| dc.description.abstract | Exopolysaccharide (EPS) extracted from O. sinensis and supplied by Institute of
Research and Hi-tech Application in Agriculture of Dalat University had firstly
treated by deproteination and acetylation before being analyzed by gas
chromatography (GC) to determine the sugar composition. The sulfation with sulfur
trioxide pyridine complex (SO3.Py) was then applied to increase the bioactivity and
solubility of EPS. The sign of successful reaction was determined by Fouriertransform infrared (FTIR) spectroscopy assay. The sulfated exopolysaccharide
(SEPS) were then tested for the hygroscopic and moisture retention activities and
compared to exopolysaccharide, chitin and hyaluronic acid (HA) for positioning. The
hygroscopic activity was examined following the method of placing the samples in
closed system with saturated calcium chloride (CaCl2). The purposes are to set the
similar condition for all samples, maintain the same humidity and measuring the
changes in weight per certain time. The moisture retention activity was tested by
humidifying the samples and then dehydrating by placing them in the closed system
with silica gel and measuring the percentage of water losing per certain time. The
bioactivities such as collagenase inhibitory activity and cytotoxicity against fibroblast
cell line of EPS and SEPS were tested. Afterward, SEPS and EPS were applied in
developing moisturizer gel cream.
The results indicate that EPS contains mainly three kinds of monosaccharide such as
glucose, mannose and galactose with the ratio of 1.8 : 2.3 : 1. The SEPS was
synthesized by the sulfation with SO3.Py. Its IR spectrum showed the absorption
band at 1253 cm-1 related to a >S=O stretching vibration of the sulphate group
(Lloyd et al., 1961). The collagenase inhibitory activity of SEPS was more potent
than that of EPS, with the inhibition percentage (I%) of 35.66 ± 1.014 (%) and
31.77 ± 1.123 (%), respectively, at the concentration of 2000 µg/ml. Based on the
final results, the cytotoxicity against fibroblast cell line of EPS and SEPS were -2.08
± 5.99 (%) and -1.28 ± 6.85 (%), respectively, showing their cell proliferation
abilities. In addition, the hygroscopic and moisture retention activities of EPS were
proved to be better than SEPS. | en_US |
