Cinnamaldehyde hydrazone derivatives as potential cathepsin B inhibitors: parallel in-vitro investigation in liver and cerebrospinal fluid

The emergence of cathepsins as a potential target for anticancer drugs has led to extensive research in the development of their inhibitors. In the present study, we designed, synthesized, and characterized several cinnamaldehyde schiff bases employing diverse hydrazines, as potential cathepsin B inhibitors. The parallel studies on cathepsin B isolated from liver and cerebrospinal fluid unveiled the significance of the synthesized compounds as cathepsin B inhibitors at nanomolar concentrations. The compound, 7 exhibited the highest inhibition of 83.48 % and 82.96 % with an IC50 value of 0.06 nM and 0.09 nM for liver and cerebrospinal fluid respectively. The inhibitory potential of synthesized compounds has been extremely effective in comparison to previous reports. With the help of molecular docking studies using iGEMDOCK software, we found that the active site -CH2SH group is involved in the case of α-N-benzoyl-D, l-arginine-b-naphthylamide (BANA), curcumin 2, 3, 6, and 7. For toxicity prediction, ADMET studies were conducted and the synthesized compounds emerged to be non-toxic. The results obtained from the in vitro studies were supported with in silico studies. The synthesized cinnamaldehyde schiff bases can be considered promising drug candidates in conditions with elevated cathepsin B levels.

Differential binding of piperine & curcumin with modified cellulose, alginate and pectin supports: In-vitro & in-silico studies

Use of natural polymer in the development of Drug Delivery Systems (DDS) has greatly increased in recent past because of their biocompatible, non-allergic and biodegradable nature. Natural polymers are usually hydrophilic supports, so in order to be a carrier of a hydrophobic drug their nature needs to be changed. Each developed system behaves differently towards different drugs in terms of loading and sustained release of the drug as well. In the present work we report differential binding of piperine & curcumin with cetyltrimethylammonium bromide (CTAB) modified cellulose, alginate and pectin. Difference in interaction between the piperine and curcumin with supports has been visualized using in-vitro as well as in-silico studies. Initial results obtained after in-silico studies have been validated via time dependent anti-trypsin, serum protein binding, anti-cathepsin, anti-oxidant, and anti-α-amylase activities. FT-IR, SEM, fluorescence and Particle size have been used to characterize the piperine loaded on CTAB-modified polymeric supports.

Synthesis, characterization and application of copper oxide chitosan nanocomposite for green regioselective synthesis of [1,2,3]triazoles

Chitosan copper (II) oxide nanocomposite was synthesized, characterized and used to synthesize [1,2,3]triazoles. Nanocomposite was characterized by using FTIR, XRD, FESEM, and EDS techniques, which reflected rough morphology. The powerful catalytic activity of hybrid nanocomposite was utilized to synthesize chalcones (3a-p) in relatively high yields (82%-98%) and multicomponent regio-selective cycloaddition of chalones, aryl halides (4), and sodium azide to afford the expected N-2-aryl[1,2,3]triazoles (5a-h) (80%-95% yield) rather than N-1-aryl[1,2,3]-triazoles (6a-h). The performance of nanomaterial was optimized by several variables. The capability of the nanocomposite was compared with previous work and the nanocomposite was found more efficient, economic and reproducible. The hybrid nanocomposite could be easily isolated form the reaction mixture and recycled four times without any significant loss of its catalytic activity. The reported catalyst is an inexpensive for good yields of the triazoles and may be used at industrial production for the reported compounds.

Synthesis and biological evaluation of novel synthetic chalcone derivatives as anti-tumor agents targeting Cat L and Cat K

A series of chalcone derivatives bearing benzamide or benzenesulfonamide moieties were synthesized and evaluated for their anti-tumor effect on HCT116, MCF7 and 143B cell lines in vitro. SAR analysis showed that compounds bearing a benzenesulfonamide group had greater potency than those bearing a benzamide group. It was also shown that compounds with a mono-methyl or mono-halogen group at the 3-position on the terminal phenyl ring were more effective than those with trifluoromethyl or methoxy groups. Compound 8e exhibited the most potent anti-tumor activities against HCT116, MCF7 and 143B cell lines, with IC₅₀ values of 0.597, 0.886 and 0.791μM, respectively. Molecular docking studies and enzymatic assays demonstrated that the anti-tumor activity of compound 8e might be regulated by Cat L and Cat K.

SAR studies of some acetophenone phenylhydrazone based pyrazole derivatives as anticathepsin agents

Cathepsins have emerged as promising molecular targets in a number of diseases such as Alzeimer's, inflammation and cancer. Elevated cathepsin's levels and decreased cellular inhibitor concentrations have emphasized the search for novel inhibitors of cathepsins. The present work is focused on the design and synthesis of some acetophenone phenylhydrazone based pyrazole derivatives as novel non peptidyl inhibitors of cathepsins B, H and L. The synthesized compounds after characterization have been explored for their inhibitory potency against cathepsins B, H and L. The results show that some of the synthesized compounds exhibit anti-catheptic activity with K_i value of the order of 10^-10M. Differential inhibitory effects have been observed for cathepsins B, H and L. Cathepsin L is inhibited more pronounced than cathepsin B and cathepsin H in that order.

Quinazoline derivatives as cathepsins B, H and L inhibitors and cell proliferating agents

Cysteine Cathepsins well known to be involved in cancer, inflammation and regulation of degenerative processes like apoptosis have become specific targets in drug designing. The potential of quinazolines and their derivatives in medicinal chemistry led us to synthesise a novel series of seven compounds of quinazolines to evaluate their effect on cathepsins and cellular aspects of HepG2 cells. In the present work we report the solvent free microwave assisted synthesis of (E)-8-benzylidene-5,6,7,8-tetrahydro-2,4-diarylquinazolines as inhibitors of mammalian hepatic cysteine proteases viz. Cathepsins B, H and L. In vitro inhibition of Cathepsins B, H and L is correlated well with in vitro studies when tested using MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay on HepG2 cells, hepatocellular carcinoma cell line. The studies have been extended to evaluate the type of inhibition exhibited by the individual enzyme. Out of the seven compounds 1g i.e. (E)-8-(4-fluorobenzylidene)-4-(4-fluorophenyl)-2-phenyl-5, 6, 7, 8-tetrahydroquinazoline has been found to be most inhibitory for Cathepsins B, H and L to a maximum extent with the K_i values of 10^-10M, 10^-10M and 10^-9M order respectively. In silico studies of all compounds have also been done at the active sites of Cathepsin B, H and L.

2,5-Diaryloxadiazoles and their precursors as novel inhibitors of cathepsins B, H and L

High levels of cathepsins indicated in various pathological conditions like arthritis, cancer progressions, and atherosclerosis explains the need to explore potential inhibitors of these proteases which can be of great therapeutic significance. We, in the present work, report the synthesis of some 2,5-diaryloxadiazoles from N-subsitutedbenzylidenebenzohydrazides. The synthesized compounds were screened for their inhibitory potential on cathepsins B, H and L. Structure Activity Relationship studies show that 2,5-diaryloxadiazoles were less inhibitory than their precursors. 1i and 2k have been found to be most inhibitory to cathepsins B and L. Their Ki values have been calculated as 11.38×10(-8)M and 66.4×10(-8)M for cathepsin B and 4.2×10(-9)M and 47.31×10(-9)M for cathepsin L, respectively. However, cathepsin H activity was maximally inhibited by compounds, 1e and 2c with Ki values of 4.4×10(-7)M and 5.6×10(-7)M, respectively. Enzyme kinetic studies suggest that these compounds are competitive inhibitors to the enzymes. The results have been compared with docking results obtained using iGemDock.

Cathepsin B, H and L inhibitors as cell proliferating agents: design, synthesis, computational and pharmacological studies of some novel 2-(2-naphthoyl)-6,6-dimethyl-3-aryl-2,3,6,7-tetrahydrobenzofuran-4(5H)-ones

A novel series of 2-(2-naphthoyl)-6,6-dimethyl-3-aryl-2,3,6,7-tetrahydrobenzofuran-4(5H)-one derivatives synthesized and structure confirmed by X-ray crystallography have been evaluated as inhibitors to cathepsins B, H and L as well as cell proliferating agents.