Development of a natural preservative system using the mixture of chitosan-Inula helenium L. extract.

The aim of this study was to develop a new natural preservative system making up for the weak points of chitosan as a preservative. As reported in a previous manuscript (20th IFSCC Congress, Cannes, France, 1998), the minimum inhibitory concentrations (MICs) of water-soluble chitosan against bacteria and yeast were 0.9-3.0 mg mL(-1), whereas MICs of chitosan against Aspergillus niger were over 5.0 mg mL(-1). However, the result of recent study showed that the MICs of Inula helenium L. extract against A. niger were below 1.0 mg mL(-1). Thus, we could develop a new preservative system containing both chitosan and I. helenium L. extract named CI-mixture. MICs of CI-mixture against bacteria and fungi (yeast and mould) were 2.0-4.0 mg mL(-1). When 10.0% of the mixture (the ratio of chitosan to I. helenium L. extract = 7.5% : 2.5%) was applied to cosmetic formulae such as skin lotion, milk lotion, cream and pack, it revealed appropriate preservative efficacy. Our result of the patch test also showed that this preservative system reduced skin irritation by about 30-50%, as compared to the organic preservative system. Therefore, the good natural preservative system including chitosan and Inula helenium L. extract could be incorporated in cosmetic formulations.

Novel findings in inhibition of mast cell-dependent immediate-type cutaneous reactions by Gahmi-Shini-San.

This report describes an inhibitory effect of Gahmi-Shini-San (GSS) on mast cell-mediated immediate-type allergic reactions. GSS is an Oriental herbal medication, which has been successfully used in Korea for the treatment of allergic disorders, mainly skin anaphylactic diseases. GSS inhibited the ear swelling response induced by intradermal injection of compound 48/80 in a mouse model on a concentration-dependent basis. The mast cells in mouse ear tissue were stained by alcian blue/nuclear fast red. GSS significantly inhibited the compound 48/80-induced degranulation from mast cells in ear tissue. GSS dose-dependently inhibited the histamine release from the rat peritoneal mast cells by compound 48/80. We also studied the effect of GSS on mast cell-dependent passive cutaneous anaphylaxis activated by dinitrophenyl IgE antibody. GSS showed inhibition of passive cutaneous anaphylaxis following oral administration. These results indicated that GSS has inhibitory effect on mast cell-dependent immediate type cutaneous reactions.

Disodium cromoglycate inhibits production of immunoglobulin E.

Disodium cromoglycate (DSCG) has been shown to inhibit the release of mediators from mast cells. In the present study, the effect of DSCG on active anaphylactic reaction was studied in mice. DSCG dose-dependently inhibited the active systemic anaphylactic reaction and serum immunoglobulin (Ig)E production induced by immunization with ovalbumin, Bordetella pertussis toxin and aluminum hydroxide gel. DSCG strongly inhibited IL-4-dependent IgE production by lipopolysaccharide-stimulated murine whole spleen cells. In the case of U266 human IgE-bearing B cells, DSCG also showed an inhibitory effect on the IgE production. These results suggest that DSCG has an anti-anaphylactic activity by inhibition of IgE production from B cells.

Effects of N-acetylation degree on N-acetylated chitosan hydrolysis with commercially available and modified pectinases.

Three types of N-acetylated chitosans (NACs) with different degrees of acetylation (DA) were prepared and used as a substrate for enzymatic hydrolysis with a commercially available pectinase and a modified one. Pectinase modification was conducted using polyalkyleneoxide-maleic anhydride copolymer (PEO-MA copolymer). The effects of DA on enzymatic reaction with native and modified pectinases were investigated experimentally. Initial hydrolysis rate and Michaelis-Menten kinetic parameters were measured by analysis of reducing sugars. DA of NAC strongly affected the hydrolytic characteristics of native and modified pectinases. N-acetylation of chitosan increased the initial hydrolysis rate and the enzyme-substrate affinity with respect to both pectinases: NACs with DA over 0.3 showed high initial hydrolysis rate and strong affinity between enzyme and substrate. Especially, when NAC with DA over 0.3 was treated with modified pectinase, the affinity became much stronger than the native pectinase.

Extraction of heavy metals from MSW incinerator fly ash using saponins.

An extraction process with saponins was evaluated for removing heavy metals from MSW (municipal solid waste) incinerator fly ashes. Two different fly ashes, A and B, were treated on a laboratory scale with three triterpene-glycoside type of saponins, M, Q, and T, in the pH range 4-9. The results were compared with those of the HCI and EDTA treatment. The treatment with saponins extracted 20-45% of Cr from the fly ashes. Saponins were also effective in extracting Cu from fly ash A attaining 50-60% extraction. Saponin T extracted 100% of Pb from fly ash A at pH around 4. The extraction of Zn with the saponin treatment was similar to that of the HCl treatment. Further, Cr, Cu, Pb, and Zn were fractionated by sequential extraction to investigate the effect of saponins on each fraction. Extraction behavior of other elements during the saponin treatment was also studied. The leaching test on the residues received after the saponin treatment showed that the fly ashes were successfully detoxified to meet the landfilling guideline.

Extraction of heavy metals from MSW incinerator fly ashes by chelating agents.

An extraction process has been studied on a laboratory scale for the pretreatment of municipal solid waste (MSW) incinerator fly ash to remobilize Cr, Cu, Pb, and Zn. Five different types of fly ashes were treated with HCl, nitrilotriacetic acid (NTA), ethylendiaminetetraacetate (EDTA), or diethylenetriaminepentaacetate (DTPA) in a batch process in the pH range 2.5-10. The extraction of heavy metals by HCl was dependent on pH, increasing with increasing acid concentration. The efficiency of the chelating agents was independent of pH. By the treatment with 3.0% EDTA or DTPA, 20-50% of Cr, 60-95% of Cu, 60-100% of Pb, and 50-100% of Zn were extracted in the pH range 3-9. NTA was also effective in extracting Cr, Cu, and Zn. The maximum extraction of Cr, Cu, Pb, and Zn was obtained at 0.3-1.0% concentration of the chelating agents. NTA was effective in extracting Pb at a concentration as low as 0.1%. Extraction behavior of other elements during the treatment was also studied. The leaching test on the residues after the treatment with chelating agents showed that the fly ashes were successfully detoxified to meet the guideline for landfilling.

Development of effective modified cellulase for cellulose hydrolysis process.

Cellulase was modified with amphilic copolymers made of alpha-allyl-omega-methoxy polyoxyalkylene (POA) and maleic acid anhydride (MAA) to improve the cellulose hydrolytic reactivity and cellulase separation. Amino groups of the cellulase molecule are covalently coupled with the MAA functional groups of the copolymer. At the maximum degree of modification (DM) of 55%, the modified cellulase activity retained more than 80% of the unmodified native cellulase activity. The modified cellulase shows greater stability against temperature, pH, and organic solvents, and demonstrated greater conversion of substrate than native cellulase does. Cellulase modification is also useful for controlling strong adsorption of cellulase onto substrate. Moreover, cellulase modified with the amphiphilic copolymer displays different separation characteristics which are new. One is a reactive two-phase partition and another is solubility in organic solvents. It appears that these characteristics of modified cellulase work very effectively in the hydrolysis of cellulose as a total system, which constitutes the purification of cellulase from culture broth, hydrolysis of cellulose, and recovery of cellulase from the reaction mixture. (c) 1995 John Wiley & Sons, Inc.

Effects of nonionic surfactant on enzymatic hydrolysis of used newspaper.

Effects of five types of nonionic surfactant having a polyoxyethylene glycol (POG) group on enzymatic hydrolysis of used newspaper were studied. The surfactants examined in this work always enhanced the saccharification. The optimum surfactant concentration was 0.05% (wt/substrate wt) in the case of POG(21) sorbitane oleic ester. Among the surfactants, POG phenyl ether types showed the highest enhancement effect, for example, with two times higher conversion at 80 h than that without surfactant. Using POG nonylphenyl ether series, the effects of surfactant were considered from the point of the HLB (hydrophile-lypophile balance) value. The GFC (gel filtration chromatography) analysis of free enzyme quantity were also done to study the effect of surfactant on enzyme adsorption onto substrate. As the HLB value increased, the free enzyme quantity and the conversion both increased. It appears that surfactants help the enzyme to desorb from the binding site on the substrate surface after the completion of saccharification at that site.