Medicinal Chemistry - Volume 11, Issue 8, 2015

Currently, the treatment for HBV infection suffers from adverse side effects and drug resistance. The dramatic development of new HBV inhibitors is focused on discovering diverse non-nucleoside compounds with either novel structures or new mechanisms of action. Capsid assembly is crucial to the completion of the viral life cycle, which makes it an attractive target for antivirus discovery. Inhibitors that block the formation of the HBV capsid have been developed, and several candidates have been proposed. In this review, we focus on the recent advances in several distinct classes of synthetic small molecular non-nucleosides targeting at the capsid assembly.

The search for new specific chemotherapeutic drugs designed to minimize the toxic side effects resulting from chemotherapy is still a subject of intense research. The objective of the current study was to design a non-steroidal-platinum(II) derivative that would target the estrogen receptor alpha (ERα) without triggering estrogenic cell proliferation. For this purpose, the amino acid L-tyrosine was modified and attached to a cisplatin analog. Hence, the L-tyrosine portion of the molecule could possibly act as a transporter to target the ER#945; protein and, by doing so concentrate the cytotoxic moiety to hormone-dependent breast cancer cells. Herein, we describe three different alternative methodologies that were used to make these new anticancer molecules. The L-tyrosine-Pt(II) hybrid 5b was made in four steps with 36% overall yield by the first method, in six steps with 11% overall yield by the second method and, in four steps with 23% overall yield by the third method. Preliminary biological activity on breast cancer cell lines indicated that the final hybrids (5a and 5b) were unfortunately inactive but their platinum(II) precursors (14a and 14b) showed activity similar to that of cisplatin.

Histone deacetylases (HDAC) are currently a group of validated targets for anticancer drug discovery and development. In our research program to find novel small molecules targeting these enzymes, we designed and synthesized two series of 3-hydroxyimino-2-oxoindoline- and 3- methoxyimino-2-oxoindoline-based N-hydroxypropenamides (3a-g, 6a-g). The results show that these propenamides potently inhibited HDAC2 with IC50 values in sub-micromolar range, approximately 10-fold lower than that of SAHA (also known as suberoylanilohydroxamic acid). Evaluation of cytotoxicity of these compounds in three human cancer cell lines revealed that most of the synthesized compounds were up to 5-fold more cytotoxic than SAHA. Docking studies showed that the compounds bound to HDAC2 at the binding site with higher binding affinities compared to SAHA. Our present results demonstrate that these novel 3-substituted-2-oxoindoline-based N-hydroxypropenamides are potential for further development as anticancer agents.

Selective Estrogen Receptor Modulators (SERMs) are characteristically capable of being antagonist and agonist of estrogen receptors and, therefore, they can inhibit or stimulate estrogen production in different tissues. Aiming to contribute to the identification of new synthetic SERMs candidates, the basic skeletons of raloxifene and tamoxifene were used as model. Here of, a set of 2,3-diaryl-quinoxalines having 2-(piperidin-1- yl)ethanol in the side chain have been synthesized and evaluated against human mammary carcinoma cells estrogen dependent (MCF-7), as well as in recombinant yeast assays (RYA) expressing estrogen receptor. Compound LSPN332 showed 40% inhibition of MCF-7 and EC50=290.6 μM in RYA. The efficient synthesis of 2,3-diarylquinoxalines represents an excellent opportunity to identify new SERMs, and should therefore be of interest to the medicinal chemistry community.

Daumone, a dauer-inducing pheromone and a series of lipid derivatives were synthesized from daumone to investigate structure-activity trends. Lipid derivatives demonstrated potent in vivo antiangiogenic activity on the chorioallantoic membrane, which exceeded that of fumagillin and thalidomide as reference agents. Among the 11 synthetic compounds tested, new derivatives 3, 11 and 13 showed the most potent antiangiogenic activity, which was twice that of fumagillin and thalidomide, replacing these as the most potent known antiangiogenic agents.

A series of twenty molecules belonging to 2,5-disubstituted-1,3,4-oxadiazole derivatives of Diclofenac and Naproxen were designed, synthesized and their structures were confirmed by spectroscopy. The target compounds were evaluated for anti-inflammatory and analgesic activity. The result indicates that the compounds 12, 4, 6, 7 and 15 were found to have good analgesic and anti-inflammatory activities, while the compounds 12 and 14 were found to have good analgesic and the compound 22 were found to have good anti-inflammatory activities. HQSAR and Topomer QSAR studies were performed to get insights in the structures contributing for biological activity. The compounds bearing mono-substitution such as Cl, OCH3 and NO2 in the phenyl ring were found to have maximum analgesic and anti-inflammatory activities.

The 3D-QSARs models of 29 flavone-8-acetic acid derivatives of aminopeptidase N inhibitors were generated by applying the molecular interaction fields at various 3D grid spacing. The cross-validated correlation coefficient q2LMO (0.6019) and conventional correlation coefficient r2 (0.9756) were obtained at a 1.0 Å 3D grid spacing, indicating the statistical significance of this class of compounds. The calculated inhibitory activities showed a high degree of agreement with experimental values. Then, the 4 ns MD simulation of ligand–receptor complex was carried out. The stable binding mode of the compound 19b was determined.

A series of styrylquinolines and quinolineamides based on the 8-hydroxyquinoline moiety were investigated as potential antimycobacterial agents. The lipophilicity of the compounds was measured using RP-HPLC and the tests of their activity against Mycobacterium kansasii, the M. avium complex, M. smegmatis, M. abscessus, M. tuberculosis and M. avium paratuberculosis was performed. Several of the compounds that were obtained appeared to be more effective than isoniazid and ciprofloxacin. The 5,7-dinitro-8-hydroxyquinoline derivative possessed the highest potency against M. abscessus and M. Smegmatis, which was about twice as effective as ciprofloxacin, while 2-(2-hydroxystyryl)-8-hydroxyquinoline-7-carboxylic acid appeared to be comparable with the standard drugs that are against the M. avium complex. The structure activity relationships are discussed.

We have previously reported that polysaccharides extracted from Pyracantha fortuneana (Maxim.) Li (P. fortuneana) lowered the oxidative stress and inhibited the inflammatory responses in mice. Our present study aims to determine the effects of Selenium enriched P. fortuneana polysaccharides (Se-PFPs) against carbon tetrachloride (CCl4)-induced liver injury in a mouse model. Our results displayed that CCl4 remarkably elevated the levels of alanine transferase (ALT), aspartate transaminase (AST), lactic dehydrogenase (LDH), cholesterol, triglycerides in serum. However, similar to BP treatment, supplementation of mice with Se-PFPs resulted in reversal of ALT, AST, LDH, cholesterol, triglycerides in serum. Contrary to CCl4, supplementation of mice with Se-PFPs elevated the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and levels of glutathione (GSH) in liver. Furthermore, Se-PFPs treatment increased the expression of GPx and catalase (CAT) at mRNA and protein levels in liver which were decreased in CCl4 group. Contrary to CCl4, Se-PFPs supplement decreased the levels of thiobarbituric acid reactive substances (TBAR) and H2O2, which served as lipid peroxidation biomarker. Our study indicates that Se-PFPs administration is effective in attenuating CCl4-induced liver injury. The mechanism underlying this effect may be attributed to the reduction of oxidative stress and inflammation in the liver by Se-PFPs through up-regulation of the antioxidant system. Our study suggests that Se-PFPs might be a potential dietary agent in the prevention of hepatic damage.

The reaction of various substituted 2, 4-dichloroquinolines with ethyl 4-(3-hydroxyphenyl)- 2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate was carried out in the presence of K2CO3 as a mild and efficient base at controlled temperature leading to novel 2-chloroquinoline based polyhydroquinoline with high regioselectivity. All the synthesized compounds were characterized using IR, NMR, Mass spectral data and then subjected to an in-silico analysis against P. falciparum lactate dehydrogenase.

Acid hydrazides are vital chemical entities due to their biological activities. Upon complexation with certain metal ions, their biological activities are known to be positively enhanced. The present work describes the synthesis of Cr(III)-hydrazide complexes, and their structural, spectroscopic and antioxidant properties to reveal their chemistry and biochemistry. Physical (magnetic moment, conductivity measurements), analytical (C, H, N and Cr analysis) and spectral (EI-Mass, FTIR) techniques are used for the characterization of synthesized compounds. All Cr(III)-hydrazide complexes exhibit octahedral geometry with general formula [Cr(L)2(H2O)2]Cl3. In these complexes, the hydrazide ligands are coordinated via carbonyl oxygen and terminal amino nitrogen in a bidentate fashion. All Cr(III)-hydrazide complexes were screened for in vitro diphenyldipicryl hydrazine (DPPH), superoxide dismutase and nitric oxide radical scavenging activities. Majority of the Cr(III)-hydrazide complexes were found to be more potent scavengers than their uncoordinated hydrazide ligands. This study demonstrates an interesting structure-activity relationship (SAR) which is presented here.