Selective MMP-13 Inhibitors: Promising Agents for the Therapy of Osteoarthritis.

Osteoarthritis (OA) is an age-related degenerative disease, which is characterized by chronic joint pain, inflammation and the damage of joint cartilage. At present, steroidal drugs and nonsteroidal anti-inflammatory drugs (NSAIDS), selective cyclooxygenase-2 (COX-2) inhibitors, are the first-line drugs for the treatment of OA. However, these drugs could lead to some cardiovascular side effects.

Pharmacokinetic, metabolic profiling and elimination of brusatol in rats.

Brusatol, a quassinoid isolated from the traditional Chinese medicine Brucea javanica, has been reported to be an inhibitor of Nrf2 pathway and has great potential to be developed into a novel chemotherapeutic adjuvant. However, the in vivo process of brusatol has not been comprehensively explained yet. Therefore, this paper focused on the pharmacokinetic metabolism and excretion of brusatol in rats using a simple and reproducible LC-MS/MS method.

A simple and economical method of gas chromatography-mass spectrometry to determine the presence of 6 pesticides in human plasma and its clinical application in patients with acute poisoning.

An economical, rapid, and sensitive method of gas chromatography-mass spectrometry (GC-MS) was developed and validated to determine the presence of six pesticides (dichlorvos, acetochlor, atrazine, chlorpyrifos, α-endosulfan, and β-endosulfan) in human plasma. The pesticides were extracted with acetonitrile and concentrated using anhydrous sodium sulfate. Then, the target compounds were analyzed and quantified with GC-MS using borneol as an internal standard.

Comparison of the docetaxel concentration in human plasma measured with liquid chromatography-tandem mass spectrometry (LC-MS/MS) and a nanoparticle immunoassay and clinical applications of that assay.

To determine the feasibility of using a nanoparticle immunoassay for clinical therapeutic drug monitoring (TDM) of docetaxel concentrations, a sensitive and simple method of liquid chromatography-tandem mass spectrometry (LC-MS/MS) was established to measure the docetaxel concentration in human plasma and the results of LC-MS/MS and the immunoassay were compared. Docetaxel and paclitaxel (the internal standard, or IS) in human plasma were extracted through protein precipitation, separated on a Diamonsil C18 column (150 mm × 4.6 mm, 5 μm), ionized with positive ions, and detected with LC-MS/MS in multi-reaction monitoring (MRM) mode.

Design, synthesis and evaluation of novel HIV-1 NNRTIs with dual structural conformations targeting the entrance channel of the NNRTI binding pocket.

On the basis of structure-based bioisosteric replacement and molecular hybridization strategy, a series of novel dual structural-conformation inhibitors targeting the "entrance channel" of HIV-1 NNRTIs binding pocket (NNIBP) were designed and synthesized. All of the new compounds were evaluated for their anti-HIV activities in MT-4 cells using the MTT method. Five compounds exhibited moderate to excellent potencies inhibiting wild-type (wt) HIV-1 replication with EC50 values ranging from 31.

Recent advance of the hepatitis B virus inhibitors: a medicinal chemistry overview.

Hepatitis B Virus (HBV) is one of the most prevalent viral infections of human worldwide. The therapies are limited in the clinical context because of negative side effects of interferons and the development of viral resistance to the nucleoside/nucleotide inhibitors. In this review, we summarize the recent advances in design and development of potent anti-HBV inhibitors from natural sources and synthetic compounds, targeting different steps in the life cycle of HBV.

Design, Synthesis, and Anti-HIV Evaluation of Novel Triazine Derivatives Targeting the Entrance Channel of the NNRTI Binding Pocket.

A novel series of triazine derivatives targeting the entrance channel of the HIV-1 non-nucleoside reverse transcriptase inhibitor binding pocket (NNIBP) were designed and synthesized on the basis of our previous work. The results of a cell-based antiviral screening assay indicated that most compounds showed good-to-moderate activity against wild-type HIV-1 with EC50 values within the concentration range of 0.0078-0.

Design, synthesis and preliminary SAR studies of novel N-arylmethyl substituted piperidine-linked aniline derivatives as potent HIV-1 NNRTIs.

A series of novel N-arylmethyl substituted piperidine-linked aniline derivatives were designed, synthesized and evaluated for their anti-HIV activity in MT-4 cells. All the new compounds showed moderate to potent activities against wild-type (wt) HIV-1 with an EC₅₀ range from 0.022 to 2.

Novel piperidinylamino-diarylpyrimidine derivatives with dual structural conformations as potent HIV-1 non-nucleoside reverse transcriptase inhibitors.

A series of novel piperidinylamino-diarylpyrimidine (pDAPY) derivatives with dual structural conformations was designed through a molecular hybridization strategy and expected to bind into the non-nucleoside inhibitor binding pocket (NNIBP) of HIV-1 RT in a flexible manner. A cell-based antiviral screening assay showed that some compounds were active against both wild-type and drug-resistant mutant virus strains (K103N+Y181C RT) of HIV-1 (compound 10b3 with EC50 = 0.047 and 4.

Design, synthesis and biological evaluation of 3-benzyloxy-linked pyrimidinylphenylamine derivatives as potent HIV-1 NNRTIs.

A novel series of 3-benzyloxy-linked pyrimidinylphenylamine derivatives (8a-8s) was designed, synthesized and evaluated for their in vitro anti-HIV activity in MT-4 cell cultures. Most of the compounds inhibited wild-type (wt) HIV-1 replication in the lower micromolar concentration range (EC(50)=0.05-35 μM) with high selectivity index (SI) values (ranged from 10 to >4870).

Discovery of piperidine-linked pyridine analogues as potent non-nucleoside HIV-1 reverse transcriptase inhibitors.

In our continued efforts to discover more active and less toxic HIV-1 non-nucleoside reverse transcriptase inhibitors, we recently designed a novel series of piperidine-linked pyridine analogues on the basis of diarylpyrimidine derivatives, among which two drugs-etravirine and rilpivirine-are approved for use by the US FDA. The title compounds were evaluated for activity against wild-type and resistant mutant strains of HIV-1 as well as HIV-2 in MT-4 cells. The highly potent compound BD-c1 (EC50 =10 nM, CC50 ≥146 μM, SI≥14 126) displays lower cytotoxicity and higher selectivity than etravirine (EC50 =2.

Recent advances of diaryl ether family as HIV-1 non-nucleoside reverse transcriptase inhibitors.

Diaryl ether family as one of the promising second generation HIV-1 non-nucleoside reverse transcriptase inhibitors has attracted considerable attention over the past few years, among which clinical candidate MK-4965 has been advanced into phase II clinical trials. The successful development of diaryl ether family provides valuable avenues in traditional medicinal chemistry, crystallography and computer-aided drug design fields for the design of other novel anti-HIV drug candidates. In this review, the development of diaryl ether family is present including the evolutionary history, design strategies, extensive structural modifications, structure-activity relationship studies and computer-aided molecular simulation of the binding mode in detail.

Discovery of novel 2-(3-(2-chlorophenyl)pyrazin-2-ylthio)-N-arylacetamides as potent HIV-1 inhibitors using a structure-based bioisosterism approach.

The present work is an extension of our ongoing efforts towards the development and identification of new molecules with anti-HIV activity which have previously led to the discovery of arylazolylthioacetanilides as highly active NNRTIs. In this article, a series of 2-2-(3-(2-chlorophenyl)pyrazin-2-ylthio)-N-arylacetamide derivatives were synthesized and evaluated for in vitro anti-HIV activity. Most of the tested compounds exhibited moderate activities against wild-type HIV-1.

Structure-based bioisosterism design, synthesis and biological evaluation of novel 1,2,4-triazin-6-ylthioacetamides as potent HIV-1 NNRTIs.

The development of new HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) offers the possibility of generating novel chemical entities of increased potency. Previous investigations in our laboratory resulted in the discovery of several novel series of arylazolylthioacetanilides as potent NNRTIs. In this study, based on the structure-based bioisosterism strategy, novel 1,2,4-triazin-6-yl thioacetamide derivatives were designed, synthesized and evaluated for their anti-HIV activity in MT-4 cells.

Arylazolyl(azinyl)thioacetanilides. Part 10: design, synthesis and biological evaluation of novel substituted imidazopyridinylthioacetanilides as potent HIV-1 inhibitors.

In continuation of our efforts toward the discovery of potent HIV-1 NNRTIs with novel structures, we have employed a scaffold hopping strategy to explore the chemically diversed space of bioactive compounds. The original arylazolylthioacetanilide platform was replaced with different imidazopyridinylthioacetanilide scaffolds to yield the optimal pharmacophore moieties in order to generate novel NNRTIs with desirable potency. Some of the new compounds proved able to inhibit HIV-1 replication in the low micromolar range.

Arylazolyl(azinyl)thioacetanilide. Part 9: Synthesis and biological investigation of thiazolylthioacetamides derivatives as a novel class of potential antiviral agents.

In continuation of our endeavor to develop new, potent, selective and less toxic antiviral agents, a novel series of 2-(2-amino/chloro-4-(2,4-dibromophenyl) thiazol-5-ylthio)acetamide derivatives was synthesized via an expeditious route and evaluated for their anti-HIV activities against wild-type virus and clinically relevant mutant strains, and for their anti-influenza virus activities against influenza A (H1N1 and H3N2) and influenza B in cellular assays. The selected active compounds were also assayed for their enzymic inhibitory activities. The results showed that some 2-chloro substituted thiazolylthioacetamide derivatives possessed potent activity against wild type HIV-1 and several key mutant strains (E138K, K103N, L100I) of HIV-1 in MT-4 cells with EC(50) values in micromolar range.

Design, synthesis, anti-HIV evaluation and molecular modeling of piperidine-linked amino-triazine derivatives as potent non-nucleoside reverse transcriptase inhibitors.

A novel series of piperidine-linked amino-triazine derivatives were designed, synthesized and evaluated for in vitro anti-HIV activity as non-nucleoside reverse transcriptase inhibitors on the basis of our previous work. Screening results indicated that most compounds showed excellent activity against wild-type HIV-1 with EC(50) values in low nanomolar concentration range (especially compound 6b3, EC(50) = 4.61 nM, SI = 5945) and high activity against K103N/Y181C resistant mutant strain of HIV-1 with EC(50) values in low micromolar concentration range.

Synthesis and biological evaluation of piperidine-substituted triazine derivatives as HIV-1 non-nucleoside reverse transcriptase inhibitors.

A novel series of piperidine-substituted triazine derivatives have been synthesized and evaluated for anti-HIV activities in MT-4 cells. Most compounds displayed extremely promising activity against wild-type HIV-1 with EC(50) values in low nanomolar concentration, better than that of Nevirapine, Delavirdine, Zidovudine and Dideoxycitidine, and higher potency towards the resistant mutant strain K103N/Y181C than that of Nevirapine and Delavirdine. Selected compounds were also assayed against reverse transcriptase with lower IC(50) values than that of Nevirapine.

Arylazolylthioacetanilide. Part 8: Design, synthesis and biological evaluation of novel 2-(2-(2,4-dichlorophenyl)-2H-1,2,4-triazol-3-ylthio)-N-arylacetamides as potent HIV-1 inhibitors.

The development of novel HIV-1 NNRTIs offers the possibility of generating novel structures with increased potency. Based on the bioisosteric principle, a novel series of 2-(2-(2,4-dichlorophenyl)-2H-1,2,4-triazol-3-ylthio)-N-arylacetamide derivatives were designed, synthesized using a simple and efficient synthetic route, structurally confirmed by spectral analysis, evaluated for their anti-HIV activity in MT-4 cells and their inhibitory effect on HIV-1 RT. The results showed that some of the new compounds displayed low micromolar potency for inhibiting HIV-1 replication and promising activities against several selected resistant strains that confer resistance to current NNRTIs.

HIV-1 NNRTIs: structural diversity, pharmacophore similarity, and implications for drug design.

Nonnucleoside reverse transcriptase inhibitors (NNRTIs) nowadays represent very potent and most promising anti-AIDS agents that specifically target the HIV-1 reverse transcriptase (RT). However, the effectiveness of NNRTI drugs can be hampered by rapid emergence of drug-resistant viruses and severe side effects upon long-term use. Therefore, there is an urgent need to develop novel, highly potent NNRTIs with broad spectrum antiviral activity and improved pharmacokinetic properties, and more efficient strategies that facilitate and shorten the drug discovery process would be extremely beneficial.

Recent advances in DAPYs and related analogues as HIV-1 NNRTIs.

HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) nowadays represent most promising anti-AIDS drugs that specifically inhibit HIV-1 reverse transcriptase (RT). They have a unique antiviral potency, high specificity and low cytotoxicity. However, to a great extent, the efficacy of HIV-1 NNRTIs is compounded by rapid emergence of drug resistant virus strains, which calls for continuous efforts to develop novel HIV-1 NNRTIs.

Functional roles of azoles motif in anti-HIV agents.

Currently, there has been considerable interest in the discovery of original molecules with broad-spectrum anti-HIV activity and favourable pharmacokinetic profiles, to be used as an alternative to the approved anti-HIV/AIDS drugs, should they fail as therapeutics. Five-membered azole heterocycles represent an important class of lead structures for novel anti-HIV drug development. They can serve as versatile building blocks to introduce different new functional groups, (i) as scaffolds to anchor these groups into the optimal space for interactions with the target, (ii) as basic pharmacophore elements to make hydrogen bonds or hydrophobic interaction for facilitating the spatial filling at the binding site, (iii) as ester surrogates to improve metabolic stability, or (iv) as pharmacophoric motif of metal coordination to coordinate metal ions (i.