Study on a specific recognition mechanism for mugineic acid-Fe (III) complex in gramineous plants

为了阐明mugineic酸-Fe（III）复合物的质膜转运蛋白的分子结构，本研究首先合成了一些mugineic酸类似物。(1)本文报道了3 ′（S）-N- [3-羧基-（3-羧基丙基氨基）丙基]甘氨酸在三个单元NaBH_3CN存在下的还原偶联反应，γ-丁内酯、L-高丝氨酸和甘氨酸。以类似的方法，在NaBH_3CN存在下，由保护的L-N-（3-羧基丙基）间苯二甲醛与L-高丝氨酸内酯缩合，合成了2（S），3 ′（S）-N- [3-羧基-（3-羧基丙基氨基）丙基]高丝氨酸。(2)以甘氨酸和2分子L-高丝氨酸内酯为原料，在NaBH_3CN存在下，通过还原偶联反应合成了3 ′（S），3 ″（S）-N- [3-羧基-（3-氨基-3-羧基丙基氨基）丙基]甘氨酸。以3 ′（S）-N-[3-氨基-3-羧基丙基]高丝氨酸醛为保护基，在NaBH_3CN存在下与L-高丝氨酸内酯缩合，合成了2（S），3 ′（S），3 ″（S）-N-[3-羧基-（3-氨基-3-羧基丙基）丙基]高丝氨酸。(3)在此基础上，用NaBH_3CN还原缩合法合成了3 ′（S），3 ″（S）-N- [3-羧基-（3-羧基-3-羟丙基）氨丙基]甘氨酸，L-α-羟基-γ-丁内酯由L-苹果酸、L-天冬氨酸衍生的L-高丝氨酸醛和甘氨酸制备。3 ′（S），3 ″（R）-N- [3-羧基-（3-羧基-3-羟丙基）氨丙基]甘氨酸与D-α-羟基-γ-丁内酯在NaBH_3CN存在下缩合，得到3 ′（S），3 ″（R）-N-[3-羧基-（3-羧基-3-羟丙基）氨丙基]甘氨酸。

In order to elucidate a molecular structure of plasma membrane-located transporter for mugineic acid-Fe (III) complex, a few mugineic acid analogs were first synthesized in the present study.(1) The systhesis of 3'(S) -N- [3-carboxy- (3-carboxypropylamino) propyl] glycine was performed by reductive coupling in the presence of NaBH_3CN of three units, i.e., gamma-butyrolactone, L-homoserine, and glycine. In a similar manner as above, 2 (S), 3'(S) -N- [3-carboxy- (3-carboxypropylamino) propyl] homoserine was synthesized by the condensation of the protected L-N- (3-carboxyprpyl) homeserine aldehyde with L-homoserine lactone in the presence of NaBH_3CN.(2) The synthesis of 3'(S), 3"(S) -N- [3-carboxy- (3-amino-3-carboxypropylamino) propyl] glycine was achieved by reductive coupling in the presence of NaBH_3CN of three units, namely glycine and 2 molecular L-homoserine lactone. 2 (S), 3'(S), 3"(S) -N- [3-carboxy- (3-amino-3-carboxypropylamino) propyl] homo-serine was similarly synthesized by the condensation of the protected 3'(S) -N- [3-amino-3-carboxyprpyl) homoserine aldehyde with L-homeserine lactone in the presence of NaBH_3CN.(3) Furthermore, the synthesis of 3'(S), 3"(S) -N- [3-carboxy- (3-carboxy-3-hydroxypropyl) aminopropyl] glycine was carried out by reductive condensation in the presence of NaBH_3CN of three units, ie., L-alpha-hydroxy-gamma-butyrolactone prepared from L-malic acid, L-homoserine aldehyde derived from L-aspartic acid and glycine. 3'(S), 3"(R) -N- [3-carboxy- (3-carboxy-3-hydroxypropyl) aminopropyl] glycine was similarly synthesized by the condensation of the protected 3'(S) -N- (3-carboxy-3-aminopropyl) glycine with D-alpha-hydroxy-gamma-butyrolactone prepared from D-malic acid in the presence of NaBH_3CN.