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Ten new decalin polyketides, zosteropenilline M ( 1 ), 11- epi -8-hydroxyzosteropenilline M ( 2 ), zosteropenilline N ( 3 ), 8-hydroxyzosteropenilline G ( 4 ), zosteropenilline O ( 5 ), zosteropenilline P ( 6 ), zosteropenilline Q ( 7 ), 13-dehydroxypallidopenilline A ( 8 ), zosteropenilline R ( 9 ) and zosteropenilline S ( 10 ), together with known zosteropenillines G ( 11 ) and J ( 12 ), pallidopenilline A ( 13 ) and 1-acetylpallidopenilline A ( 14 ), were isolated from the ethyl acetate extract of the fungus Penicillium yezoense KMM 4679 associated with the seagrass Zostera marina . The structures of isolated compounds were established based on spectroscopic methods. The absolute configurations of zosteropenilline Q ( 7 ) and zosteropenilline S ( 10 ) were determined using a combination of the modified Mosher's method and ROESY data. The absolute configurations of zosteropenilline M ( 1) and zosteropenilline N ( 3 ) were determined using time-dependent density functional theory (TD-DFT) calculations of the ECD spectra. A biogenetic pathway for compounds 1 - 14 is proposed. The antimicrobial, cytotoxic and cytoprotective activities of the isolated compounds were also studied. The significant cytoprotective effects of the new zosteropenilline M and zosteropenillines O and R were found in a cobalt chloride (II) mimic in in vitro hypoxia in HEK-293 cells. 1-Acetylpallidopenilline A ( 14 ) exhibited high inhibition of human breast cancer MCF-7 cell colony formation with IC 50 of 0.66 µM and its anticancer effect was reduced when MCF-7 cells were pretreated with 4-hydroxitamoxifen. Thus, we propose 1-acetylpallidopenilline A as a new xenoestrogen with significant activity against breast cancer.

Three new monosulfated polyhydroxysteroid glycosides, spiculiferosides A ( 1 ), B ( 2 ), and C ( 3 ), along with new related unsulfated monoglycoside, spiculiferoside D ( 4 ), were isolated from an ethanolic extract of the starfish Henricia leviuscula spiculifera collected in the Sea of Okhotsk. Compounds 1 - 3 contain two carbohydrate moieties, one of which is attached to C-3 of the steroid tetracyclic core, whereas another is located at C-24 of the side chain of aglycon. Two glycosides ( 2 , 3 ) are biosides, and one glycoside ( 1 ), unlike them, includes three monosaccharide residues. Such type triosides are a rare group of polar steroids of sea stars. In addition, the 5-substituted 3-OSO 3 -α-L-Araf unit was found in steroid glycosides from starfish for the first time. Cell viability analysis showed that 1 - 3 (at concentrations up to 100 μM) had negligible cytotoxicity against human embryonic kidney HEK293, melanoma SK-MEL-28, breast cancer MDA-MB-231, and colorectal carcinoma HCT 116 cells. These compounds significantly inhibited proliferation and colony formation in HCT 116 cells at non-toxic concentrations, with compound 3 having the greatest effect. Compound 3 exerted anti-proliferative effects on HCT 116 cells through the induction of dose-dependent cell cycle arrest at the G2/M phase, regulation of expression of cell cycle proteins CDK2, CDK4, cyclin D1, p21, and inhibition of phosphorylation of protein kinases c-Raf, MEK1/2, ERK1/2 of the MAPK/ERK1/2 pathway.

Eight sulfated triterpene glycosides, peronioside A ( 1 ) and psolusosides A ( 2 ), B ( 3 ), G ( 4 ), I ( 5 ), L ( 6 ), N ( 7 ) and P ( 8 ), were isolated from the sea cucumber Psolus peronii . Peronioside A ( 1 ) is a new glycoside, while compounds 2 - 8 were found previously in Psolus fabricii , indicating the phylogenetic and systematic closeness of these species of sea cucumbers. The activity of 1 - 8 against human erythrocytes and their cytotoxicity against the breast cancer cell lines MCF-7, T-47D and triple-negative MDA-MB-231 were tested. The most active against cancer cell compounds, psolusosides A ( 2 ) and L ( 6 ), which were not cytotoxic to the non-transformed cells of the mammary gland, were chosen to study the inhibition of the migration, formation and growth of colonies of the cancer cell lines. Glycoside 2 effectively inhibited the growth of colonies and the migration of the MDA-MB-231 cell line. Compound 6 blocked the growth of colonies of T-47D cells and showed a pronounced antimigration effect on MDA-MB-231 cells. The quantitative structure-activity relationships (QSAR) indicated the strong impact on the activity of the form and size of the molecules, which is connected to the length and architecture of the carbohydrate chain, the distribution of charge on the molecules' surface and various aspects of hydrogen bond formation, depending on the quantity and positions of the sulfate groups. The QSAR calculations were in good accordance with the observed SAR tendencies.

Four extracts of the marine-derived fungus Penicillium velutinum J.F.H. Beyma were obtained via metal ions stress conditions based on the OSMAC (One Strain Many Compounds) strategy. Using a combination of modern approaches such as LC/UV, LC/MS and bioactivity data analysis, as well as in silico calculations, influence metal stress factors to change metabolite profiles Penicillium velutinum were analyzed. From the ethyl acetate extract of the P. velutinum were isolated two new piperazine derivatives helvamides B (1) and C (2) together with known saroclazin A (3) (4S,5R,7S)-4,11-dihydroxy-guaia-1(2),9(10)-dien (4). Their structures were established based on spectroscopic methods. The absolute configuration of helvamide B (1) as 2R,5R was determined by a combination of the X-ray analysis and by time-dependent density functional theory (TD-DFT) calculations of electronic circular dichroism (ECD) spectra. The cytotoxic activity of the isolated compounds against human prostate cancer PC-3 and human embryonic kidney HEK-293 cells and growth inhibition activity against yeast-like fungi Candida albicans were assayed., (© 2024. The Author(s).)

Two new steroid 3β,21-disulfates ( 1 , 2 ) and two new steroid 3β,22- and 3α,22-disulfates ( 3 , 4 ), along with the previously known monoamine alkaloid tryptamine ( 5 ) were found in the ethanolic extract of the Far Eastern slime sea star Pteraster marsippus . Their structures were determined on the basis of detailed analysis of one-dimensional and two-dimensional NMR, HRESIMS, and HRESIMS/MS data. Compounds 1 and 2 have a Δ 22 -21-sulfoxy-24-norcholestane side chain. Compounds 3 and 4 contain a Δ 24(28) -22-sulfoxy-24-methylcholestane side chain, which was first discovered in the polar steroids of starfish and brittle stars. The influence of substances 1 - 4 on cell viability, colony formation, and growth of human breast cancer T-47D, MCF-7, and MDA-MB-231 cells was investigated. It was shown that compounds 1 and 2 possess significant colony-inhibiting activity against T-47D cells, while compounds 3 and 4 were more effective against MDA-MB-231 cells.

Six previously unknown triterpene glycosides, pacificusosides L-Q ( 1 - 6 ), and two previously known triterpene glycosides, cucumariosides B 1 ( 7 ) and A 5 ( 8 ), were isolated from an alcoholic extract of Pacific sun star, Solaster pacificus . The structures of 1 - 6 were determined using 1D and 2D NMR, ESIMS, and chemical modifications. Compound 1 is a rare type of triterpene glycoside with non-holostane aglycon, having a linear trisaccharide carbohydrate chain. Pacificusosides M-P ( 2 - 5 ) have new structures containing a Δ 8(9) -3,16,18-trihydroxy tetracyclic triterpene moiety. This tetracyclic fragment in sea star or sea cucumber triterpene glycosides was described for the first time. All the compounds under study exhibit low or moderate cytotoxic activity against colorectal carcinoma HCT 116 cells, and breast cancer MDA-MB-231 cells were assessed by MTS assay. Compound 2 effectively suppresses the colony formation of cancer cells at a non-toxic concentration, using the soft-agar assay. A scratch assay has shown a significant anti-invasive potential of compound 2 against HCT 116 cells, but not against MDA-MB-231 cells.

Four new mono- and trisulfated triterpene penta- and tetraosides, djakonoviosides C 1 ( 1 ), D 1 ( 2 ), E 1 ( 3 ), and F 1 ( 4 ) were isolated from the Far Eastern sea cucumber Cucumaria djakonovi (Cucumariidae, Dendrochirotida), along with six known glycosides found earlier in other Cucumaria species. The structures of unreported compounds were established on the basis of extensive analysis of 1D and 2D NMR spectra as well as by HR-ESI-MS data. The set of compounds contains six different types of carbohydrate chains including two new ones. Thus, djakonovioside C 1 ( 1 ) is characterized by xylose as the second residue, that was a branchpoint in the pentasaccharide chain. Meanwhile, only quinovose and rarely glucose have been found earlier in pentasaccharide chains branched at C-2 of the second sugar unit. Djakonovioside E 1 ( 3 ) is characterized by a tetrasaccharide trisulfated chain, with glucose as the second residue. So, in the series of isolated glycosides, three types of sugars in the second position were presented: the most common, quinovose-in six compounds; glucose-in three substances; and the rare xylose-in one glycoside. The set of aglycones was composed of holostane- and non-holostane-type polycyclic systems; the latter comprised normal and reduced side chains. Noticeably, isokoreoside A ( 9 ), isolated from C. djakonovi , was a single glycoside having a 9(11)-double bond, indicating two oxidosqualenecyclases are operating in the process of the biosynthesis of aglycones. Some of the glycosides from C. djakonovi , which were characterized by pentasaccharide branched chains containing one to three sulfate groups, are chemotaxonomic features of the representatives of the genus Cucumaria . The assortment of sugar parts of Cucumaria's glycosides was broadened with previously undescribed penta- and tetrasaccharide moieties. The metabolic network of sugar parts and aglycones is constructed based on biogenetic relationships. The cytotoxic action of compounds 1 - 10 , isolated from C. djakonovi , against human breast cancer cell lines was investigated along with the hemolytic activity. Erythrocytes were, as usual, more sensitive to the membranolytic action of the glycosides than cancer cells. The triple-negative breast cancer MDA-MB-231 cell line was more vulnerable to the action of glycosides in comparison with the other tested cancer cells, while the MCF-7 cell line was less susceptible to cytotoxic action. Djakonovioside E 1 ( 3 ) demonstrated selective action against ER-positive MCF-7 and triple-negative MDA-MB-231 cell lines, while the toxic effect in relation to normal mammary epithelial cells (MCF-10A) was absent. Cucumarioside A 2 -5 ( 6 ) inhibited the formation and growth of colonies of cancer cells to 44% and tumor cell migration to 85% of the control. Quantitative structure-activity relationships (QSAR) were calculated on the basis of the correlational analysis of the physicochemical properties and structural features of the glycosidic molecules and their membranolytic activity. QSAR revealed the extremely complex nature of such relationships, but these calculations correlated well with the observed SAR.

Two new cyclopiane diterpenes and a new cladosporin precursor, together with four known related compounds, were isolated from the marine sediment-derived fungus Penicillium antarcticum KMM 4670, which was re-identified based on phylogenetic inference from ITS, BenA , CaM , and RPB2 gene regions. The absolute stereostructures of the isolated cyclopianes were determined using modified Mosher's method and quantum chemical calculations of the ECD spectra. The isolation from the natural source of two biosynthetic precursors of cladosporin from a natural source has been reported for the first time. The antimicrobial activities of the isolated compounds against Staphylococcus aureus , Escherichia coli , and Candida albicans as well as the inhibition of staphylococcal sortase A activity were investigated. Moreover, the cytotoxicity of the compounds to mammalian cardiomyocytes H9c2 was studied. As a result, new cyclopiane diterpene 13- epi -conidiogenone F was found to be a sortase A inhibitor and a promising anti-staphylococcal agent.

Investigation of the Vietnamese marine sponge Rhabdastrella globostellata led to the isolation of two new polar isomalabaricanes: rhabdastrellosides A ( 1 ) and B ( 2 ). Their structures and stereochemistry were elucidated with the application of 1D and 2D NMR, HRESIMS, and HRESIMS/MS methods, as well as chemical modifications and GC-MS analysis. Metabolites 1 and 2 are the first isomalabaricanes with non-oxidized cyclopentane ring in the tricyclic core system. Moreover, having a 3-O-disaccharide moiety in their structures, they increase a very rare group of isomalabaricane glycosides. We report here a weak cytotoxicity of 1 and 2 toward human neuroblastoma SH-SY5Y cells and normal rat H9c2 cardiomyocytes, as well as the cytoprotective activity of rhabdastrelloside B ( 2 ) at 1 µM evaluated using CoCl 2 -treated SH-SY5Y and H9c2 cells.

Fucoidans are complex fucose-containing sulfated polysaccharides with pronounced anticancer effects. Their structure-anticancer activity relationships are difficult to determine due to fucoidans' complex, often irregularities-including structures. Fucoidan-active enzymes can be used for this propose. We have investigated two new recombinant endo-fucanases FWf3 and FWf4 from the marine bacterium Wenyingzhuangia fucanilytica CZ1127 T that belong to the 107 family of glycoside hydrolases (GH). Both enzymes cleaved α-(1→4)-glycosidic bonds but in fucoidan fragments with different sulfation patterns. FWf3 is the first characterized endo-fucanase that cleaves glycosidic bonds between 2O- and 2,4diO-sulfated L-fucose residues. The obtained endo-fucanases were used to produce low- and high-molecular weight fucoidan derivatives with different sulfate group locations. Low- and high-molecular weight fucoidan derivatives rich with 2,4diO-sulfation were shown to inhibit MDA-MB-231 cell colony formation more efficiently than the native fucoidan and the derivatives sulfated otherwise. Such derivatives effectively suppressed the mitochondrial membrane potential of MDA-MB-231 cells and reduced the expression of the glucose transporter 1 (GLUT1). Co-treatment of MDA-MB-231 cells with the fucoidan derivatives and oligomycin (an OXPHOS inhibitor) resulted in a synergistic anticancer effect. The data obtained demonstrate, that fucoidan and its 2,4diO-sulfated derivatives can be an effective adjunct in TNBC therapy targeting cell metabolism., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ermakova Svetlana Pavlovna, Silchenko Artem Sergeevich, Zueva Anastasiya Olegovna reports financial support was provided by Russian Science Foundation (RSF), project no. 21-14-00321., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Seven new monosulfated triterpene glycosides, djakonoviosides A ( 1 ), A 1 ( 2 ), A 2 ( 3 ), and B 1 -B 4 ( 4 - 7 ), along with three known glycosides found earlier in the other Cucumaria species, namely okhotoside A 1 -1, cucumarioside A 0 -1, and frondoside D, have been isolated from the far eastern sea cucumber Cucumaria djakonovi (Cucumariidae, Dendrochirotida). The structures were established on the basis of extensive analysis of 1D and 2D NMR spectra and confirmed by HR-ESI-MS data. The compounds of groups A and B differ from each other in their carbohydrate chains, namely monosulfated tetrasaccharide chains are inherent to group A and pentasaccharide chains with one sulfate group, branched by C-2 Qui2, are characteristic of group B. The aglycones of djakonoviosides A 2 ( 3 ), B 2 ( 5 ), and B 4 ( 7 ) are characterized by a unique structural feature, a 23,16-hemiketal fragment found first in the sea cucumbers' glycosides. The biosynthetic pathway of its formation is discussed. The set of aglycones of C. djakonovi glycosides was species specific because of the presence of new aglycones. At the same time, the finding in C. djakonovi of the known glycosides isolated earlier from the other species of Cucumaria , as well as the set of carbohydrate chains characteristic of the glycosides of all investigated representatives of the genus Cucumaria , demonstrated the significance of these glycosides as chemotaxonomic markers. The membranolytic actions of compounds 1 - 7 and known glycosides okhotoside A 1 -1, cucumarioside A 0 -1, and frondoside D, isolated from C. djakonovi against human cell lines, including erythrocytes and breast cancer cells (MCF-7, T-47D, and triple negative MDA-MB-231), as well as leukemia HL-60 and the embryonic kidney HEK-293 cell line, have been studied. Okhotoside A 1 -1 was the most active compound from the series because of the presence of a tetrasaccharide linear chain and holostane aglycone with a 7(8)-double bond and 16 β - O -acetoxy group, cucumarioside A 0 -1, having the same aglycone, was slightly less active because of the presence of branching xylose residue at C-2 Qui2. Generally, the activity of the djakonoviosides of group A was higher than that of the djakonoviosides of group B containing the same aglycones, indicating the significance of a linear chain containing four monosaccharide residues for the demonstration of membranolytic action by the glycosides. All the compounds containing hemiketal fragments, djakonovioside A 2 ( 3 ), B 2 ( 5 ), and B 4 ( 7 ), were almost inactive. The most aggressive triple-negative MDA-MB-231 breast cancer cell line was the most sensitive to the glycosides action when compared with the other cancer cells. Okhotoside A 1 -1 and cucumarioside A 0 -1 demonstrated promising effects against MDA-MB-231 cells, significantly inhibiting the migration, as well as the formation and growth, of colonies.

Three new ceramides (1−3) and three new cerebrosides (4, 8, and 9), along with three previously known cerebrosides (ophidiocerebrosides C (5), D (6), and CE-3-2 (7)), were isolated from a deep-sea starfish species, the orange cookie starfish Ceramaster patagonicus. The structures of 1−4, 8, and 9 were determined by the NMR and ESIMS techniques and also through chemical transformations. Ceramides 1−3 contain iso-C21 or C23 Δ9-phytosphingosine as a long-chain base and have C16 or C17 (2R)-2-hydroxy-fatty acids of the normal type. Cerebroside 4 contains C22 Δ9-sphingosine anteiso-type as a long-chain base and (2R)-2-hydroxyheptadecanoic acid of the normal type, while compounds 8 and 9 contain saturated C-17 phytosphingosine anteiso-type as a long-chain base and differ from each other in the length of the polymethylene chain of (2R)-2-hydroxy-fatty acids of the normal type: C23 in 8 and C24 in 9. All the new cerebrosides (4, 8, and 9) have β-D-glucopyranose as a monosaccharide residue. The composition of neutral sphingolipids from C. patagonicus was described for the first time. The investigated compounds 1−3, 5−7, and 9 exhibit slight to moderate cytotoxic activity against human cancer cells (HT-29, SK-MEL-28, and MDA-MB-231) and normal embryonic kidney cells HEK293. Compounds 2, 5, and 6 at a concentration of 20 µM inhibit colony formation of MDA-MB-231 cells by 68%, 54%, and 68%, respectively. The colony-inhibiting activity of compounds 2, 5, and 6 is comparable to the effect of doxorubicin, which reduces the number of colonies by 70% at the same concentration.

The cytotoxicity-bioassay-guided fractionation of the ethanol extract from the marine sponge Guitarra abbotti , whose 1- O -alkyl- sn -glycerol ethers (AGEs) have not been investigated so far, led to the isolation of a complex lipid fraction containing, along with previously known compounds, six new lipids of the AGE type. The composition of the AGE fraction as well as the structures of 6 new and 22 previously known compounds were established using 1 H and 13 C NMR, GC/MS, and chemical conversion methods. The new AGEs were identified as: 1- O -(Z-docos-15-enyl)- sn -glycerol ( 1 ), 1- O -(Z-docos-17-enyl)- sn -glycerol ( 2 ), 1- O -(Z-tricos-15-enyl)- sn -glycerol ( 3 ), 1- O -(Z-tricos-16-enyl)- sn -glycerol ( 4 ), 1- O -(Z-tricos-17-enyl)- sn -glycerol ( 5 ), and 1- O -(Z-tetracos-15-enyl)- sn -glycerol ( 6 ). The isolated AGEs show weak cytotoxic activity in THP-1, HL-60, HeLa, DLD-1, SNU C4, SK-MEL-28, and MDA-MB-231 human cancer cells. A further cytotoxicity analysis in JB6 P + Cl41 cells bearing mutated MAP kinase genes revealed that ERK2 and JNK1 play a cytoprotective role in the cellular response to the AGE-induced cytotoxic effects.

Five new triterpene di-, tri- and tetrasulfated hexaosides (chitonoidosides I ( 1 ), J ( 2 ), K ( 3 ), K 1 ( 4 ) and L ( 5 )) were isolated from the Far-Eastern sea cucumber Psolus chitonoides , collected near Bering Island (Commander Islands) from a depth of 100-150 m. The structural variability of the glycosides concerned both the aglycones (with 7(8)- or 9(11)-double bonds) and carbohydrate chains differing from each other by the third sugar residue (Xyl or sulfated by C-6 Glc) and/or by the fourth-terminal in the bottom semi-chain-residue (Glc or sulfated by C-6 MeGlc) as well as by the positions of a sulfate group at C-4 or C-6 in the sixth-terminal in the upper semi-chain-residue (MeGlc). Hemolytic activities of these compounds 1 - 5 against human erythrocytes as well as cytotoxicity against human cancer cell lines, HeLa, DLD-1 and HL-60, were studied. The hexaosides, chitonoidosides K ( 3 ) and L ( 5 ) with four sulfate groups, were the most active against tumor cells in all the tests. Noticeably, the sulfate group at C-4 of MeGlc6 did not decrease the membranolytic effect of 5 as compared with 3 , having the sulfate group at C-6 of MeGlc6. Erythrocytes were, as usual, more sensitive to the action of the studied glycosides than cancer cells, although the sensitivity of leukemia promyeloblast HL-60 cells was higher than that of other tumor cells. The glycosides 1 and 2 demonstrated some weaker action in relation to DLD-1 cells than against other tumor cell lines. Chitonoidoside K 1 ( 4 ) with a hydroxyl at C 25 of the aglycone was not active in all the tests. The metabolic network formed by the carbohydrate chains of all the glycosides isolated from P. chitonoides as well as the aglycones biosynthetic transformations during their biosynthesis are discussed and illustrated with schemes.

Sea stars or starfish (class Asteroidea) and holothurians or sea cucumbers (class Holothuroidea), belonging to the phylum Echinodermata (echinoderms), are characterized by different sets of glycosidic metabolites: the steroid type in starfish and the triterpene type in holothurians. However, herein we report the isolation of eight new triterpene glycosides, pacificusosides D−K (1−3, 5−9) along with the known cucumarioside D (4), from the alcoholic extract of the Far Eastern starfish Solaster pacificus. The isolated new compounds are closely related to the metabolites of sea cucumbers, and their structures of 1−3 and 5−9 were determined by extensive NMR and ESIMS techniques. Compounds 2, 5, and 8 have a new type of tetrasaccharide chain with a terminal non-methylated monosaccharide unit. Compounds 3, 6, and 9 contain another new type of tetrasaccharide chain, having 6-O-SO3-Glc as one of the sugar units. The cytotoxic activity of 1−9 against non-cancerous mouse epidermal cells JB6 Cl41 and human melanoma cell lines SK-MEL-2, SK-MEL-28, and RPMI-7951 was determined by MTS assay. Compounds 1, 3, 4, 6, and 9 showed potent cytotoxicity against these cell lines, but the cancer selectivity (SI > 9) was observed only against the SK-MEL-2 cell line. Compounds 1, 3, 4, 6, and 9 at the non-toxic concentration of 0.1 μM significantly inhibited neoplastic cell transformation of JB6 Cl41 cells induced by chemical carcinogens (EGF, TPA) or ionizing radiation (X-rays and UVB). Moreover, compounds 1 and 4 at the non-toxic concentration of 0.1 µM possessed the highest inhibiting activity on colony formation among the investigated compounds and decreased the colonies number of SK-MEL-2 cells by 64% and 70%, respectively. Thus, triterpene glycosides 1 and 4 can be considered as prospective cancer-preventive and anticancer-compound leaders.

New steroidal 3β,21-disulfates ( 2 - 4 ), steroidal 3β,22-disulfate ( 5 ), and the previously known related steroidal 3β,21-disulfate ( 1 ) were isolated from the ethanolic extract of the Far Eastern starfish Pteraster marsippus , collected off Urup Island in the Sea of Okhotsk. The structures of these compounds were determined by intensive NMR and HRESIMS techniques as well as by chemical transformations. Steroids 2 and 3 have an oxo-group in the tetracyclic nucleus at position C-7 and differ from each other by the presence of the 5(6)-double bond. The Δ 24 -22-sulfoxycholestane side chain of the steroid 5 has not been found previously in the starfish or ophiuroid steroids. The cytotoxic activities of 1 , 4 , 5 , and the mixture of 2 and 3 were determined on the models of 2D and 3D cultures of human epithelial kidney cells (HEK293), melanoma cells (SK-MEL-28), small intestine carcinoma cells (HuTu80), and breast carcinoma cells (ZR-75-1). The mixture of 2 and 3 revealed a significant inhibitory effect on the cell viability of human breast carcinoma ZR-75-1 cells, but other tested compounds were less effective.

Four new triterpene disulfated glycosides, chitonoidosides E 1 ( 1 ), F ( 2 ), G ( 3 ), and H ( 4 ), were isolated from the Far-Eastern sea cucumber Psolus chitonoides and collected near Bering Island (Commander Islands) at depths of 100-150 m. Among them there are two hexaosides ( 1 and 3 ), differing from each other by the terminal (sixth) sugar residue, one pentaoside ( 4 ) and one tetraoside ( 2 ), characterized by a glycoside architecture of oligosaccharide chains with shortened bottom semi-chains, which is uncommon for sea cucumbers. Some additional distinctive structural features inherent in 1 - 4 were also found: the aglycone of a recently discovered new type, with 18(20)-ether bond and lacking a lactone in chitonoidoside G ( 3 ), glycoside 3- O -methylxylose residue in chitonoidoside E 1 ( 1 ), which is rarely detected in sea cucumbers, and sulfated by uncommon position 4 terminal 3- O -methylglucose in chitonoidosides F ( 2 ) and H ( 4 ). The hemolytic activities of compounds 1 - 4 and chitonoidoside E against human erythrocytes and their cytotoxic action against the human cancer cell lines, adenocarcinoma HeLa, colorectal adenocarcinoma DLD-1, and monocytes THP-1, were studied. The glycoside with hexasaccharide chains ( 1 , 3 and chitonoidoside E) were the most active against erythrocytes. A similar tendency was observed for the cytotoxicity against adenocarcinoma HeLa cells, but the demonstrated effects were moderate. The monocyte THP-1 cell line and erythrocytes were comparably sensitive to the action of the glycosides, but the activity of chitonoidosides E and E 1 ( 1 ) significantly differed from that of 3 in relation to THP-1 cells. A tetraoside with a shortened bottom semi-chain, chitonoidoside F ( 2 ), displayed the weakest membranolytic effect in the series.

Two new natural compounds, sulfated polyhydroxysteroid, microdiscusol G ( 1 ), and polyhydroxysteroid bioside, microdiscusoside A ( 2 ), along with eight previously known polar steroid substances 3-10 , were isolated from the Arctic starfish Asterias microdiscus . The structures of 1 and 2 have been elucidated by extensive 1D and 2D NMR spectroscopy and HRESIMS techniques. The 28-sulfooxy-24-methylcholestane side chain in 1 has been found among starfish steroid metabolites for the first time. Steroid saponins 9 and 10 exhibited cytotoxic effects against normal cells JB6 Cl41 and cancer cells HT-29, MDA-MB-231, THP-1, and Raji and effectively suppressed cell proliferation and colony formation of cancer cells HT-29 and MDA-MB-231 in non-toxic concentrations. Compounds 5 , 7 , and 8 were inactive or less active in the same experiments.

Six new triterpene tetra-, penta- and hexaosides, chitonoidosides A ( 1 ), A 1 ( 2 ), B ( 3 ), C ( 4 ), D ( 5 ), and E ( 6 ), containing one or two sulfate groups, have been isolated from the Far-Eastern sea cucumber Psolus chitonoides , collected near Bering Island (Commander Islands) from the depth of 100-150 m. Three of the isolated compounds ( 1 , 3 and 6 ) are characterized by the unusual aglycone of new type having 18(20)-ether bond and lacking a lactone in contrast with wide spread holostane derivatives. Another unexpected finding is 3- O -methylxylose residue as a terminal unit in the carbohydrate chains of chitonoidosides B ( 3 ), C ( 4 ), and E ( 6 ), which has never been found before in the glycosides from holothurians belonging to the Psolidae family. Moreover, this monosaccharide is sulfated in the compound 4 into unprecedented 3- O -methylxylose 4- O -sulfate residue. Chitonoidoside C ( 4 ) is characterized by tetrasaccharide moiety lacking a part of the bottom semi-chain, but having disaccharide fragment attached to C-4 of Xyl1. Such architecture is not common in sea cucumber glycosides. Cytotoxic activities of the compounds 1 - 5 against mouse and human erythrocytes and human cancer cell lines: adenocarcinoma HeLa, colorectal adenocarcinoma DLD-1, and leukemia promyeloblast HL-60 cells were studied. The cytotoxic effect of chitonoidoside d ( 5 ) was the most significant in this series due to the presence of pentasaccharide disulfated sugar chain in combination with holostane aglycone. Surprisingly, the glycosides 1 and 3 , comprising the new aglycone without γ-lactone, demonstrated similar activity to the known compounds with holostane aglycones. Chitonoidoside C ( 4 ) was less cytotoxic due to the different architecture of the carbohydrate chain compared to the other glycosides and probably due to the presence of a sulfate group at C-4 in 3- O -MeXyl4.

Nine new mono-, di-, and trisulfated triterpene penta- and hexaosides, kurilosides A 3 ( 1 ), D 1 ( 2 ), G ( 3 ), H ( 4 ), I ( 5 ), I 1 ( 6 ), J ( 7 ), K ( 8 ), and K 1 ( 9 ) and two desulfated derivatives, DS-kuriloside L ( 10 ), having a trisaccharide branched chain, and DS-kuriloside M ( 11 ), having hexa- nor -lanostane aglycone with a 7(8)-double bond, have been isolated from the Far-Eastern deep-water sea cucumber Thyonidium (=Duasmodactyla) kurilensis (Levin) and their structures were elucidated based on 2D NMR spectroscopy and HR-ESI mass-spectrometry. Five earlier unknown carbohydrate chains and two aglycones (having a 16 β ,(20S)-dihydroxy-fragment and a 16 β -acetoxy,(20S)-hydroxy fragment) were found in these glycosides. All the glycosides 1 - 9 have a sulfate group at C-6 Glc, attached to C-4 Xyl1, while the positions of the other sulfate groups vary in different groups of kurilosides. The analysis of the structural features of the aglycones and the carbohydrate chains of all the glycosides of T. kurilensis showed their biogenetic relationships. Cytotoxic activities of the compounds 1 - 9 against mouse neuroblastoma Neuro 2a, normal epithelial JB-6 cells, and erythrocytes were studied. The highest cytotoxicity in the series was demonstrated by trisulfated hexaoside kuriloside H ( 4 ), having acetoxy-groups at C(16) and C(20), the latter one obviously compensated the absence of a side chain, essential for the membranolytic action of the glycosides. Kuriloside I 1 ( 6 ), differing from 4 in the lacking of a terminal glucose residue in the bottom semi-chain, was slightly less active. The compounds 1 - 3 , 5 , and 8 did not demonstrate cytotoxic activity due to the presence of hydroxyl groups in their aglycones.

Three new triterpene glycosides, pacificusosides A-C ( 1 - 3 ), and three previously known triterpene glycosides, cucumariosides C 1 ( 4 ), C 2 ( 5 ), and A 10 ( 6 ), were isolated from the alcoholic extract of the Far Eastern starfish Solaster pacificus . The structures of 1 - 3 were elucidated by extensive NMR and ESIMS techniques and chemical transformations. Compound 1 has a novel, unique structure, containing an aldehyde group of side chains in its triterpene aglycon. This structural fragment has not previously been found in the sea cucumber triterpene glycosides or starfish steroidal glycosides. Probably, pacificusoside A ( 1 ) is a product of the metabolism of the glycoside obtained through dietary means from a sea cucumber in the starfish. Another two new triterpene glycosides ( 2 , 3 ) have closely related characteristics to sea cucumber glycosides. The cytotoxicity of compounds 1 - 6 was tested against human embryonic kidney HEK 293 cells, colorectal carcinoma HT-29 cells, melanoma RPMI-7951 cells, and breast cancer MDA-MB-231 cells using MTS assay. Compounds 4 - 6 revealed the highest cytotoxic activity against the tested cell lines, while the other investigated compounds had moderate or slight cytotoxicity. The cytotoxic effects of 2 - 6 were reduced by cholesterol like the similar effects of the previously investigated individual triterpene glycosides. Compounds 3 , 4 , and 5 almost completely suppressed the colony formation of the HT-29, RPMI-7951, and MDA-MB-231 cells at a nontoxic concentration of 0.5 µM.

The research described here presents data on the effect of galactans of red algae, carrageenans (λ/μ/ν-, κ-, κ/β-, and ι/κ-types), and agar on complement system activation in normal human serum. The experiments were based on well surfaces coated with triggering agents for binding initiating complement components -C3 and C4. The sulfated galactans inhibited C3 binding to lipopolysaccharide with direct dependence on the sulfation degree of polysaccharides. Sulfation degree was also important in carrageenans' capacity to reduce C4 binding to mannan. However, C4 binding to antibodies was considerably activated by carrageenans, especially with 3,6-anhydrogalactose. The gelling carrageenans were able to block antigen binding centers of total serum IgM and with more intensity than non-gelling. No structural characteristics mattered in ameliorating C5 cleavage by plasmin in extrinsic protease complement activation, but λ/μ/ν- and κ/β-carrageenans almost completely inhibited C5 cleavage. Thus, galactans participated in cell surface biology by imitating surface glycans in inhibition of C3 binding and mannose binding lectin, but as to the tthe heclassical pathway these substances stimulated complement, probably due to their structure based on carrabiose., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

New asterosaponin, acanthaglycoside G ( 1 ), along with three previously known steroidal oligoglycosides ( 2‒4 ), were isolated from the ethanolic extract of the starfish Acanthaster planci , collected off the coast of Vietnam. The structure of 1 was mainly elucidated by extensive NMR and ESIMS techniques as sodium 6- O -{ β -D-fucopyranosyl-(1→2)- β -D-quinovopyranosyl-(1→4)-[ β -D-quinovopyranosyl-(1→2)]- β -D-quinovopyranosyl-(1→3)- β -D-quinovopyranosyl}-6 α -hydroxy-5 α -pregn-9(11)-en-20-one-3 β -yl sulfate. Compounds 3 and 4 showed slight cytotoxic activities against cancer RPMI-7951, HT-29, and MDA-MB-231 cell lines, but effectively inhibited in non-toxic concentrations colony formation of HT-29 and MDA-MB-231 cells and cell migration of MDA-MB-231 cells. Compounds 1 and 2 were inactive or less active, respectively.

In continuation of our studies on a Vietnamese collection of a Stelletta sp., sponge we have isolated two new isomalabaricane triterpenoids, stellettins Q and R ( 1 and 2 ), and four new isomalabaricane-derived nor -terpenoids, stellettins S-V 3 - 6 , along with previously known globostelletin N. Among them, compound 3 contains an acetylenic fragment, unprecedented in the isomalabaricane family and extremely rare in other marine sponge terpenoids. The structures and absolute configurations of all new compounds were established by extensive NMR, MS, and ECD analyses together with quantum-chemical modeling. Additionally, according to obtained new data we report the correction in stereochemistry of two asymmetric centers in the structures of two known isomalabaricanes, 15 R ,23 S for globostelletin M and 15 S ,23 R for globostelletin N.

Genomic analysis of the marine bacterium Wenyingzhuangia fucanilytica CZ1127 T revealed the presence of four fucoidanase genes fwf1, fwf2, fwf3, fwf4 that belonged to the glycoside hydrolase family 107 (GH107, CAZy), which is located in one gene cluster putatively involved in fucoidan catabolism. Genes encoding two fucoidanases fwf1 and fwf2 were cloned, and the proteins FWf1 and FWf2 were produced in Escherichia coli cells. The recombinant fucoidanases were purified and the biochemical properties of these enzymes were studied. The amino acid sequences of FWf1 and FWf2 showed 41 and 51% identity respectively with a fucoidanase FcnA from the marine bacterium Mariniflexile fucanivorans, with the established 3D structure. Structures of the oligosaccharides produced during enzymatic hydrolysis of fucoidan by FWf1 and FWf2 have been determined by NMR spectroscopy. Detailed substrate specificities of FWf1 and FWf2 were studied using fucoidans and sulfated fucooligosaccharides with different structures. Both fucoidanases catalyzed hydrolysis of 1→4-glycosidic bonds between sulfated α-l-fucose residues but had different specificities regarding sulfation patterns of the fucose residues in fucoidan molecules. Specific cleavage sites recognizable by the fucoidanases in fucoidan molecules were determined. The obtained results provide new knowledge about differences between specificities of the fucoidanases belonging to the GH107 family., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Six new monosulfated triterpene tetra-, penta- and hexaosides, namely, the kurilosides A 1 ( 1 ), A 2 ( 2 ), C 1 ( 3 ), D ( 4 ), E ( 5 ) and F ( 6 ), as well as the known earlier kuriloside A ( 7 ), having unusual non-holostane aglycones without lactone, have been isolated from the sea cucumber Thyonidium (= Duasmodactyla) kurilensis (Levin) (Cucumariidae, Dendrochirotida) , collected in the Sea of Okhotsk near Onekotan Island from a depth of 100 m. Structures of the glycosides were established by 2D NMR spectroscopy and HR-ESI mass spectrometry. Kurilosides of the groups A and E contain carbohydrate moieties with a rare architecture (a pentasaccharide branched by C(4) Xyl1), differing from each other in the second monosaccharide residue (quinovose or glucose, correspondingly); kurilosides of the group C are characterized by a unique tetrasaccharide branched by a C(4) Xyl1 sugar chain; and kurilosides of the groups D and F are hexaosides differing from each other in the presence of an O -methyl group in the fourth (terminal) sugar unit. All these glycosides contain a sulfate group at C-6 of the glucose residue attached to C-4 Xyl1 and the non-holostane aglycones have a 9(11) double bond and lack γ-lactone. The cytotoxic activities of compounds 1 - 7 against mouse neuroblastoma Neuro 2a, normal epithelial JB-6 cells and erythrocytes were studied. Kuriloside A 1 ( 1 ) was the most active compound in the series, demonstrating strong cytotoxicity against the erythrocytes and JB-6 cells and a moderate effect against Neuro 2a cells.

Structure of the fucoidan from Sargassum horneri and products of its enzymatic transformation with molecular weight over 20 kDa were investigated. Fucoidan was hydrolyzed by recombinant fucoidanase FFA1 and its fraction of higher molecular weight was fractionated using anion-exchange chromatography, resulting in three sulphated polysaccharides of various molecular weight (63-138 kDa). Their structures were analyzed using NMR spectroscopy, showing the fucoidan (ShF) to be a branched polysaccharide with the backbone consisting of the repeating →3-α-l-Fucp(2SO 3 - )-1→4-α-l-Fucp(2,3SO 3 - )-1→ fragment and side chains including the α-l-Fucp-1→2-α-l-Fucp-1→ or α-l-Fucp-1→3-α-l-Fucp(4SO 3 - )-1→ fragments attached to the main chain at C4. The fragment F3 differing by molecular weight and side chain from other fucoidans fragments possessed the most significant anticancer and radiosensitizing activities., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Thirteen new mono-, di-, and trisulfated triterpene glycosides, quadrangularisosides A-D 4 ( 1-13 ) have been isolated from the sea cucumber Colochirus quadrangularis, which was collected in Vietnamese waters. The structures of these glycosides were established by 2D NMR spectroscopy and HR-ESI (High Resolution Electrospray Ionization) mass spectrometry. The novel carbohydrate moieties of quadrangularisosides D-D 4 ( 8 - 12 ), belonging to the group D, and quadrangularisoside E ( 13 ) contain three sulfate groups, with one of them occupying an unusual position-at C(4) of terminal 3- O -methylglucose residue. Quadrangularisosides A ( 1 ) and D 3 ( 11 ) as well as quadrangularisosides A 1 ( 2 ) and D 4 ( 12 ) are characterized by the new aglycones having 25-hydroperoxyl or 24-hydroperoxyl groups in their side chains, respectively. The cytotoxic activities of compounds 1 - 13 against mouse neuroblastoma Neuro 2a, normal epithelial JB-6 cells, erythrocytes, and human colorectal adenocarcinoma HT-29 cells were studied. All the compounds were rather strong hemolytics. The structural features that most affect the bioactivity of the glycosides are the presence of hydroperoxy groups in the side chains and the quantity of sulfate groups. The membranolytic activity of monosulfated quadrangularisosides of group A ( 1 , 2 ) against Neuro 2a, JB-6 cells, and erythrocytes was relatively weak due to the availability of the hydroperoxyl group, whereas trisulfated quadrangularisosides D 3 ( 11 ) and D 4 ( 12 ) with the same aglycones as 1 , 2 were the least active compounds in the series due to the combination of these two structural peculiarities. The erythrocytes were more sensitive to the action of the glycosides than Neuro 2a or JB-6 cells, but the structure-activity relationships observed for glycosides 1 - 13 were similar in the three cell lines investigated. The compounds 3 - 5 , 8 , and 9 effectively suppressed the cell viability of HT-29 cells. Quadrangularisosides A 1 ( 2 ), C ( 6 ), C 1 ( 7 ), and E ( 13 ) possessed strong inhibitory activity on colony formation in HT-29 cells. Due to the synergic effects of these glycosides (0.02 μM) and radioactive irradiation (1 Gy), a decreasing of number of colonies was detected. Glycosides 1 , 3, and 9 enhanced the effect of radiation by about 30%.

Leptogorgins A-C ( 1 - 3 ), new humulane sesquiterpenoids, and leptogorgoid A ( 4 ), a new dihydroxyketosteroid, were isolated from the gorgonian Leptogorgia sp. collected from the South China Sea. The structures were established using MS and NMR data. The absolute configuration of 1 was confirmed by a modification of Mosher's method. Configurations of double bonds followed from NMR data, including NOE correlations. This is the first report of humulane-type sesquiterpenoids from marine invertebrates. Sesquiterpenoids leptogorgins A ( 1 ) and B ( 2 ) exhibited a moderate cytotoxicity and some selectivity against human drug-resistant prostate cancer cells 22Rv1.

Four new conjugates, esters of polyhydroxysteroids with long-chain fatty acids ( 1 - 4 ), were isolated from the deep-water Far Eastern starfish Ceramaster patagonicus . The structures of 1 - 4 were established by NMR and ESIMS techniques as well as chemical transformations. Unusual compounds 1 - 4 contain the same 5α-cholestane-3β,6β,15α,16β,26-pentahydroxysteroidal moiety and differ from each other in the fatty acid units: 5'Z,11'Z-octadecadienoic ( 1 ), 11'Z-octadecenoic ( 2 ), 5'Z,11'Z-eicosadienoic ( 3 ), and 7'Z-eicosenoic ( 4 ) acids. Previously, only one such steroid conjugate with a fatty acid was known from starfish. After 72 h of cell incubation, using MTS assay it was found that the concentrations of compounds 1 , 2 , and 3 that caused 50% inhibition of growth (IC 50 ) of JB6 Cl41 cells were 81, 40, and 79 µM, respectively; for MDA-MB-231 cells, IC 50 of compounds 1 , 2 , and 3 were 74, 33, and 73 µM, respectively; for HCT 116 cells, IC 50 of compounds 1 , 2 , and 3 were 73, 31, and 71 µM, respectively. Compound 4 was non-toxic against tested cell lines even in three days of treatment. Compound 2 (20 µM) suppressed colony formation and migration of MDA-MB-231 and HCT 116 cells., Competing Interests: The authors declare no conflict of interest.

Four new polyhydroxylated steroids 1 - 4 were isolated along with two previously known related steroids 5 and 6 from the methanolic extract of the starfish Anthenoides laevigatus collected off the coastal waters of Vietnam. Structures of new compounds were substantially elucidated by one-dimensional (1D) and two-dimensional (2D) NMR spectroscopy and HRESIMS techniques. Heptaol 1 and hexaol 2 contain the common 5α-cholestane skeleton, while hexaol 3 and heptaol 4 have the rare among starfish steroid compounds 5β-cholestane skeleton. Compounds 1 , 5 , and 6 do not show cytotoxic effects against normal JB6 Cl41 and cancer HT-29 and MDA-MB-231 cells, however they inhibit cell proliferation and colony formation of cancer HT-29 and MDA-MB-231 cells.

Two novel C 19 terpenoids ( 1 , 2 ) with an unprecedented carbon skeleton ( A ) were isolated from a Stelletta sp. sponge collected from Vietnamese waters. Their structures and absolute configurations were established by extensive NMR, MS, and ECD analyses together with quantum chemical modeling and biogenetic considerations. The probable pathways of biogenesis of 1 and 2 from isomalabaricane triterpenoids are discussed. Compounds 1 and 2 significantly increase the production of reactive oxygen species in murine peritoneal macrophages.

Ten new di-, tri- and tetrasulfated triterpene glycosides, psolusosides B 1 ( 1 ), B 2 ( 2 ), J ( 3 ), K ( 4 ), L ( 5 ), M ( 6 ), N ( 7 ), O ( 8 ), P ( 9 ), and Q ( 10 ), were isolated from the sea cucumber Psolus fabricii collected in the Sea of Okhotsk near the Kurile Islands. Structures of these glycosides were established by two-dimensional (2D) NMR spectroscopy and HR-ESI mass-spectrometry. It is particularly interesting that highly polar compounds 9 and 10 contain four sulfate groups in their carbohydrate moieties, including two sulfates in the same terminal glucose residue. Glycoside 2 has an unusual non-holostane aglycone with 18(16)-lactone and a unique 7,8-epoxy fragment. Cytotoxic activities of compounds 1 - 10 against several mouse cell lines such as Ehrlich ascites carcinoma cells, neuroblastoma Neuro 2A, normal epithelial JB-6 cells, and erythrocytes were quite different depending both on structural peculiarities of these glycosides and the type of cells subjected to their actions. Psolusoside L ( 5 ), pentaoside, with three sulfate groups at C-6 of two glucose and one 3- O -methylglucose residue and holostane aglycone, is the most active compound in the series. The presence of a sulfate group at C-2 of the terminal glucose residue attached to C-4 of the first (xylose) residue significantly decreases activities of the corresponding glycosides. Psolusosides of group B ( 1 , 2 , and known psolusoside B) are inactive in all tests due to the presence of non-holostane aglycones and tetrasaccharide-branched sugar chains sulfated by C-2 of Glc4., Competing Interests: The authors declare no conflicts of interest.

Six new polyhydroxylated steroids conjugated with taurine, microdiscusols A-F, were isolated from the alcoholic extract of the Arctic starfish Asterias microdiscus. Three of them have been found to have additional sulfate groups in tetracyclic cores. The structures of new compounds were established by 1D and 2D NMR and HRESIMS techniques. The found steroid taurine conjugates resemble, by their structures, salts of bile acids and alcohols of lower vertebrates., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Seven sulfated triterpene glycosides, psolusosides B ( 1 ), E ( 2 ), F ( 3 ), G ( 4 ), H ( 5 ), H 1 ( 6 ), and I ( 7 ), along with earlier known psolusoside A and colochiroside D have been isolated from the sea cucumber Psolus fabricii collected in the Sea of Okhotsk. Herein, the structure of psolusoside B ( 1 ), elucidated by us in 1989 as a monosulfated tetraoside, has been revised with application of modern NMR and particularly MS data and proved to be a disulfated tetraoside. The structures of other glycosides were elucidated by 2D NMR spectroscopy and HR-ESI mass-spectrometry. Psolusosides E ( 2 ), F ( 3 ), and G ( 4 ) contain holostane aglycones identical to each other and differ in their sugar compositions and the quantity and position of sulfate groups in linear tetrasaccharide carbohydrate moieties. Psolusosides H ( 5 ) and H 1 ( 6 ) are characterized by an unusual sulfated trisaccharide carbohydrate moiety with the glucose as the second sugar unit. Psolusoside I ( 7 ) has an unprecedented branched tetrasaccharide disulfated carbohydrate moiety with the xylose unit in the second position of the chain. The cytotoxic activities of the compounds 2 - 7 against several mouse cell lines-ascite form of Ehrlich carcinoma, neuroblastoma Neuro 2A, normal epithelial JB-6 cells, and erythrocytes-were quite different, at that hemolytic effects of the tested compounds were higher than their cytotoxicity against other cells, especially against the ascites of Ehrlich carcinoma. Interestingly, psolusoside G ( 4 ) was not cytotoxic against normal JB-6 cells but demonstrated high activity against Neuro 2A cells. The cytotoxic activity against human colorectal adenocarcinoma HT-29 cells and the influence on the colony formation and growth of HT-29 cells of compounds 1 - 3 , 5 - 7 and psolusoside A was checked. The highest inhibitory activities were demonstrated by psolusosides E ( 2 ) and F ( 3 ).

Four new oxysterols 1 ⁻ 4 along with previously known oxygenated sterols 5 ⁻ 14 were isolated from the sponge Inflatella sp., collected from the Sea of Okhotsk. Structures of 1 ⁻ 4 were elucidated by the detailed NMR spectroscopic and mass-spectrometric analyses as well as by comparison of the corresponding experimental data with those reported in literature. The influence of compounds 1 ⁻ 14 on the viability of neuronal Neuro2a cells treated by 6-hydroxydopamine and reactive oxygen species (ROS) formation in these cells was investigated.

New marine glycoconjugates-the steroidal glycosides designated as anthenosides V⁻X ( 1 ⁻ 3 )-and the seven previously known anthenosides E ( 4 ), G ( 5 ), J ( 6 ), K ( 7 ), S1 ( 8 ), S4 ( 9 ), and S6 ( 10 ) were isolated from the extract of the tropical starfish Anthenea aspera . The structures of 1 ⁻ 3 were elucidated by extensive NMR and ESIMS techniques. Glycoside 1 contains a rare 5α-cholest-8(14)-ene-3α,7β,16α-hydroxysteroidal nucleus. Compounds 2 and 3 were isolated as inseparable mixtures of epimers. All investigated compounds ( 1 ⁻ 10 ) at nontoxic concentrations inhibited colony formation of human melanoma RPMI-7951, breast cancer T-47D, and colorectal carcinoma HT-29 cells to a variable degree. The mixture of 6 and 7 possessed significant anticancer activity and induced apoptosis of HT-29 cells. The molecular mechanism of the proapoptotic action of this mixture was shown to be associated with the regulation of anti- and proapoptotic protein expression followed by the activation of initiator and effector caspases.

Eight new triterpene olygoglycosides, cladolosides C 4 (1), D 1 (2), D 2 (3), M (4), M 1 (5), M 2 (6), N (7) and Q (8), were isolated from the tropical Indo-West Pacific sea cucumber Cladolabes schmeltzii (Sclerodactylidae, Dendrochirotida). Structures of these glycosides were elucidated by 2D NMR spectroscopy and HR ESI mass spectrometry. A novel hexasaccharide carbohydrate chain having xylose residues as the first, second and third sugars was found in the glycoside 7. Cladoloside C 4 (1) contains an uncommon 20,21,22,23,24,25,26,27-octa-norlanostane aglycone. Cladolosides D 1 (2), D 2 (3) and Q (8) were new representatives of the hexaosides with a non-methylated terminal sugar unit in the "upper" half-chain. Cytotoxic activities of the isolated compounds against ascite form of mouse Ehrlich carcinoma cells, mouse erythrocytes and human colorectal adenocarcinoma HT-29 cells were examined and their structure-activity relationships were analyzed. In addition, the majority of tested compounds, except for cladoloside D 2 (3), inhibited the colony formation and growth of HT-29 cells at non-cytotoxic concentrations. The highest inhibitory activity was demonstrated by cladoloside M 1 (5). Moreover, synergism of effects of radioactive irradiation and non-toxic dose of compounds 1-8 decreasing the number of colonies of HT-29 cells was observed. Cladoloside N (7) was the most active and increased the inhibitory effect from radiation by 75%. The biosynthetic transformations of the aglycones are discussed., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The sea cucumber Cladolabes schmeltzii (Sclerodactylidae, Dendrochirotida) contains diverse glycosides, including several dozen individual compounds. Six new triterpene oligoglycosides, cladolosides O (1), P (2), P 1 (3), P 2 (4), P 3 (5) and R (6), were isolated from this sea cucumber. Their structures were elucidated by 2D NMR spectroscopy and HR ESI mass spectrometry. Cladoloside O (1) has a pentasaccharide carbohydrate chain. Cladolosides of the group P and cladoloside R (6) include novel hexasaccharide carbohydrate chains with different positions of non-methylated terminal sugar units. All the isolated compounds demonstrate strong cytotoxic activities against cells of mouse Ehrlich carcinoma cells (ascite form) and mouse erythrocytes. The cytotoxicity of these compounds against human colorectal adenocarcinoma HT-29 cells was somewhat lower. The compounds 1-6 also inhibit the colony formation and growth of HT-29 cells at non-cytotoxic concentrations. The highest inhibition effect was demonstrated by cladoloside P 1 (3). Moreover, synergism of effects of radioactive irradiation and non-toxic dose of compounds 1-6 on colony formation of HT-29 cells was observed. Cladolosides P 2 (4) and P 3 (5) were the most active and increased the inhibitory effect of radiation by more than 70%. The metabolic network demonstrating the biosynthetic pathways to carbohydrate chains of the glycosides of C. schmeltzii, based on a comparison of their structures, was constructed., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Fucoidans belong to a structurally heterogeneous class of sulfated polysaccharides isolated from brown algae. They have a wide spectrum of biological activities. The complex structures of these polysaccharides hinder structure-activity relationships determination. Fucoidan sulfatases can make useful tools for the determination of the fine chemical structure of fucoidans. In this study, identification and preparation of two recombinant sulfatases able to catalyze the cleavage of sulfate groups from fragments of fucoidan molecules is described for the first time. Two genes of sulfatases swf1 and swf4 of the marine bacterium Wenyingzhuangia fucanilytica CZ1127 T were cloned and the proteins were produced in Escherichia coli cells. Sulfatases SWF1 and SWF4 are assigned to S1_17 and S1_25 subfamilies of formylglycine-dependent enzymes of S1 family (SulfAtlas). Some molecular and biochemical characteristics of recombinant fucoidan sulfatases have been studied. Detailed specificity and catalytic features of sulfatases were determined using various sulfated fucooligosaccharides. Structures of products produced by SWF1 and SWF4 were established by nuclear magnetic resonance (NMR) spectroscopy. Based on the obtained data, the enzymes are classified as fucoidan exo -2 O -sulfatase (SWF1) and fucoidan exo -3 O -sulfatase (SWF4). In addition, we demonstrated the sequential action of sulfatases on 2,3-di- O -sulfated fucooligosacchrides, which indicates an exolitic degradation pathway of fucoidan by a marine bacterium W. fucanilytica CZ1127 T .

Enzymatic depolymerization of fucoidans attracts many researchers due to the opportunity of obtaining standardized fucoidan fragments. Fucoidanase catalyzes the cleavage of fucoidan from Fucus evanescens (FeF) to form low molecular weight products (LMP) and a polymeric fraction (HMP) with 50.8 kDa molecular weight and more than 50% yield. NMR spectroscopy shows that the HMP fraction has regular structure and consists of a repeating fragment [→3)-α-l-Fucp2,4OSO 3 - -(1 → 4)-α-l-Fucp2,4OSO 3 - -(1 → 4)-α-l-Fucp2OSO 3 - -(1→] n . The anticancer effects of FeF fucoidan and its derivative (HMP) were studied in vitro on colon cancer cells HCT-116, HT-29, and DLD-1. The anticancer activity of the HMP fraction was found to be slightly lower than that of the FeF fucoidan. Research and practical applications of the enzyme include modification of native fucoidans for purposes of regular and easier characterized derivatives acquisition., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The O-polysaccharide was isolated from the lipopolysaccharide of a marine bacterium Pseudomonas glareae KMM 9500 T and studied by chemical methods along with 1D and 2D 1 H and 13 C NMR spectroscopy including 1 H, 1 H-TOCSY, 1 H, 1 H-COSY, 1 H, 1 H-ROESY, 1 H, 13 C-HSQC and 1 H, 13 C-HMBC experiments. The O-polysaccharide was found to consist of linear tetrasaccharide repeating units constituted by D-glucuronic acid (D-GlcA), L-rhamnose (L-Rha), D-glucose (D-Glc) and 5-acetamido-7,9-O-[(S)-1-carboxyethylidene]-3,5-dideoxy-L-glycero-L-manno-non-2-ulosonic acid (Sug7,9(S-Pyr)), partially O-acetylated at position 8 (∼70%): →4)-α-D-GlcpA-(1→3)-β-L-Rhap-(1→4)-β-D-Glcp-(1→4)-β-Sugp8Ac(∼70%)7,9(S-Pyr)-(2→., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Two new polyhydroxysteroidal glycosides, anthenosides A₁ ( 1 ) and A₂ ( 2 ), and one previously known steroidal glycoside anthenoside A ( 3 ) were isolated from extract of the tropical starfish Anthenea aspera . Structures of 1 ⁻ 3 were determined by analysis of the spectroscopic data as well as chemical transformations. As a result, the structure of anthenoside A has been revised and the structures of 1 and 2 were established. Glycosides 1 ⁻ 3 contain a 2-acetamido-2-deoxy-4- O -methyl-β-d-glucopyranosyl residue, found in the starfish steroidal glycosides for the first time. All the isolated compounds slightly inhibited cell viability of human cancer T-47D cells and did not show cytotoxic effects against RPMI-7951 cells. Glycoside 1 slightly inhibited colony formation of human cancer RPMI-7951 cells by 16% while compound 2 decreased the number of colonies of T-47D cells by 40%.

Six new polyhydroxysteroidal glycosides, anthenosides S1  - S6 (1 - 6), along with a mixture of two previously known related glycosides, 7 and 8, were isolated from the methanolic extract of the starfish Anthenea sibogae. The structures of 1 - 6 were established by NMR and HR-ESI-MS techniques as well as by chemical transformations. All new compounds have a 5α-cholest-8(14)-ene-3α,6β,7β,16α-tetrahydroxysteroidal nucleus and differ from majority of starfish glycosides in positions of carbohydrate moieties at C(7) and C(16) (1 - 4, 6) or only at C(16) (5). The 4-O-methyl-β-d-glucopyranose residue (2) and Δ 24 -cholestane side chain (3) have not been found earlier in the starfish steroidal glycosides. The mixture of 7 and 8 slightly inhibited the proliferation of human breast cancer T-47D cells and decreased the colony size in the colony formation assay., (© 2018 Wiley-VHCA AG, Zurich, Switzerland.)

We presented the structure of the sulfated polysaccharide moiety and anticancer activity in vitro of the О-deacylated lipopolysaccharide (DPS) isolated from the marine bacterium Poseidonocella pacifica KMM 9010 T . The structure of O-polysaccharide was investigated by chemical methods along with 1 H and 13 C NMR spectroscopy. The O-polysaccharide was built up of sulfated disaccharide repeating units consisted of d-rhamnose (d-Rhaр) and 3-deoxy-d-manno-oct-2-ulosonic acid (Kdop): →7)-β-Kdoр4Ac5S-(2→3)-β-d-Rhaр2S-(1→. We demonstrated that the DPS from P. pacifica KMM 9010 T non-toxic for normal mouse epidermal cells (JB6 Cl41 cell line) and inhibited colony formation of human colorectal carcinoma HT-29, breast adenocarcinoma MCF-7 and melanoma SK-MEL-5 cells in a dose-dependent manner., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Structure and anticancer activity of fucoidan from Sargassum horneri and from products of its enzymatic transformation were investigated. A gene that encodes fucoidanase ffa1 in the marine bacteria F. algae was identified, cloned and the protein (FFA1) was produced in Escherichia coli. The mass of the gene product FFA1 is 111kDa. Sequence analysis has revealed that fucoidanase FFA1 belongs to the GH107 (CAZy) family. Recombinant fucoidanase FFA1 was used to produce fucooligosaccharides. Structure of 5 sulphated oligosaccharides with polymerization degree 4-10 was established by NMR-spectroscopy. The fucoidan extracted from S. horneri is almost pure fucan. The main chain of the fucoidan is established to consist mostly of the repeating →3-α-l-Fucp(2SO 3 - )-1→4-α-l-Fucp(2,3SO 3 - )-1→ fragment, with insertions of →3-α-l-Fucp(2,4SO 3 - )-1→ fragment. Unsulphated side chains with the α-l-Fucp-1→2-α-l-Fucp-1→ structure connect to the main one at the C4 of monosaccharide residue., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Seven new asterosaponins, pentaregulosides A-G (1-7), including two furostane-type steroid oligoglycosides (2, 3), along with four previously known compounds (8-11) were isolated from the ethanolic extract of the starfish Pentaceraster regulus, collected off the coast of Vietnam. The structures of 1-7 were elucidated by extensive NMR and ESIMS techniques as well as chemical transformations. The aglycons of compounds 1 and 3 have not previously been observed in starfish steroid oligoglycosides, while the aglycons of compounds 2 and 4-6 are very rare for this structural group. Compound 1 exhibited cytotoxic activity with an IC 50 value of 6.4 ± 0.3 μM against RAW 264.7 murine macrophages. In contrast, nontoxic asterosaponins 3, 4, and 5 showed a potential immunomodulatory action at a concentration of 5 μM, reducing by 40%, 28%, and 55%, respectively, reactive oxygen species formation in the RAW 264.7 cells, co-stimulated with the pro-inflammatory endotoxic lipopolysaccharide from E. coli.

The first representatives of a new group of manzamine-related alkaloids with a previously unknown skeletal systems, namely, lissodendoric acids A (1) and B (2), were isolated from the sponge Lissodendoryx florida collected from the Sea of Okhotsk. The structures and absolute configurations have been elucidated by extensive spectroscopic analysis together with chemical transformations and quantum-chemical modeling. The lissodendoric acids show a potent capability to decrease the production of reactive oxygen species in neuroblastoma Neuro 2a and somewhat increase the survival of these cells upon treatment with 6-hydroxydopamine (an in vitro antiparkinson biotest).

Seven new triterpene glycosides, erylosides F 8 (1), V 1 (2), V 2 (3), V 3 (4), W (5), W 1 (6) and W 2 (7), were isolated from a Carribean sponge Erylus goffrilleri collected from the Carribean Sea near the Arrecife-Seco reef (Cuba). Structures of the glycosides were determined using 1 H and 13 C NMR spectroscopy, including 2D NMR procedures ( 1 H- 1 H COSY, 1 H- 13 С HMBC, 1 H- 13 С HSQC and NOESY) and HR ESI mass spectrometry. Erylosides 1 and 4 have 14-carboxy-24,25-dimethyllanost-8(9)-en-3β,25-diol as aglycone whereas glycosides 2, 3, 5, 6 and 7 are 14-carboxy-24-acetoxy-24-methyllanost-8(9)-en-3β-ol glycoconjugates. Cytotoxic activities of the isolated compounds against Ehrlich carcinoma cells and hemolysis were examined and their dependence on eryloside structure was evaluated., (Copyright © 2017. Published by Elsevier Ltd.)

Nine new sulfated triterpene glycosides, magnumosides A₁ ( 1 ), A₂ ( 2 ), A₃ ( 3 ), A₄ ( 4 ), B₁ ( 5 ), B₂ ( 6 ), C₁ ( 7 ), C₂ ( 8 ) and C₄ ( 9 ) as well as a known colochiroside B₂ ( 10 ) have been isolated from the tropical Indo-West Pacific sea cucumber Neothynidium (= Massinium ) magnum (Phyllophoridae, Dendrochirotida) collected in the Vietnamese shallow waters. The structures of new glycosides were elucidated by 2D NMR spectroscopy and mass-spectrometry. All the isolated new glycosides were characterized by the non-holostane type lanostane aglycones having 18(16)-lactone and 7(8)-double bond and differed from each other by the side chains and carbohydrate moieties structures. Magnumoside A₁ ( 1 ) has unprecedented 20(24)-epoxy-group in the aglycone side chain. Magnumosides of the group A ( 1 - 4 ) contained disaccharide monosulfated carbohydrate moieties, of the group B ( 5 , 6 )-tetrasaccharide monosulfated carbohydrate moieties and, finally, of the group C ( 7 - 9 )-tetrasaccharide disulfated carbohydrate moieties. The cytotoxic activities of the compounds 1 - 9 against mouse spleen lymphocytes, the ascites form of mouse Ehrlich carcinoma cells, human colorectal carcinoma DLD-1 cells as well as their hemolytic effects have been studied. Interestingly, the erythrocytes were more sensitive to the glycosides action than spleenocytes and cancer cells tested. The compounds 3 and 7 significantly inhibited the colony formation and decreased the size of colonies of DLD-1 cancer cells at non-cytotoxic concentrations. Moreover, the synergism of effects of radioactive irradiation and compounds 3 and 7 - 9 at subtoxic doses on proliferation of DLD-1 cells was demonstrated., Competing Interests: The authors declare no conflict of interest.