Mini Reviews in Medicinal Chemistry - Volume 15, Issue 2, 2015

Transmissible spongiform encephalopathies (TSEs) are infectious neurodegenerative disorders for which symptomatic, curative, or prophylactic treatments are not available. TSEs arise as a consequence of the conversion of soluble cellular prion protein (PrPC) into the scrapie isoform (PrPSc), which aggregates and accumulates in the central nervous system. Proposed drugs against TSEs range from small organic compounds to antibodies; various therapeutic strategies have been proposed, including blocking the conversion of PrPC to PrPSc, increasing PrPSc clearance, and/or stabilizing PrPC. While several compounds have been effective in vitro and in animal models, none have proven effective in clinical studies to date. Such lack of in vivo efficacy is attributable to high compound toxicity and the lack of permeability of the selected compounds across the blood–brain barrier. In this review, we discuss recent advances in the screening and evaluation of organic compounds for anti-prion activity using multiple approaches, including initial screening in prion-infected cell cultures, in silico prediction of pharmacokinetic and physicochemical properties, ex vivo evaluation of cellular toxicity, and in vitro assays using purified recombinant prion proteins. The main challenges for effective discrimination of candidate lead compounds as therapeutic agents for TSEs, and the disadvantages of each screening strategy are discussed. We propose that a combination of in vitro, ex vivo, and in silico approaches would be useful for the rapid identification of novel anti-prion drug candidates with suitable pharmacokinetic and pharmacodynamic properties that would support their use as drugs.

This is a second part of a review under a main title Antiviral medication in sexually transmitted diseases. In the part we published in Mini Rev Med Chem. 2013,13(13):1837-45, we have described mechanisms of action and mechanism of resistance to antiviral agents used in genital herpes and genital HPV infection. The Part II review focuses on therapeutic options in HIV infection. In 1987, 6 years after the recognition of AIDS, the FDA approved the first drug against HIV - zidovudine. Since then a lot of antiretroviral drugs are available. The most effective treatment for HIV is highly active antiretroviral therapy - a combination of several antiretroviral medicines that cause a reduction of HIV blood concentration and often results in substantial recovery of impaired immunologic function. At present, there are over 20 drugs licensed and used for the treatment of HIV/AIDS, and these drugs are divided into one of six classes. Investigational agents include GS-7340, the prodrug of tenofovir and BMS-663068 - the first in a novel class of drugs that blocks the binding of the HIV gp120 to the CD4 receptor.

Diabetes mellitus, including type 1 and type 2 diabetes mellitus (2-DM) are the main threats to human health in the worldwide. Protein tyrosine phosphatase 1B (PTP1B) is a promising molecular level legitimate therapeutic target in the effective management of 2-DM. For the search of potent PTP1B inhibitors, much investigation has revealed a large number of small-molecule compounds obtained from natural sources or prepared by synthesis/semi-synthesis with various skeletons and promising anti-PTP1B activities in the treatment of 2-DM. Although some reviews on the development of PTP1B inhibitors have been published, they were mainly concentrated on the results reported in journal articles. In this review, we will provide an overview of the developments of the potent PTP1B inhibitors claimed in recent patents during the past five years (2009-2013) with their structural features and biological features, as well as the structure-activity relationships (SARs) and strategies for finding potent and specific PTP1B inhibitors. This paper will provide valuable information for understanding the current anti-PTP1B investigation and developing potent PTP1B inhibitors as treating 2-DM drugs.

Rheumatoid Arthritis (RA) is an autoimmune disease characterized by persistent inflammation and joint damage. The main aim of RA treatment is to control the disease progress. Despite the success of biologicals like Adalimumab, Atlizumab, infliximab, etc. in treatment of RA, the high cost and associated immunological adverse effects have triggered discovery of small molecules targeting RA. This review describes the last 15 years of small molecular drug discovery in RA, focused mainly on preclinical and clinical studies.

Piperine is a simple alkaloid isolated from the seeds of Piper nigrum. Piperine and its derivatives exhibited a wide range of biological properties such as antitumor activity, antioxidant activity, antiinflammatory activity, antimycobacterial activity, insecticidal activity, etc. Although five excellent reviews have recently been described by Srinivasan in 2007, Mao in 2011, Butt in 2013, and Meghwal in 2013, respectively, their topics were mainly focused on the biological effects. Therefore, in the present review, the progress in the structural modifications on the aliphatic chain and the amide moiety of piperine was reported. Meanwhile, the biological activities and structure-activity relationship of piperine and its derivatives were also described.

Higher fungi (i.e. macrofungi) do not form a natural taxonomic or ecological group. They are defined as those fungi that produce large, easily observed and collected sporocarps. Most of the higher fungi species are from the phyla Basidiomycota and Ascomycota. These fungi are of particular interest because of their importance as food resource and culture component in many places of the world. Therefore, study of their diverse natural products has become a hot topic. China has the most diverse fungi in the world. We investigated the chemical constituents of Basidiomycetes and Ascomycetes from China, and our ongoing search bioactive metabolites from higher fungi could potentially be developed into new ‘lead’ compounds. We review the isolation, structural elucidation and biologically activity of the rich natural products newly derived from higher fungi collected in China after July 2007.