Letters in Drug Design & Discovery - Volume 9, Issue 6, 2012

Intensive insulin therapy to control blood glucose level increases survival among critically ill patients in intensive care unit and hospital. Hyperglycemia is potentially harmful because it acts as a procoagulant, induces insulin resistance, causes apoptosis, impairs neutrophil function, increases the infection rate and is associated with the risk of morbidity and mortality. Hyperglycemia and insulin resistance are virtually universally in sepsis, which is the leading cause of death in critically ill patients. Initially, sepsis is characterized by a hyper-inflammatory response; but as sepsis persists, there is a shift toward an anti-inflammatory immunosuppressive state. The intensive insulin therapy also reduces the infection rate and the mortality in septic patients. Arachidonate cascade is one of the factors associated with hyperglycemia, sepsis and infection. The cascade is involved in the upregulation of proinflammtory cytokines and the dysfunction of immune cells. Especially, we focused on prostaglandin D2 (PGD2), which is produced from innate and adaptive immune cells. PGD2 is non-enzymatically metabolized to 15-deoxy-Δ12,14-PGJ2, (15d-PGJ2). 15d-PGJ2 is an endogenous ligand for the nuclear receptor, peroxysome proliferators-activated receptor γ (PPARγ) and induces apoptosis in the both immune cells. This review presents plausible roles of arachidonate cascade in hyperglycemia-impaired immunity. Furthermore, we shed light on therapeutic potentials of PPARγ ligands for critically ill patients under the insulin resistant state.

In this paper some semicarbazide and 1,2,4-triazolin-5-one derivatives are evaluated in vitro for their anticancer activity towards human tumour cell line: ovary (TOV 112D), lung (A 549), breast (T47D) and uterus (Hela). Compounds 2-4 have been found to show the most effective in vitro activity against ovary cancer cell line. For compound 4 the growth inhibition (80% and 70%) is observed in two concentrations (100 μg/ml and 50 μg/ml). The cytotoxic effect of examined compounds seems to be dose-dependent and time-dependent. Compound 7 has GI=80% values towards the breast cancer cell line in concentration of 100 μg/ml. Structure-activity relationship (SAR) studies are carried out for all the compounds of the series. Compounds 2-4 show an activity profile that can be improved through medicinal chemistry strategies.

Fifteen berberine–bile acid analogues were synthesized. Anticancer activities of these analogues compared with berberine (BBR) were evaluated in vitro; among the analogues, A4, B4, and B5 had higher cytotoxicity than that of BBR. Most of the analogues showed higher antimicrobial activity against Staphylococcus aureus ATCC 25923 and Staphylococcus albus ATCC 8799 than that of BBR, but Bacillus subtilis AS 1.398 and Escherichia coli ATCC 31343 were not sensitive to all of the analogues. A4 and B4 were stable in the serum stability assay. B4 showed promising oral bioavailability in mice.

Three-dimensional quantitative structure-activity relationship (3-D QSAR) was performed using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) techniques in order to understand the carbonic anhydrase inhibition activity. A large number of 25 structurally and functionally diverse series of aromatic heterocyclic sulfonamides carbonic anhydrase (CA, EC 4.2.1.1) inhibitors, such as hCA II were chosen for the study. Based on the alignment generated by docking conformations, a highly predictive comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) models were developed with q2 value of 0.532 and 0.486 & r2 value of 0.978 and 0.952, respectively. Further, mapping of contours onto the active site validated each other in terms of residues involved with reference to respective contours. This integrated molecular docking based alignment followed by 3D-QSAR studies should provide further insights to support structure based design of human carbonic anhydrase II inhibitors with improved activity profile.

The current treatment of organophosphorus compounds induced intoxication consists of combined administration of anticholinergic drug, oxime reactivator and anticonvulsant. Oxime reactivators are causal treatment of organophosphorus intoxication and they are able to cleave OP moiety from the molecule of inhibited acetylcholinesterase. Unfortunately, none of the currently used oximes is sufficiently effective against all nerve agents and pesticides. Thus, finding of new potent acetylcholinesterase reactivators is necessary. In this study, the reactivation efficacy of three series of novel bisquaternary reactivators with prop-1,3-diyl, but-1,4-diyl and but-2-ene-1,4-diyl linker against paraoxon inhibited acetylcholinesterase in vitro is presented. The obtained results were compared to the commercially used reactivators (pralidoxime, trimedoxime, obidoxime, methoxime, asoxime). Some newly prepared compounds showed promising ability of paraoxon in vitro reactivation, even in human attainable plasma concentrations. The structure-activity relationship for reactivators of paraoxon induced inhibition was determined.

A set of 28 compounds with inhaled general anesthetics properties and with the literature values of their biological activity was used to search for relationships between structural parameters obtained from PCM (Polarizable Continuum Model) method. Ab initio calculations have been done for molecules in vacuo and also placed in the aquatic environment and the environment of an organic solvent (ethanol). Finally the data examined the biological activity of compounds was related to their structural multiparametric indicators using stepwise, progressive regression analysis and principal component analysis (PCA) of structural descriptors for the selected environment. Obtained results showed that values of total three descriptors: dipole moment (TDM), energy gap (EG) between energy of HOMO and LUMO and isotropic polarizability (IPOL) depends the most on the biological activity data for the checked general anesthetics in all examined environments.

We report the synthesis, evaluation and rationalisation of the inhibitory activity of a series of 3,5-dibromo derivatives of 4-hydroxyphenyl ketone as probes of the active site of the type 3 of 17β-hydroxysteroid dehydrogenase (17β-HSD3). The results support the important role of hydrogen bonding interaction in the inhibition of 17β-HSD3.

A series of twelve novel azetedinones 4a-l have been synthesized by cyclocondensation of various Schiff bases of amino thiadiazole with chloroacetyl chloride in the presence of triethylamine. Various novel Schiff bases 3a-l were synthesized by condensation of 2-amino-5-aryl-5H-thiazolo[4,3-b]-l,3,4-thiadiazole with various aryl aldehydes. The synthesized compounds were characterized by FTIR, 1H-NMR, 13C-NMR and mass spectra. The titled compounds 3a-l and 4a-l were evaluated for anti-tubercular activity at a concentration of 0.1-100 μg/mL by Microplate Blue Alamar Assay method. Azetedinones 4a-l showed very good inhibition against the growth of Mycobacterium tuberculosis compared to compounds 3a-l and standard Streptomycin and Pyrazinamide.

3-Amino-5-methyl-2,4-dicarbonitrile biphenyl derivatives 1-14 have been synthesized and all compounds were screened for their antibacterial effects against fourteen Gram-positive and sixteen Gram-negative bacterial strains and showed varying degree of activities. Compounds 1, 2, 4, 5, 6, 8, 13, and 14 were found to be significantly active against various Gram-positive bacteria, however, compounds 1, 3, 4, 6, 9, 12, and 13 were found to be significantly active against various Gram-negative bacterial strains. These compounds were also screened against fourteen fungal strains but showed weak activities against some fungal strains.

A series of 2-amino-(5 or 7-substituted-2-oxoindolin-3-ylidene) benzoxazole-5-carbohydrazide derivatives were synthesized by treating 2-aminobenzoxazole-5-carbohydrazide with different substituted isatins. All the synthesized derivatives (VI a-l) were screened for their in vitro anticancer (against HeLa, IMR-32 & MCF-7 cancer cell lines), antioxidant (against DPPH radicals) and antimicrobial activities. The results of these studies showed the dose dependant anticancer, antioxidant and antimicrobial activities of the test compounds and the IC50 values of some compounds were comparable with their standard agent. The test compounds having substitution with different electron withdrawing groups at C-5 position showed more potent anticancer, antioxidant and antibacterial activities than those at C-7 position.

Several new, N2-substituted derivatives of 1,2,4-triazole-3-thione were synthesised in order to analyse the impact of substituent in the N-4 position on antibacterial activity. Structure of the compounds in question was confirmed on the basis of 1H NMR and IR spectra as well as by means of the elementary analysis (C, H, N). Microbiological studies were conducted on Gram-positive and Gram-negative bacteria strains. One of the compounds inhibited growth of Bacillus cereus ATCC 10876 with the same efficiency as ampicillin. The analysis of the structure-activity relationship indicated that introduction of a chlorine atom into the phenyl ring in the N-4 position significantly improved antibacterial activity.

1-Methylhydantion is a compound, which was isolated from Oviductus Ranae for the first time. In our study, we found that it showed good antitussive and anti-inflammatory activity. It is also the first report which illustrates the antitussive activity of hydantion derivative. A series of hydantion derivatives were synthesized and evaluated for their anti-inflammatory and antitussive activity in vivo. The pharmacological tests showed that compounds 7a, 7c and 7d have good anti-inflammatory and antitussive activity compared to Ibuprofen and codeine. Compound 7a in particular showed two-fold stronger anti-inflammatory activity than Ibuprofen.