Laura Vargiu

1,5-Benzodiazepines. Part XII. Synthesis and biological evaluation of tricyclic and tetracyclic 1,5-benzodiazepine derivatives as nevirapine analogues

A number of properly substituted 5H-pyrimido[4,5-b][1,5]benzodiazepines (2) and pyrazolo[3,4-b][1,5]benzodiazepines (3 and 4), as well as compounds 5-7, which are derivatives of new tetracyclic systems, were prepared as nevirapine analogues through multistep synthetic routes. The cytotoxic and anti-HIV-1 properties of compounds 2-7 were evaluated in cell-based assays, together with their inhibitory activity against the HIV-1 recombinant reverse transcriptase (rRT) in enzyme assays. The modifications introduced into nevirapine heterocyclic skeleton proved to have a negative effect for the anti-HIV-1 activity. It is worth noting that some of the new derivatives proved to be cytotoxic in the low micromolar range.

Classification and characterization of human endogenous retroviruses; mosaic forms are common

BackgroundHuman endogenous retroviruses (HERVs) represent the inheritance of ancient germ-line cell infections by exogenous retroviruses and the subsequent transmission of the integrated proviruses to the descendants. ERVs have the same internal structure as exogenous retroviruses. While no replication-competent HERVs have been recognized, some retain up to three of four intact ORFs. HERVs have been classified before, with varying scope and depth, notably in the RepBase/RepeatMasker system. However, existing classifications are bewildering. There is a need for a systematic, unifying and simple classification. We strived for a classification which is traceable to previous classifications and which encompasses HERV variation within a limited number of clades.ResultsThe human genome assembly GRCh 37/hg19 was analyzed with RetroTector, which primarily detects relatively complete Class I and II proviruses. A total of 3173 HERV sequences were identified. The structure of and relations between these proviruses was resolved through a multi-step classification procedure that involved a novel type of similarity image analysis (“Simage”) which allowed discrimination of heterogeneous (noncanonical) from homogeneous (canonical) HERVs. Of the 3173 HERVs, 1214 were canonical and segregated into 39 canonical clades (groups), belonging to class I (Gamma- and Epsilon-like), II (Beta-like) and III (Spuma-like). The groups were chosen based on (1) sequence (nucleotide and Pol amino acid), similarity, (2) degree of fit to previously published clades, often from RepBase, and (3) taxonomic markers. The groups fell into 11 supergroups. The 1959 noncanonical HERVs contained 31 additional, less well-defined groups. Simage analysis revealed several types of mosaicism, notably recombination and secondary integration. By comparing flanking sequences, LTRs and completeness of gene structure, we deduced that some noncanonical HERVs proliferated after the recombination event. Groups were further divided into envelope subgroups (altogether 94) based on sequence similarity and characteristic “immunosuppressive domain” motifs. Intra and inter(super)group, as well as intraclass, recombination involving envelope genes (“env snatching”) was a common event. LTR divergence indicated that HERV-K(HML2) and HERVFC had the most recent integrations, HERVL and HUERSP3 the oldest.ConclusionsA comprehensive HERV classification and characterization approach was undertaken. It should be applicable for classification of all ERVs. Recombination was common among HERV ancestors.

Synthesis and antiproliferative activity of 3-aryl-2-(1H-benzotriazol-1-yl)acrylonitriles. Part III

A new series of 30 3-aryl-2-(1H-benzotriazol-1-yl)acrylonitriles were synthesized and tested for biological activity as part of our research in the antimicrobial and antitumor fields. In particular, title compounds were evaluated in vitro against representative strains of Gram-positive and Gram-negative bacteria (S. aureus, Salmonella spp), mycobacteria (M. fortuitum, M. smegmatis ATCC 19420 and M. tuberculosis ATCC 27294), yeast and mould (C. albicans ATCC 10231 and A. fumigatus). Furthermore, their antiretroviral activity against HIV-1 was determined in MT-4 cells together with cytotoxicity. In these assays title compounds and 47 additional derivatives described previously (P. Sanna, A. Carta, M.E. Rahbar Nikookar, Eur. J. Med. Chem. 35 (2000) 535-543; P. Sanna, A. Carta, L. Gherardini, M.E. Rahbar Nikookar, Farmaco 57 (2002) 79-87) were tested for their capability to prevent MT-4 cell growth. All compounds resulted devoid of antibacterial, antifungal and anti-HIV-1 activity. In anti-mycobacterial assays several compounds resulted active (MIC(50)=6.0-70 microM) against M. tuberculosis. However, since they showed cytotoxicity against MT-4 cells at lower concentrations (CC(50)=0.05-25 microM), their anti-mycobacterial activity was not selective. For this reason, the most cytotoxic compounds were also evaluated for antiproliferative activity against a panel of human cell lines derived from both hematological and solid tumors. Compound 34 resulted the most potent compound against the above human tumor-derived cell lines.

Isolation of Juniperus phoenicea Volatiles by Supercritical Carbon Dioxide Extraction and Bioactivity Assays

Abstract By means of a supercritical fluid extractor, extract of Juniperus phoenicea L. was obtained in a single extraction stage. The yield was 0.2% by mass. The operative conditions were: extractor, pressure, P = 90 bar and temperature, T = 50°C; first separator, P = 90 bar and T = −10°C; second separator, P = 15 bar and T = 10°C. The hydrodistilled oil gave a yield of 0.3% by mass. In both extracts, the three compounds present in the biggest quantity were: α-pinene (18.4 versus 13.9% in the SFE and HD oil, respectively), germacrene D (14.3 versus 8.1%) and β-caryophyllene (8.7 versus 5.4%). The extracts obtained at different pressures were tested for antiviral, antiproliferative and antimicrobial activities. The results showed that the extracts obtained at 200 and 300 bar were cytotoxic against different cell lines and were active against a single-stranded RNA+ virus. The extracts containing the most cytotoxic active principles showed also antiproliferative activity against a panel of human cell lines derived from liquid and solid tumors. When tested for antimicrobial activity none of the samples resulted active.

Pyrazole Related Nucleosides 5.1 Synthesis and Biological Activity of 2′-Deoxy- 2′, 3′-dideoxy- and Acyclo-analogues of 4-Iodo-1-β-D-ribofuranosyl-3-carboxymethyl Pyrazole (IPCAR)

Abstract Continuing our studies on the structure-activity relationships (SAR) of 4-iodo-1-β-D-ribofuranosyl-3-carboxymethyl pyrazole (IPCAR), the ribofuranosyl moiety has been substituted with acyclic chains, namely 1-[(2-hydroxyethoxy)methyl]- and 1-[(1,3-dihydroxy-2-propoxy)methyl]-pyrazole derivatives (4, 5 and 8, 9 respectively), with the 2′-deoxy-β-D-ribofuranosyl group (12 and 13) and finally with the 2′,3′-dideoxy-D-glycero-pentofuranosyl-moiety (16 and 17). None of the new compounds display any interesting biological activity.

Disoxaril-related 3-(diethylamino)-5-phenylisoxazoles.

Previous research has shown that 3-(dialkylamino)-5-phenylisoxazoles possessing a compact structure were active against HRV-2 and, consequently, presented a type B activity. In this paper, 3-(diethylamino)-5-phenylisoxazoles, which are structurally more elongated and related to Disoxaril, were synthesized in view to attempt type A activity against HRV-14. Unfortunately, all tested compounds were devoid of activity against HRV-14 (and HIV-1) or exhibited great toxicity.

Identification and analysis of HML2 sequences in human genome assembly GRCh37/hg19

Background Human endogenous retroviruses (HERVs) originated from exogenous retroviral infections of the human germ line cells and spread in the human population through vertical transmission over millions of years. Among HERVs, the HML2 proviruses [1] are the most recently integrated and show the most intact proviral genomes. HML-2 expression has tentatively been associated with different pathological conditions, including Hodgkin’s lymphoma, melanoma, breast and testicular cancer. A comprehensive recent study identified 91 HML2 proviruses [2].