JP2004244371A - Moisturizing composition and method of producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moisturizing composition for cosmetic, having excellent permeability to the skin, and effective in moisture-retaining effects from the inside of the skin and prevention of rough skin; and to provide a moisturizing composition usable for a processed food. <P>SOLUTION: The moisturizing agent for the cosmetic and the processed food, comprising an oligopeptide of a pentamer or a lower oligomer, having serine in the N-terminal amino acid are produced by a hydrothermal reaction of an aqueous solution of sericin under a condition of 20-80 atm and 170-250°C. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００１２】
表１よりセリシンのアミノ酸としてはセリンが最も多いことが特徴的であり、このようなセリンの多い蛋白質を他の動物に求めることはできない。
【００１３】
また、皮膚におけるセリンの位置づけを、ＮＭＦ（ｎａｔｕｒａｌ ｍｏｉｓｔｕｒｉｚｉｎｇ ｆａｃｔｏｒ）により示したのが、表２である。
【００１４】
【表２】

【００１５】
表２によれば、ＮＭＦの中でセリンの含有率が最も多いことがわかる。このことは、セリンが肌の保湿性に重要な機能を果たして、肌荒れや老化防止に役立つことを示すものである。
【００１６】
【特許文献】
【文献１】特開平１０−２４５３４５号公報
【文献２】特開昭６２−０３６３０８号公報
【文献３】特開平０８−１３３９６３号公報
【文献４】特開２００１−０１７９０９７号公報
【文献５】特開平１１−９２５６４号公報
【文献６】特開平４−２０２４３５号公報
【文献７】特開平９−２６８１６６号公報
【文献８】特開２００２−２４１２９０号公報
【非特許文献】
ＦＲＡＧＲＡＮＣＥ ＪＯＵＲＮＡＬ ６５頁、１０月号、２００１年
【００１７】
【課題を解決するための手段】
本発明では、オリゴペプチドのＮ末端アミノ酸にセリンを有し、アミノ酸数が５個以下のオリゴペプチド又は該オリゴペプチドのナトリウム塩を０．１重量％以上含有することによって、化粧料又は加工食品に有効利用できる保湿組成物を得ることを特徴とするものである。
本発明では、水熱反応によりセリシンが分解するが、その際、分子のＮ末端アミノ酸としてセリンを有し、かつアミノ酸数がが５個以下のオリゴペプチドとすることによって保湿組成物を製造することをも特徴とするものである。
【００１８】
本発明は、基本的には以下の構成によりなるものである。
（１）オリゴペプチドのＮ末端アミノ酸にセリンを有し、アミノ酸数が５個以下のオリゴペプチド又は該オリゴペプチドのナトリウム塩を０．１重量％以上含有することを特徴とする保湿組成物。
（２）化粧料に使用することを特徴とする（１）の保湿組成物。
（３）消炎剤、紫外線防止剤又は美白剤から選ばれた少なくとも一成分を含有する化粧料に配合することを特徴とする（２）の保湿組成物。
（５）加工食品に配合することを特徴とする（１）の保湿組成物。
（４）水熱反応によりセリシンが分解されてなり、分子のＮ末端アミノ酸としてセリンを有し、かつアミノ酸数が５個以下のオリゴペプチドであることを特徴とする保湿組成物を製造する方法。
（６）セリシン水溶液に、１５０℃〜２００℃の温度で７気圧〜２０気圧の圧力による水熱反応処理を行って、分子のＮ末端アミノ酸にセリンを有し、アミノ酸数が５個以下のオリゴペプチドとすることを特徴とする保湿組成物を製造する方法。
（７）原料セリシンの分子量に応じて水熱反応の温度・圧力・時間を設定することを特徴とする（１）〜（４）のいずれかに記載の保湿組成物を製造する方法。
【００１９】
本発明で原料として用いるセリシンは、蚕の繭や生糸から精錬や熱湯処理によって溶出するセリシンを回収して用いるが、セリシンを含有する水溶液は、腐敗しやすく保存が難しいので凍結乾燥や噴霧乾燥により粉末状にして、使用時に水溶液として用いることが好ましい。
本発明に用いるセリシンの分子量は特定されるものではなく、セリシンの回収により部分加水分解したものでよい。
【００２０】
本発明の実施例において用いた原料セリシンについて、ペプチド鎖中のＮ末端アミノ酸の結合順序をアミノ酸配列分析装置によって分析した結果を表３に示す。
【００２１】
【表３】

表３中、横軸は、アミノ酸の配列順序であり、例えば「５」とは、「末端より５番目」の位置にあるアミノ酸名を意味する
縦軸は、アミノ酸の種類と存在比率を示す。
アミノ酸としては、圧倒的にセリンが各配列に多く含まれているが、多種類のアミノ酸が配列していることがわかる。
【００２２】
水熱反応を行う条件として、「臨界水」や「亜臨界水」中で行うことが知られている。水の温度・圧力を３７５℃、２２ＭＰａ（２１７気圧）まで上げると、水でもない蒸気でもない均一な流体となり、この状態は「臨界水」と呼ばれている。臨界水以上の状態を「超臨界水」と呼び、臨界水よりも低い状態を「亜臨界水」という。亜臨界水では、２００℃、１００〜２００気圧の状態をいう。
本発明は、亜臨界水として使われている条件より緩やかな領域であり、１５０〜２００℃で飽和蒸気圧以上の圧力を用いることができ、３０気圧以下でよく、条件的には穏やかな加圧、加熱条件であり、経済的に得られる条件であることが本発明における最も重要な特徴である。
【００２３】
本発明では、原料セリシンの分子量に応じて水熱反応の温度、圧力及び時間を以下のように設定する。セリシンの分子量が、１０，０００以上では、１８０℃、１２気圧以上、あるいは２００℃、２０気圧以下の範囲が好ましい。分子量が、１０，０００以下では、１５０℃、７気圧以上、あるいは１８０℃、１５気圧以下の範囲で行う。分解する分子長を所望の長さに調節するには反応時間を３０〜６０分程度の範囲内で行う。
１５０℃以下では、水熱反応による分解が低いので適さない。２００℃以上は、水熱反応が激しくて、分解が進み２〜３量体が得られ難く、条件的に適さない。
【００２４】
水熱反応で分解処理するセリシン水溶液の濃度は１〜６重量％の範囲、特に２〜４重量％ が好ましい。６重量％でも、反応は可能であるが、着色が著しくなる。１重量％以下では、反応効率が著しく低下する。
製造したペプチドは、０．１重量％以上であれば、保湿効果に有効であり、この濃度に化粧料に対する配合を調整すればよい。
水熱反応による着色は、珪藻土、酸性白土、ゼオライト、活性アルミナ等を用いて脱色することができる。化粧料の配合適性によりペプチドをナトリウム塩とする。また、加工食品には味の好みによりナトリウム塩を使用する。
【００２５】
本発明による保湿組成物は、Ｎ末端にセリンを有するペプチドで、セリン単独よりも優れた保湿性を発揮するものであり、グリシン・トリペプチドと類型の２〜３量体のペプチドから類型として浸透性の優れることが期待される。皮膚の内部から作用する新規な保湿組成物として、ドライスキン用、中高年向けスキンケア剤、毛髪用に用いることができて、「敏感肌」のスキンケアにも有効である。
消炎剤としては、アラントイン又はその誘導体、グリチルリチン又はその誘導体、ビタミンＥ、より選ばれた消炎剤と本発明の保湿組成物を組み合わせた配合により消炎効果が相乗的に向上する。
紫外線防止剤としては、パラアミノ安息香酸（ＰＡＢＡ）、ＰＡＢＡの誘導体、アントラニル系の紫外線防止剤、サリチル酸系紫外線防止剤、桂皮酸系紫外線防止剤又はベンゾフェノン系紫外線防止剤より選ばれた紫外線防止剤と本発明の保湿組成物を組合わせた配合により紫外線遮断効果が高くなり肌荒れを防止することができる。
美白剤として、コウジ酸又はその誘導体、ビタミンＣ又はその誘導体と本発明の保湿組成物を組合わせた配合により、美白効果を高め、しみやそばかすの美白に有効となる。
加工食品では、にぎりすし、おむすび、豆腐、パン、ピザの味覚保持と硬化防止に有効である。ご飯を炊く時に、本発明の保湿組成物米重量当たり０．１％〜０．５％添加して炊き上げると、ご飯の味覚を維持し、固くなるのを防止することができる。
【００２６】
本発明による保湿組成物の効果は、次の試験によって測定することができる。
「皮膚浸透性」；
剃毛したラット背部中央に、試験試料液をトリチウム標識法により、ピリジン・トリチウム水・無水酢酸の混合液を作用させて、銀粒子（グレイン）を標識として皮膚に塗布する。８時間後にラットの皮膚を摘出して、該皮膚をミクロオートラジオグラフィー法によって、顕微鏡下で皮膚組織中に銀粒子（グレイン）を追跡して見出すことで、本保湿組成物の皮膚に対する浸透性を確認評価することができる。
【００２７】
「皮膚保湿性」；
パネラーの前腕屈側部に、１０％ドデシル硫酸ナトリウム溶液を１時間塗布して肌荒れ状態を作成する。この部分に試料を１時間後及び３時間後に塗布する。次いで２時間後に角質の水分量をインピーダンスメーター（ＳＫＩＣＯＮ−２００ ＩＢＳ社製）により測定する。荒れ肌における測定値を１００として角質の水分率の増加率を求めて皮膚保湿性を示す。水分の増加率の多い程保湿性は優れる。
【００２８】
「肌荒れ改善性」；
パネラーの前腕屈側部に、１０％ドデシル硫酸ナトリウム溶液を１時間塗布して肌荒れ状態を作成する。次いで、該肌荒れ部に毎日朝晩２回試験試料を該肌荒れモデル部に塗布して２９日間継続する。試験をスタートしてから経日的にＴＥＷＡＭＥＴＥＲ ＴＭ−２１０によりＴＥＷＬ値を測定して経表皮水分損失を求めて肌荒れの回復率として肌荒れの改善性を示すことができる。
【００２９】
本発明について実施例により具体的に説明する。
【実施例１】
表１に示したセリシンを用いて、精製水に溶解して３重量％の溶液とした。該溶液を５００ｍｌの容器に充填して、密閉し１８０℃で、１３気圧の下に１時間の水熱反応を行った。冷却後に酸性白土と活性炭を用いて１時間脱色処理をして濾過して濾液を回収して実施例１のペプチドとした。
得られたペプチドをアミノ酸配列分析装置によって分析した結果は表４の通りである。
【００３０】
【表４】

【００３１】
Ｎ末端アミノ酸にセリンを有することが示されている。
実施例１のペプチドについて、ゲル濾過クロマトグラフィ（ＧＰＣ）によって分子量分布を調べた結果を図１に示す。
図１の縦軸は、ペプチド含有量を示す検出器の応答の大きさを示し、横軸は、ペプチドの分子量に対応する溶出液量を示す。
【００３２】
ゲル濾過クロマトグラフィの測定条件は以下の通りである。

【００３３】
図１のゲル濾過クロマトグラフィー（ＧＰＣ）によるチャートでは、セリシンの分子量は、６０００付近に大きなピークがあるのが、水熱反応により１８０℃、２００℃ともに分子量６０００付近のピークは消えて、分子量２００付近のピーク、分子量４００ 付近に最大ピークがあることを示している。
このことは、分子量６０００のセリシンが分解して４量体〜２量体のオリゴペプチドを生成していることを示しているものと認められる。
【００３４】
【実施例２】
図１のゲル濾過クロマトグラフィーに示したセリシンを原料として、精製水に溶解して３重量％の溶液とした。該溶液を５００ｍｌの容器に充填して、密閉し２００℃で１８気圧のもとで１時間の水熱反応を行った。冷却後に珪藻土と活性炭を用いて１時間脱色処理をして濾過して濾液を回収して実施例２のペプチドとした。
実施例２のペプチドをアミノ酸配列分析装置によって分析した結果は、表５の通りである。
【００３５】
【表５】

【００３６】
表５によれば、Ｎ末端アミノ酸にセリンを有することが示されている。
実施例２のペプチドについて、ゲル濾過クロマトグラフィにより分子量分布を調べたところ、図１と同様のものが測定できた。
前記アミノ酸配列のペプチドは、４量体〜２量体が生成されているものと認められる。
【００３７】
【実施例３】
実施例１、実施例２で得られたオリゴペプチド水溶液を用いて、（１）皮膚浸透性、（２）皮膚保湿性、（３）肌荒れ改善性、の効果を測定した結果は次の通りである。
「皮膚浸透性効果」；
前記の皮膚浸透性試験方法によりペプチド０．５重量％液の効果を試験した。ラット皮膚組織について顕微鏡でグレインを探して浸透性を調べた結果、実施例１、実施例２のペプチドは角質のしたにある組織の表皮から更に真皮にまでグレインが確認された。これに対して原料としたセリシンでは、角質には存在したがそれ以下の組織には浸透が認められなかった。
【００３８】
「皮膚保湿性効果」；
前記の皮膚保湿性試験方法により、実施例によるペプチドの保湿効果を測定した。インピダンスメーターによる皮膚深度１５μｍ部の水分率の変化は表６の通りである。本発明のペプチドが０．１重量％以上において優れた保湿性を有することが確認された。
【００３９】
【表６】

【００４０】
「肌荒れ改善性効果」；
前記の肌荒れ改善試験方法により、実施例によるペプチドの肌荒れ改善効果を測定して表７に示した。本発明のペプチドが０．１重量％以上において肌荒れ改善効果が顕著であると判定される。
【００４１】
【表７】

【００４２】
【実施例４】
実施例１で得られたオリゴペプチドを水酸化ナトリウムを用いて、ナトリウム塩とした。米をといだ後で、米重量に対して０．２重量％を配合してご飯を炊いた。おにぎりを作って室温２０℃、湿度６５％に３日間放置した。通常の水のみのものはご飯が硬化してバリバリになった。本発明のペプチドを配合した場合には、しっとりとして柔軟性が保持されて保湿効果がよかった。
比較試験として、原料セリシンを用いた試験では、しっとり感と保湿性はやや保たれていたが油しみた味覚で好ましくなかった。セリンを用いた場合には味が劣り好ましくなかった。
【００４３】
【発明の効果】
本発明においては、昆虫の蚕の繭より得られる生糸より、除去廃棄されるセリシンを回収して、薬品や酵素を用いることなく、水のみで高温高圧の水熱反応によってセリシンを分解して、分子のＮ末端アミノ酸にセリンを有し、重合度が２〜３のオリゴペプチドを製造する技術でセリシンを原料として、Ｎ末端アミノ酸にセリンを配した重合度が５以下のオリゴペプチドを製造することができるので浸透性の優れた保湿剤として、化粧料として皮膚、毛髪分野に利用される。
また、その外にすし、おにぎり、パン、ピザ等の加工食品の硬化を防止して味覚を保持するという顕著な効果を発揮することができる。
【図面の簡単な説明】
【図１】実施例１のペプチドについて、ゲル濾過クロマトグラフィ（ＧＰＣ）によって分子量分布を調べた結果を示す。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a moisturizing composition derived from sericin and having excellent permeability.
More specifically, the present invention relates to a moisturizing composition containing serine at the N-terminal amino acid of a peptide and containing an oligopeptide having 5 or less amino acids or a sodium salt thereof.
Further, the moisturizing composition of the present invention is useful as a humectant having excellent permeability to skin and hair or a food humectant having excellent permeability to processed foods.
[0002]
[Prior art]
Conventionally, moisturizers (1) prevent rough skin, (2) apply skin, (3) moisturize skin, (4) maintain skin softness, (5) make skin wrinkles inconspicuous It plays an important role in doing things. As humectants used for this purpose, glycerin, propylene glycol, 1,3-butylene glycol, polyethylene glycol, sorbitol, sodium lactate, sodium 2-pyrrolidone-5-carboxylate, sodium hyaluronate, collagen and the like are known. . Sericin is promising as a moisturizer, but it was a colloidal substance and could not be used as a main ingredient in cosmetics if used as a raw material. Regarding sericin emitted from the silk industry, a sericin recovery technology has been developed as an effective use of waste resources, and advanced utilization of the moisturizing effect of sericin is strongly expected from the aspect of industrial regeneration.
[0003]
As an example of the use form of sericin, for example, in Japanese Patent Application Laid-Open No. 62-036308, cosmetics containing sericin obtained from silk refining waste liquid and a rice bran solution contained sericin in Japanese Patent Application Laid-Open No. Hei 8-133963. Bath agents are said to be effective in moisturizing the bare skin after bathing and improving swelling. JP-A-2001-017097 also reports that raw rice contains components of silkworms, cocoons, and silk to improve the taste when cooked.
However, the utilization technology utilizing the moisturizing properties of sericin remains at the above-mentioned state of the art, and a highly utilized technology that satisfies all the properties desired for the above moisturizer has not been known yet.
[0004]
While conventional moisturizers have been applied to the surface of the skin to moisturize the outer surface of the skin, recent studies have shown that the skin can penetrate the dermis from the epidermis under the keratin of the skin and It is attracting attention as a moisturizer to act on. It is common practice to repair wrinkles from the depression inside the skin wrinkles.
For this purpose, the collagen and polypeptides themselves do not penetrate into the epidermis and dermis of the skin, and the present inventors cut the peptide molecules into short amino acids to make the degree of amino acid polymerization trimer, and We focused on obtaining permeability and functionality by designing a terminal amino acid to have an amino acid that expects functionality.
[0005]
For example, in the case of collagen derived from pig, the development of a trip peptide having glycine at the N-terminal amino acid and consisting of three amino acids was referred to. In this development, we discovered an enzyme that can selectively cleave the main chain, and decompose collagen with the enzyme to produce collagen tripeptide (CTP) in which [Gly-xy] is regularly arranged. Became possible. The obtained CTP is attracting attention as a novel humectant that acts from the inside of the skin to obtain a moisturizing effect, because CTP has excellent permeability to the skin and penetrates the keratin from the epidermis to the dermis. (FRAGRANCE JOURNAL October 2001).
[0006]
Also, according to Japanese Patent Application Laid-Open No. H11-92564, it is known that the average molecular weight of sericin constituting the cocoon thread is 60,000 to 300,000 (measured by SDS electrophoresis), but it is actually used. The sericin used has an average molecular weight of about 20,000 as disclosed in, for example, JP-A-10-245345. As the hydrolysis of sericin is promoted, the molecular weight ranges from 300 to 50,000 or 5,000 to 50,000 as described in JP-A-4-202435.
For hydrolysis of sericin, an acid hydrolysis method and an enzymatic method are known.
For example, in the acid hydrolysis method, the rate at which amino acids are further decomposed to amino acids is high, and it has been difficult with conventional methods to obtain pentamers or less in good yield. In addition, the enzymatic method is more suitable for cutting to a longer length than the acid hydrolysis method, but since the type of enzyme determines the cleavage site, it is necessary to search for the enzyme to cut sericin in a desired manner. Even if it is possible, it is not easy because there is no guarantee that the enzyme can be applied industrially.
[0007]
A method for decomposing proteins by a hydrothermal reaction has been developed. In Japanese Patent Application Laid-Open No. 9-268166, a method based on a reaction at 300 to 400 ° C., 221 to 1000 atm, and 1 to 40 seconds is known. According to Japanese Patent Application Laid-Open No. 2000-241290, a substance containing at least one of cocoon, raw silk, fiproin, sericin, and pupa reacts rapidly in a subcritical water region and reacts in a short time in seconds. The target peptide cannot be produced.
[0008]
Serine is superior to glycine as an effective amino acid for the moisturizing effect.
Serine is a special amino acid contained in large amounts only in sericin, and serine cannot be obtained from porcine collagen or marine collagen. On the other hand, cattle-derived CTP has also been shunned due to the BSE problem and the like, and social needs to minimize the use of cattle-derived raw materials have become apparent.
[0009]
[Problems to be solved by the invention]
The sericin that is removed and discarded is collected from the raw silk obtained from the cocoon of the insect silkworm, and the sericin is decomposed by a high-temperature, high-pressure hydrothermal reaction using only water without using chemicals or enzymes, and the N-terminal amino acid of the molecule is obtained. If an oligopeptide having serine and a degree of polymerization of 5 or less can be produced, the raw material protein, the reaction technology, and the product are clean.
Therefore, if the present inventors can produce an oligopeptide having serine at the N-terminal amino acid and having an amino acid polymerization degree of 5 or less using sericin as a raw material, the present inventors will consider it as a moisturizer having excellent permeability and as a cosmetic. In addition to being used in the field of hair, the present inventors considered that the hardening of processed foods such as sushi, onigiri, bread, pizza and the like would be prevented and the taste would be maintained, leading to advanced use.
In the present invention, by using sericin as a raw material, an oligopeptide having serine at the N-terminal amino acid of the molecule and having a degree of polymerization of 5 or less is obtained, which is superior in moisturizing property to skin, hair, and processed food as compared with serine alone. It is an object of the present invention to provide a moisturizing composition that gives the following.
[0010]
Table 1 shows the types and contents of amino acids constituting sericin.
However, tryptophan was measured by high performance liquid chromatography, and other amino acids were measured by an automatic amino acid measuring device.
[0011]
[Table 1]

[0012]
From Table 1, it is characteristic that serine is the most amino acid of sericin, and such a serine-rich protein cannot be obtained from other animals.
[0013]
In addition, Table 2 shows the positioning of serine in the skin by NMF (natural moisturizing factor).
[0014]
[Table 2]

[0015]
According to Table 2, it is found that the serine content is the highest in NMF. This indicates that serine plays an important role in moisturizing the skin and helps prevent rough skin and aging.
[0016]
[Patent Document]
[Reference 1] Japanese Patent Application Laid-Open No. H10-245345 [Reference 2] Japanese Patent Application Laid-Open No. 62-036308 [Reference 3] Japanese Patent Application Laid-Open No. 08-133963 [Reference 4] Japanese Patent Application Laid-Open No. 2001-0179097 [Reference 5] Japanese Unexamined Patent Application Publication No. Hei 11-92564 [Document 6] Japanese Patent Application Laid-Open No. 4-202435 [Document 7] Japanese Patent Application Laid-Open No. 9-268166 [Document 8] Japanese Patent Application Laid-Open No. 2002-241290 [Non-patent Document]
FRAGANCE JOURNAL, p. 65, October, 2001
[Means for Solving the Problems]
In the present invention, a cosmetic or processed food is prepared by containing 0.1% by weight or more of an oligopeptide having serine at the N-terminal amino acid of the oligopeptide and having 5 or less amino acids or a sodium salt of the oligopeptide. It is characterized by obtaining a moisturizing composition that can be used effectively.
In the present invention, sericin is decomposed by a hydrothermal reaction. At this time, a moisturizing composition is produced by using an oligopeptide having serine as the N-terminal amino acid of the molecule and having 5 or less amino acids. Is also characterized.
[0018]
The present invention basically has the following configuration.
(1) A moisturizing composition comprising an oligopeptide having serine at the N-terminal amino acid and containing 0.1% by weight or more of an oligopeptide having 5 or less amino acids or a sodium salt of the oligopeptide.
(2) The moisturizing composition according to (1), which is used for cosmetics.
(3) The moisturizing composition according to (2), which is blended in a cosmetic containing at least one component selected from an anti-inflammatory agent, an ultraviolet inhibitor, and a whitening agent.
(5) The moisturizing composition according to (1), which is added to a processed food.
(4) A method for producing a moisturizing composition, wherein sericin is decomposed by a hydrothermal reaction, the serine as an N-terminal amino acid of the molecule, and an oligopeptide having 5 or less amino acids.
(6) The sericin aqueous solution is subjected to a hydrothermal reaction at a temperature of 150 ° C. to 200 ° C. under a pressure of 7 to 20 atm to provide an oligo having serine at the N-terminal amino acid of the molecule and having 5 or less amino acids. A method for producing a moisturizing composition comprising a peptide.
(7) The method for producing a moisturizing composition according to any one of (1) to (4), wherein the temperature, pressure, and time of the hydrothermal reaction are set according to the molecular weight of the raw material sericin.
[0019]
Sericin used as a raw material in the present invention is used by recovering sericin eluted from silkworm cocoons and raw silk by refining or hot water treatment, but an aqueous solution containing sericin is easily rotted and is difficult to store, so freeze drying or spray drying is used. It is preferable to make it into a powder form and use it as an aqueous solution at the time of use.
The molecular weight of sericin used in the present invention is not specified, and may be partially hydrolyzed by recovering sericin.
[0020]
Table 3 shows the results obtained by analyzing the binding sequence of the N-terminal amino acid in the peptide chain of the raw material sericin used in the examples of the present invention using an amino acid sequence analyzer.
[0021]
[Table 3]

In Table 3, the horizontal axis indicates the sequence of amino acids, and for example, "5" means the name of the amino acid at the position "fifth from the end", and the vertical axis indicates the type of amino acid and the abundance ratio.
As amino acids, serine is predominantly contained in each sequence, but it can be seen that many types of amino acids are arranged.
[0022]
It is known that hydrothermal reaction is performed in "critical water" or "subcritical water". When the temperature and pressure of water are raised to 375 ° C. and 22 MPa (217 atm), the water becomes a uniform fluid that is neither water nor steam, and this state is called “critical water”. The state above the critical water is called “supercritical water”, and the state below the critical water is called “subcritical water”. Subcritical water refers to a state of 200 ° C. and 100 to 200 atm.
The present invention is in a region that is milder than the condition used as subcritical water, can use a pressure higher than the saturated vapor pressure at 150 to 200 ° C., can be lower than 30 atm, and conditionally is a moderate pressure. The most important features of the present invention are pressure and heating conditions, and economical conditions.
[0023]
In the present invention, the temperature, pressure and time of the hydrothermal reaction are set as follows according to the molecular weight of the starting sericin. When the molecular weight of sericin is 10,000 or more, the range is preferably 180 ° C. and 12 atm or 200 ° C. and 20 atm or less. When the molecular weight is 10,000 or less, the reaction is carried out at 150 ° C. and 7 atm or more, or at 180 ° C. and 15 atm or less. In order to adjust the molecular length to be decomposed to a desired length, the reaction time is set within a range of about 30 to 60 minutes.
If the temperature is lower than 150 ° C., the decomposition by the hydrothermal reaction is low, so that it is not suitable. At 200 ° C. or higher, the hydrothermal reaction is intense, the decomposition proceeds, and it is difficult to obtain a dimer or trimer, which is not suitable for conditions.
[0024]
The concentration of the aqueous sericin solution to be decomposed by the hydrothermal reaction is preferably in the range of 1 to 6% by weight, particularly preferably 2 to 4% by weight. Even at 6% by weight, the reaction is possible, but the coloration is remarkable. When the content is less than 1% by weight, the reaction efficiency is significantly reduced.
When the produced peptide is 0.1% by weight or more, it is effective for the moisturizing effect, and the concentration of the peptide in the cosmetic may be adjusted to this concentration.
Coloring by the hydrothermal reaction can be decolorized using diatomaceous earth, acid clay, zeolite, activated alumina and the like. The peptide is converted into a sodium salt depending on the suitability of the cosmetic. In addition, sodium salts are used in processed foods depending on taste preferences.
[0025]
The moisturizing composition according to the present invention is a peptide having a serine at the N-terminus and exhibits a better moisturizing property than serine alone, and penetrates as a type from a glycine / tripeptide and a type of 2-3 trimer peptide. Is expected to be excellent. As a new moisturizing composition that acts from the inside of the skin, it can be used for dry skin, middle-aged and older skin care agents and hair, and is also effective for skin care of "sensitive skin".
As the anti-inflammatory agent, the anti-inflammatory effect is synergistically improved by combining the anti-inflammatory agent selected from allantoin or its derivative, glycyrrhizin or its derivative, vitamin E, and the moisturizing composition of the present invention.
Examples of the ultraviolet ray inhibitor include an ultraviolet ray inhibitor selected from para-aminobenzoic acid (PABA), a derivative of PABA, an anthranil type ultraviolet ray inhibitor, a salicylic acid type ultraviolet ray inhibitor, a cinnamic acid type ultraviolet ray inhibitor or a benzophenone type ultraviolet ray inhibitor. By the combination of the moisturizing composition of the present invention, the effect of blocking ultraviolet rays is increased, and rough skin can be prevented.
The combination of kojic acid or a derivative thereof, vitamin C or a derivative thereof and the moisturizing composition of the present invention as a whitening agent enhances the whitening effect and is effective for whitening spots and freckles.
In processed foods, Nigiri sushi, rice ball, tofu, bread, and pizza are effective for maintaining taste and preventing hardening. When rice is cooked, if the moisturizing composition of the present invention is added in an amount of 0.1% to 0.5% per rice weight and cooked, the taste of the rice can be maintained and hardened.
[0026]
The effect of the moisturizing composition according to the present invention can be measured by the following test.
"Skin permeability";
At the center of the back of the shaved rat, a test solution is applied with a mixed solution of pyridine, tritium water, and acetic anhydride by a tritium labeling method, and silver particles (grain) are applied to the skin as a label. Eight hours later, the skin of the rat is excised, and the skin is examined by microautoradiography to track and find silver particles (grain) in the skin tissue under a microscope. Can be confirmed and evaluated.
[0027]
"Skin moisturizing";
A 10% sodium dodecyl sulfate solution is applied to the forearm flexion side of the panel for 1 hour to create a rough skin condition. The sample is applied to this part after 1 hour and 3 hours. Then, two hours later, the water content of the keratin is measured by an impedance meter (manufactured by SKICON-200 IBS). The moisturizing property of the skin is shown by calculating the rate of increase in the moisture content of the keratin with the measured value for rough skin as 100. The higher the rate of increase in moisture, the better the moisture retention.
[0028]
"Improvement of rough skin";
A 10% sodium dodecyl sulfate solution is applied to the forearm flexion side of the panel for 1 hour to create a rough skin condition. Then, a test sample is applied to the rough skin twice daily in the morning and evening, and the test is continued for 29 days. After the test is started, the TEWL value is measured daily using TEWAMETER TM-210 to determine the transepidermal water loss, and the improvement rate of the rough skin can be shown as the recovery rate of the rough skin.
[0029]
The present invention will be specifically described with reference to examples.
Embodiment 1
Using sericin shown in Table 1, it was dissolved in purified water to obtain a 3% by weight solution. The solution was filled in a 500 ml container, sealed, and subjected to a hydrothermal reaction at 180 ° C. under 13 atm for 1 hour. After cooling, the mixture was subjected to a decolorization treatment using acid clay and activated carbon for 1 hour, and filtered to collect the filtrate, thereby obtaining the peptide of Example 1.
The results obtained by analyzing the obtained peptide using an amino acid sequence analyzer are shown in Table 4.
[0030]
[Table 4]

[0031]
It has been shown to have serine at the N-terminal amino acid.
FIG. 1 shows the results of examining the molecular weight distribution of the peptide of Example 1 by gel filtration chromatography (GPC).
The vertical axis in FIG. 1 shows the magnitude of the response of the detector indicating the peptide content, and the horizontal axis shows the amount of eluate corresponding to the molecular weight of the peptide.
[0032]
The measurement conditions of gel filtration chromatography are as follows.

[0033]
In the chart by gel filtration chromatography (GPC) of FIG. 1, the molecular weight of sericin has a large peak near 6000, but the peak near the molecular weight of 6000 disappears at 180 ° C. and 200 ° C. due to the hydrothermal reaction, and the molecular weight of 200 This indicates that there is a peak near the peak and a maximum peak near a molecular weight of 400.
This is considered to indicate that sericin having a molecular weight of 6000 is decomposed to form tetramer to dimer oligopeptides.
[0034]
Embodiment 2
Sericin shown in the gel filtration chromatography of FIG. 1 was used as a raw material and dissolved in purified water to prepare a 3% by weight solution. The solution was filled in a 500 ml container, sealed, and subjected to a hydrothermal reaction at 200 ° C. under 18 atm for 1 hour. After cooling, the mixture was decolorized using diatomaceous earth and activated carbon for 1 hour, filtered, and the filtrate was collected to obtain the peptide of Example 2.
Table 5 shows the results of the analysis of the peptide of Example 2 using an amino acid sequence analyzer.
[0035]
[Table 5]

[0036]
Table 5 shows that the N-terminal amino acid has serine.
When the molecular weight distribution of the peptide of Example 2 was examined by gel filtration chromatography, the same one as in FIG. 1 could be measured.
It is recognized that the peptide having the amino acid sequence has been formed into a tetramer to a dimer.
[0037]
Embodiment 3
Using the oligopeptide aqueous solutions obtained in Examples 1 and 2, the results of measuring the effects of (1) skin permeability, (2) skin moisturizing properties, and (3) skin roughness improving properties are as follows. is there.
"Skin penetrating effect";
The effect of a 0.5% by weight solution of the peptide was tested by the skin permeability test method described above. As a result of examining the permeability of the rat skin tissue with a microscope to find the grains, the peptides of Example 1 and Example 2 were confirmed to have grains from the epidermis of the keratinized tissue to the dermis. On the other hand, sericin as a raw material was present in the stratum corneum, but no permeation was observed in tissues below it.
[0038]
"Skin moisturizing effect";
The moisturizing effect of the peptide according to the example was measured by the skin moisturizing test method described above. Table 6 shows the change in the water content at a skin depth of 15 μm with an impedance meter. It was confirmed that the peptide of the present invention had excellent moisture retention at 0.1% by weight or more.
[0039]
[Table 6]

[0040]
"Skin roughness improvement effect";
Table 7 shows the effect of the peptides of the examples for improving skin roughness according to the test method for skin roughness improvement described above. When the peptide of the present invention is 0.1% by weight or more, it is determined that the skin roughness improving effect is remarkable.
[0041]
[Table 7]

[0042]
Embodiment 4
The oligopeptide obtained in Example 1 was converted into a sodium salt using sodium hydroxide. After the rice was harvested, the rice was cooked with 0.2% by weight based on the rice weight. Onigiri was prepared and left at room temperature of 20 ° C. and humidity of 65% for 3 days. With ordinary water only, the rice hardened and became crunchy. When the peptide of the present invention was blended, the softness was kept moist and the moisturizing effect was good.
As a comparative test, in a test using sericin as a raw material, the moist feeling and the moisturizing property were slightly maintained, but were unfavorable due to the oily taste. When serine was used, the taste was inferior and was not preferred.
[0043]
【The invention's effect】
In the present invention, sericin removed and discarded is collected from raw silk obtained from the silkworm cocoon of insects, and without using chemicals or enzymes, sericin is decomposed by high-temperature and high-pressure hydrothermal reaction with water alone, A technique for producing oligopeptides having serine at the N-terminal amino acid of the molecule and having a degree of polymerization of 2-3 using sericin as a raw material to produce oligopeptides having serine at the N-terminal amino acid and a degree of polymerization of 5 or less. As a humectant with excellent permeability, it is used as a cosmetic in the skin and hair fields.
In addition, a remarkable effect of preventing hardening of processed foods such as sushi, rice balls, bread, pizza and the like and maintaining taste can be exerted.
[Brief description of the drawings]
FIG. 1 shows the results of examining the molecular weight distribution of the peptide of Example 1 by gel filtration chromatography (GPC).

Claims (7)

A moisturizing composition comprising a serine at the N-terminal amino acid of the oligopeptide and containing 0.1% by weight or more of an oligopeptide having 5 or less amino acids or a sodium salt of the oligopeptide. The moisturizing composition according to claim 1, which is used for cosmetics. 3. The moisturizing composition according to claim 2, wherein the composition is blended with a cosmetic containing at least one component selected from an anti-inflammatory agent, an ultraviolet inhibitor and a whitening agent. The moisturizing composition according to claim 1, which is blended in a processed food. A method for producing a moisturizing composition, wherein sericin is decomposed by a hydrothermal reaction, and the oligopeptide has serine as the N-terminal amino acid of the molecule and has an amino acid number of 5 or less. The sericin aqueous solution is subjected to a hydrothermal reaction at a temperature of 150 ° C. to 200 ° C. under a pressure of 7 to 20 atm to obtain an oligopeptide having serine at the N-terminal amino acid of the molecule and having 5 or less amino acids. A method for producing a moisturizing composition, comprising: The method for producing a moisturizing composition according to any one of claims 1 to 4, wherein the temperature, pressure, and time of the hydrothermal reaction are set according to the molecular weight of the raw material sericin.

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