Four novel borondipyrromethene (BDP) and -diindomethene (BDI) dyes with one or two (dimethylamino)styryl extensions at the chromophore were synthesized and spectroscopically investigated. An X-ray crystal structure shows that the extended auxochrome is virtually planar. All dyes thus display intense red/near infrared (NIR) absorption and emission. The (dimethylamino)styryl group induces a charge-transfer character that entails bright solvatochromic fluorescence, which is only quenched with increasing solvent polarity according to the energy-gap law. The dye with an additional dimethylanilino group at the meso position of BDP shows a remarkable switching of lipophilicity by protonation. Two dyes with an 8-hydroxyquinoline ligand at the meso position display quenched emission in the presence of Hg2+ or Al3+ owing to electron transfer from the excited BDP to the complexed receptor. The BDI dye presents a pH indicator with bright fluorescence and extremely low fluorescence anisotropy.
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Sci Rep
January 2025
Centre for Molecular and Materials Science, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada.
This paper describes muon spin spectroscopy studies of 12-phosphatetraphene stabilized by a peri-trifluoromethyl group and a meso-aryl substituent. Even though the prepared solution in tetrahydrofuran (THF) was quite dilute (0.060 M) for transverse-field muon spin rotation (TF-µSR) measurements, the π-extended heavier congener of tetraphene presented a pair of signals due to a muoniated radical from which the muon hyperfine coupling constant (hfc) was determined.
View Article and Find Full Text PDFMolecules
December 2024
School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, China.
The esterase EstSIT01 from can catalyze the asymmetric hydrolysis of -dimethyl ester to produce the crucial chiral intermediate (4, 5)-hemimethyl ester for -biotin synthesis. Despite its high yields and stereoselectivity, the low thermostability of EstSIT01 limits its practical application. Herein, two kinds of rational strategies were combined to enhance the thermostability of EstSIT01.
View Article and Find Full Text PDFBioorg Chem
December 2024
Universidade da Coruña, CICA - Centro Interdisciplinar de Química e Bioloxía and Departamento de Química, Facultad de Ciencias, Campus A Zapateira, 15071 A Coruña, Spain. Electronic address:
In this study, a series of BODIPY dyes were synthesized, containing various substituents at meso position. Further functionalization of the BODIPY framework at C2 and C2-C6 position(s) by palladium-catalysed cross-coupling reactions using organoindium reagents (RIn) was efficiently assessed, starting from C2(6)-halogenated BODIPYs, and their optical properties were measured. The cytotoxicity of BODIPY dyes on SH-SY5Y neuronal cells by MTT assay showed that those compounds bearing thien-2-yl and benzonitrile moieties at meso position, exhibited great efficiency in maintaining cell viability under all tested conditions (up to 50 µM for 24 h and 48 h).
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Department of Chemistry, Khalifa University, SAN Campus, Abu Dhabi, United Arab Emirates.
ACS Chem Biol
January 2025
School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore.
Bacterial peptidoglycan, the essential cell surface polymer that protects bacterial integrity, also serves as the molecular pattern recognized by the host's innate immune system. Although the minimal motifs of bacterial peptidoglycan fragments (PGNs) that activate mammalian NOD1 and NOD2 sensors are well-known and often represented by small canonical ligands, the immunostimulatory effects of natural PGNs, which are structurally more complex and potentially can simultaneously activate both the NOD1 and NOD2 signaling pathways in hosts, have not been comprehensively investigated. In particular, many bacteria incorporate additional structural modifications in peptidoglycans to evade host immune surveillance, resulting in diverse structural variations among natural PGNs that may influence their biological effects in hosts.
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