery and Atta sexdens rubropilosa Forel. Bioassays of exposure pathways (contact and fumigation) and binary mixtures of the major compounds were performed. The major compounds identified in the essential oils of H. pectinata were β-caryophyllene, caryophyllene oxide and calamusenone. The essential oils of H. pectinata were toxic to the ants in both exposure pathways. Essential oils were more toxic than their major compounds alone. The chemotype calamusenone was more toxic to A. balzani in both exposure pathways. A. sexdens rubropilosa was m...

Leaf-cutting ants are pests of great economic importance due to the damage they cause to agricultural and forest crops. The use of organosynthetic insecticides is the main form of control of these insects. In order to develop safer technology, the objective of this work was to evaluate the formicidal activity of the essential oils of two Hyptis pectinata genotypes (chemotypes) and their major compounds on the leaf-cutting ants Acromyrmex balzani Emery and Atta sexdens rubropilosa Forel. Bioassays of exposure pathways (contact and fumigation) and binary mixtures of the major compounds were performed. The major compounds identified in the essential oils of H. pectinata were β-caryophyllene, caryophyllene oxide and calamusenone. The essential oils of H. pectinata were toxic to the ants in both exposure pathways. Essential oils were more toxic than their major compounds alone. The chemotype calamusenone was more toxic to A. balzani in both exposure pathways. A. sexdens rubropilosa was m...

This study was conducted to assess the allelopathic effect of essential oils (EOs) obtained from the aerial parts of two different ecotypes (ECTPs A and B) of Zataria multiflora Boiss. with the aim of evaluating their in vitro germination and growth inhibition potential. Gas ...

Twenty-five samples of Thymus pulegioides L. representing two varieties of subsp. silvestris and four varieties of subsp. pulegioides were collected from 11 localities in Lithuania and the composition of their essential oil was analysed by capillary gas chromatography (GC) and ...

Withaferin A (WA) is an important withanolide holding promise in cancer treatment and as a relatively safe radiosensitive/chemotherapeutic agent, which is present in traces in all parts of Withania somnifera except the leaves, where as it is reported to be present in only two non-Indian chemotypes (South African chemotype/Israel chemotype 1). The present studies have marked its presence in all Indian populations (wild/cultivated), as well as two identified Indian chemotypes (AGB002 and AGB025). The quantitative dynamics of WA production in Indian populations and interchemotypic hybrids developed at our institute have been studied, and the results were compared with five previously reported chemotypes from Israel, South Africa and India. An analysis on inheritance characteristics based on presence/absence of WA in hybrid plants and their respective parents is given for future studies on the chemogenetics of this complex species in greater detail. Further, the production potential of ...

Se compararon las composiciones químicas de los aceites esenciales (AEs) de plantas de Lippia alba recolectadas en 15 regiones de Colombia. Los AEs fueron obtenidos por hidrodestilación asistida por la radiación de microondas (MWHD) y analizados por GC-MS. ...

The fumonisin B14 (FB1_4) toxin-producing capacities of 60 strains of Fusarium verticillioides isolated in the main maize-cultivating areas of Hungary were screened on rice grains in vitro. The amounts of FBI., FB2, FB3 and FB4 in the extracts of the culture material were determined by RP-HPLC/ESI-IT MS without any sample clean-up. All F verticillioides strains produced all analogues (FB1_4) of the fumonisin B series. The strains did not differ significantly in their cultural characteristics, though the analytical results allowed the distinction of three idiosyncratic FB1_4-producing chemotypes with characteristic proportions of the fumonisin B analogues. The dominant chemotype produced them in the sequence FBI > FB2 > FB3 > FB4, with large amounts of FBi and FB2. A second chemotype produced a higher amount of FB3 than of FB2, while the third chemotype produced large amounts of FB2 and FB4. The proportion of FBi in the extracts was inversely correlated with the total FB yield. No differences in FB1_4 producing capacity were observed between strains isolated from various locations or different sources.