Pyrazine biological activity

Before the discovery of streptomycin, pyrazinamide (126) was one of the front runners in the treatment of tuberculosis. A broad spectrum of biological activity has been associated with pyrazine derivatives, ranging from the herbicidal activity of (127) to antibiotic activity... 

Synthetic studies on biological activities of marine-origin polycyclic bis-steroid systems with 0-heterocyclic and pyrazine fragments or spirooxazoline fragment 99PAC1095. 

The preparation of biologically active [l,2,4]triazolo[l,5- ]pyrazines has been reported recently. The reaction routes are shown in Scheme 50. Dowling et al. reported <2005BML4809> the synthesis of aryl-substituted derivatives 411. The first step was the transformation of the 2-aminopyrazine compound 409 to an amidine 410, which was subjected... 

A second example of a mammalian multicomponent pheromone is the puberty-delaying pheromone from female house mice, Mus musculus. Two acetate esters and a pyrazine are biologically active in various combinations, but the pyrazine is also active alone (Novotny etal, 1985a). 

The biologically active relatives of folic acid and biopterin are the tetrahydro compounds with a reduced pyrazine ring. Reduction to this level occurs rapidly in vivo. The corresponding electrochemical process is well illustrated by reduction of the N-methylated analogue 28 [95], Reduction to the 5,8-dihydro stage is a reversible two-electron and two-proton process. The product rapidly tautomerises to the... 

The bis(indolo)pyrazine moiety is a structural motif that attracted attention due to its potent biological activity. An elegant construction of the frame reported by Jiang and co-workers utilizes the sequential crosscoupling of indole units and the pyrazine core. 2,5-Dibromo-3-... 

Reference has already been made in this article to pyrazines with antibacterial, antituberculous, antidepressant, diuretic, pesticidal, and herbicidal activity. A review further illustrates the wide range of biological activities of pyrazine derivatives.432... 

The volatile components from the urine of normal and adrenalectomized female mice were compared and chemical differences identified through gas chromatographic analysis.131 Six simple compounds accounted for the majority of the difference, at least from the perspective of concentration. These were 2-heptanone (41), ( )-hept-5-en-2-one (42), ( )-hept-4-en-2-one (43), -pentyl acetate (44), (Z)-pent-2-enyl acetate (45), and 2,5-dimethylpyrazine (46). When authentic samples of 41—46 were added to urine from adrenalectomized animals and their concentrations restored to the levels of normal urine, full recovery of biological activity (delay of first estrus) was observed.131 Subsequent studies have confirmed the biological responses to pyrazine 46.132... 

The general term oxypyrazine is used here to include derivatives such as the cy-cloamidic tautomeric pyrazinones (1), the alcoholic hydroxyalkylpyrazines (2), the etherial alkoxypyrazines (3-5), the cycloamidic nontautomeric pyrazinones (6), and pyrazine A-oxides (7, 8) in addition, related types like diketopiperazines, acy-loxypyrazines, pyrazine quinones, and endoperoxypyrazines are covered as appropriate. Some brief ancillary information on trivial names, natural occurrence, and biological activities of pyrazines (mainly oxy derivatives) is collected in a final Appendix section. 

The antitubercular activity of 2-carbamoylpyrazine and biological activity of pyrazines generally has been mentioned in Section 1.4. Certain pyrimidinyl derivatives of 2-carbamoylpyrazine have been shown to have lower toxicity and rather greater in vitro activity against Mycobacterium tuberculosis than 2-carbamoylpyrazine (1388), and the antitubercular activity of some extranuclear )V-substituted carbamoylpyrazines also showed a higher activity than 2-carbamoylpyrazine (1201). When tested on mice in vivo, 2-carbamoyl-5-methoxypyrazine and 2-hydrazino-carbonylpyrazine had less antitubercular activity than did 2-carbamoylpyrazine (1098) the antitubercular activities in a series of hydrazinocarbonyl-, carbamoyl-, and thiocarbamoylpyrazines have been examined and compared (1399). 

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