Cucumariosides

Frondoside B (9a), Cucumariosides A2-4 (9b) and A7-3 (9c), Fig. (9) as well as several triterpene glycosides isolated from the sea cucumbers Stichopus chloronotus (lOa-lOh) and Thelenota ananas (lOi, lOj), Fig. (10) contain the simple 3 (5-hydroxyholost-7-ene as the aglycone. An additional acetoxyl group in the side chain is present in compounds 10a-... 

The crude holothurins from Philippine sea cucumbers belonging to Holothuriidae family have indirect mutagenic and clastogenic activity. Although no activity was noted in vitro (Rec- assay and Ames test) after metabolic activation, these holothurins produced aberration scores in Swiss albino mice (micronuclear test) when administered intraperitoneally [29]. Nevertheless, at peroral injection, they exhibited a 35-fold reduction in activity, which indicates inactivation in the alimentary canal [29]. On the contrary, Polycarpova et al. showed the absence of mutagenic activity of cucumarioside - triterpene glycoside from the sea cucumber Cucumaria Japonica [27]. 

Cucumarioside Gi (8) and cucumarioside G2 (15) are native glycosides from the sea cucumber Eupentacta fraudatrix. Substances 3, 4, 5, 6, 7, 9 and 10 are derivatives of cucumariosides Gi- Substances 11 and 12 are dihydroderivatives of cucumariosides C2 and H from E. fraudatrix, correspondingly. Frondoside A (2) is a glycoside from the Cucumaria frondosa, cucumarioside A4-2 (13) is a glycoside from Cucumaria japonica, and the substance 14 is a derivative of cucumarioside A4-2. The data are shown in Table 1. 

Table 1. The hemolytic activity, rate and delay time of hemolysis and the rate of loss induced by cucumariosides and their derivatives...

Cucumariosides A3 (20) and Ae 2 (19) from Cucumaria japonica showed IC50 = 1 ftg/nil when tested in vitro against standard mouse and human tumoral cell lines (P-388, Schabel, A-549, HT-29 and Mel-28) [70]. 

The crude holothurin from A. agasssizi stimulated hemopoesis in bone marrow of frog [24]. A minimal immunomodulatory dose (0.05 p-g/kg) of crude cucumarioside from Cucumaria japonica induced delay of rat liver cell mitosis 28 to 32 hours after hepatoectomy but after 40 to 44 hours induced the compensatory increase in mitotic activity [94]. The authors concluded that the triterpene glycosides affect the regulation of proliferative processes. 

Cucumariosides from C. japonica showed also antiviral activity [103, 104]. Cucumariosides demonstrated a restorative effect in mink infected by Aleutian disease virus [103]. The authors suggested that the effect of the cucumariosides may be related to the increased interaction of T- and B- lymphocytes and humoral... 

As it was already mentioned above, glycosides from Cucumaria japonica demonstrate a restorative effect in mice with acquired immunodeficiency induced by radiation [102]. Individual triterpene glycoside cucumarioside A2-2 (18) from C. japonica and glycoside preparation trepangin from the Far Eastern sea cucumber Apostichopus japonicus showed radioprotective properties while cucumarioside A2-2 was significantly more active in this respect. Survival of lethally radiated mice (y-rays, Cs at 7.7 GR, 5-10 min) after glycoside 18 administration at the dose of 1 pg/kg was about 40 % over control and after 60 min radiation was about 20 %. The restoration of hemopoesis was observed in the radiated glycoside-dosed animals [108]. 

A mechanism of antiviral activity of sea cucumber triterpene glycosides may be connected with antiviral protection at the stage of virus-cell interaction. This type of protection was confirmed by experiments on inhibition of the cytopathic effect of vesicular stomatite, poliomyelitis and other viruses in cell culture by cucumariosides [104]. Cucumarioside A2-2 (18) was shown to be... 

Popov has demonstrated general correlation between hemolytic, cytotoxic against tumor cell lines activities and possibility to induce the [ " C]glucose loss from liposomes containing cholesterol (Table 13) for holothurin A (101), holothurin B (105), holothurin A2 (57), holothurin Bi (56) holotoxin Ai (33) and cucumarioside G, (7) [120]. 

The three holothurins possess the same pentasaccharide moiety and differ from each other in the aglycone side chain. Frondoside A2-3 (49b) contains a A double bond and a hydroxy group at C-25. This side chain has been previously identified in the aglycones of cucumarioside G4 from... 

Another example of an holothurin containing aglycon 51 with a (3-acetoxy group at C-16, Cucumarioside A2-5 (51c), was isolated from the sea cucumber Cucumaria conicospermium, collected in the Sea of Japan [71]. The same aglycone has been found earlier only in Cucumarioside Aq-1, isolated from Cucumaria japonica [72]. 

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