Modern Characterization of Some Novel Compmplexes By Pyrazine as Ligand

Abstract

Pyrazine is less basic than pyridine, pyridazine and pyrimidine. Derivatives such as Phenazine are well known for their antitumor, antibiotic and diuretic activities. Tetramethyl pyrazine, also known as ligustrazine, is reported to scavenge superoxide anion and decrease nitric oxide production in human polymorphonuclear leukocytes and is a component of some herbs in traditional Chinese medicine. Alkylpyrazines are chemical compounds based on pyrazine with different substitution patterns. Some alkylpyrazines are naturally occurring highly aromatic substances which often have a very low odour threshold and contribute to the taste and aroma of various foods including coffee and wines. Alkylpyrazines are also formed during the cooking of some foods via Maillard reactions. 2,3-Dimethylpyrazine is a component of the aroma of roasted sesame seeds. Dimethylpyrazine is used as flavour additive and adorant in foods such as cereals and products such as cigarettes. It occurs naturally in asparagus, black or green tea, crisp bread, malt, raw shrimp, soya, Swiss cheeses, and wheat bread. Methoxy pyrazines are a class of chemical compounds that produce odours. The odours tend to be undesirable as in the case of certain wines, or as in the case of the Asian lady beetle which produces isopropyl methoxy pyrazine. They have also been identified as additive in cigarettes.