Natalia V. Ivanchina

Steroid glycosides from marine organisms

Structures, taxonomic distribution and biological activities of steroid glycosides isolated from marine organisms over the last 8-10 years are reviewed. The bibliography includes 130 references.

Glycosides from marine sponges (Porifera, Demospongiae): structures, taxonomical distribution, biological activities and biological roles.

Literature data about glycosides from sponges (Porifera, Demospongiae) are reviewed. Structural diversity, biological activities, taxonomic distribution and biological functions of these natural products are discussed.

Two new asterosaponins, archasterosides A and B, from the Vietnamese starfish Archaster typicus and their anticancer properties

New asterosaponins archasterosides A (1), B (2), and the known regularoside A (3) were isolated from the Vietnamese starfish Archaster typicus and structurally elucidated by extensive NMR techniques and chemical transformations. Compounds 1-3 showed moderate cytotoxic activities against HeLa and mouse JB6 P(+) Cl41 cell lines. The most active, 2, induced basal AP-1- and p53-, but not NF-kappaB-transcriptional activations in JB6 Cl41 cells.

Neuritogenic and Neuroprotective Effects of Polar Steroids from the Far East Starfishes Patiria pectinifera and Distolasterias nipon

The neuritogenic and neuroprotective activities of six starfish polar steroids, asterosaponin Р1, (25S)-5α-cholestane-3β,4β,6α,7α,8,15α,16β,26-octaol, and (25S)-5α-cholestane-3β,6α,7α,8,15α,16β,26-heptaol (1–3) from the starfish Patiria pectinifera and distolasterosides D1–D3 (4–6) from the starfish Distolasterias nipon were analyzed using the mouse neuroblastoma (NB) C-1300 cell line and an organotypic rat hippocampal slice culture (OHSC). All of these compounds enhanced neurite outgrowth in NB cells. Dose-dependent responses to compounds 1–3 were observed within the concentration range of 10–100 nM, and dose-dependent responses to glycosides 4–6 were observed at concentrations of 1–50 nM. All the tested substances exhibited notable synergistic effects with trace amounts of nerve growth factor (NGF, 1 ng/mL) or brain-derived neurotrophic factor (BDNF, 0.1 ng/mL). Using NB cells and OHSCs, it was shown for the first time that starfish steroids 1–6 act as neuroprotectors against oxygen-glucose deprivation (OGD) by increasing the number of surviving cells. Altogether, these results suggest that neurotrophin-like neuritogenic and neuroprotective activities are most likely common properties of starfish polyhydroxysteroids and the related glycosides, although the magnitude of the effect depended on the particular compound structure.

Four new asterosaponins, hippasteriosides A - D, from the Far Eastern starfish Hippasteria kurilensis.

Four new sulfated steroidal glycosides (asterosaponins), hippasteriosides A–D (1–4, resp.), were isolated from the alcoholic extract of the Far Eastern starfish Hippasteria kurilensis, collected in the Sea of Okhotsk near Kuril Islands. Compounds 1–4 were determined to contain the same unprecedented hexasaccharide moiety, β‐D‐xylopyranosyl‐(1→3)‐β‐D‐fucopyranosyl‐(1→2)‐β‐D‐quinovopyranosyl‐(1→4)‐[β‐D‐quinovopyranosyl‐(1→2)]‐β‐D‐xylopyranosyl‐(1→3)‐β‐D‐quinovopyranosyl, linked to C(6) of 3‐O‐sulfonylated steroidal aglycons, which differ from each other in their side‐chain structures. Structures 1–4 were elucidated by extensive NMR and MS techniques, and chemical transformations. Not all the asterosaponins show a prominent cytotoxic activity against human colon tumor HT‐29 cells, but some of them, especially compound 4 demonstrate a remarkable inhibition of the HT‐29 colony formation in soft‐agar clonogenic assay, suggesting its anticancerogenic properties.

Alkaloidosteroids from the starfish Lethasterias nanimensis chelifera

Abstract New ionic compounds containing an alkaloidal cation and a steroidal anion have been isolated by reverse-phase liquid chromatography from the extracts of the starfish Lethasterias nanimensis chelifera . Their structures have been elucidated by NMR and mass spectroscopy as 1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinolinium salts of 3- O -sulfoasterone 1 , 3- O -sulfo iso asterone 2 and 3- O -sulfothornasterol A 3 . In addition, the alkaloid 1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCA) 4 was found in this starfish.

Cyclic Steroid Glycosides from the Starfish Echinaster luzonicus: Structures and Immunomodulatory Activities

Five new steroid glycosides, luzonicosides B-E (2-5), belonging to a rare structure group of marine glycosides, containing carbohydrate moieties incorporated into a macrocycle, and a related open carbohydrate chain steroid glycoside, luzonicoside F (6), were isolated from the starfish Echinaster luzonicus along with the previously known cyclic steroid glycoside luzonicoside A (1). The structures of compounds 2-6 were established by extensive NMR and ESIMS techniques as well as chemical transformations. Luzonicoside A (1) at concentrations of 0.01-0.1 μM was shown to be potent in lysosomal activity stimulation, intracellular ROS level elevation, and NO synthesis up-regulation in RAW 264.7 murine macrophages. Luzonicoside D (4) was less active in these biotests.

Steroidal monoglycosides from the Far Eastern starfish Hippasteria kurilensis and hypothetic pathways of polyhydroxysteroid biosynthesis in starfish.

Five new steroidal monoglycosides, kurilensosides E (1), F (2), G (3), H (4) and 15-O-sulfate of echinasteroside C (5) were isolated along with the previously known echinasteroside C (6) from the alcoholic extract of the Far Eastern starfish Hippasteria kurilensis collected near Kuril Islands. Compounds 1-3 were determined to contain unusual polyhydroxysteroidal aglycons lacking 6-hydroxy group. Aglycon moiety of kurilensoside H (4) was shown to be the first case of marine polar steroids containing 4,5-epoxy functionality. Hypothetic pathways of the biosynthesis of polyhydroxysteroids and related glycosides in starfish and the existence of the late C-6 oxidation pathway in H. kurilensis are discussed.

Steroidal Triglycosides, Kurilensosides A, B, and C, and Other Polar Steroids from the Far Eastern Starfish Hippasteria kurilensis

Three novel steroidal triglycosides, designated as kurilensosides A, B, and C (1- 3), were isolated along with a new steroidal diglycoside, kurilensoside D (4), and two new (6, 7) and one known (5) polyhydroxysteroid from the alcoholic extract of the Far Eastern starfish Hippasteria kurilensis. Compounds 1-3 are the first triglycosides containing two carbohydrate chains found from starfish. The structures of 1-7 were elucidated by spectroscopic methods (mainly 2D NMR) and chemical derivatization. Glycosides 1-4 and steroids 6 and 7 inhibited sea urchin egg fertilization by sperm preincubated with these compounds.

Asterosaponins from the Far Eastern starfish Leptasterias ochotensis and their anticancer activity.

Six new asterosaponins, leptasteriosides A-F (3-8), one new and one previously known asterogenins (1, 2) were isolated from the alcoholic extract of the Far Eastern starfish Leptasterias ochotensis. The structures of 1-8 were elucidated by extensive NMR and ESI-MS techniques. Compounds 2-8 showed slight or moderate cytotoxic activities against cancer cell lines RPMI-7951 and T-47D. The asterosaponins 3-5 demonstrated a significant inhibition of RPMI-7951 and T-47D cell colony formation in soft agar clonogenic assay in nontoxic doses.