[structure: see text] The whole set (five compounds) of partially O-methylated products of p-tert-butyl[3.1.3.1]homooxacalixarene, currently named p-tert-butyltetrahomodioxacalix[4]arene, have been prepared. Their structure has been investigated in solution through NMR techniques and in the solid state by single-crystal X-ray diffraction. A systematic investigation, extended to the parent tetraphenol and to the tetramethyl ether derivative, has been carried out on the complexation of tetramethylammonium, acetylcholine, N-methylpyridinium, and tetraethylammonium picrate in CDCl3. The observed trends in the binding and in the selectivity of the strictly related hosts could be analyzed on the basis of the varying importance of intramolecular hydrogen bonding and its effects on the conformation of the free and of the complexed ligands. On increasing the number of methyl ether functions, the cone conformation appears to be relatively less stable but deeper, so small organic cations can be more effectively encircled.
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http://dx.doi.org/10.1021/jo051922t | DOI Listing |
J Am Chem Soc
January 2025
Center for Sustainable Catalysis and Engineering, KU Leuven, Celestijnenlaan 200F, Leuven 3001, Belgium.
The local environment of the active site, such as the confinement of hydronium ions within zeolite pores, significantly influences catalytic turnover, similar to enzyme functionality. This study explores these effects in the hydrolysis of guaiacols─lignin-derived compounds─over zeolites in water. In addition to the interesting catechol products, this reaction is advantageous for study due to its bimolecular hydrolysis pathway, which involves a single energy barrier and no intermediates, simplifying kinetic studies and result interpretation.
View Article and Find Full Text PDFCell Biochem Biophys
January 2025
Department of Zoology, MMV, Banaras Hindu University, Varanasi, 221005, UP, India.
Putranjiva roxburghii is an important medicinal plant utilized for remedy of female reproductive ailments. Its seed extract is being used as a uterine health booster due to the presence of several pharmaceutically important phytochemicals. However, the presence of phytochemicals in its leaf is still unexplored.
View Article and Find Full Text PDFJ Insect Sci
January 2025
Department of Entomology, University of Georgia, Griffin, GA USA.
The granulate ambrosia beetle, Xylosandrus crassiusculus (Motschulsky), and the black stem borer, Xylosandrus germanus (Blandford) are important pests in ornamental nurseries in the eastern USA. These beetles are managed mainly using preventative trunk applications of pyrethroids, such as permethrin or bifenthrin when females typically fly out of woodlots and attack young trees in the spring. Verbenone and methyl salicylate are potential phytochemicals reported as repellants but not completely validated in ornamental nurseries for ambrosia beetle management as an alternative option.
View Article and Find Full Text PDFPlant J
January 2025
Unit of Aromatic and Medicinal Plants, Newe Ya'ar Research Center, Volcani Institute, Ramat-Yishay, Israel.
Basil, Ocimum basilicum L., is a widely cultivated aromatic herb, prized for its culinary and medicinal uses, predominantly owing to its unique aroma, primarily determined by eugenol for Genovese cultivars or methyl chavicol for Thai cultivars. To date, a comprehensive basil reference genome has been lacking, with only a fragmented draft available.
View Article and Find Full Text PDFDalton Trans
January 2025
Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
The oxomolybdenum complexes Mo1, Mo2 and Mo3, which share a common ONO donor ligand backbone but differ in their peripheral substituents, were explored to study their reactivity in organic transformations in water. The ligand backbones of Mo1 and Mo2 were covalently linked to a methyl group and a single hydrophobic -hexadecyl chain an ether linkage, respectively. The complex Mo3 was found to possess two -hexadecyl chains attached to the ligand backbone a common amine-N.
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