دانلود رایگان مقاله توضیح ساختاری سه پلی ساکارید آنتی اکسیدانی از قارچ کرکیلبه lobayense

ABSTRACT

Tricholoma lobayense is a nutritious mushroom with great health benefits. Three polysaccharides with purity higher than 99% were successfully extracted from Tricholoma lobayense. The molecular weights of TLH-1, TLH-2 and TLH-3 were determined to be 8.43 × 105, 5.36 × 105 and 4.53 × 103 Da, respectively. The backbones of TLH-1 and TLH-2 were mainly composed of 1,4-linked -d-glucopyranosyl. However, polysaccharide TLH-3 was found to be a highly branched glucogalactan, which is made up of 1,3-linked -d-glucopyranosyl branched at C-6 and 1,3-linked ˇ-d-galactopyranosyl. In vitro antioxidant activity assays revealed that TLH-3 exhibited highest antioxidant activities among the polysaccharides from Tricholoma lobayense, which were comparable to those of ascorbic acid. The results suggested that the outstanding antioxidant activities of TLH-3 might depend on its low molecular weight, high branch degree, versatile linkage types and complex conformation. These characteristics make TLH-3 an attractive natural antioxidant for food and pharmaceutical applications.

5. Conclusions

In summary, three polysaccharides with purity greater than 99% were obtained from Tricholoma lobayense. TLH-1 and TLH-2 were determined to be glucans, whereas TLH-3 is a novel glucogalactan. Based on the structural elucidation, possible structural schemes for TLH-1, TLH-2 and TLH-3 are depicted in Fig. 3.Although the molecular weight of TLH-3 is the lowest, its structure is the most complex. This novel glucogalactan with hyper branch and diverse connection sequence exhibits the most excellent antioxidant activities. Altogether, glucogalactan TLH-3 might be the active substance responsible for the health benefits of the edible mushroom Tricholoma lobayense. These results lay the foundation for future research on polysaccharides from Tricholoma lobayense.