Antimicrobial Activity of Coronarin D and Its Synergistic Potential with Antibiotics

Coronarin D is a labdane-type diterpene from the rhizomes of Hedychium coronarium. In the view of our ongoing effort to explore its novel biological activity, antimicrobial activity study of coronarin D was performed. The results showed that coronarin D was active against tested Gram-positive bacteria, inactive for tested Gram-negative bacteria, and weakly active against tested fungi. The antibacterial effect of the combination of coronarin D with nine classical antibiotics against four Gram-positive bacteria was also evaluated. The fractional inhibitory concentration indices (FIC I ) of coronarin D-antibiotics combinations, calculated from the checkerboard assay, were used as synergism indicator. Out of 36 combinations, 47% showed total synergism, 33% had partial synergistic interaction, 17% showed no effect, and 3% showed antagonism. By combination with coronarin D at concentration of 0.25 minimal inhibitory concentration (MIC), the activities of antibiotics were boosted to 4-to 128-fold. These finding suggested an attractive approach to combat the infectious diseases by using coronarin D-antibiotic drug combination

Novel 2-Chloro-8-arylthiomethyldipyridodiazepinone Derivatives with Activity against HIV-1 Reverse Transcriptase

Based on the molecular modeling analysis against Y181CHIV-1 RT, dipyridodiazepinone derivatives containing an unsubstituted lactamnitrogen and 2-chloro-8-arylthiomethyl were synthesized via an efficientroute. Some of them were evaluated for their antiviral activity against HIV-1RT subtype E and were found to exhibit virustatic activity comparable to some clinically usedtherapeutic agents

Synthesis of 3-aminocoumarin-N-benzylpyridinium conjugates with nanomolar inhibitory activity against acetylcholinesterase

A series of 3-amino-6,7-dimethoxycoumarins conjugated with the N-benzylpyridinium moiety through an amide-bond linkage was synthesized and evaluated for their acetylcholinesterase inhibitory activity. A number of the benzylpyridinium derivatives exhibited potent activities with inhibitory concentration (IC50) values in the nanomolar concentration range. Among them, the 2,3-difluorobenzylpyridinium-containing compound was the most potent inhibitor with an IC50 value of 1.53 ± 0.01 nM. Docking studies revealed that the synthesized compounds inhibit the target enzyme by a dual binding site mechanism whereby the coumarin portion binds with the peripheral anionic site while the N-benzylpyridinium residue binds with the catalytic anionic site of the enzyme

1-(2-Bromobenzoyl)-6,7-(methylenedioxy)isoquinoline

In the title molecule, C17H10BrNO3, the mean planes of tricycle and bromophenyl fragments form a dihedral angle of 75.5 (1)°. In the crystal, π–π interactions [centroid–centroid distances = 3.556 (2) and 3.898 (8) Å] between the isoquinoline systems link molecules into stacks parallel to the a axis. The crystal packing also exibits weak intermolecular C—H...O hydrogen bonds

Dipyridodiazepinone derivatives; synthesis and anti HIV-1 activity

Ten dipyridodiazepinone derivatives were synthesized and evaluated for their anti HIV-1 reverse transcriptase activity against wild-type and mutant type enzymes, K103N and Y181C. Two of them were found to be promising inhibitors for HIV-1 RT