Study on extraction of agaropectin from Gelidium amansii and its anticoagulant activity

Gelidium amansii agar was fractionated on DEAE-cellulose and four fractions were obtained sequentially. The yields of 1.0 mol/L NaCl fraction and 2.5 mol/L NaCl fraction were 2.80% and 2.03%. They are highly sulfated agar, and named as agaropectin with sulfate content being 22.8% and 32.5%, respectively. The anticoagulant experiment results show that agaropectin could effectively prolong the coagulation time in a dose-dependent manner in vitro. Agaropection could be absorbed and effectively prolong the plasma coagulation time in vivo. After intragastric administration at the doses of 100, 200, and 400 mg/kg.d in rats for 15 days, TT (thrombin time), CT (coagulation time), PT (prothrombin time), and APTT (activated partial thromboplastin time) could be effectively prolonged and the plasma Fib level could be significantly lowered.

Identification and assessing the cultivars of Laminaria Lamx. (phaeophyceae) with molecular markers

Molecular markers were used to identify and assess cultivars of Laminaria Lamx. and to delineate their phylogenetic relationships. Random amplified polymorphic DNA (RAPD) analysis was used for detection. After screening, 11 primers were selected and they yielded 133 bands in all, of which approximately 99.2% were polymorphic. The genetic distances between gametophytes ranged from 0.412 to 0.956. Two clusters were formed with the unweighted pair group method with arithmetic mean (UPGMA) dendrogram based on the simple matching coefficient. All cultivars of Laminaria japonica Aresch. used for breeding in China fell into one cluster. L. japonica from Japan, L. saccharina (L.) Lam., and L. angustata Kjellm. formed the other cluster and showed higher genetic variation than L. japonica from China. Nuclear ribosomal DNA (rDNA) sequences, including internal transcribed spacers (ITS1 and ITS2) were studied and aligned. The nucleotides of the sequences ranged from 634 to 668, with a total of 692 positions including TTS1, ITS2, and the 5.8S coding region. The phylogenetic tree obtained by the neighbor-joining method favored, to some extent, the results revealed by RAPD analysis. The present study indicates that RAPD and ITS analyses could be used to identify and assess Laminaria germplasm and to distinguish some species and, even intraspecies, in Laminaria.