Composition of Triterpene Glycosides of the Far Eastern Sea Cucumber Levin et Stepanov; Structure Elucidation of Five Minor Conicospermiumosides A-1, A-2, A-3, A-1, and A-2; Cytotoxicity of the Glycosides Against Human Breast Cancer Cell Lines; Structure-Activity Relationships.

Five new non-holostane di- and trisulfated triterpene pentaosides, conicospermiumosides A-1 (), A-2 (), A-3 (), A-1 (), and A-2 () were isolated from the Far Eastern sea cucumber Levin et Stepanov (Cucumariidae, Dendrochirotida). Twelve known glycosides found earlier in other species were also obtained and identified. The structures of new compounds were established on the basis of extensive analysis of the 1D and 2D NMR spectra, as well as by the HR-ESI-MS data.

Stonikacidin A, an Antimicrobial 4-Bromopyrrole Alkaloid Containing L-Idonic Acid Core from the Northwestern Pacific Marine Sponge .

Stonikacidin A (), the first representative of a new class of 4-bromopyrrole alkaloids containing an aldonic acid core, was isolated from the marine sponge . The compound is named in honor of Prof. Valentin A.

Sulfated Polyhydroxysteroid Glycosides from the Sea of Okhotsk Starfish and Potential Mechanisms for Their Observed Anti-Cancer Activity against Several Types of Human Cancer Cells.

Three new monosulfated polyhydroxysteroid glycosides, spiculiferosides A (), B (), and C (), along with new related unsulfated monoglycoside, spiculiferoside D (), were isolated from an ethanolic extract of the starfish collected in the Sea of Okhotsk. Compounds - 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 (, ) are biosides, and one glycoside (), unlike them, includes three monosaccharide residues.

Honoring Prof. Dr. Valentin A. Stonik for His Outstanding Contribution to Marine Natural Product Chemistry on the Occasion of His 80th Birthday.

Marine natural products are a very structurally diverse group of preferably low-weight organic molecules [...

Lipopolysaccharides of Herbaspirillum species and their relevance for bacterium-host interactions.

The lipopolysaccharides of Herbaspirillum lusitanum P6-12 (HlP6-12) and H. frisingense GSF30 (HfGSF30) was isolated by phenol-water extraction from bacterial cells and was characterized using chemical analysis and SDS-PAGE. It was shown that these bacteria produce LPSs that differ in their physicochemical properties and macromolecular organization.

The effect of membrane composition on the interaction between human CYP51 and its flavonoid inhibitor - luteolin 7,3'-disulfate.

Cytochromes P450 (CYP) are a family of membrane proteins involved in the production of endogenous molecules and the metabolism of xenobiotics. It is well-known that the composition of the membrane can influence the activity and orientation of CYP proteins. However, little is known about how membrane composition affects the ligand binding properties of CYP.

New Rare Triterpene Glycosides from Pacific Sun Star, , and Their Anticancer Activity.

Six previously unknown triterpene glycosides, pacificusosides L-Q (-), and two previously known triterpene glycosides, cucumariosides B () and A (), were isolated from an alcoholic extract of Pacific sun star, . The structures of - were determined using 1D and 2D NMR, ESIMS, and chemical modifications. Compound is a rare type of triterpene glycoside with non-holostane aglycon, having a linear trisaccharide carbohydrate chain.

Sulfated Triterpene Glycosides from the Far Eastern Sea Cucumber : Djakonoviosides C, D, E, and F; Cytotoxicity against Human Breast Cancer Cell Lines; Quantitative Structure-Activity Relationships.

Four new mono- and trisulfated triterpene penta- and tetraosides, djakonoviosides C (), D (), E (), and F () were isolated from the Far Eastern sea cucumber (Cucumariidae, Dendrochirotida), along with six known glycosides found earlier in other 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.

Molecular Cloning, Heterologous Expression, Purification, and Evaluation of Protein-Ligand Interactions of CYP51 of Azole-Resistant Fungal Strain.

Due to the increasing prevalence of fungal diseases caused by fungi of the genus and the development of pathogen resistance to available drugs, the need to find new effective antifungal agents has increased. Azole antifungals, which are inhibitors of sterol-14α-demethylase or CYP51, have been widely used in the treatment of fungal infections over the past two decades. Of special interest is the study of CYP51, since this fungus exhibit resistance not only to azoles, but also to other antifungal drugs and there is no available information about the ligand-binding properties of CYP51 of this pathogen.

Rhabdastrellosides A and B: Two New Isomalabaricane Glycosides from the Marine Sponge , and Their Cytotoxic and Cytoprotective Effects.

Investigation of the Vietnamese marine sponge led to the isolation of two new polar isomalabaricanes: rhabdastrellosides A () and B (). 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 and are the first isomalabaricanes with non-oxidized cyclopentane ring in the tricyclic core system.

Identification of Antibody-Mediated Hydrolysis Sites of Oligopeptides Corresponding to the SARS-CoV-2 S-Protein by MALDI-TOF Mass Spectrometry.

Antibodies recognizing RBD and the S-protein have been previously demonstrated to be formed in humans after SARS-CoV-2 infection and vaccination with the Sputnik V adenovirus vaccine. These antibodies were found to be active when hydrolyzing FITC-labeled oligopeptides corresponding to linear epitopes of the S-protein. The thin-layer chromatography method allows the relative accumulation of the reaction product to be estimated but cannot identify hydrolysis sites.

Isolation of Extracellular Vesicles of Holothuria (Sea Cucumber ).

Extracellular vesicles (EVs), carriers of molecular signals, are considered a critical link in maintaining homeostasis in mammals. Currently, there is growing interest in studying the role of EVs, including exosomes (subpopulation of EVs), in animals of other evolutionary levels, including marine invertebrates. We have studied the possibility of obtaining appropriate preparations of EVs from whole-body extract of holothuria using a standard combination of centrifugation and ultracentrifugation.

A Mass Spectrometry Database for Sea Cucumber Triterpene Glycosides.

Sea cucumber triterpene glycosides are a class of secondary metabolites that possess distinctive chemical structures and exhibit a variety of biological and pharmacological activities. The application of MS-based approaches for the study of triterpene glycosides allows rapid evaluation of the structural diversity of metabolites in complex mixtures. However, the identification of the detected triterpene glycosides can be challenging.

Djakonoviosides A, A, A, B-B - Triterpene Monosulfated Tetra- and Pentaosides from the Sea Cucumber : The First Finding of a Hemiketal Fragment in the Aglycones; Activity against Human Breast Cancer Cell Lines.

Seven new monosulfated triterpene glycosides, djakonoviosides A (), A (), A (), and B-B (-), along with three known glycosides found earlier in the other species, namely okhotoside A-1, cucumarioside A-1, and frondoside D, have been isolated from the far eastern sea cucumber (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.

EAE of Mice: Enzymatic Cross Site-Specific Hydrolysis of H2A Histone by IgGs against H2A, H1, H2B, H3, and H4 Histones and Myelin Basic Protein.

Histones play vital roles in chromatin function and gene transcription; however, they are very harmful in the intercellular space because they stimulate systemic inflammatory and toxic responses. Myelin basic protein (MBP) is the major protein of the axon myelin-proteolipid sheath. Antibodies-abzymes with various catalytic activities are specific features of some autoimmune diseases.

Phytoceramides from the Marine Sponge : Structural Analysis and Cytoprotective Effects.

In our research on sphingolipids from marine invertebrates, a mixture of phytoceramides was isolated from the sponge (Western Australia). Total ceramide, ceramide molecular species (obtained by RP-HPLC, high-performance liquid chromatography on reversed-phase column) and their sphingoid/fatty acid components were analyzed by NMR (nuclear magnetic resonance) spectroscopy and mass spectrometry. Sixteen new (, , , , , , , , , , -) and twelve known (, , , , , -, , , , ) compounds were shown to contain phytosphingosine-type backbones -t17:0 (), -t17:0 (), -t18:0 (), -t18:0 (), -t19:0 (), or -t19:0 (), -acylated with saturated (2)-2-hydroxy C (), C (), C (), C (), C (), C (), or C () acids.

EAE of Mice: Enzymatic Cross Site-Specific Hydrolysis of H2B Histone by IgGs against H1, H2A, H2B, H3, and H4 Histones and Myelin Basic Protein.

Histones have vital roles in chromatin functioning and gene transcription. At the same time, they are pernicious in intercellular space because they stimulate systemic inflammatory and toxic responses. Myelin basic protein (MBP) is the major protein of the axon myelin-proteolipid sheath.

Recombinant Analogs of Sea Anemone Kunitz-Type Peptides Influence P2X7 Receptor Activity in Neuro-2a Cells.

Purinergic P2X7 receptors (P2X7) have now been proven to play an important role and represent an important therapeutic target in many pathological conditions including neurodegeneration. Here, we investigated the impact of peptides on purinergic signaling in Neuro-2a cells through the P2X7 subtype in in vitro models. We have found that a number of recombinant peptides, analogs of sea anemone Kunitz-type peptides, are able to influence the action of high concentrations of ATP and thereby reduce the toxic effects of ATP.

Chilensosides E, F, and G-New Tetrasulfated Triterpene Glycosides from the Sea Cucumber (Caudinidae, Molpadida): Structures, Activity, and Biogenesis.

Three new tetrasulfated triterpene glycosides, chilensosides E (), F (), and G (), have been isolated from the Far-Eastern sea cucumber (Caudinidae, Molpadida). The structures were established based on extensive analysis of 1D and 2D NMR spectra and confirmed by HR-ESI-MS data. The compounds differ in their carbohydrate chains, namely in the number of monosaccharide residues (five or six) and in the positions of sulfate groups.

Analysis of Proteins and Peptides of Highly Purified CD9 and CD63 Horse Milk Exosomes Isolated by Affinity Chromatography.

Exosomes are nanovesicles with a 40-150 nm diameter and are essential for communication between cells. Literature data suggest that exosomes obtained from different sources (cell cultures, blood plasma, urea, saliva, tears, spinal fluid, milk) using a series of centrifugations and ultracentrifugations contain hundreds and thousands of different protein and nucleic acid molecules. However, most of these proteins are not an intrinsic part of exosomes; instead, they co-isolate with exosomes.

New Guanidine Alkaloids Batzelladines O and P from the Marine Sponge Induce Apoptosis and Autophagy in Prostate Cancer Cells.

Two new guanidine alkaloids, batzelladines O () and P (), were isolated from the deep-water marine sponge The structures of these metabolites were determined by NMR spectroscopy, mass spectrometry, and ECD. The isolated compounds exhibited cytotoxic activity in human prostate cancer cells PC3, PC3-DR, and 22Rv1 at low micromolar concentrations and inhibited colony formation and survival of the cancer cells. Batzelladines O () and P () induced apoptosis, which was detected by Western blotting as caspase-3 and PARP cleavage.

Multiple Sclerosis: Enzymatic Cross Site-Specific Recognition and Hydrolysis of H3 Histone by IgGs against H3, H1, H2A, H2B, H4 Histones, Myelin Basic Protein, and DNA.

Histones have a specific key role in the remodeling of chromatin and gene transcription. In the blood, free histones are damage-connected proteins. Myelin basic protein (MBP) is the major component of the myelin-proteolipid sheath of axons.

Nicotinic Acetylcholine Receptors Are Novel Targets of APETx-like Toxins from the Sea Anemone .

The nicotinic acetylcholine receptors (nAChRs) are prototypical ligand-gated ion channels, provide cholinergic signaling, and are modulated by various venom toxins and drugs in addition to neurotransmitters. Here, four APETx-like toxins, including two new toxins, named Hmg 1b-2 Met and Hmg 1b-5, were isolated from the sea anemone and characterized as novel nAChR ligands and acid-sensing ion channel (ASIC) modulators. All peptides competed with radiolabeled α-bungarotoxin for binding to muscle-type and human α7 nAChRs.