Three new gelsedine-type oxindole alkaloids, GS-1, GS-2, and GS-3, and one new iridoid, GSIR-1, were isolated from the stems and leaves of cultivated Carolina jasmine (Gelsemium sempervirens AIT. f.) and their structures were determined by spectroscopic analysis.
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http://dx.doi.org/10.1248/cpb.51.1211 | DOI Listing |
J Am Chem Soc
January 2025
Institute of Chemical Biology, Shenzhen Bay Laboratory, Shenzhen 518132, China.
The absolute and relative configurations of bioactive chiral molecules are typically relevant to their biological properties. It is thus highly important and desirable to construct all possible stereoisomers of a lead candidate or a given bioactive natural compound. Synergistic dual catalysis has been recognized as a reliable synthetic strategy for a variety of predictable stereodivergent transformations.
View Article and Find Full Text PDFACS Omega
January 2025
Department of Chemistry, Middle East Technical University, 06800 Ankara, Türkiye.
This work describes the development of the first enantioselective addition reaction between 1,3,5,7-tetramethyl-BODIPYs and isatin derivatives. The reaction utilizes bifunctional quinine/squaramide organocatalysts and affords nine novel chiral BODIPY dyes under mild conditions, with enantioselectivities reaching up to 60%. The synthesized BODIPY-oxindoles exhibit high fluorescence emissions, consistent with their parent BODIPYs, and display tunable colors.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
The structural groups of 2-oxindole and tricyclic 3a-hydroxy-hexahydropyrrolo-[2,3-]indole (HO-HPI) are important pharmacophores. Chemical synthesis of complex alkaloids containing a 2-oxindole or HO-HPI moiety, especially the latter one, has been a long-standing challenge. Herein, we characterized the P450 enzyme AfnD, and its homologue proteins, HmtT, ClpD, KtzM, and LtzR, as cyclopeptide 2-oxindole and HO-HPI monooxygenases (cpOPMOs) that could introduce a 2-oxindole or HO-HPI moiety into the tryptophan-containing cyclopeptides in a pH-dependent manner.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
Chongqing Research Center for Pharmaceutical Engineering, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China.
A novel palladium-catalyzed allylic C-H alkylation of terminal olefins with 3-carboxamide oxindoles is described. A variety of new 3-carboxamide-3-allylation oxindoles with an all-carbon quaternary center were obtained in moderate to good yields (up to 99%). In addition, the asymmetric version of this reaction was also explored, providing moderate enantioselectivity.
View Article and Find Full Text PDFChemSusChem
January 2025
Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.
We demonstrate the application of mechanochemistry in the synthesis of indolone-based photoswitches (hemiindigos, hemithioindigos, and oxindoles) via Knoevenagel condensation reactions. Utilizing ball-milling and an organic base (piperidine) acting as catalyst and solvent for liquid assisted grinding (LAG) conditions, we achieve rapid, solvent-free transformations, obtaining a set of known and previously unreported photoswitches, including highly functional amino acid-based photoswitches, multichromophoric derivatives and photoswitchable cavitands based on resorcin[4]arenes. The reaction under mechanochemical conditions gives moderate-to-high yields and is highly stereoselective leading to Z-isomers of hemiindigos and hemithioindigos and E-isomers of oxindoles.
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