大型海藻中环二肽类抑藻活性化合物的分离纯化

Isolation and purification of diketopiperazines with antialgal activity from marine macroalgae

中文关键词:  龙须菜  条斑紫菜  抑藻活性  环二肽  分离纯化

英文关键词:acidGracilaria lemaneiformis  Porphyra yezoensis  antialgal activity  diketopiperazines  isolationification  warming  Porolithon onkodes  Pocillopora damicornis  larval settlement  bacterial community

中文摘要:

      采用茚三酮试剂显色的薄层原位化学反应和抑藻活性检测方法，从龙须菜、条斑紫菜、鹿角藻和裙带菜中筛选环肽，发现龙须菜和条斑紫菜中存在具有抑藻活性的环肽。以龙须菜和条斑紫菜粉末为原料，采用硅胶柱层析和（或）硅胶薄层层析制备等方法，从龙须菜中分离到环（脯氨酸-甘氨酸）、环（丝氨酸-脯氨酸）和环（丙氨酸-色氨酸），从条斑紫菜中纯化到环（亮氨酸-脯氨酸）和环（缬氨酸-酪氨酸）。除环（丝氨酸-脯氨酸）外，其余4种环二肽均是首次从相应大型海藻中获得。环（脯氨酸-甘氨酸）、环（亮氨酸-脯氨酸）和环（缬氨酸-酪氨酸）明显抑制了强壮前沟藻、赤潮异弯藻和球形棕囊藻的生长，对米氏凯伦藻和中肋骨条藻有选择性抑制作用。在50 μg/mL时，3种环二肽对强壮前沟藻、赤潮异弯藻和球形棕囊藻的生长抑制率≥50%（第4d）；环（脯氨酸-甘氨酸）对米氏凯伦藻以及环（亮氨酸-脯氨酸）对中肋骨条藻的生长抑制率超过或接近50%。随后，获得环二肽对赤潮微藻生长的半抑制效应浓度EC50-96h。结果表明，环（脯氨酸-甘氨酸）、环（亮氨酸-脯氨酸）和环（缬氨酸-酪氨酸）在抑制米氏凯伦藻、球形棕囊藻或赤潮异弯藻方面比重铬酸钾更有优势，有望开发为环境友好型赤潮微藻抑藻剂。

英文摘要:

      The cyclic peptides with antialgal activity were screened from Gracilaria lemaneiformis, Neoporphyra yezoensis, Silvetia siliguosa and Undaria pinnatifida, by thin-layer in-situ chemical reaction with ninhydrin reagent and antialgal activity test. The cyclic peptides with antialgal activity were found in the extracts of Gracilaria lemaneiformis and Neoporphyra yezoensis, respectively. Cyclo (Pro-Gly), cyclo (Ser-Pro), cyclo (Ala-Trp) were finally isolated from Gracilaria lemaneiformis, and cyclo (Leu-Pro) and cyclo (Val-Tyr) were purified from Neoporphyra yezoensis by repeated silica gel column chromatography and (or) silica gel thin layer chromatography. Except for cyclo (Ser-Pro), the other four cyclic dipeptides were obtained from corresponding marine macroalgae for the first time. Cyclo (Pro-Gly), cyclo (Leu-Pro) and cyclo (Val-Tyr) significantly inhibited the growth of Amphidinium carterae, Heterosigma akashiwo, and Phaeocystis globosa; they showed selective growth inhibition for Karenia mikimotoi and Skeletonema costatum. At the concentration of 50 μg/mL, the growth inhibition of cyclo (Pro-Gly), cyclo (Leu-Pro) and cyclo (Val-Tyr) for Amphidinium carterae, Heterosigma akashiwo and Phaeocystis globosa was ≥50% (on?the?4th?day); the growth inhibition of cyclo (Pro-Gly) for Karenia mikimotoi and that of cyclo (Leu-Pro) for Skeletonema costatum were more than or close to 50%. Further, EC50-96h of cyclic dipeptide for red tide microalgae was obtained. EC50-96h of cyclo (Pro-Gly) for Karenia mikimotoi and Phaeocystis globosa, EC50-96h of cyclo (Leu-Pro) and cyclo (Val-Tyr) for Heterosigma akashiwo were less than that of potassium dichromate for corresponding red tide microalgae. This suggested that cyclo (Pro-Gly), cyclo (Leu-Pro) and cyclo (Val-Tyr) have more advantages in inhibiting Karenia mikimotoi, Phaeocystis globosa or Heterosigma akashiwo. And they are expected to be developed into an environment-friendly algal inhibitor against red tide microalgae.