RESUMEN
Eggshell membrane (ESM), a plentiful biological waste, consists of collagen-like proteins and glycosaminoglycans (GAGs) such as hyaluronic acid (HA). Here we used a keratinase (oeMtaker)-mediated system to decompose ESM. The best reaction condition was established by incubating the solution containing oeMtaker, sodium sulfite, and ESM with a weight ratio of 1:120:600. ESM enzymatic hydrolysate (ESM-EH) showed a high proportion of essential amino acids and type X collagen peptides with 963-2259 Da molecular weights. The amounts of GAGs and sulfated GAGs in ESM-EH were quantified as 6.4% and 0.7%, respectively. The precipitated polysaccharides with an average molecular weight of 1300-1700 kDa showed an immunomodulatory activity by stimulating pro-inflammatory cytokines (IL-6 and TNF-α) production. In addition, a microorganism-based system was established to hydrolyze ESM by Meiothermus taiwanensis WR-220. The amounts of GAGs and sulfated GAGs in the system were quantified as 0.9% and 0.1%, respectively. Based on our pre-pilot tests, the system shows great promise in developing into a low-cost and high-performance process. These results indicate that the keratinase-mediated system could hydrolyze ESM more efficiently and produce more bioactive substances than ever for therapeutical applications and dietary supplements.
Asunto(s)
Cáscara de Huevo , Péptido Hidrolasas , Animales , Bacterias , Cáscara de Huevo/metabolismo , Glicosaminoglicanos/metabolismo , Péptido Hidrolasas/metabolismoRESUMEN
Meleagrin B is a terpene-alkaloid hybrid natural product that contains both the conidiogenone and meleagrin scaffold. Their derivatives show diverse biological activities. We characterized the biosynthesis of (-)-conidiogenone B (1), which involves a diterpene synthase and a P450 monooxygenase. In addition, an α,ß-hydrolase (Con-ABH) was shown to catalyze an aza-Michael addition between 1 and imidazole to give 3S-imidazolyl conidiogenone B (6). Compound 6 was more potent than 1 against Staphylococcus aureus strains.