Degradation of Polysaccharide in Fenton Oxidative Cleavage Reaction and Their Antioxidant Activity

( Shaheen Amna ),( Bo Mi Lee ),( Choon Geun Lee ),( You Jin Hwang ),( Jae Kweon Park ) 한국키틴키토산학회 2016 한국키틴키토산학회지 Vol.21 No.1

One of well known methods for degrading polysaccharide is to use the reactive oxygen species. The fenton reaction can produce aggressive OH-radical, which is one of potential species of ROS, from hydrogen peroxide in the presence of catalytic metal ions. Ascorbic acid acts as a potent antioxidant necessary to cope up these oxidative damages. We found that ascorbic acid also exhibits pro-oxidant characteristics in the presence of catalytic metal ions, which can reduce the redox-active metal ions. Active size of molecules was obtained via degradation of higher molecular weight chitosan and hyaluronic acid, to obtain such active molecules, fast digestion was performed based on fenton reaction to determine the anti-oxidant activity of these molecules. Our results indicated that lysates from both the parental polysaccharides possess significant radical scavenging activity which proves that chitosan and hyaluronic acid are good anti-oxidants in terms of scavenging free radicals.

Characteristic Analysis of Chitosan Thermo-Hydrogels: Molecular Weight Dependent Chitosan/β-glycerophosphate Hydrogel

( Shaheen Amna Kashif ),( Sang Hun Jung ),( Jae Kweon Park ) 한국키틴키토산학회 2020 한국키틴키토산학회지 Vol.25 No.4

Chitosan (CTSN) and β-glycerophosphate (GP) based hydrogels were prepared and characterized to elucidate the chemical interactions involved in the formation of these hydrogels depending upon the molecular weight of chitosan. Characterization of nanostructure of the resulting hydrogels was investigated by Fourier Transform-Infrared Spectroscopy (FT-IR). We observed that the major interaction which might be responsible for the formation of these hydrogels is between phosphate groups (PO₄ ^3- ) of GP and amine groups of chitosan. Whereas, the addition of hyaluronic acid (HA) which may act as a crosslinker has a negative effect on available free phosphate groups in the hydrogel confirmed by FT-IR analysis (971.9 cm ^-1 peak). Decisively, the outcomes of spectrophotometric analysis also coincide with the findings of FT-IR for the CTSN/GP/HA thermo-hydrogel system. This study demonstrates the standard protocol to provide a practical approach for the analysis of interactions involved in the formation of CTSN/GP/HA hydrogels that could be potently useful in pharmacological and pharmaceutical applications.

Enzymatically Hydrolyzed Water-Soluble Chitosan as a Potent Anti-Microbial Agent

Shaheen Amna Kashif,박제권 한국고분자학회 2019 Macromolecular Research Vol.27 No.6

Biological activities of chitosan depend upon its degree of polymerization (DP), fraction of acetylation (FA), and possibly on their pattern of acetylation (PA). Active molecular weight chitosan (AMC) was obtained from water soluble chitosan (WSC) by enzymatic hydrolysis over 600 h of time period. By the end of hydrolysis WSC was hydrolyzed to AMC with final concentration of 14 mM of reducing sugars with lowest viscosity (1.99 mm2/sec). Matrix assisted laser desorption/ionizationtime of flight mass spectrometer (MALDI-TOF) analysis has shown homo- and hetero- oligomers in the reaction mixture. Intense infra-red (IR) bands appeared through 500-3700cm-1 were assigned to be asymmetric and symmetric stretching of common sugars. WSC-AMC has inhibited 80% growth of Candida albicans and Penicillium italicum with highest zone of inhibition of 22 and 25 mm respectively. Mechanism of action for cellular growth inhibition involves the reactive oxygen species (ROS) elimination beyond the normal levels along with inactivation of β-lactamase like enzymes. Our results demonstrated that after hydrolysis the biological activities of WSC improved along with its flow properties and other biological activities.

Correlation between the Difference in Chemical Composition and Antioxidant Activity of Water Soluble Compounds derived from Marine Photosynthetic Microalgae

( Shaheen Amna ),( Geun Young Nam ),( Jae Kweon Park ) 한국키틴키토산학회 2018 한국키틴키토산학회지 Vol.23 No.2

The aim of this study is to elucidate the relationship between the chemical composition and antioxidant activity of water soluble compounds derived from the degradation of microalgal biomass. Since some of particular species of microalgae are promising source for biofuel production, a vast amount of wastes after extracting lipids are treated as trash. To address the potent utilization as a bio-resource, water soluble compounds (WSC) were isolated by the enzymatic and chemical degradation of microalgal biomasses. To test biological activities of WSC, antioxidant activity was determined by DPPH, ABTS, and FRAP based on free radical-scavenging assay. As the result, we found that WSC obtained after enzymatic or chemical treatments have been shown difference in chemical composition and relative antioxidant activities. Although WSC has shown the less significant antioxidant activities, our data suggest that technical development for the extraction and utilization of WSC from microalga are very important to make a good understanding the correlation between the chemical compositions and biological activity.

Antioxidant Activity of Extracellular Polysaccharides (EPS) from Marine Microalga Tetraselmis tertiolecta Depending upon their Molecular Weight

( Shaheen Amna ),( Ah Young Yoo ),( Jae Kweon Park ) 한국키틴키토산학회 2018 한국키틴키토산학회지 Vol.23 No.3

The aim of this study was to isolate and characterize the extracellular polysaccharides (EPS) from defatted microalga Tetraselmis KCTC 12236 BP (T1) and Tetraselmis KCTC 12432 BP (T2), both were isolated and used microalgal biomasses for the production of biodiesel. The difference of molecular diversity of EPS in T1 were obviously observed from each sample based on MALDI-TOF mass spectra analysis. Higher productivity and significant antioxidant activity were only observed from the EPS isolated from T1 than that of T2. Therefore, EPS from T1 were used for further study to elucidate the relationship between the EPS and its biological activity. These results suggest the importance of the understanding of primary structure to address the biological role of EPS in microalgal species.

Antioxidant Activity of Manno-oligosaccharides Derived from the Hydrolysis of Polymannan by Extracellular Carbohydrase of Bacillus N3

Amna, Kashif Shaheen,Park, So Yeon,Choi, Min,Kim, Sang Yeon,Yoo, Ah Young,Park, Jae Kweon The Korean Society for Marine Biotechnology 2018 한국해양바이오학회지 Vol.10 No.1

The aim of this study is to elucidate the biochemical properties of manno-oligosaccharides (MOS) hydrolyzed by extracellular enzyme of Bacillus N3. We strived to characterize the biochemical properties of MOS since N3 can effectively hydrolyzed natural polymannans such as galactomannan (GM) and konjac (glucomannan, KM), respectively. The hydrolysis of GM and KM was applied by the strain N3 in terms of reducing sugars and the highest production of reducing sugars was estimated to be about 750 mg/L and 370 mg/L respectively, which were quantified after 7 days of cultivation in the presence of both substrates. Hydrolysates derived from the hydrolysis of KM showed the significant antioxidant activity based on DPPH and ABTS radical scavenging activity with increasing of tyrosinase inhibitory activity. On the other hand, hydrolysates derived from the hydrolysis of GM showed only ABTS radical scavenging activity without showing significant changes on tyrosinase inhibitory activity. Our data suggest that those biological characteristics may be depend on the primary structure and the size of MOS, which may be useful as potent additives for diet foods.

Antioxidant Activity of Manno-oligosaccharides Derived from the Hydrolysis of Polymannan by Extracellular Carbohydrase of Bacillus N3

Kashif Shaheen Amna,So Yeon Park,Min Choi,Sang Yeon Kim,Ah Young Yoo,Jae Kweon Park 한국해양바이오학회 2018 한국해양바이오학회지 Vol.10 No.1

The aim of this study is to elucidate the biochemical properties of manno-oligosaccharides (MOS) hydrolyzed by extracellular enzyme of Bacillus N3. We strived to characterize the biochemical properties of MOS since N3 can effectively hydrolyzed natural polymannans such as galactomannan (GM) and konjac (glucomannan, KM), respectively. The hydrolysis of GM and KM was applied by the strain N3 in terms of reducing sugars and the highest production of reducing sugars was estimated to be about 750 ㎎/L and 370 ㎎/L respectively, which were quantified after 7 days of cultivation in the presence of both substrates. Hydrolysates derived from the hydrolysis of KM showed the significant antioxidant activity based on DPPH and ABTS radical scavenging activity with increasing of tyrosinase inhibitory activity. On the other hand, hydrolysates derived from the hydrolysis of GM showed only ABTS radical scavenging activity without showing significant changes on tyrosinase inhibitory activity. Our data suggest that those biological characteristics may be depend on the primary structure and the size of MOS, which may be useful as potent additives for diet foods.

Biochemical Properties of Water Soluble Polysaccharides from Photosynthetic Marine Microalgae Tetraselmis Species

Babita Dogra,Shaheen Amna,박용일,박제권 한국고분자학회 2017 Macromolecular Research Vol.25 No.2

Water soluble polysaccharides (WSPs) were isolated from defatted microalgae Tetraselmis sp. KCTC 12432 BP (T.S1) and KCTC 12236 BP (T.S2), and purified by a combination of ethanol precipitation, immobilized metal affinity chromatography and size-exclusion column chromatography. Biochemical properties of WSPs obtained from the supernatant (S 1 and S 2) and purification steps (EP 1 and EP 2) have been elucidated for their potential use as a biologically active material. Oxidative effect on efficiency from the hydrolytic fenton reaction (FS 1 and FS 2) was also employed to assess the WSPs production and biological activity from T.S1 and T.S2, respectively. Antioxidant activity of the purified WSPs from EP 2 toward 1,1-diphenyl-2-picryl-hy-drazyl (DPPH), 2,2’-Azinobis (3-ethylbenzothiazoline-6-sulfonic acid) di-ammonium salt (ABTS), and ferric reducing antioxidant power (FRAP) of radical-scavenging showed significant differences depending on the monosaccharide compositions of WSPs. On the other hand, a significant specific tyrosinase inhibitory activity was observed from the WSPs purified from EP 1 (10 μmol/g/min) indicating the potential use as a whitening source. The outcomes of our study support the utilization of WSPs from these microalgal species as a potential source of naturally occurring whitening and antioxidants to ease oxidative stresses. According to our knowledge related to microalgal studies, until now this is the first study which demonstrates the significance between primary structure and potential biological activities of WSPs purified from the defatted microalgae Tetraselmis species.

Production and Characterization of Enzymes Involved in Chitin Catabolic Cascade from a Bacterial Strain Isolated from Soil

이지현,이정인,박소연,이해창,장유경,임유빈,정영민,이종화,Amna Shaheen,이혜윤,박제권 한국키틴키토산학회 2019 한국키틴키토산학회지 Vol.24 No.1

The present study was aimed to isolate the bacteria producing chitinolytic enzymes including chitin deacetylase (CDA) from soil origin. About 24 bacteria were screened for their chitinolytic enzymes producing ability on the basis of colloidal chitin. Amongst one of the most potent isolates designated to JI-02 was further selected as the most prominent chitinolytic and CDAlike enzyme (CDA-X) producer based on the ability of deacetylation of an artificial substrate pNP-acetamilide. The maximum production of CDA-X in crude enzyme from JI-02 was observed in the presence of 1% colloidal chitin at 37°C and pH 6.4 after 120 h of incubation. Potent enzyme activity of CDA-X was determined toward pNP-acetamilide, demonstrating that optimal pH, temperature and ionic strength of the CDA-X were assessed to be 7.0, 52°C and 125 mM, respectively. Unexpectedly, Nacetylglucosamine (GlcNAc) was not fully converted by the action of CDA-X to glucosamine (GlcN) under the established conditions. Further study on enzyme activity toward chitin-oligosaccharides consisting of multi-N-acetylglucosamine (GlcNAc) n , n=2-5 may be necessary to elucidate the mode of action which requires the minimum size of (GlcNAc) n. However, our data suggest that CDA-X can convert chitin to chitosan with the maximum yield of approximately 0.08g/L during the fermentation of the strain in the presence of chitin. Furthermore, we found that crude enzyme showed the significant chitosanolytic activity. Taken together, our data suggest that the strain JI-02 may be a potential candidate as a particular strain for better understating of chitin catabolic pathway.

Synergistic versus Additive Effect of Active Molecular Chitosan with Biochemical Compounds of Sorghum bicolor

( Da Gyung Lee ),( Jhulee Park ),( Hae Jung Yoo ),( Seo Ju Oh ),( Joo Young Jang ),( Shaheen Amna ),( Jae Kweon Park ) 한국키틴키토산학회 2016 한국키틴키토산학회지 Vol.21 No.3

The synergistic or additive effect of active molecular chitosan (AMC) with Sorghum bicolor ethanol extract (ES) and fermentative supernatant was invesigated in this study. ES had 29% less content of phenolic compounds, 78% less contents of total carbohydrates containing reducing sugars, and 56% less tannin contents than that of S. bicolor fermentative supernatant (SF). It has shown the significantly higher antioxidant activity than SF and other fermantative substances (S and Y). These results suggest that flavonoid in the ES may be the key molecule as it contains 28% higher concentration of flavonoids than SF and Y substances and hence ES showed the remarkablely higher specific activity of whitenning effect. Further more SF was selected for heat stability studies, tyrosinase inhibitory, and antibacterial activity in the presence or absence of active molecular chitosan (AMC). Although less significant synergistic antibacterial activity of SF toward Candida albicans in the presence of AMC was observed, both substances still can be useful as antioxidant or whitenning substances in combination with AMC. whereas a strong antibacterial activity of AMC toward Candica albicans was observed, and also is one of the ingredients in functional food and cosmaceutical compounds with potential health-promoting properties.