Enantiospecific Synthesis of Both Enantiomers of the Longtailed Mealybug Pheromone and Their Evaluation in a New Zealand Vineyard

The irregular monoterpenoid sex pheromone of <i>Pseudococcus longispinus</i> and its enantiomer were prepared from the corresponding bornyl acetates. The use of readily accessible chiral starting materials and lactone–lactone rearrangement are the highlights of the present synthesis. The biological activities of the two enantiomers and racemic mixture were tested in a New Zealand vineyard. The (<i>S</i>)-(+)-enantiomer was significantly more attractive to <i>P. longispinus</i> males than the racemic mixture or the (<i>R</i>)-(−)-enantiomer

Syntheses and Determination of Absolute Configurations and Biological Activities of the Enantiomers of the Longtailed Mealybug Pheromone

Preparation and assignment of absolute configurations to both enantiomers of the sex pheromone of the longtailed mealybug, an irregular monoterpenoid with extraordinary biological activity, has been completed. Comparison of the biological activities of both enantiomers and the racemate in field trials showed that the (<i>S</i>)-(+)-enantiomer was highly attractive to male mealybugs, strongly suggesting that female longtailed mealybugs produce this enantiomer. The (<i>R</i>)-(−)-enantiomer was benign, being neither attractive nor inhibitory

Silicon Incorporated Morpholine Antifungals: Design, Synthesis, and Biological Evaluation

Known morpholine class antifungals (fenpropimorph, fenpropidin, and amorolfine) were synthetically modified through silicon incorporation to have 15 sila-analogues. Twelve sila-analogues exhibited potent antifungal activity against different human fungal pathogens such as <i>Candida albicans</i>, <i>Candida glabrata</i>, <i>Candida tropicalis</i>, <i>Cryptococcus neoformans</i>, and <i>Aspergillus niger</i>. Sila-analogue <b>24</b> (fenpropimorph analogue) was the best in our hands, which showed superior fungicidal potential than fenpropidin, fenpropimorph, and amorolfine. The mode of action of sila-analogues was similar to morpholines, i.e., inhibition of sterol reductase and sterol isomerase enzymes of ergosterol synthesis pathway

Design, Synthesis, and Identification of Silicon Incorporated Oxazolidinone Antibiotics with Improved Brain Exposure

Therapeutic options for brain infections caused by pathogens with a reduced sensitivity to drugs are limited. Recent reports on the potential use of linezolid in treating brain infections prompted us to design novel compounds around this scaffold. Herein, we describe the design and synthesis of various oxazolidinone antibiotics with the incorporation of silicon. Our findings in preclinical species suggest that silicon incorporation is highly useful in improving brain exposures. Interestingly, three compounds from this series demonstrated up to a 30-fold higher brain/plasma ratio when compared to linezolid thereby indicating their therapeutic potential in brain associated disorders