Trees species, activity against

Tea Tree oil was as effective as benzoyl peroxide in reducing the number of scars, but that it had a lower irritant effect on skin. Tea Tree oil has also been shown to have in vitro activity against 60 methicillin-resistant strains of Staph, aureus (MRSA) and was clinically effective in vaginitis and in chronic infections due to Trichophyton species. 

C6H.3N04, Mr 163.17, mp. 192-195 °C, [a] +47.5° (H2O). D. is a glucose-like piperidine derivative from the bark of the mulberry tree Moms). It can also be obtained by fermentation from Streptomyces species. On account of their ability to inhibit intestinal a-glu-cosidases, D. derivatives have been developed as oral antidiabetic drugs (e.g., Miglitol , Emiglitate ). D. derivatives also exhibit antiviral activity against Hiv (inhibition of the glycosylation of viral proteins). 

Chlorfenapyr is active against larvae and adults of many pest species, including insects and crop mites in the orders Lepidoptera, Coleoptera, Thysanoptera, Iso-ptera, Orthoptera, Hymenoptera and Acarina. Its broad spectrum of activity has provided commercial opportunities for use in control of pests in a wide range of crops, including vegetables, tree fruits, vines, cotton and ornamentals. 

Numerous plant species have been reported to be resistant to attack from subterranean termites. Many of these plants and extracts derived from them were tested for leads as potential natural product basexl pesticides. Forty plant and tree extracts reported to be active against termites displayed poor activity against the Formosan subterranean termite at rates < 0.5% wt/wt. Most naphthoquinones were active with a non-polar substitution in the 2-position. Anthroquinones generally had little termiticidal activity. None of the plant extracts or natural products tested were sufficiently active to be considered useful for control of the Formosan subterranean termite without structural modification. 

The discovery of taxol originated from a screening programme instituted in 1960 by the US national cancer institute. One of plants screened was the Pacific yew tree Taxus brevifolia where extracts were found to have in vitro qrtotoxic activity against tumour cells. Initially, there was a lack of interest in the compound since it was only found in very small amounts in T. brevifolia but eventually better sources were found in other Taxus species. Figure 21.21 shows the important stmctural features for taxol which contribute to its activity. As with the Vinca... 

Secondary Metabolites from Higher Plants as Pest Control Agents An activity related to various efforts to Identify compounds in plants with resistance to pests, and subsequently to attempt selection of lines with higher concentrations, is the utilization of these compounds (or the synthetic species) in field pest control. The following includes a few examples from a very large scientific activity. Jacobson (23) has tested azadlrachtin, a sesquiterpenoid from the neera tree, Azadlrachta indlca (A. Juss), against several insects and nematodes. It is effective at concentrations as low as... 

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