A ruthenium-catalyzed electrochemical dehydrogenative annulation reaction of imidazoles with alkynes has been established, enabling the preparation of various bridgehead N-fused [5,6]-bicyclic heteroarenes through regioselective electrochemical C-H/N-H annulation without chemical metal oxidants. Novel azaruthenabicyclo[3.2.0]heptadienes were fully characterized and identified as key intermediates. Mechanistic studies are suggestive of an oxidatively induced reductive elimination pathway within a ruthenium(II/III) regime.
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http://dx.doi.org/10.1002/anie.202000762 | DOI Listing |
Biomed Chromatogr
February 2024
Institute of Biochemistry, Samarkand State University, Samarkand, Uzbekistan.
Considering the limited data available on tree species in Uzbekistan, this research aimed to provide new insights. We gathered plant samples from different locations within Samarkand city and thoughtfully selected 15 tree species that represent the country's flora. Using scanning electron microscopy, we conducted comprehensive analyses of pollen morphology, revealing a diverse range of variations in the shapes, dimensions, and surface characteristics displayed by pollen grains.
View Article and Find Full Text PDFBiochem Pharmacol
November 2022
SignPath Pharma, Sandy, UT, United States.
Considerable interest continues to be focused on the development of curcumin either as an effective stand-alone therapeutic or as an adjunct therapy to established therapies. Curcumin (1, 7-bis (4-hydroxy-3-methoxyphenyl)-1, 6-heptadiene-3, 5- dione; also called diferuloylmethane) is a polyphenolic phytochemical extracted from the root of curcuma longa, commonly called turmeric. Despite evidence from in vitro (cell culture) and preclinical studies in animals, clinical studies have not provided strong evidence for a therapeutic effect of curcumin.
View Article and Find Full Text PDFOrg Lett
August 2021
Department of Chemistry, National Tsing Hua University, Hsin-chu 30013, Taiwan.
A series of novel chiral diene ligands (14), which are based on the bicyclo[2.2.1]heptadiene skeleton and are substituted with methyl and an ester group at the bridgehead carbons, were synthesized through rhodium-catalyzed asymmetric arylative bis-cyclization of 1,6-enyne as a key step.
View Article and Find Full Text PDFDrug Deliv
December 2021
Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.
Curcumin (1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione) is a potent anticancer drug with versatile biological activities, while the clinical translation of curcumin is severely limited due to its hydrophobicity, rapid elimination, and metabolism in the blood circulation. Herein, we aim to unravel the potential of curcumin as a synergistic agent with immunotherapy in the treatment of cancers. In an effort to minimize premature release and improve the systemic bioavailability, a superior blood stable and reduction sensitive curcumin micellar formulation, of which the release can be triggered by cancer cells, is rationally designed.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
June 2020
Institut für Organische und Biomolekulare Chemie, and Wöhler Research Institute for Sustainable Chemistry, Georg-August-Universität Göttingen, Tammannstrasse 2, 37077, Göttingen, Germany.
A ruthenium-catalyzed electrochemical dehydrogenative annulation reaction of imidazoles with alkynes has been established, enabling the preparation of various bridgehead N-fused [5,6]-bicyclic heteroarenes through regioselective electrochemical C-H/N-H annulation without chemical metal oxidants. Novel azaruthenabicyclo[3.2.
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