Bioactivity-directed isolation, characterization, and quantification of an anxiolytic flavonoid from Brassica oleracea L.

Brassica oleracea L. or Broccoli, is known for its numerous health benefits attributed to the rich array of phytochemicals. Our earlier study showed the hydroalcoholic extract of Broccoli had significant antianxiety activity. The present study involved bioactivity-directed fractionation of the active extract with the aim of separating the constituent responsible for the activity. The bioactive extract was fractionated by column chromatography. The antianxiety activity of the obtained fractions and sub-fractions was evaluated using the elevated plus maze model in mice. It led to the isolation of the bioactive compound. The antianxiety effect was confirmed by hole-board test and mirror chamber test. Structure of the compound was characterized by UV, IR, 1 H NMR, 13 C NMR, MS techniques, and was found to be kaempferol-3-O-ß-D-glucoside. The content of kaempferol-3-O-ß-D-glucoside in florets of B. oleracea was determined by HPTLC. It was found to be present to the extent of 0.061% w/w. PRACTICAL APPLICATIONS: Anxiety disorders cause immense suffering worldwide and hence search for safe and effective antianxiety drugs has become important area of research. Most commonly and widely prescribed drugs for anxiety that is, benzodiazepines may cause many adverse effects such as drowsiness, confusion, dizziness etc. They also cause physical dependence and withdrawal symptoms. Flavonoids, and their semi-synthetic derivatives, moreover, do not cause any such side effects unlike benzodiazepines. Broccoli or Brassica oleracea is reported to contain a number of flavonoids like quercetin, kaempferol, and their derivatives. In the present investigation, bioactivity-guided isolation showed that the antianxiety activity of B. oleracea is due to kaempferol-3-O-ß-D-glucoside, a compound which has been earlier reported to be present in B. oleracea. Hence, after detailed investigation this compound can be developed into a potential antianxiety drug.

Discovery of Highly Selective Inhibitors of Calmodulin-Dependent Kinases That Restore Insulin Sensitivity in the Diet-Induced Obesity in Vivo Mouse Model.

Polymorphisms in the region of the calmodulin-dependent kinase isoform D (CaMK1D) gene are associated with increased incidence of diabetes, with the most common polymorphism resulting in increased recognition by transcription factors and increased protein expression. While reducing CaMK1D expression has a potentially beneficial effect on glucose processing in human hepatocytes, there are no known selective inhibitors of CaMK1 kinases that can be used to validate or translate these findings. Here we describe the development of a series of potent, selective, and drug-like CaMK1 inhibitors that are able to provide significant free target cover in mouse models and are therefore useful as in vivo tool compounds. Our results show that a lead compound from this series improves insulin sensitivity and glucose control in the diet-induced obesity mouse model after both acute and chronic administration, providing the first in vivo validation of CaMK1D as a target for diabetes therapeutics.

Structure based drug discovery for designing leads for the non-toxic metabolic targets in multi drug resistant Mycobacterium tuberculosis.

BACKGROUND: The problem of drug resistance and bacterial persistence in tuberculosis is a cause of global alarm. Although, the UN's Sustainable Development Goals for 2030 has targeted a Tb free world, the treatment gap exists and only a few new drug candidates are in the pipeline. In spite of large information from medicinal chemistry to 'omics' data, there has been a little effort from pharmaceutical companies to generate pipelines for the development of novel drug candidates against the multi drug resistant Mycobacterium tuberculosis. METHODS: In the present study, we describe an integrated methodology; utilizing systems level information to optimize ligand selection to lower the failure rates at the pre-clinical and clinical levels. In the present study, metabolic targets (Rv2763c, Rv3247c, Rv1094, Rv3607c, Rv3048c, Rv2965c, Rv2361c, Rv0865, Rv0321, Rv0098, Rv0390, Rv3588c, Rv2244, Rv2465c and Rv2607) in M. tuberculosis, identified using our previous Systems Biology and data-intensive genome level analysis, have been used to design potential lead molecules, which are likely to be non-toxic. Various in silico drug discovery tools have been utilized to generate small molecular leads for each of the 15 targets with available crystal structures. RESULTS: The present study resulted in identification of 20 novel lead molecules including 4 FDA approved drugs (droxidropa, tetroxoprim, domperidone and nemonapride) which can be further taken for drug repurposing. This comprehensive integrated methodology, with both experimental and in silico approaches, has the potential to not only tackle the MDR form of Mtb but also the most important persister population of the bacterium, with a potential to reduce the failures in the Tb drug discovery. CONCLUSION: We propose an integrated approach of systems and structural biology for identifying targets that address the high attrition rate issue in lead identification and drug development We expect that this system level analysis will be applicable for identification of drug candidates to other pathogenic organisms as well.

Erratum: Data Intensive Genome Level Analysis for Identifying Novel, Non-Toxic Drug Targets for Multi Drug Resistant Mycobacterium tuberculosis.

This corrects the article DOI: 10.1038/srep46595.

Data Intensive Genome Level Analysis for Identifying Novel, Non-Toxic Drug Targets for Multi Drug Resistant Mycobacterium tuberculosis.

We report the construction of a novel Systems Biology based virtual drug discovery model for the prediction of non-toxic metabolic targets in Mycobacterium tuberculosis (Mtb). This is based on a data-intensive genome level analysis and the principle of conservation of the evolutionarily important genes. In the 1623 sequenced Mtb strains, 890 metabolic genes identified through a systems approach in Mtb were evaluated for non-synonymous mutations. The 33 genes showed none or one variation in the entire 1623 strains, including 1084 Russian MDR strains. These invariant targets were further evaluated for their experimental and in silico essentiality as well as availability of their crystal structure in Protein Data Bank (PDB). Along with this, targets for the common existing antibiotics and the new Tb drug candidates were also screened for their variation across 1623 strains of Mtb for understanding the drug resistance. We propose that the reduced set of these reported targets could be a more effective starting point for medicinal chemists in generating new chemical leads. This approach has the potential of fueling the dried up Tuberculosis (Tb) drug discovery pipeline.

Concomitant nitrene and carbene insertion accompanying ring expansion: spectroscopic, X-ray, and computational studies.

Reinvestigation of the thermolysis of azido-meta-hemipinate (I) yielded, in addition to known II, unusual products III and IV. These products are formed via a rare intramolecular nitrene insertion into an adjacent methoxy C-H bond followed by an intermolecular reaction during a ring-expansion and a ring-extrusion reaction followed by a carbene insertion. The structures of the new compounds were confirmed using a battery of techniques, including HRMS (ESI-QTOF) and 2D NMR as well as X-ray crystallography for compound IV. Density functional theory methods were used to support the proposed mechanism of formation of the products.

Anxiolytic effects of Equisetum arvense Linn. extracts in mice.

The petroleum ether (PE), chloroform (CH), ethanol (ETH) and water extracts of E. arvense stems were evaluated for anti-anxiety activity in mice using elevated plus maze model. Ketamine induced hypnosis and actophotometer was used to evaluate sedative effect with various extracts in mice. The results were compared with standard drug diazepam. The ethanolic extract of E. arvense (50 and 100 mg/kg) significantly increased the time-spent and the percentage of the open arm entries in the elevated plus-maze model which was comparable to diazepam. Ethanolic extract (100 mg/kg) prolonged the ketamine-induced total sleeping time and decreased the locomotor activity in mice. The results suggest that the ethanolic extract of E. arvense seems to possess anxiolytic effect with lower sedative activity than that of diazepam. The results could be attributed to the flavonoid content of the ethanolic extract.