Apostichopus japonicus belongs to the phylum Echinodermata, class Holothuroides, order Aspidochirotida, and family Stichopodidae. It is mainly distributed in East Asian countries such as China, Russia, Japan, and the Korean Peninsula. Imitation sea cucumber is one of the most nutritious species among echinoderms, and also the most precious species among sea cucumbers. It is a traditional Chinese food and medicinal herb, known as the “crown of ginseng”. Sea cucumber is one of the most important marine aquaculture economic species in northern China. In 2021, the cultivation area of sea cucumber in China was 247400 hectares, with a yield of 222700 tons and a seedling production of 60.1 billion heads. The value of the entire sea cucumber industry chain is about 9 billion US dollars.
Sea cucumber is composed of its body wall and internal organs. The internal organs of sea cucumber mainly consist of its intestinal wall, reproductive gland, and respiratory tree. Research has shown that the body wall of sea cucumbers is rich in nutrients such as protein, amino acids, fatty acids, minerals, and vitamins. In addition, the body wall of sea cucumber also contains triterpene saponins, sea cucumber polysaccharides, collagen, sea cucumber peptides, phenols, cerebrosides, sphingosine like substances and other bioactive substances, which have potential antioxidant, anti-cancer, antihypertensive, anti-inflammatory, antithrombotic, anti diabetes, anti obesity and antibacterial activities, and high nutritional and medicinal value. At present, in the fields of healthcare and medicine, most research mainly focuses on developing the functions of sea cucumbers using their body walls as raw materials, and there is relatively little development on the functions of sea cucumber viscera. Research has shown that the viscera of sea cucumber contain rich active ingredients such as protein, amino acids, polysaccharides, fatty acids, saponins, etc., just like the body wall. Therefore, sea cucumber viscera have functions such as enhancing immunity, antioxidation, anti-tumor, as well as lowering blood sugar, blood lipids, and promoting bacteria. This indicates that sea cucumber viscera also have high nutritional and medicinal value. However, in the sea cucumber industry, sea cucumber organs have not received sufficient attention and lack in-depth research, resulting in little development and utilization of sea cucumber organs, leading to their direct disposal. The chemical components in the viscera of sea cucumbers are worthy of in-depth research and development. In summary, the chemical components in the viscera of sea cucumbers have potential development value. To further understand the chemical composition of sea cucumber, this experiment conducted a study on the chemical composition of ethanol extract from the viscera of sea cucumber.

Fourteen monomeric compounds were isolated from the internal organs of sea cucumbers. Compound 1 is a new compound, compounds 1 and 2 are cis trans isomers of each other, belonging to the same group of sulfated olefins. Compounds 3 and 4 are sulfated alkanes. Sulfate ester compounds are important secondary metabolites produced by marine echinoderms. Currently, literature has reported the isolation of a series of sulfate ester substituted hydrocarbon compounds from marine animals such as starfish, sea cucumber, sponge, sea snake tail, and sea urchin. Studies on the activity of sulfate ester hydrocarbon molecules have shown that these molecules have antibacterial activity, antifungal activity, cytotoxicity, and inhibition of matrix metalloproteinase 2. Compound 5 is a dipeptide compound composed of lactate and phenylalanine, which is a novel “exercise factor” produced by humans during exercise and can reduce the weight and fat tissue content of obese mice. Compounds 6-14 are nitrogen-containing compounds. This research achievement deepens the understanding of the chemical composition of sea cucumbers and provides reference for the further development of the internal health and medicinal value of sea cucumbers.