Discovery of Novel Saponins from the Viscera of the Sea Cucumber Holothuria lessoni

Abstract

Sea cucumbers, sometimes referred to as marine ginseng, produce numerous compounds with diverse functions and are potential sources of active ingredients for agricultural, nutraceutical, pharmaceutical and cosmeceutical products. We examined the viscera of an Australian sea cucumber Holothuria lessoni Massin et al. 2009, for novel bioactive compounds, with an emphasis on the triterpene glycosides, saponins. The viscera were extracted with 70% ethanol, and this extract was purified by a liquid-liquid partition process and column chromatography, followed by isobutanol extraction. The isobutanol saponin-enriched mixture was further purified by high performance centrifugal partition chromatography (HPCPC) with high purity and recovery. The resultant purified polar samples were analyzed using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS)/MS and electrospray ionization mass spectrometry (ESI-MS)/MS to identify saponins and characterize their molecular structures. As a result, at least 39 new saponins were identified in the viscera of H. lessoni with a high structural diversity, and another 36 reported triterpene glycosides, containing different aglycones and sugar moieties. Viscera samples have provided a higher diversity and yield of compounds than observed from the body wall. The high structural diversity and novelty of saponins from H. lessoni with potential functional activities presents a great opportunity to exploit their applications for industrial, agricultural and pharmaceutical use.

Structural Elucidation of Novel Saponins in the Sea Cucumber Holothuria lessoni

“…The decomposition of the parent ion can also be triggered by the loss of sugar moiety, namely Glc, MeGlc, Xyl, and Qui followed by the aglycone which generated the product ions indicated in Figure 3i. It should be noted that the major characteristic peaks at 493, 507 and 511 correspond to either the sodiated partial glycoside compositions or the sodiated aglycone moieties [12,59,77,106], which further confirmed the presence of isomeric saponins. The full analysis can be seen in Supplementary Figure S2.…”

“…[12]. Firstly, fragmentation patterns were built, and the generated fingerprint signals were reconstructed according to the measurement of the mass transitions between the successive collision-activated fragmentation signals.…”

“…The carbohydrate moieties of the isomeric saponins were found to be composed of four sugar units, which were identical to the sugar component of Holothurinoside C, Desholothurin A, Intercedenside D and Eximisoside A [12,37,105]. …”

A novel antitumor compound nobiliside D isolated from sea cucumber (Holothuria nobilis Selenka)

“…Saponins are established to have anti-tumor activity (13,14). Saponins are the main metabolites of sea cucumber (5,6) and currently >10 types of saponin have been isolated and purified (15,16). The abundance of novel compounds from sea cucumber suggests potential for biopharmaceutical applications (17)(18)(19)(20).…”

Cosmeceuticals Properties of Sea Cucumbers: Prospects and Trends

“…Saponins are reported as the major bioactive compound in many effective traditional Chinese and Indian herbal medicines [58]. They play an important role in chemical defence and possess a wide spectrum of pharmacological activities [59][60][61][62][63][64][65][66][67][68].…”