1,720,985 research outputs found
Design, synthesis and biological activity evaluation of new HIV-1 reverse transcriptase dual inhibitors
No full textShape based computer aided similarity screening: a valid tool in the discovery of new scaffolds for the inhibition of HIV-1 reverse transcriptase associated ribonuclease H function
No full textBackground. The human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) is one of the most attractive targets in the design of new antivirals. It is a key enzyme for viral replication which has two associated catalytic functions: a DNA polymerase activity, that recognizes both RNA and DNA as template, and a ribonuclease H (RNase H) activity that selectively degrades the RNA of the hybrid RNA:DNA replicative intermediate. Recently, a few hydrazone derivatives has been reported to selectively inhibit the HIV-1 RNase H function.
Methods. The highly optimized screening platform Rapid Overlay of Chemical Structures (ROCS) was used to perform in silico similarity screening. HIV-1 RT activities were measured in biochemical assays and HIV-1 replication was tested in cell culture assays.
Results. We focused on the design of new scaffolds for the inhibition of the HIV-1 RT-associated RNase H function by performing a computer sided shape based similarity screening study whose driving force is the assumption that molecules with similar shape to known active ones should exhibit comparable biological properties. In particular, using the highly optimized screening platform ROCS for shape-based virtual screening of the large database obtained from the National Cancer Institute we have identified a set of molecules characterized by different scaffolds which have been tested on the HIV-1 RT functions. Compounds with different scaffolds have shown to inhibit one or both RT-associated activities.
Conclusions. New scaffolds for the inhibition of the HIV-1 RT-associated RNase H function have been identified and will be further developed
1H NMR study of the interaction of trans-resveratrol with soybean phosphatidylcholine liposomes
Full text linkResveratrol (RSV) is a well-known natural derivative with a wide range of biological and pharmacological activities. Despite of these demonstrated properties, it exhibits low both aqueous solubility and chemical stability and therefore low bioavailability. Consequently, the major concern of the technological research is to exploit delivery systems able to overcome bioavailability problems. In the recent past liposomes have been successfully studied for these purposes. In this paper, 1H-NMR spectroscopy, Nuclear Overhauser Spectroscopy (NOESY) as well as Paramagnetic Relaxation Enhancements (PRE) experiments have been carried out to quantitatively investigate the incorporation of resveratrol, at both the liposome preparation stage and by preformed liposomes, also with the aim to characterize resveratrol- soybean phosphatidylcholine (P90G) lipid bilayer interactions. Overall results of 1H NMR spectroscopy analysis suggest that RSV is located nearby the phosphocholine headgroups and also provide quantitative data on the incorporation of RSV (5% w/w), which corresponds to a 150-fold increase with respect to the solubility of RSV in water. Beside, considering that the same level of RSV incorporation was obtained via spontaneous uptake by preformed P90G liposomes, it can be concluded that RSV easily diffuses through the lipid bilayer
Synthesis and antimicrobial activity of novel arylideneisothiosemicarbazones
No full textArylidenimidazoles bearing a thioethereal function in the position 2 of the imidazole ring show good antimicrobial activity. We now report on the synthesis and the biological properties of some novel arylidenisothiosemicarbazones, structurally related to the arylideneiminoimidazoles of which they can be considerecd the linear precursors. Particular attention has been put on the influence of structural modifications on the biological activity. Copyright (C) 2000 Elsevier Science S.A
Progettazione e sintesi di 4-(5-ariliden-3-metil-4-ossotiazolidin-2-ilidenamino)benzensulfonamidi e 4-(5-alchiliden-3-metil-4-ossotiazolidin-2-ilidenammino)benzensulfonamidi quali potenziali inibitori selettivi delle ciclossigenasi 2
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Characterization of 2,5-diaryl-1,3,4-oxadiazolines by multinuclear magnetic resonance and DFT calculations. Investigation on a case of very remote Hammett correlation
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