Quinolones are considered as a big family of multi-faceted drugs; their chemical synthesis is flexible and can be easily adapted to prepare new congeners with rationally devised structures. This is shown by the description of many thousands of derivatives in the literature. Scientists could accurately describe their QSAR, which is essential for effective drug design. This also gave them the chance to discover new and unprecedented activities, which makes quinolones an endless source of hope and enables further development of new clinically useful drugs.Quinolones are among the most common frameworks present in the bioactive molecules that have dominated the market for more than four decades. Since 1962, 4(1H)-quinolone-3-carboxylic acid derivatives are widely used as antibacterial agents. Quinolones have a broad and potent spectrum of activity and are also used as second-line drugs to treat tuberculosis (TB). Recently, quinolones have been reported to display "nonclassical" biological activities, such as antitumor, anti-HIV-1 integrase, anti-HCV-NS3 helicase and -NS5B-polymerase activities.The present review focuses on the structural modifications responsible for the transformation of an antibacterial into an anticancer agent and/or an antiviral agent. Indeed, quinolones' antimicrobial action is distinguishable among antibacterial agents, because they target different type II topoisomerase enzymes. Many derivatives of this family show high activity against bacterial topoisomerases and eukaryotic topoisomerases, and are also toxic to cultured mammalian cells and in vivo tumor models. Moreover, quinolones have shown antiviral activity against HIV and HCV viruses. In this context the quinolones family of drugs seem to link three different biological activities (antibacterial, anticancer, and the antiviral profiles) and the review will also provide an insight into the different mechanisms responsible for these activities among different species.

BackgroundOmega-3 polyunsaturated fatty acids (n-3 PUFA) have been shown to alleviate the symptoms of metabolic disorders, such as heart disease, diabetes, obesity and insulin resistance. Several putative mechanisms by which n-3 PUFA elicit beneficial health effects have been proposed; however, there is still a shortage of knowledge on the proteins and pathways that are regulated by n-3 PUFA.MethodsUsing two dimensional polyacrylamide gel electrophoresis (2D-PAGE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, we investigated the effects of diets high or low in n-3 PUFA on hepatic proteomic profile of C57BL/6 mice.ResultsThe findings show for the first time that high dietary n-3 PUFA reduced the expression of regucalcin, adenosine kinase and aldehyde dehydrogenase. On the other hand, diets high in n-3 PUFA increased the expression of apolipoprotein A-I, S-adenosylmethionine synthase, fructose-1, 6-bisphosphatase, ketohexokinase, malate dehydrogenase, GTP-specific succinyl CoA synthase, ornithine aminotransferase and protein disulfide isomerase-A3.ConclusionsOur findings revealed for the first time that n-3 PUFA causes alterations in several novel functional proteins involved in regulating lipid, carbohydrate, one-carbon, citric acid cycle and protein metabolism, suggesting integrated regulation of metabolic pathways. These novel proteins are potential targets to develop therapeutic strategies against metabolic disorders.

-Purpose. Diabetes mellitus is characterized by hyperglycemia resulting from defects in insulin secretion, action or both. The use of medicinal plants for the treatment of diabetes mellitus dates back from the Ebers papyrus of about 1550 B.C. One of the major problems with herbal drugs is that the active ingredients are not well defined. It is important to know the active components and their molecular interactions which will help to analyze their therapeutic efficacy and also to standardize the product. There are a number of medicinal plants known for their anti-diabetic effect that possess similarities in their active chemical components, e.g. iridoid and secoiridoid glycosides. Methods. In this study, we have compared the structure of various iridoid and secoiridoid glycosides to design a novel pharmacophore. We further developed a structure-activity relationship for the inhibition of glycogen phosphorylase-a. Conclusion. By using docking studies, we are proposing, for the first time, that inhibition of glycogen phosphorylase-a activity is a common target for iridoids and secoiridoids to elicit anti-diabetic effects.

Novel polycyclic quinoline‐based heterocycles, structurally modeled on a promising antineoplastic agent, are synthesized.

Heterocyclic systems with a quinoline nucleus represent the most spectacular example of privileged molecules in medicinal chemistry, as their biological activities are surely affected by changes in structural features.Quinoline derivatives have been shown to display a wide spectrum of biological activities such as antibacterial, antifungal, antiparasitic, antiviral, cytotoxic and anti-inflammatory activities. In this study, several 7-hydroxy-8-oxo-8,9-dihydrobenzo[h]thieno[2,3-b]quinoline-9-carboxylic acids were designed, synthesized, and were further subjected to chemical reactions such as alkylation and annelation.The synthesized compounds were also subjected to docking study and biological evaluation. This work was mainly designed to shed light on the requirements for the quinoline nucleus to act as an anticancer agent. Unexpectedly, the synthesized derivatives showed weak or no cytotoxicity against cancer cell lines and the increase in the extent of aromatic/condensed rings did not increase the affinity toward the double stranded DNA. Our virtual screening demonstrated that the chelation with Mg 2+ is a determining factor in the expected interaction with Topoisomerases. Key synthetic issues, crystallographic and docking studies have also been described.