The Isolation And Determination Of ABA From Kelp Laminaria Japonica Aresch. And Study On Its Bioactivity For Marine Algaes

An optimal isolation method, which was successfully utilized to isolate ABA from kelp, was established based on the optimazation of a series of isolation conditions. A HPLC method, which was applicable for the detection of ABA from kelp extraction, was established and utilized to identify the existence of ABA in kelp. The structure of ABA was further confirmed by atmospheric pressure electrospray mass spectrometry (APESI-MS). Furthermore, the bioactivity of ABA in algaes was studied.The optimal isolation process was established. First of all, the kelp tissue is homogenized with 80% aqueous methanol in darkness under normal temperature for 24 hours and then filtered. The solvent is collected and the residue is washed with 80% aqueous methanol twice and MeOH was removed from the combined filtrates under reduced pressure. Then, ethyl acetate is utilized to extract ABA from the concentrated solvent .The extraction is discolored with gel column. After further purification with Sephadex LH-20, RP-HPLC and APESI-MS are employed in the qualitative and quantitative analysis for ABA in the sample. The result showed that abscisic acid does exist in kelp and its concentration is 30.5-60.5μg/kg·FW.The research showed that ABA, whose concentraton ranged froml to 1000μg/mL, exhibited different effects on the growth of different algaes. ABA obviously inhibited the growth of Dunaliella salina, Chaetoceros muelleri. However, ABA did not effect the growth of Chlorella sp., Porphyridium Cruentum. When it's concentration reached to 100 and 1000μg/mL, ABA remarkably inhibite the growth of Chaetoceros muelleri..It is revealed in experiment for the antioxidative effect of ABA in algaes that ABA can alleviate the oxidative damage caused by paraquate to 4 kinds of algaes.