Current Medicinal Chemistry - Volume 13, Issue 2, 2006

Leukotrienes play an important role in the inflammatory process accompanying allergic diseases of respiratory, gastrointestinal and dermatological systems. Leukotrienes are generated from arachidonic acid as a result of the 5-lipoxygenase action. This paper deals with 5-lipoxygenase action mechanism and the following biosynthesis of all leukotrienes. In this article, potential antileukotrienic agents are classified according to their mechanism of action. The original antileukotrienic compounds of the Research Institute for Pharmacy and Biochemistry in Prague (VUFB), Czech Republic are presented in a separate chapter of the paper.

Symmetry plays a crucial role in a variety of biological processes. For instance, many protein receptors, upon activation, dimerize to its active form and subsequently produce its biological action. Hence, there is a renewal of curiosity for the synthesis of dimeric molecules (or bivalent ligands) capable, not only to interact with specific biologic receptors, but also to induce greater biological responses than the corresponding monomeric counterpart. This is a vast and diverse theme of research. Hence, this review will discuss recent developments into this flourishing research field and will focus mainly into four specific topics namely dimeric 1) anticancer agents, 2) anti-HIV, 3) steroid derivatives and 4) opioid antagonists.

The proteasome recently gained an exceptional attention as a novel drug target, therefore its inhibitors became important subjects for rational drug design. A synthetic competitive inhibitor Velcade was lately approved in a fast-track process to treat multiple myeloma and is tested with other types of cancers. The proteasome is a major proteolytic assembly in eukaryotic cells responsible for the degradation of most intracellular proteins, including proteins crucial to cell cycle regulation and apoptosis. The ubiquitin-proteasome pathway has been implicated in many diseases such as cancer, autoimmune diseases, inflammation, and stroke. The activity of the proteasome can be blocked for therapeutic purposes with competitive inhibitors like Velcade, which trigger apoptosis in target cells. However, much more versatile outcomes and a true control of the proteasome can be achieved with allosteric regulators. Certain natural proteins and peptides bind to the catalytic core of the proteasome and allosterically induce a wide array of effects ranging from changes in product size to substrate-specific inhibition. Designing small synthetic compounds allosterically interacting with the proteasome represents a novel approach that has enormous potential for the treatment of a wide range of diseases. Below we provide a review of current knowledge about proteasomal allosteric ligands.

In this article we provide an overview on the medicinal chemistry of new bioactive N-acylhydrazone (NAH) derivatives designed through the structural optimization of N-arylhydrazone precursors, originally planned by molecular hybridization of two known 5-lipoxygenase inhibitors, i.e. CBS-1108 and BW-755c. The analgesic, antiedematogenic and platelet anti-aggregating profile of several isosteric NAH compounds was investigated by using classical in vivo and ex-vivo pharmacological assays, which allowed the identification of new potent centrally and peripherically-acting analgesic leads, new antiinflammatory agents and new antithrombotic prototypes. During this study, dozens of active NAH compounds were discovered, clarifying the structure-activity relationships for this series of derivatives and indicating the pharmacophoric character of the N-acylhydrazone moiety for its biological profile.

Prenyloxycoumarins and prenyloxyfuranocoumarins (isopentenyloxy-, geranyloxy-, linear and cyclic sesquiterpenyloxy compounds and their biosynthetic derivatives) represent a family of secondary metabolites that have been considered for years just as intermediates of other coumarin-based compounds. Only in the last two decades these secondary metabolites have been recognized as interesting and valuable biologically active natural products. Up to now more than 160 compounds have been isolated from plants mainly belonging to the families of Rutaceae and Umbelliferae, comprising common edible vegetables and fruits like lemons, oranges and grapefruits. In view of the biological activity of some natural prenyloxycoumarins, very recently syntheses of structurally related analogs aimed to establish detailed structure-activity relationships have also been carried out. Many of the isolated prenyloxy- and prenyloxyfuranocoumarins and their semisynthetic derivatives were shown to exert in vitro and in vivo remarkable antitumoral, anti-inflammatory and anti-viral effects. The object of this review is to examine in detail the different types of prenyloxycoumarins and prenyloxyfuranocoumarins from the chemical, phytochemical and biological point of view.

The solubility of drugs and drug-like compounds has been the subject of extensive studies aimed at finding a way to predict solubility from molecular structure. The aqueous solubility of a drug is an important factor that influences its absorption, distribution and elimination in the body. Poor aqueous solubility often causes a drug to appear inactive and may cause other biological problems. Compound solubility in DMSO represents another serious problem in early stages of drug discovery. An appreciation of the factors affecting a compound's DMSO solubility could help in predicting the storage conditions and appropriateness of compounds for primary bioscreening programs. In silico procedures for estimation of water and DMSO solubility represent extremely useful tools for the drug discovery practitioners. In this review, we provide a critical discussion of in silico models for the prediction of DMSO and water solubility of drug-like compounds used for virtual screening. We describe the main tendencies in the field, "booming" approaches and unsolved problems. A critical analysis of the accuracy and applicability of methods is provided.