Ten simple stimuli from the heterocyclic class of nitrogen chemicals known as pyrazines were arranged in a three-dimensional space by INDSCAL using similarity judgments by 12 young and 11 elderly subjects as input. Odor quality at two intensity levels, moderate and strong, was examined. At both concentrations, pyrazines with the highest intrinsic polarity were arranged separate from unsubstitut...

Pyrazines and substituted pyrazines undergo addition of boron reagents having B-B, Si-B, and H-B bonds under transition-metal-free conditions, leading to high-yield synthesis of N-borylated 1,4-dihydropyrazines and 1,2,3,4-tetrahydropyrazine.

The effects of a number of 1,2-dihydropyrido[3,4-b]pyrazines (1-deaza-7,8-dihydropteridines) upon the proliferation and the mitotic index of cultured L1210 cells and upon the survival of mice bearing P388 leukemia were determined. The 1,2-dihydrostructure and amino groups or masked amino groups at positions 5 and 7 were necessary for activity, and various substituents at positions 2 and 3 had c...

Pyrazines are specific Maillard reaction compounds known to contribute to the unique aroma of many products. Most studies concerning the generation of pyrazines in the Maillard reaction have focused on amino acids, while little information is available on the impact of peptides and proteins. The present study investigated the generation of pyrazines in model systems containing whey protein, hyd...

• Pyrazines are compounds naturally found in varieties like Sauvignon blanc and Cabernet Sauvignon, as well as in most unripe grapes. There are many types of pyrazines, the best known being isobutylmethoxypyrazine (IBMP), responsible for the bell pepper aroma. Another methoxypyrazine, isopropylmethoxypyrazine (IPMP) has recently been identified as the causal agent of “ladybug taint” (LBT), firs...

Transition metal-catalyzed reactions are generally used for carbon-carbon bond formation on pyrazines and include, but are not limited to, classical palladium-catalyzed reactions like Sonogashira, Heck, Suzuki, and Stille reactions. Also a few examples of carbon-heteroatom bond formation in pyrazines are known. This perspective reviews recent progress in the field of transition metal-catalyzed ...

Palladium-catalyzed cross-coupling of (di)chloropyrazines with phosphorus pronucleophiles in the presence of a base gave the phosphorylated pyrazines in 81-95% yields. Based on this methodology a series of appropriately functionalized pyrazines was prepared as potential extractants of trivalent cations from highly acidic nuclear waste. A few hydrophilic derivatives exhibited a very good selecti...

OF Ph.D. THESIS Design and Synthesis of Pyrazines, Imidazolones, Chromones and their Anticancer and Transacetylase Activities TO BE SUBMITTED TO THE UNIVERSITY OF DELHI FOR THE AWARD OF DEGREE OF DOCTOR OF PHILOSOPHY

Epeolus, Coelioxys, Cephalic Secretions, Pyrazines, Spiroacetals Volatile cephalic secretions from females of four cleptoparasitic bee species, Epeolus cruciger (Pz.), E. variegatus, (L.) (Anthophoridae) and Coelioxys (Coelioxys) quadridentata (L.), C. (Schizocoelioxys) mandibularis Nyl. (Megachilidae) were analysed by combined gas chromatog­ raphy/mass spectroscopy. There are considerable simi...

Using a 2,3-diamino pyrazine substrate and yttrium triflate catalyst, various 2-alkyl and aryl substituted 3,8-diaminoimidazo[1,2-a]pyrazines were efficiently prepared through Groebke-Blackburn-Bienaymé MCR. In particular, a novel 2-piperonyl 3,8-diaminoimidazo[1,2-a]pyrazine structure was prepared exclusively with this new method and was found to have moderate Hsp90 inhibitory activity. A crys...