Tuberculosis and other mycobacterial diseases are considered to be one of the most important problems of contemporary health service. Since 1985 and particularly in the 1990s and at present the search for new structures of antimycobacterial agents have ranked among the foremost areas of chemotherapeutic research. The present review paper is already the 16 th communication in a group of review papers about the development of new antituberculotics in recent 15 years. The literature search is based on the journal Chemical Abstracts, Current Awareness in Biomedicine, part Mycobacteria, and original papers. Current Awareness in Biomedicine is, however, a very imperfect literature search source, recording only a fraction of communications. Though none of the ortho-condensed heterocyclic compounds has been introduced into practice, the in vitro evaluated activities of some of them equalled those of routine antituberculotics. Polycyclic systems make it possible to widely model the structures, and therefore the present review paper can inspire a search for new structures of antimycobacterial agents.

        Key words: tuberculostatics - heterocycles - mycobacteria