The aerial parts of Ocimum basilicum L. were collected from four different geographical locations, Sindhuli and Biratnagar (Nepal), Chormaghzak village (Tajikistan), and Sana'a (Yemen). The essential oils were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry. A cluster analysis of 179 essential oil compositions revealed six major chemotypes: Linalool, eugenol, estragole, methyl eugenol, 1,8-cineole, and geraniol. All four of the basil oils in this study were of the linalool-rich variety. Some of the basil oils were screened for bioactivity including antimicrobial, cytotoxicity in human cancer cells, brine shrimp lethality, nematicidal, larvicidal, insecticidal, and antioxidant. The basil oils in this study were not notably antibacterial, cytotoxic, antioxidant, nor nematicidal, but were active in the brine shrimp lethality test, and did show larvicidal and insecticidal activities.

Origanum tyttanthum Gontsch. was collected from two different sites in south-central Tajikistan. The essential oils were obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. A total of 52 compounds were identified representing 99.0-100% of total oil compositions. The major components of Origanum tyttanthum Gontsch. oil were carvacrol (34.3-59.2%), thymol (10.8-46.4%), p-cymene (0.7-7.3%), β-thujone (1.9-4.1%), piperitenone oxide (0.1-3.8%), γ-terpinene (0.3-3.5%), cis-piperitone epoxide (0.8-3.3%), carvacrol acetate (0.4-2.4%), menthone (0.6-2.1%) and borneol (1.0-2.3%).

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in Wiley Online Library (wileyonlinelibrary.com).2-Alkyl-, 2-aryl-, and 2-halo-substituted derivatives of 7-methyl-6-fluoro-1,3,4-thiadiazolo[3,2-a]pyrimidin-6-one (3) were prepared by reaction of 2-substituted 5-amino-1,3,4-thiadiazoles (1) and ethyl 2-fluoroacetoacetate (2) in polyphosphoric acid. A convenient procedure was developed for the synthesis of new 2-amino derivatives of 2-R-7-methyl-6-fluoro-1,3,4-thiadiazolo[3,2-a]pyrimidin-6-one (5).

Fused pyrimidine derivatives R 0515Synthesis and Antimicrobial Activity of 2-Bromo-7-methyl-5-oxo-5H-1,3,4-thiadiazolo[3,2-a]pyrimidine. -The title compound (III) shows a wide spectrum of antimicrobial activity on the level of oxytetracyclin hydrochloride. -(SALIMOV, T. M.; KUKANIEV, M. A.; SATTOROV, I. T.; OSIMOV, D. M.; Khim.-Farm. Zh. 39 (2005) 6, 28-29; Tajik Vet. Res. Inst., Acad. Agric. Sci., Dushanbe 734005, Tajikistan; Russ., Abstr. Eng.) -Y. Steudel 43-175

2‐Amino substituted 7H‐1,3,4‐thiadiazolo[3,2‐α]pyrimidin‐7‐ones 11a‐e were prepared by the reaction of 2‐bromo‐5‐amino‐1,3,4‐thiadiazole (1b) and diketene (8), subsequent cyclocondensation (9b → 3b) and displacement of the bromo substituents by the reaction with primary or secondary amines (3b → 11a‐e). The hydrogen atom 6‐H in the heterobicycle 3b is replaced by a Cl or Br atom in the transformation of 3b → 14a,b. The 2‐bromo‐6‐chloro compound 14a reacts chemoselectively in the 2‐position with dimethylamine (14a → 15). The structure elucidations are based on one‐ and two‐dimensional NMR techniques including a heteronuclear NOE measurement.

The reaction of primary or secondary amines with 2,5-dibromo-6-phenylimidazo[2,1-b][1,3,4]-thiadiazole (5) leads to a chemoselective replacement of the 2-Br substituent. The process represents a convenient route to the corresponding 2-ylamines 7a-d. Hydrazine reacts in an analogous fashion (5 7e). The structure determinations are based on an X-ray crystal structure analysis and on one-and two-dimensional NMR measurements.

The synthesis of 2-bromo-7-methyl-5-oxo-5H-1,3,4-thiadiazolo[3,2-a]pyrimidine is described. This compound exhibits a broad spectrum of antimicrobial action and can be useful in the search for new antimicrobial drugs.