JP5343282B2 - Double-chain hydrogelator - Google Patents

Description

  The present invention relates to a novel hydrogelator and hydrogel.

  A low molecular gel is a gel in which solvent molecules are captured by forming a three-dimensional network by self-assembly of low molecular compounds by intermolecular forces (see, for example, Non-Patent Document 1).

  Low molecular gels are expected to be applied to various fields such as separation membranes, sensors, catalysts, electronic materials, biomaterials, etc., since molecular design of low molecular compounds that form gels is possible. Patent Document 2).

  We have also synthesized 3,4,5-long-chain alkyloxybenzamide derivatives having a novel structure (see Patent Document 1), and found that some of these compounds gel organic solvents. The compound which has the ability was provided (refer patent document 2).

  There was no report on gel formation of 3,5-long chain alkyloxybenzamide derivatives.

  However, when considering application to biomaterials, it is clear that water gelled hydrogels are preferable to organogel gels, but there are few reports of low molecular hydrogels (for example, Non-Patent Document 3). Further, when the obtained hydrogel is used as a biomaterial, it is desirable that the hydrogel itself has biocompatibility, but there has been almost no report from this viewpoint.

  We have synthesized 3,4,5-long chain alkyloxybenzamide derivatives to which oligomers or polymer derivatives of ethylene glycol have been bound so far, and these compounds are intended to impart biocompatibility to medical materials. It has been disclosed that these compounds can be used (see Patent Document 3), and that these compounds gel organic solvents (see Patent Document 4), and further, these compounds have been found to form hydrogels ( (See Patent Document 5). However, development of a hydrogelator having a new molecular structure is desired in order to optimize the properties and preparation methods of the hydrogel according to the purpose and application.

JP 2001-122889 A JP 2004-262809 A JP 2005-232061 A JP-A-2005-232278 JP 2007-217551 A Chemical Review (Chem. Rev.), 1997, Vol. 97, p. 3133-3159 Angewante Chemie International Edition (Angew. Chem. Int. Ed.), 2000, 39, p. 2263-2266 Chemical Review (Chem. Rev.), 2004, 104, p. 1201-1217

  An object of the present invention is to provide a novel hydrogelator and a hydrogel.

  As a result of intensive studies on the above problems, the present inventors found that organogel formation of 3,5-long-chain alkyloxybenzamide derivatives was not observed, and that gel formation has structural specificity.

  Furthermore, unlike the gelation ability expected from the result of organogel formation, the present inventors bound an oligomer or polymer derivative of ethylene glycol represented by the formula (1), and a long-chain alkyloxy group at the 3,5-positions. Benzamide derivatives having groups have been found to form hydrogels by appropriate selection of hydrophilic ethylene glycol oligomer or polymer moiety length, hydrophobic alkyl moiety length, and gelling conditions; The present invention has been completed. The compound represented by the formula (1) gives diversity to the chemical structure in addition to the benzamide derivative having a long-chain alkyloxy group at the 3, 4, and 5 positions, and optimizes the physical properties of the hydrogel. It is effective when.

（式中で、ＸはＯＨ又はＮＨ_２を、ｋは０から４までの整数を、ｍは１から、好ましくは７から、１００までの整数を、ｎは１から、好ましくは２から、６までの整数を、ｐは９から、好ましくは１１から、１７までの整数を表す。）
すなわち、本発明は、式（１）で示される化合物を有効成分として含むヒドロゲル化剤、及び、式（１）で示される化合物と水とを含んでなるヒドロゲルを提供する。

(In the formula, the X is OH or NH _2, the integer k is from 0 to 4, m is from 1, preferably an integer of from 7 to 100, n is from 1, preferably from 2, 6 And p represents an integer from 9, preferably from 11 to 17.)
That is, the present invention provides a hydrogelator comprising a compound represented by formula (1) as an active ingredient, and a hydrogel comprising a compound represented by formula (1) and water.

  The present invention adds a variety of new molecular structures to a rare molecular species in which a compound having an ethylene glycol oligomer or polymer as a partial structure hydrogels by molecular self-assembly.

（式中で、ＸはＯＨ又はＮＨ_２を、ｋは０から４までの整数を、ｍは１から、好ましくは７から、１００までの整数を、ｎは１から、好ましくは２から、６までの整数を、ｐは９から、好ましくは１１から、１７までの整数を表す。）
なお、室温付近でのヒドロゲル形成の観点からｍは７以上、ｐは１１以上が好ましく、合成工程の観点からｎは２以上が好ましい。
式（１）で示される化合物は、既に開示した様に、エチレングリコールのオリゴマー又はポリマーのアミン誘導体と、３，５位にアルキルオキシ基を有する安息香酸誘導体とのアミド縮合によって得られる（特開２００５−２３２０６１号公報）。また、末端のＸとエチレングリコールのオリゴマー又はポリマーの間のアルキル鎖長、及び、ベンズアミドとエチレングリコールのオリゴマー又はポリマーの間のアルキル鎖長は、下に記載のエチレングリコールのオリゴマー又はポリマーのアミン誘導体の合成法に準じて、適当な末端修飾を施すことによって得られる。 The hydrogelator of the present invention contains a compound represented by the formula (1) as an active ingredient.

(In the formula, the X is OH or NH _2, the integer k is from 0 to 4, m is from 1, preferably an integer of from 7 to 100, n is from 1, preferably from 2, 6 And p represents an integer from 9, preferably from 11 to 17.)
Note that m is preferably 7 or more and p is 11 or more from the viewpoint of hydrogel formation near room temperature, and n is preferably 2 or more from the viewpoint of the synthesis step.
As already disclosed, the compound represented by the formula (1) can be obtained by amide condensation between an ethylene glycol oligomer or polymer amine derivative and a benzoic acid derivative having an alkyloxy group at the 3,5-positions (JP, A 2005-232061). The alkyl chain length between the terminal X and the ethylene glycol oligomer or polymer and the alkyl chain length between the benzamide and ethylene glycol oligomer or polymer are the amine derivatives of the ethylene glycol oligomer or polymer described below. According to the synthesis method of (2), it can be obtained by applying an appropriate terminal modification.

  The ethylene glycol oligomer or polymer amine derivative is obtained by, for example, sequentially tosylating, iodination of tosyl group, conversion of iodine group to phthalimide, hydrazine by one end or both ends of commercially available ethylene glycol oligomer or polymer. Obtained by deprotection. For oligomers with lengths that are not commercially available, one end of oligoethylene glycol is protected, the other end is tosylated, and condensed with oligoethylene glycol, the total length of which is required, followed by deprotection. One or both ends of a compound (J. Org. Chem. 2004, 69, p.639-647), which is tosylated, iodinated tosyl group, iodine Obtained by conversion of the group to phthalimide, deprotection with hydrazine (Biochemistry 1980, 19, p. 4595-4600). Alternatively, a similar compound can be obtained by tosylation followed by azidation of the tosyl group and subsequent reduction.

  The compound represented by the formula (1) can be used as a hydrogelator as it is, or as a mixture with a substance that does not hinder its hydrogelation.

  The hydrogel is prepared by suspending an appropriate amount of a hydrogelator containing a compound represented by the formula (1) as an active ingredient in water and heating it to a temperature at which the hydrogel is used as it is, or once the hydrogelator is dissolved. It is manufactured by heating to temperature and then cooling to room temperature, heating again after the cooling, or cooling to a lower temperature after the cooling.

  The present invention will be described in more detail below, but the present invention is not limited to the following description. In the following, EDC.HCl is an abbreviation for water-soluble carbodiimide hydrochloride, HOBt is an abbreviation for 1-hydroxybenzotriazole hydrate, and PEG is an abbreviation for polyethylene glycol.

<Synthesis Example 1>
(Synthesis of a compound in which X = OH, k = 0, m = 29 to 32, n = 2, p = 13 in the formula (1))
3,5-dihydroxybenzoic acid (3.08 g, 20.0 mmol) was dissolved in distilled DMF (200 ml), 1-bromotetradecane (19.8 ml, 70.0 mmol) and K ₂ CO ₃ (20 g) were added, The mixture was heated to 65 ° C. and stirred overnight under a N ₂ stream. After completion of the reaction, the temperature was returned to room temperature, 5% aqueous HCl (200 ml) and hexane were added, and the mixture was stirred at room temperature. The mixture was washed with 4% NaHCO ₃ aqueous solution and saturated NaCl in this order, and the organic phase was dehydrated with anhydrous sodium sulfate. The desiccant was filtered off and the solvent was distilled off. Purification by silica gel column chromatography (hexane: dichloromethane = 1: 1) and recrystallization from ethanol gave tetradecyl 3,5-bis (tetradecyloxy) benzoate (10.22 g, 13.74 mmol, 69%). .

White powder; ¹ H-NMR (CDCl ₃ ) δ = 7.15 (2H, s, 2,6-H), 6.62 (1H, s, 4-H), 4.28 (2H, t, J = 7 Hz, 1- COOCH ₂ ), 3.96 (4H, t, J = 7 Hz, 3,5-OCH ₂ ), 1.77 (6H, m, 1-COOCCH ₂ , 3,5-OCCH ₂ ), 1.43 (6H, m, 1- COOC ₂ CH ₂ , 3,5-OC ₂ CH ₂ ), 1.26 (60H, m, 1-COOC ₃ C ₁₀ H ₂₀ , 3,5-OC ₃ C ₁₀ H ₂₀ ), 0.88 (9H, t, J = 7 Hz, 1-COOC ₁₃ CH ₃ , 3,5-OC ₁₃ CH ₃ ).
Tetradecyl 3,5-bis (tetradecyloxy) benzoate (2.23 g, 3.00 mmol) was dissolved in methanol (30 ml) and dichloromethane (10 ml), sodium methoxide (0.162 g, 3.00 mmol) was added, and room temperature was added. And stirred overnight under N ₂ stream. After completion of the reaction, the reaction mixture was neutralized with Amberlite IR-120 (plus) resin and the solvent was distilled off. Recrystallization from ethanol gave methyl 3,5-bis (tetradecyloxy) benzoate (1.72 g, 2.46 mmol, 82%).

White powder; ¹ H-NMR (CDCl ₃ ) δ = 7.15 (2H, s, 2,6-H), 6.63 (1H, s, 4-H), 3.96 (4H, t, J = 7 Hz, 3, 5-OCH ₂ ), 3.89 (3H, s, 1-COOCH ₃ ), 1.77 (4H, quintet, J = 7 Hz, 3,5-OCCH ₂ ), 1.44 (4H, m, 3,5-OC ₂ CH ₂ ), 1.26 (40H, m, 3,5-OC ₃ C ₁₀ H ₂₀ ), 0.88 (6H, t, J = 7 Hz, 3,5-OC ₁₃ CH ₃ ).
Methyl 3,5-bis (tetradecyloxy) benzoate (5.084 g, 9.06 mmol) is dissolved in ethanol (90 ml) and water (30 ml), and potassium hydroxide (5.00 g) is added. Refluxed overnight. The reaction solution was returned to room temperature, 2% HCl (200 ml) and dichloromethane (120 ml) were added, and the mixture was further stirred for 50 hours. After completion of the reaction, the solvent was distilled off and methanol was added to obtain crude crystals. The dried crude crystals were added to 1-propanol (200 ml) and dissolved by heating to 55 ° C. When the reaction solution was returned to room temperature and further cooled, crystals were precipitated. The crystal was washed with methanol to obtain 3,5-bis (tetradecyloxy) benzoic acid (4.55 g, 8.32 mmol, 92%).

White powder; ¹ H-NMR (CDCl ₃ ) δ = 7.18 (2H, s, 2,6-H), 6.67 (1H, s, 4-H), 3.97 (4H, t, J = 7 Hz, 3, 5-OCH ₂ ), 1.78 (4H, quintet, J = 7 Hz, 3,5-OCCH ₂ ), 1.44 (4H, m, 3,5-OC ₂ CH ₂ ), 1.26 (40H, m, 3,5 -OC ₃ C ₁₀ H ₂₀ ), 0.88 (6H, t, J = 7 Hz, 3,5-OC ₁₃ CH ₃ ); MS (APCI) found: m / z 547.6, calcd for C ₅₃ H ₉₉ NO ₆ : M ⁺ , 547.5.
Dissolve 3,5-bis (tetradecyloxy) benzoic acid (0.273 g, 0.500 mmol) in dichloromethane (5 ml) and add HOBt (0.085 g, 0.600 mmol) and EDC · HCl (0.115 g, 0.600 mmol). And stirred at room temperature for 1 hour. PEG 1540 mono-amine was dissolved in dichloromethane (5 ml), and the mixture was further stirred for 2 hours while dropping into the reaction solution using a dropping funnel. After completion of the reaction, the organic phase was washed with 4% NaHCO ₃ aqueous solution and saturated NaCl aqueous solution in this order, and dehydrated with anhydrous sodium sulfate. The desiccant was filtered off and the solvent was distilled off. The residue was purified by silica gel column chromatography (chloroform: methanol = 9: 1) to obtain the compound of Synthesis Example 1 (0.592 g, 0.303 mmol, 61%).

¹ H-NMR (CDCl ₃ ) δ = 6.91 (2H, s, 2,6-H), 6.55 (1H, s, 4-H), 3.96 (4H, t, J = 7 Hz, 3,5-OCH ₂ ), 3.71-3.59 (128H, m, OCH ₂ CH ₂ × 32), 1.76 (4H, quintet, J = 7 Hz, 3,5-OCCH ₂ ), 1.43 (4H, m, 3,5-OC ₂ CH ₂ ), 1.26 (40H, m, 3,5-OC ₃ C ₁₀ H ₂₀ ), 0.88 (6H, t, J = 7 Hz, 3,5-OC ₁₃ CH ₃ ).
<Example 1>
(Hydrogel formation)
The compound synthesized in Synthesis Example 1 was dispersed in pure water to a concentration of 60 mM, heated once to 100 degrees, and then returned to room temperature. Although it was in a highly viscous sol state at room temperature, it was confirmed by an inversion method that a hydrogel was given at 60 ° C. when the temperature was further increased. The inversion method is a method for confirming that the solution is in a gel state by inverting the sample container.

  The hydrogel provided by the present invention has an ethylene glycol oligomer or polymer structure known to be biocompatible, and can be used for three-dimensional cell culture, separation and purification of cells and proteins, sustained release of protein pharmaceuticals, and the like. .

Claims (3)

A hydrogelator comprising a compound represented by the formula (1) as an active ingredient.

(In the formula, the X is OH or NH _2, k is an integer from 0 to 4, the integer m is from 1 to 100, the n is an integer from 1 to 6, integers p from 9 17 Represents.) A hydrogelator comprising a compound represented by formula (2) as an active ingredient.

(In the formula, the X is OH or NH _2, the integer k is from 0 to 4, the integer m is from 7 to 100, the integer n is from 2 to 6, p is from 11 to 17 Represents an integer.)   A hydrogel comprising the compound of formula (1) of claim 1 or formula (2) of claim 2 and water.