Synthesis,antiproliferative and apoptosis induction potential activities of novel bis(indolyl)hydrazide-hydrazone derivatives

In recent years, indole-indazolyl hydrazide-hydrazone derivatives with strong cell growth inhibition and apoptosis induction characteristics are being strongly screened for their cancer chemo-preventive potential. In the present study, N-methyl and N,N-dimethyl bis(indolyl)hydrazide-hydrazone analog derivatives were designed, synthesized and allowed to evaluate for their anti-proliferative and apoptosis induction potential against cervical (HeLa), breast (MCF-7 and MDA-MB-231) and lung (A549) cancer cell lines relative to normal HEK293 cells. The MTT assay in conjunction with mitochondrial potential assays and the trypan blue dye exclusion were employed to ascertain the effects of the derivatives on the cancer cells. Further, mechanistic studies were conducted on compound 14a to understand the biochemical mechanisms and functional interactions with various signaling pathways triggered in HeLa and MCF-7 cells. Compound 14a induced apoptosis via caspase independent pathway through the participation of mitogen-activated protein kinases (MAPK) such as extracellular signal related kinase (ERK) and p38 as well as p53 pathways. It originates the activation of pro-apoptotic proteins such as Bak and Mcl-1s and also strongly induced the generation of reactive oxygen species. In downstream signaling pathway, activated p53 protein interacted with MAPK pathways, including SAPK/c-Jun N-terminal protein kinase (JNK), p38 and ERK kinases resulting in apoptotic cell death. The involvement of MAPK cascades such as p38, ERK and p38 on compound 14a induced apoptotic cell death was evidenced by the fact that the inclusion of specific inhibitors of p38, ERK1/2 and JNK MAPK (SB2035809, PD98059 and SP600125) prevented the compound 14a towards induced apoptosis. The results clearly showed that MAP kinase cascades were crucial for apoptotic response in compound 14a induced cellular killing and were dependent on p53 activity. Based on the results, compound 14a was identified as a promising candidate for cancer therapeutics and these findings furnish a basis for further in vivo experiments on anti-proliferative activity.     

Anti-cholinesterase hybrids as multi-target-directed ligands against Alzheimer’s disease (1998–2018)

Alzheimer’s disease (AD) is a genetically complex, progressive and irreversible neurodegenerative disorder of the brain which involves multiple associated etiological targets. The complex pathogenesis of AD gave rise to multi-target-directed ligands (MTDLs) principle to combat this dreaded disease. Within this approach, the design and synthesis of hybrids prevailed greatly because of their capability to simultaneously target the intertwined pathogenesis components of the disease. The hybrids include pharmacophoric hybridization of two or more established chemical scaffolds endowed with the desired pharmacological properties into a single moiety. In AD, the primary foundation of medication therapy and drug design strategies includes the inhibition of cholinesterase (ChE) enzymes. Hence the development of ChE inhibition based hybrids is the central choice of AD medicinal chemistry research. To illustrate the progress of ChE inhibition based hybrids and novel targets, we reviewed the medicinal chemistry and pharmacological properties of the multi-target molecules published since 1998-December 2018. We hope that this article will allow the readers to easily follow the evolution of this prominent medicinal chemistry approach to develop a more efficient inhibitor.     

A life cycle sustainability assessment (LCSA) of oxymethylene ether as a diesel additive produced from forest biomass

The International Journal of Life Cycle Assessment - Due to efforts to reduce dependence on limited fossil energy reserves and increasing GHG emissions related to fossil fuel extraction and use in...     

DrRecQ regulates guanine quadruplex DNA structure dynamics and its impact on radioresistance in Deinococcus radiodurans

The GC‐rich genome of Deinococcus radiodurans contains a very high density of putative guanine quadruplex (G4) DNA motifs and its RecQ (drRecQ) was earlier characterized as a 3′→5′ dsDNA helicase. We saw that N‐Methyl mesoporphyrin IX (NMM), a G4 DNA binding drug affected normal growth as well as the gamma radiation resistance of the wild‐type bacterium. Interestingly, NMM treatment and recQ deletion showed additive effect on normal growth but there was no effect of NMM on gamma radiation resistance of recQ mutant. The recombinant drRecQ showed ~400 times higher affinity to G4 DNA (K_d = 11.74 ± 1.77 nM) as compared to dsDNA (K_d = 4.88 ± 1.30 µM). drRecQ showed ATP independent helicase function on G4 DNA, which was higher than ATP‐dependent helicase activity on dsDNA. Unlike wild‐type cells that sparingly stained for G4 structure with Thioflavin T (ThT), recQ mutant showed very high‐density of ThT fluorescence foci on DNA indicating an important role of drRecQ in regulation of G4 DNA structure dynamics in vivo. These results together suggested that drRecQ is an ATP independent G4 DNA helicase that plays an important role in the regulation of G4 DNA structure dynamics and its impact on radioresistance in D. radiodurans.     

Targeting metabolic pathways proteins of Orientia tsutsugamushi using combined hierarchical approach to combat scrub typhus

Orientia tsutsugamushi (Ott) is a causative agent of chigger‐borne zoonosis, scrub typhus which is life threatening and highly pervasive illness in humans. In this report, we have mined and classified the proteins involved in pathways unique to Ott by using high‐throughput computational techniques. The 12 metabolic pathways were found to be unique to the pathogen. Forty‐six proteins were reported to be essential for the pathogen's survival and non‐homologous to the humans. The proteins were categorized into different classes, ie, enzymes, transporters, DNA‐binding, secretory, and outer membrane proteins. Further, in silico analysis of 46 proteins showed that 25 proteins were suitable therapeutic targets with known druggable properties. The structural modeling of B3CSG3 (MurA) protein was carried out and catalytic site essential for its functioning was analyzed. Virtual screening of chemical compounds was performed against modeled structure. The docking study by AutodockVina reported compound from PubChem with CID: 16036947 as best and potential inhibitor by means of docking score and binding affinity. The reliability and stability of the MurA‐16036947 complex were confirmed with molecular dynamics simulation. The report will provide insight to understand the mechanism of pathogenesis of Ott and instigate the development of effective treatment strategies against this disease.