низина

Химические свойства

Crystals from ethanol. Derived from Streptococcus lactis Lancefield Group N.

Использование

Nisin is an antimicrobial agent derived from pure culture fermenta- tions of certain strains of streptococcus lactis lancefield group n. nisin preparation contains nisin, a group of related peptides with antibiotic activity. it is used to inhibit the outgrowth of clostridium botulinum spores and toxin formation in pasteurized cheese spreads and pasteurized process cheese spreads; pasteurized cheese spread with fruits, vegetables, or meats; and pasteurized process cheese spread with fruits, vegetables, or meats.

Определение

ChEBI: A type-A lantibiotic containing 34 amino acid residues (including lanthionine (Lan), methyllanthionine (MeLan), didehydroalanine (Dha) and didehydroaminobutyric acid (Dhb)) and five thioether bridges. It is obtained by fermentation of the bacterium L ctococcus lactis and shows particular activity against Clostridium botulinum. It is used in the production of various processed foods to suppress Gram-positive spoilage and pathogenic bacteria and so extend shelf life.

Побочные эффекты

Although Nisin E234 generally regarded as a very safe and effective supplement, there can be some minor side effects. Possible side effects: pruritus, nausea, and flushing. Other side effects include: pruritus, skin rash, and vomiting.

Методы очистки

This polypeptide from S. lactis is purified by crystallisation from 80% (v/v) EtOH and by countercurrent distribution. The synthetic polypeptide antibiotic can also be purified by preparative HPLC and assayed by HPLC on a Nucleosil 3007C18 (6 x 250mm) column using a MeCN—0.01M HCl gradient (30-50%), at 2%/minute, and flow rate of 1.5mL/minute to give a retention time of 8.1 minutes; or MeCN—0.3M guanidine-HCl gradient (30-50%), at 2%/minute, and flow rate of 1.5ml/minute to give a retention time of 10.9minutes. FAB-MS gave the pseudomolecular ion m/z at 3352.7 (M + H)+. It is soluble in dilute acid and is stable even on boiling. [Berridge et al. Biochem J 52 529 1952, synthesis by Fukase et al. Tetrahedron Lett 29 795 1988.]