Highly regioselective α-alkylation of α,β,γ,δ-unsaturated aldehydes.

The first α-alkylation of α,β,γ,δ-unsaturated aldehydes is achieved under mild reaction conditions. Several α,β,γ,δ-unsaturated aldehydes and diarylcarbinols are successfully tested for the synthesis of MBH-type α-alkylated products with an excellent regioselectivity. Simple pyrrolidine is efficiently used as a catalyst to achieve a perfect E/Z selectivity of the α-alkylated products.

Expression of chitinase genes of Metarhizium anisopliae isolates in lepidopteran pests and on synthetic media.

Pathogenecity of the well characterized entomopathogenic fungus Metarhizium anisopliae used for biocontrol of a wide range of insect pests secretes hydrolytic enzymes that degrade the host cuticle. The chitinolytic activity of high and low virulent isolates of M. anisopliae was assayed on minimal medium (MM) + colloidal chitin and MM supplemented with insect cuticles.

Relationships among activities of extracellular enzyme production and virulence against Helicoverpa armigera in Beauveria bassiana.

Extracellular enzymes produced by Beauveria bassiana, are believed to play a key role in cuticle hydrolysis. Enzyme production and pathogenicity has been found to be positively correlated. Twenty-eight isolates of B.

Oxidative stress induced by destruxin from Metarhizium anisopliae (Metch.) involves changes in glutathione and ascorbate metabolism and instigates ultrastructural changes in the salivary glands of Spodoptera litura (Fab.) larvae.

The cyclodepsipeptidic mycotoxin, destruxin, produced by Metarhizium anisopliae is known for its larvicidal properties. The crude destruxin-treated Spodoptera litura larvae revealed a decrease in thiol content and an increment in oxidation of glutathione to glutathione disulfide and ascorbate to dehydro ascorbate in a dose- and time-dependent manner. An increase in the levels of protein carbonyls and the free radicals, hydrogen peroxide and hydroxyl radical was also observed.

Insecticidal activity of destruxin, a mycotoxin from Metarhizium anisopliae (Hypocreales), against Spodoptera litura (Lepidoptera: Noctuidae) larval stages.

Background: The cyclodepsipeptide destruxin produced by the entomopathogen Metarhizium anisopliae (Metch.) was administered by different methods, topical application, ingestion and a combination of the two, in an attempt to minimize the mycotoxin dose for efficient management of the insect pest Spodoptera litura (Fab.).