ABSTRACT
For developing intramolecular charge transfer (ICT) chemosensors for low pH values, 2-{2-[4-(dimethylamino)phenyl]-6-methyl-4H-pyran-4-ylidene}malononitrile (DPM) was designed and synthesized. The spectroscopic and pH-sensing properties of DPM were investigated by UV-Vis and fluorescence spectroscopy. This sensor exhibited a pH-dependent ratiometric absorption property in the range of pH 0-3, along with a reversible color change from yellow to colorless with increasing acid concentration. The fluorescence intensity of the sensor was increased with increasing pH within the pH range of 0-2.
Subject(s)
Colorimetry/methods , Fluorescent Dyes/chemistry , Nitriles/chemistry , Pyrans/chemistry , Color , Hydrogen-Ion Concentration , Nitriles/chemical synthesis , Pyrans/chemical synthesis , Solutions , Spectrometry, Fluorescence , Spectrophotometry, UltravioletABSTRACT
An efficient and novel two step synthetic procedure to prepare various substituted 3H,3'H-spiro[benzofuran-2,1'-isobenzofuran]-3,3'-diones A, was established from very simple and easily available starting materials. The developed method is a robust and general approach for the synthesis of these structures. The prepared compounds were tested against influenza virus type A viz., A/Taiwan/1/86 (H1N1), A/Hong Kong/8/68 (H3N2) and type B viz., B/Panama/45/90, B/Taiwan/2/62, B/Lee/40, B/Brisbane/60/2008. Among 31 compounds tested, some of them showed good activity (selective index values >10) against these influenza viruses preferentially for type B. The most active compound 3b showed activity in 3.0-16.1 µM range with a selectivity index value between 30 and 166 against these type B viruses, in which it was comparable to the antiviral agent favipiravir. Also, 3b is found to be inactive against other enveloped viruses (viz., HIV and HSV) showing its specificity for influenza viruses.
Subject(s)
Antiviral Agents/pharmacology , Benzofurans/pharmacology , Influenza B virus/drug effects , Antiviral Agents/chemical synthesis , Antiviral Agents/chemistry , Benzofurans/chemical synthesis , Benzofurans/chemistry , Dose-Response Relationship, Drug , Microbial Sensitivity Tests , Models, Molecular , Molecular Structure , Structure-Activity RelationshipABSTRACT
A series of KRIBB3 analogs were synthesized by modifying substituents at aryl moieties of KRIBB3 for examining structure-activity relationships, and their inhibitory activities on microtubule polymerization were evaluated. The presence of free phenolic hydrogens in aryl moieties of KRIBB3 analogs plays an important role in inhibition of microtubule polymerization.
Subject(s)
Anisoles/chemistry , Isoxazoles/chemistry , Tubulin Modulators/chemistry , Tubulin/chemistry , Anisoles/chemical synthesis , Anisoles/pharmacology , Humans , Isoxazoles/chemical synthesis , Isoxazoles/pharmacology , Polymerization , Structure-Activity Relationship , Tubulin/metabolism , Tubulin Modulators/chemical synthesis , Tubulin Modulators/pharmacologyABSTRACT
Terrein was isolated from Penicillium sp. 20135, prepared by a practical synthetic way, and evaluated first time for its melanin biosynthesis inhibitory activity.
Subject(s)
Cyclopentanes/chemical synthesis , Enzyme Inhibitors/pharmacology , Melanocytes/drug effects , Penicillium/chemistry , Anti-Bacterial Agents/pharmacology , Cyclopentanes/pharmacology , Dose-Response Relationship, Drug , Melanins/antagonists & inhibitors , Melanins/biosynthesis , Models, Chemical , StereoisomerismABSTRACT
[reaction: see text] We have investigated the olefin metathesis from alkenyl Baylis-Hillman adducts using second-generation Grubbs catalyst. In the experiment, the ring-closing metathesis (RCM) product could not be found, while the cross-metathesis (CM) products were found. The computational studies provided consistent explanations for the experimental result. The most limiting factor for the RCM process using second-generation Grubbs catalyst is caused by the high strain and steric effect in the metallacyclobutane intermediates.
