For a long time, high-pressure treatment has been used to destroy the compact structures of natural proteins in order to promote subsequent enzymatic hydrolysis. However, there are few reports evaluating the feasibility of directly improving the catalytic capability of proteases by using high-pressure treatments. In this study, the effects of high-pressure treatment on the catalytic capacity and structure of pepsin were investigated, and the relationship between its catalytic properties and changes in its physicochemical properties was explored. It was found that high-pressure treatment could lead to changes of the sulfhydryl group/disulfide bond content, hydrophobicity, hydrodynamic radius, intrinsic viscosity, and subunit composition of pepsin, and the conformational change of pepsin resulted in improvement to its enzymatic activity and hydrolysis efficiency, which had an obvious relationship with the high-pressure treatment conditions.
Tetropium fuscum is a harmful forest pest and attacks spruces. The contact sex pheromone of this pest, (S)-11-methyl-heptacosane, and its enantiomer were synthesized via Evans’ chiral auxiliaries. The key steps of this approach included acylation of carboxylic acid, diastereoselective methylation of oxazolidinone amide, and Wittig coupling of the aldehyde with chiral phosphonium salt. The synthetic pheromones would have potential utility in the control of this pest.
The western hemlock looper, Lambdina fiscellaria lugubrosa (Hulst) is a destructive defoliator of coniferous forests and a major cause of economic losses in forestry. A novel and efficient stereoselective synthesis of the sex pheromone of the western hemlock looper (1, 2 and 3) has been successfully achieved. The synthetic strategy integrates several key transformations, including Evans’ chiral auxiliaries, Grignard cross-coupling, hydroboration–oxidation, sulfone alkylation, and hydrogenation, providing an efficient and scalable approach for sex pheromone production. The three synthesized pheromone components were subsequently tested for their ability to attract Semiothisa cinerearia (Bremer & Grey) using both Y-tube and cage bioassays. Notably, compound 1 exhibited a cross-species attractive effect on S. cinerearia, a species that had not previously been documented to respond to the pheromone of L. fiscellaria lugubrosa. This discovery underscores the potential for cross-species attraction, broadens our understanding of pheromone specificity, and emphasizes the value of stereoselectively synthesized pheromones as molecular tools for cross-species pest monitoring and integrated pest management.
The Lichen moth, Lyclene dharma dharma (Arctiidae, Lithosiinae), plays a significant role in forest ecosystem dynamics. A concise and novel method to synthesize the active sex pheromone components, (S)-14-methyloctadecan-2-one ((S)-1), (S)-6-methyloctadecan-2-one ((S)-2), and their enantiomers has been developed. Key steps in the synthesis include the use of Evans’ chiral auxiliaries, Grignard cross-coupling reactions, hydroboration–oxidation, and Wacker oxidation. The synthesized sex pheromone components hold potential value for studies on communication mechanisms, species identification, and ecological management.
The paulownia bagworm, Clania variegata Snell, is an economically important pest of agriculture and forests. The sex pheromone of this pest and its stereoisomers were synthesized, and two of the stereoisomers were prepared for the first time. Our strategy was efficient and mainly included the ring-opening reaction of (S)-2-methyloxirane, the coupling of chiral sulfonate, the oxidative cleavage of olefin, and Yamaguchi esterification. Moreover, the overall yields of our synthesis were 23–29%, with eight steps in the longest route.
The tea tussock moth, Euproctis pseudoconspersa (Strand), is a serious pest, and its sex pheromone is (R)-10,14-dimethylpentadecyl isobutyrate. A new and concise asymmetric synthesis of the sex pheromone and its enantiomer was accomplished. The chiral methyl of the pheromone was introduced by Evans’s template, while the extension of the carbon chain was achieved through Li2CuCl4-catalyzed coupling of chiral tosylate with Grignard reagent.