Insecticidal amides. Synthesis of natural 2(),4(),10()-pipercide, its 2(), 4(), 10 ()- stereomer, and related isobutylamides

Mycobacterium alvei (ω-1)-methoxy mycolic acids: Absolute stereochemistry and synthesis

Cells of Mycobacterium alvei are known to contain a unique set of mycolic acids with a (ω-1)-methoxy group; although the various enzymes in the biosynthesis of other types of mycolic acid have been widely studied, the biosynthetic route to this substituent is unclear. We now define the stereochemistry of the (ω-1)-methoxy fragment as R, and describe the synthesis of a major R-(ω-1)-methoxy-mycolic acid and its sugar esters, and of two natural M. alvei diene mycolic acids.

Effect of Plant Essential Oils and Their Major Constituents on Cypermethrin Tolerance Associated Detoxification Enzyme Activities in Spodoptera litura (Lepidoptera: Noctuidae)

Essential oils are well known to act as biopesticides. This research evaluated the acute toxicity and synergistic effect of essential oil compounds in combination with cypermethrin against Spodoptera litura Fabricius (Lepidoptera: Noctuidae). The effects of distillation extracts of essential oils from Alpinia galanga Zingiberaceae (Zingiberales) rhizomes and Ocimum basilicum Lamiaceae (Lamiales) leaves; one of their primary essential oil compounds 1,8-cineole; and linalool were studied on second-instar S. litura by topical application under laboratory conditions. The results showed that A. galanga had the highest control efficiency, whereas1,8-cineole provided a moderate efficacy. The mixtures of linalool, 1,8-cineole, O. basilicum, or A. galanga with cypermethrin were synergistic on mortality. Activity measurements of the main detoxification enzymes show that linalool and 1,8-cineole inhibit the activity of cytochromes P450 and carboxylesterases, which could explain their synergistic effect. Based on our results, the use of these mixtures represents an ideal eco-friendly approach, helping to manage cypermethrin resistance of S. litura.

Alkamid database: Chemistry, occurrence and functionality of plant N-alkylamides

ETHNOPHARMACOLOGICAL RELEVANCE

N-Alkylamides (NAAs) are a promising group of bioactive compounds, which are anticipated to act as important lead compounds for plant protection and biocidal products, functional food, cosmeceuticals and drugs in the next decennia. These molecules, currently found in more than 25 plant families and with a wide structural diversity, exert a variety of biological-pharmacological effects and are of high ethnopharmacological importance. However, information is scattered in literature, with different, often unstandardized, pharmacological methodologies being used. Therefore, a comprehensive NAA database (acronym: Alkamid) was constructed to collect the available structural and functional NAA data, linked to their occurrence in plants (family, tribe, species, genus).

MATERIALS AND METHODS

For loading information in the database, literature data was gathered over the period 1950-2010, by using several search engines. In order to represent the collected information about NAAs, the plants in which they occur and the functionalities for which they have been examined, a relational database is constructed and implemented on a MySQL back-end.

RESULTS

The database is supported by describing the NAA plant-, functional- and chemical-space. The chemical space includes a NAA classification, according to their fatty acid and amine structures.

CONCLUSIONS

The Alkamid database (publicly available on the website http://alkamid.ugent.be/) is not only a central information point, but can also function as a useful tool to prioritize the NAA choice in the evaluation of their functionality, to perform data mining leading to quantitative structure-property relationships (QSPRs), functionality comparisons, clustering, plant biochemistry and taxonomic evaluations.