Structural Characterization, Physical Properties and Biochemical Implications.
Abstract
γ- Polyglutamic acid (γ- PGA ) produced from Bacillus subtilis var. natto on a laboratory and pilot scale fermenter have been characterized.γ- PGA in its free acid form ( H+) is insoluble in water. The salt forms of K+, Na+, NH4+, Ca++, and Mg++ of γ- polyglutamates are soluble in water. Some of their structure is characterized with infrared and 1H- and 13C- NMR spectroscopy, and their thermal properties were determined with thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The typical physical and chemical properties including typical pH-titration curve, viscosity of different concentration, and temperature-dependent viscosity were determined. The glutamic acid added to the medium was efficiently bio-converted into γ- PGA in the stationary phase via a salvage pathway (3).. The weight-averaged molecular weight of γ- PGA was estimated to be over 2x106daltons. The infrared spectrum with KBr pellet showed a characteristic strong amide absorption at about1620 -1655cm-1, a weaker carbonyl absorption at about 1395 -1455 cm-1, and a strong hydroxyl absorption at 3400-3450cm-1. The chemical shifts of 1H-NMR for sodiumγ-polyglutamate in D2O are:α-CH proton: 3.98ppm ; β- CH2 proton:1.98ppm and 1.80ppm; and γ- CH2 proton: 2.19ppm. The chemical shifts of 13C-NMR for sodium γ-polyglutamate are: α-CH2: 56.43ppm; β-CH2: 31.61ppm; and γ-CH2: 34.01ppm; CO: 182.21ppm; COO-: 182.69ppm.
Dehydration temperatures are: 109oC, 139oC, and 122oC for Na+, K+ and Mg++ salts of γ-PGA, respectively. The melting points (Tm) are 206oC, 160oC, 193oC/238oC, 219oC, 1010C, and 122oC for H+, Na+, K+, NH4+, Ca++, and Mg++ salts of γ-PGA, respectively. The decomposition temperatures (Td) are 209.8oC, 340oC, 341oC, 223oC, 220oC, 335.7oC,, and 331.8oC for the H+, Na+, K+, NH4+, Ca++, and Mg++ salts of γ-PGA, respectively.. The hydrated waters are found to be10%, 42%, 20%, 40% for Na+, K+, Ca++, Mg++ salts ofγ-PGA, respectively. The contents of the stable hydration reflect strong water binding ability and the hygroscopic nature of these products
Key words: Bacillus subtilis var. natto, γ- Polyglutamic acid (γ- PGA)---, Sodium
γ- Polyglutamate, Calcium γ- Polyglutamate, Magnesium γ- Polyglutamate.
Introduction
γ- Polyglutamic acid (γ- PGA ) was first discovered as a major constituent in the capsule of Bacillus anthracis(1). It is a naturally occurring biopolymer consisted of a single amino-acid ?glutamic acid, in a certain combination of D-form and L-form, or all D-form as first reported by Ivanovics and Brucker(2). γ- PGA is a very unusual poly-anionic biopolymer consisted of homo-polyamide linkages between α- amino and γ- carboxyl groups as shown in Figure 1. γ- PGA may be bio-synthesized via both de novo(9) and salvage(3,22) pathways in the logarithmic stage with cell growths, but in the stationary stage when glucose has consumed. γ- PGA may also be produced independently of cell growth and exclusively bio-synthesized from free glutamic acid in the medium broth via a salvage pathway(22).
γ- Polyglutamic acid (γ- PGA) has been reported to be a major component of the viscous sticky mucilage produced in natto by Bacillus subtilis(3-9) or can be isolated from the culture filtrate of some species of Bacillus bacteria(10-16). Natto has been a traditional healthy food in Japan, manufactured from steamed small soybeans and fermented by Bacillus subtilis var.natto (11-16). This group of strains was classified as Bacillus subtilis according to “Bergeys’ Manual of Determinative
Bacteriology, 3rd Edition, but because of the requirement of biotin for nutrition, growth, and production of the sticky materialγ- PGA, therefore, Bacillus subtilis var. natto is still considered in Japan to be of different species from Bacillus subtilis.
γ- PGA is a natural, biodegradable biopolymer, which is nontoxic and environmental friendly. Due to its specific biological and unique chemical functionality, γ- PGA and its derivatives have been generally proposed in the past few years for potential applications in wide areas including: for use as thickener, stabilizer and cryoprotectant in food ; as humectant or moisturizer in cosmetics; as controlled release drug carrier; as high water absorbable hydrogels in hygiene and in agriculture; as nutritional supplement in health care and animal feed supplement, biopolymer flocculant and heavy metal absorber in water treatment; as natural bacteriocide or fungicide; or as biodegradable plastics, fibers and other industrial applications. An extensive review on the progress of the microbial biosynthesis and the applications of γ-PGA in various fields was done by Ing-Lung Shih et al (28), recently.
Title) g-POLYGLUTAMATES AND g-POLYGLUTAMATE HYDROGELS AS SUPER
MOISTURIZERS FOR USE IN COSMETICS AND PERSONAL CARE PRODUCTS
The present invention is relating to the use of g-polyglutamates(Na,+, K+, Mg++ and Ca++ forms) and the g-polyglutamate hydrogels as super Mg++ moisturizers in formulating the quality cosmetic products and personal care products.
g-polyglutamates are biodegradable, non-toxic biopolymers produced from L-glutamic acid via a submerge fermentation process. g-Polyglutamates(org-PGA) possess excellent water binding properties and moisture retention capacity which have been reported(), and their biochemical and biological functionalities are being explored for applications in cosmetic products and personal care products. g-Polyglutamate (or g-PGA) was recently found to stimulate the growth of fibroblast cells, and showed long?lasting moisture retention and good whitening results in skin care applications. The objectives in this invention are to provide an economical and very effective moisturizer formulation systems for use in cosmetic products and personal care products which possess excellent wetting capability, tender and soft feeling, and health impact to the skin. A proper formulation of the super moisturizer systems includes the different types of g-polyglutamates(Na,+, K+, Mg++ and Ca++ forms) and the g-polyglutamate hydrogels as super moisturizers with proper molecular chain length and composition ratios are provided here to achieve the above-mentioned functionality.
BRIEF DESCRIPTION OF THE INVENTION
(TITLE) g-POLYGLUTAMIC ACID (g-PGA), g-POLYGLUTAMATES AND g-POLYGLUTAMATE HYDROGELS AS SUPER MOISTURIZERS FOR USE IN COSMETICS AND PERSONAL CARE PRODUCTS
(DESCRIPTION OF INVENTION) The present invention is relating to the use of g-polyglutamates(Na,+, K+, NH4+,Mg++ and Ca++ forms) and the g-polyglutamate hydrogels (Na,+, K+, NH4+, Mg++ and Ca++ forms) as super moisturizers in formulating the quality cosmetic products and personal care products.
g-Polyglutamates are biodegradable, non-toxic biopolymers produced from L-glutamic acid via a submerge fermentation process. g-Polyglutamate(Na,+ , K+, NH4+,Mg++ and Ca++ forms) possess excellent water binding properties K+and moisture retention capacity, and their biochemical and biological functionalities are being explored for applications in cosmetic products and personal care products. g-Polyglutamate was recently found to stimulate the growth of fibroblast cells, and showed long?lasting moisture retention and good whitening results in skin care applications. The objectives in this invention are to provide an economical and very effective moisturizer formulation systems for use in cosmetic products and personal care products which possess excellent wetting capability, provide tender and smooth soft feeling, and add health benefit to the skin. A proper formulation of the super moisturizer systems, containing the different types of g-polyglutamates(Na,+, K+, NH4+, Mg++ and Ca++ forms) with different molecular chain length, and the g-polyglutamate hydrogels (Na,+, K+, NH4+, Mg++ and Ca++ forms ) in different composition ratios, as super Mg++ moisturizers are provided here to achieve the above-mentioned wide range of functionality simultaneously..
DETAILED DESCRIPTION OF THE INVENTION
(001)
(TECHNICAL FIELD OF THE INVENTION)
The characteristics of this invention are: the combined functionality of the small molecular weight fractions, high molecular weight fractions of the g-polyglutamates(Na,+, K+, Mg++ and Ca++ forms), and the cross-linked super molecular weight fractions of the g-polyglutamate hydrogels (Na,+, K+, Mg++ and Ca++ forms) provides most of the functional features as required by the cosmetic and personal care products. The desired functionality include high moisturization and water retention, improved wet-ability and low TEWL(trans-epidermal water loss), soft and tender feel, smooth and long lasting effectiveness, enhancing skin elasticity, good biocompatibility and enhancing health condition of the skin.
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