Triterpene glycosides from the far eastern sea cucumber Pentamera calcigera II: disulfated glycosides.

Three new triterpene glycosides, calcigerosides D(1) (1), D(2) (2), and E (3), have been isolated from the sea cucumber Pentamera calcigera. Their structures have been deduced from extensive spectral analysis (NMR and MS) and chemical evidence. All the compounds are disulfated pentaosides differing in aglycon structure and position of sulfate group, which were determined by the measurement of NT(1) values in the cases of glycosides 1 and 2. Glycoside 1 is a nonholostane derivative, that is, it lacks an 18(20)-lactone, which is very rare among the sea cucumber glycosides.

Triterpene glycosides from the Far-Eastern sea cucumber Pentamera calcigera. 1. Monosulfated glycosides and cytotoxicity of their unsulfated derivatives.

Three new monosulfated triterpene glycosides, calcigerosides B (2), C(1) (3), and C(2) (4), along with the known cucumarioside G(2) (1), have been isolated from the sea cucumber Pentamera calcigera. Their structures have been deduced from extensive spectral analysis (NMR and MS) and chemical evidence. Compounds 2-4 present a novel pentasacharide chain never reported before in sea cucumber triterpene glycosides. The desulfated derivatives of calcigerosides B, C(1), and C(2) (5, 7, and 9, respectively) showed moderate cytotoxicity (IC(50) = 5 microg/mL) against a selection of four human and mouse tumor cell lines.

Hemolytic activities of triterpene glycosides from the holothurian order Dendrochirotida: some trends in the evolution of this group of toxins.

Hemolysis and K+ loss from mouse erythrocytes, induced by triterpene glycosides and their derivatives from this order of sea cucumbers were studied. Sulfate groups, attached to position 4 of the first xylose residue and to position 6 of the third glucose residue of the branched pentaosides, having 3-O-methyl-groups in terminal monosaccharide moieties increase K+ loss. A sulfate group at C-4 of the first xylose residue increases the hemolytic activity while a sulfate at C-6 of the third monosaccharide unit decreases it. A sulfate group at C-6 of terminal 3-O-methylglucose drastically decreases the hemolytic activity and rate of K+ loss. The presence of a sulfate group at the first xylose residue in glycosides having no 3-O-methyl group at the terminal monosaccharide decreases hemolytic activity and rate of K+ loss. The presence of the 16-ketone group in aglycones having the 7(8)-double bond significantly decreases activity. These results correlate with the previously proposed trends in evolution of sea cucumber glycosides from substances having sulfate groups at C-6 of glucose and 3-O-methylglucose units to substances sulfated at C-4 of the first xylose or having no sulfate groups, and from substances with aglycone 16-ketone to substances having no oxygen functions in this position.

[Comparative study of the proliferative activity of native and cryopreserved colony-forming units in humans and mice]. / Sravnitel'noe izuchenie proliferativnoi aktivnosti nativnykh i kriokonservirovannykh kolonieobrazuyiushchikh edinits cheloveka i myshei.

The agar culture method was used to state that colony-forming units responsible for cell structures of a hemopoietic series remained undamaged after cryopreservation (-196 degrees) in a suspension of mouse and human donor bone marrow. Cultivation of cryopreserved bone marrow revealed the inhibition of proliferative activity of cells growing in agar as compared with native ones. The inhibition of DNA synthesis was the basis of this process.

[Effect of low-temperature preservation on the proliferative activity and topography of the dissemination of donor and cadaveric colony-forming units (CFU) in an irradiated organism]. / Vliianie nizkotemperaturnoi konservatsii na proliferativnuiu aktivnost' i topografiiu rasseleniia donorskikh i trupnykh kolonie-obrazuiushchikh edinits (KOE) v obluchennom organizme.

Investigation carried out by means of chromosome marker T6T6 showed that frozen donor and cadaver bone marrow cells (6 h and 12 h after death) survive and proliferate in the organism of lethally irradiated recipient; the proliferation and differentiation intensity of cadaver cells is reduced in comparison with the donor cells.

[Cellular structures formed during bone marrow cultivation in agar]. / Kletochnye struktury, formiruemye pri kul'tivirovanii kostnogo mozga v agare.

The growth-enhancing effect and the differentiation of colonies formed by native and frozen-thawed myelokaryocytes in semiliquid agar were observed over a period from the 2nd to the 28th day. The cultivation of bone marrow in agar was shown to form colonies consisting of haemopoietic cells as well as of stromal elements. Under the cultivation of frozen-thawed bone marrow, the retardation of proliferative activity of growing cells was observed within up to 4 days. Later on the proliferative character and the rate of the myelokaryocytes of both the types were seen identical. The question of a possible existence of haemopoietic tissue and stromal elements in the progenitor cells of normal bone marrow is being discussed.