in this paper the synthesis of some new polyaromatic monocyclic β-lactams has been reported. these cycloadducts have been synthesized by the [2+2] ketene-imine cycloaddition reaction known as the staudinger reaction. all of the products have been fully characterized by ir, 1h-nmr, 13c-nmr, mass spectroscopy and elemental analyses. the x-ray crystal structure of a cis β-lactam has been also pres...

Medicinal tea tree (Melaleuca alternifolia) leaves contain large amounts of an essential oil, dominated by monoterpenes. Several enzymes of the chloroplastic methylerythritol phosphate (MEP) pathway are hypothesised to act as bottlenecks to the production of monoterpenes. We investigated, whether transcript abundance of genes encoding for enzymes of the MEP pathway were correlated with foliar t...

Cell-free systems designed to perform complex chemical conversions of biomass to biofuels or commodity chemicals are emerging as promising alternatives to the metabolic engineering of living cells. Here we design a system comprises 27 enzymes for the conversion of glucose into monoterpenes that generates both NAD(P)H and ATP in a modified glucose breakdown module and utilizes both cofactors for...

The composition of the essential oil hydrodistilled from the aerial parts of 18 individual Artemisia herba-alba Asso. plants collected in southern Tunisia was determined by GC and GCMS analysis. The oil yield varied between 0.68% v/w and 1.93% v/w. One hundred components were identified, 21 of of which are reported for the first time in Artemisia herba-alba oil. The oil contained 10 components ...

GC-MS analysis identified forty seven and fourteen components in oils extracted using HD and in the volatile fractions extracted using HSE, respectively. eudesm-7(11) en-4-ol (28.46%), α-terpinyl acetate (12%), germacrene D-4-ol(7.3%), 1,8-cineole (6.22%), δ-cadinene (6.49%), bicyclogermacrene (5.20%) and α-cadinol (5.06%) were recorded as the main components of the essential oil and The major ...

In the present paper, we report the antimicrobial efficacy of three monoterpenes [linalyl acetate, (+)menthol, and thymol] against the gram-positive bacterium Staphylococcus aureus and the gram-negative bacterium Escherichia coli. For a better understanding of their mechanisms of action, the capability of these three monoterpenes to damage biomembranes was evaluated by monitoring the release, f...

Several lymphoma T cell lines differ in membrane superficial markers and do not respond to the same drugs and compounds. Tilia x viridis (Bayer) Simonk nothosubspecie moltkei (Dippel) Xifreda is a plant widely distributed in Argentina. The aim of this work was to study comparatively the effects of dichloromethane extract and isolated compounds on BW 5147 and on another T lymphoma cell line EL-4...

The chemical composition of the volatile oil from aerial parts of Hypericum triquetrifolium Turra was studied by GC-MS. Fifty components (97.1% of the total composition) were detected in the volatile oil. Germacrene-D (21.7%), β-caryophyllene (18.3%), δ-cadinene (6.4%), trans-β-farnesene (4.3%), α-humulene (3.8%), β-selinene (3.7%), γ-cadinene (3.3%) and trans-phytol (3.2%) were found to be the...

The metabolic cross-talk between the mevalonate (MVA) and the methylerythritol phosphate (MEP) pathways was analyzed in spike lavender (Lavandula latifolia Med) on the basis of 13CO₂-labelling experiments using wildtype and transgenic plants overexpressing the 3-hydroxy-3-methylglutaryl CoA reductase (HMGR), the first and key enzyme of the MVA pathway. The plants were labelled in the presence o...

This study focuses on the biological activities of eleven chitosan products with a viscosity-average molecular weight ranging from 22 to 846 kDa in combination with the most active monoterpenes (geraniol and thymol), out of 10 tested, against four plant pathogenic bacteria, Agrobacterium tumefaciens, Erwinia carotovora, Corynebacterium fascians, and Pseudomonas solanacearum. The antibacterial a...