Preface [Hot Topic: Advances in the Studies of Anti-HIV Drugs - Part II (Guest Editor: S.P. Gupta) ]

This Part II of the hot topic issue on Advances in the Studies of Anti-HIV Drugs contains articles mainly related to integrase inhibitors. Presently, the reverse transcriptase (RT) and protease inhibitors, that have been mainly described in Part I, are used in combination to effectively treat the HIV-1 infection. Though this combination therapy has exhibited multiple clinical benefits, the emergence of resistance highlights the need of new anti-HIV agents. Consequently, the researchers focused their attention on new agents able to interfere with additional steps of viral replication and one of them, found to be most crucial, is the integration of the viral DNA into the host cell genome. This step is catalyzed by the enzyme integrase (IN). In the very first article of this issue, Soultrait et al. discuss a combination therapy of RT and IN inhibitors that is based on peptides. Though peptides have long been considered as poor drug candidates, current knowledge on improving the stability and bioavailability of these agents may lead to the effective use of peptides in therapy. Integrase Inhibitors have lately drawn great attention of the chemists and so three most comprehensive articles (2-4), covering all uptodate developments in the area have been fetched. In article 2, Gupta and Nagappa have reviewed all different categories of IN inhibitors, pointing out in each category the important structural features that may be essential for IN inhibition. On the other hand, in article 3, Maurin et al. have presented a detailed study on SARs of these inhibitors and their modes of interaction with the enzyme, and in article 4, Parrill has highlighted even more critically the binding sites, SARs, and future prospectives of these IN inhibitors. In the last article (article 5), Anatasi et al. discuss new antiviral nucleoside prodrugs which have been developed in recent years, so as to improve the efficacy of a given antiviral drug or to overcome several drug deficiencies. Examples of carrierlinked nucleoside prodrugs or nucleoside bioprecursors have been presented and their active mechanism discussed. Thus, this issue covers 5 excellent articles, which I found quite stimulating and informative and hope that the readers will also enjoy reading them. I heartily acknowledge the interest and the zeal that the authors have shown in contributing these articles.