Abstract: In this study, crude heparin was extracted from 9 marine organisms by enzymatic hydrolysis and then alcohol precipitation. The physicochemical properties and monosaccharide composition of the heparins were analyzed by ultraviolet spectroscopy, Fourier transform infrared spectroscopy and high performance liquid chromatography, and their anticoagulant activities were analyzed by in vitro experiments. The results showed that the heparin contents of the 9 crude heparin samples were 339.92 μg/mg for Penaeus vannaei heads, 239.15 μg/mg for Mactra antiquata, 234.85 μg/mg for Tegillarca granosa, 218.29 μg/mg for Sinonovacula constricta, 214.78 μg/mg for Meretrix meretrix L., 212.194 μg/mg for Tapes dorsatus, 68.52 μg/mg for Argopecten irradias, 61.48 μg/mg for Panopea abrupta, and 24.29 μg/mg for Ruditapes philippinarum. All of them, having pyranose rings, contained glucosamine, iduronic acid, and galacturonic acid. The in vitro experiments showed that the titers of the crude heparin samples were 67.1 U/mg for Mactra antiquata, 59.3 U/mg for Penaeus vannaei heads, 44.0 U/mg for Meretrix meretrix L., 39.2 U/mg for Tapes dorsatus, 35.0 U/mg for Sinonovacula constricta, 29.6 U/mg for Tegillarca granosa, 27.2 U/mg for Panopea abrupta, 27.1 U/mg for Argopecten irradias, and 24.1 U/mg for Ruditapes philippinarum. They exerted different anticoagulant activities through different pathways. This study provides a basis for the development of heparin from marine resources.

Key words: heparin, marine organisms, physicochemical properties, structural identification, anticoagulant activity