Synthesis and antituberculosis activity of novel unfolded and macrocyclic derivatives of ent-kaurane steviol.

New derivatives of steviol 1, the aglycone of the glycosides of Stevia rebaudiana, including a novel class of semisynthetic diterpenoids, namely macrocyclic ent-kauranes were synthesized. These compounds possess antituberculosis activity inhibiting the in vitro growth of Mycobacterium Tuberculosis (H37R(V) strain) with MIC 5-20 μg/ml that is close to MIC 1 μg/ml demonstrated by antituberculosis drug isoniazid in control experiment. For the first time it was found that the change of ent-kaurane geometry (as in steviol 1) of tetracyclic diterpenoid skeleton to ent-beyerane one (as in isosteviol 2) influences on antituberculosis activity.

Synthesis and antimycobacterial activity of novel 1,3-dimethylisocyanurate derivatives.

A series of novel 1,3-dimethylisocyanurates has been synthesized as potential inhibitors of β-ketoacyl synthase in mycobacteria. Most of the 25 compounds described and tested for their activity against M. tuberculosis have a bacteriostatic effect, comparable and even higher that of first-line antituberculosis drugs.

[Synthesis and antituberculosis activity of the derivatives of glycoside steviolbioside from the plant Stevia rebaudiana and diterpenoid isosteviol containing hydrazone, hydrazide and pyridinoyl moieties].

Conjugates of antitubercular drug Isoniazid (hydrazide of isonicotinic acid), nicotinic and alpha-picolinic acid hydrazides and glycoside steviolbioside from the plant Stevia rebaudiana as well as the product of its acid hydrolysis, diterpenoid isosteviol, were synthesized. Besides, isosteviol hydrazide and hydrazone derivatives as well as conjugates containing two isosteviol moieties connected by dihydrazide linker were also obtained. Both initial compounds and their synthetic derivatives inhibit the growth of Mycobacterium tuberculosis (H37Rv in vitro).

Comparison of Lumin LED fluorescent attachment, fluorescent microscopy and Ziehl-Neelsen for AFB diagnosis.

Design: Cross-sectional studies in Russia (n = 502) and Macedonia (n = 205), with fluorochrome-stained sputum examined by 1) the new Lumin light emitting diode (LED) fluorescent attachment on a light microscope, and 2) conventional fluorescent microscope (CFM) available in each laboratory, and compared to 3) Ziehl-Neelsen (ZN) restaining/reading of the same smears. Poor readings of ZN-restained smears in Russia stimulated a retrospective laboratory registry analysis for sensitivity and specificity of directly ZN-stained smears (n = 791) from a previous period.

Results: In Macedonia, the sensitivity of the Lumin and CFM were 87.