Valery M Dembitsky - Profile on Academia.edu (original) (raw)

Papers by Valery M Dembitsky

Research paper thumbnail of Comparative study of the endemic freshwater fauna of Lake Baikal—III. Phospholipid and fatty acid compositions of the amphipod crustacean of the genus Eulimnogammarus

Comparative biochemistry and physiology. B. Comparative biochemistry, Feb 1, 1994

Lipid and phospholipid compositions of an endemic deep-water freshwater gammarid, belonging to th... more Lipid and phospholipid compositions of an endemic deep-water freshwater gammarid, belonging to the subphylum Crustacea, Acanthogammarus grewingkii was studied. Content of aikenylacyl, alkylacyl and diacyi forms in the main phospholipid classes (phosphatidylethanolamine and phosphatydilcholine) were established using reaction micro-thin-layer chromatography. The fatty acids compositions of total lipids, neutral, glycoand phospholipid fractions were investigated by capillary gas chromatography-mass spectrometry. Seventy-nine fatty acids were identified: 26 saturated (iso-, anteiso-and cyclo-)

Research paper thumbnail of Comparative study of the endemic freshwater fauna of Lake Baikal—V. Phospholipid and fatty acid composition of the deep-water amphipod crustacean Acanthogammarus (Brachyuropus) grewingkii

Comparative biochemistry and physiology. B. Comparative biochemistry, Aug 1, 1994

Lipid and phospholipid compositions of an endemic deep-water freshwater gammarid, belonging to th... more Lipid and phospholipid compositions of an endemic deep-water freshwater gammarid, belonging to the subphylum Crustacea, Acanthogammarus grewingkii was studied. Content of aikenylacyl, alkylacyl and diacyi forms in the main phospholipid classes (phosphatidylethanolamine and phosphatydilcholine) were established using reaction micro-thin-layer chromatography. The fatty acids compositions of total lipids, neutral, glycoand phospholipid fractions were investigated by capillary gas chromatography-mass spectrometry. Seventy-nine fatty acids were identified: 26 saturated (iso-, anteiso-and cyclo-)

Research paper thumbnail of Comparative study of the endemic freshwater fauna of Lake Baikal—IV. Phospholipid and fatty acid compositions of two gastropod molluscs of the genus Valvata

Comparative biochemistry and physiology. B. Comparative biochemistry, Feb 1, 1994

Lipid and phospholipid compositions of an endemic deep-water freshwater gammarid, belonging to th... more Lipid and phospholipid compositions of an endemic deep-water freshwater gammarid, belonging to the subphylum Crustacea, Acanthogammarus grewingkii was studied. Content of aikenylacyl, alkylacyl and diacyi forms in the main phospholipid classes (phosphatidylethanolamine and phosphatydilcholine) were established using reaction micro-thin-layer chromatography. The fatty acids compositions of total lipids, neutral, glycoand phospholipid fractions were investigated by capillary gas chromatography-mass spectrometry. Seventy-nine fatty acids were identified: 26 saturated (iso-, anteiso-and cyclo-)

Research paper thumbnail of Comparative study of the endemic freshwater fauna of Lake Baikal-VII. Carotenoid composition of the deep-water amphipod crustaceanAcanthogammarus (Brachyuropus)grewingkii

Comparative study of the endemic freshwater fauna of Lake Baikal-VII. Carotenoid composition of the deep-water amphipod crustaceanAcanthogammarus (Brachyuropus)grewingkii

Comparative Biochemistry and Physiology B, Aug 1, 1996

Abstract The carotenoid composition of the deep-water gammaride is reported. Astaxanthin and thei... more Abstract The carotenoid composition of the deep-water gammaride is reported. Astaxanthin and their derivatives were determined to be major components of the carotenoids (58.4%). Astaxanthin-glycoside-esters comprised 21.6% of total carotenoids. A new carotenoid glycoside ester (CGE) was isolated from the deep-water gammarideAcanthogammarus (Brachyuropus)grewingkii and its structure was elucidated. The structures were determined from spectra (1H-NMR,13C-NMR, MS, IR) after their isolation and quantification by means of semipreparative RP-HPLC and capillary GC-MS.

Research paper thumbnail of Knowledge Updates 2020/2

Knowledge Updates 2020/2

Science of Synthesis

Research paper thumbnail of Fatty acid amides from freshwater green alga Rhizoclonium hieroglyphicum

Fatty acid amides from freshwater green alga Rhizoclonium hieroglyphicum

Phytochemistry, 2000

Freshwater green algae Rhizoclonium hieroglyphicum growing in the Ural Mountains were examined fo... more Freshwater green algae Rhizoclonium hieroglyphicum growing in the Ural Mountains were examined for their fatty acid amides using capillary gas chromatography-mass spectrometry (GC-MS). Eight fatty acid amides were identified by GC-MS. (Z)-9-octadecenamide was found to be the major component (2.26%).

Research paper thumbnail of Dicarboxylic and Fatty Acid Compositions of Cyanobacteria of the Genus Aphanizomenon

The occurrence of dioic, hydroxy, branched, and unsaturated fatty acids in cyanobacteria of the g... more The occurrence of dioic, hydroxy, branched, and unsaturated fatty acids in cyanobacteria of the genus Aphanizomenon growing in different freshwater lakes has been studied. Unusual dicarboxylic (from 4.52 to 7.14%) and other fatty acids were identified by gas chromatography/mass spectrometry (GC/MS).

Research paper thumbnail of Biological Activity and Structural Diversity of Steroids Containing Aromatic Rings, Phosphate Groups, or Halogen Atoms

Molecules

This review delves into the investigation of the biological activity and structural diversity of ... more This review delves into the investigation of the biological activity and structural diversity of steroids and related isoprenoid lipids. The study encompasses various natural compounds, such as steroids with aromatic ring(s), steroid phosphate esters derived from marine invertebrates, and steroids incorporating halogen atoms (I, Br, or Cl). These compounds are either produced by fungi or fungal endophytes or found in extracts of plants, algae, or marine invertebrates. To assess the biological activity of these natural compounds, an extensive examination of referenced literature sources was conducted. The evaluation encompassed in vivo and in vitro studies, as well as the utilization of the QSAR method. Numerous compounds exhibited notable properties such as strong anti-inflammatory, anti-neoplastic, anti-proliferative, anti-hypercholesterolemic, anti-Parkinsonian, diuretic, anti-eczematic, anti-psoriatic, and various other activities. Throughout the review, 3D graphs illustrating th...

Research paper thumbnail of Selective Synthesis of Unsymmetrical Peroxides: Transition-Metal-Catalyzed Oxidation of Malononitrile and Cyanoacetic Ester Derivatives by tert-Butyl Hydroperoxide at the α-Position

Selective Synthesis of Unsymmetrical Peroxides: Transition-Metal-Catalyzed Oxidation of Malononitrile and Cyanoacetic Ester Derivatives by tert-Butyl Hydroperoxide at the α-Position

Synthesis, May 5, 2011

ABSTRACT A novel method was developed for the selective oxidation of α-monosubstituted malononitr... more ABSTRACT A novel method was developed for the selective oxidation of α-monosubstituted malononitrile and cyanoacetic ester derivatives at the α-position based on transition-metal-catalyzed reaction (Cu, Fe, Mn, Co) with tert-butyl hydroperoxide giving unsymmetrical peroxides in 63-94% yields. The method is facile, does not require large excesses of reagents, and is amenable to gram-scale synthesis.

Research paper thumbnail of α-Alkyl Ketones by the Reaction of Trialkylboranes with α-Bromo Ketones

α-Alkyl Ketones by the Reaction of Trialkylboranes with α-Bromo Ketones

Boron Compounds, 2005

Research paper thumbnail of Synthesis of 5-(Dihydroxyboryl)uracil by Halogen–Metal Exchange

Synthesis of 5-(Dihydroxyboryl)uracil by Halogen–Metal Exchange

Research paper thumbnail of Addition of Thiols to Alkenylboranes

Addition of Thiols to Alkenylboranes

Boron Compounds, 2005

Research paper thumbnail of Addition of Halogens to Alkenylboranes and Alkenylboronates

Addition of Halogens to Alkenylboranes and Alkenylboronates

Boron Compounds, 2005

Research paper thumbnail of Diels–Alder Reaction of Alkenylboranes and Alkenylboronates

Diels–Alder Reaction of Alkenylboranes and Alkenylboronates

Boron Compounds, 2005

Research paper thumbnail of Addition of Hydrogen Halides to Vinylboronates

Addition of Hydrogen Halides to Vinylboronates

Boron Compounds, 2005

Research paper thumbnail of Boron Compounds

Research paper thumbnail of α-Halo-γ,γ,γ-trichloropropylborane Derivatives by Additions to Vinylboranes and Vinylboronates

α-Halo-γ,γ,γ-trichloropropylborane Derivatives by Additions to Vinylboranes and Vinylboronates

Boron Compounds, 2005

Research paper thumbnail of Metal-Exchange Reactions of Diazo Compounds

Metal-Exchange Reactions of Diazo Compounds

Boron Compounds, 2005

Research paper thumbnail of Synthesis of 1-Boraadamantane Derivatives via Hydroboration

Synthesis of 1-Boraadamantane Derivatives via Hydroboration

Boron Compounds, 2005

Research paper thumbnail of Thioboration of Ethoxyacetylene

Thioboration of Ethoxyacetylene

Boron Compounds, 2005

Research paper thumbnail of Comparative study of the endemic freshwater fauna of Lake Baikal—III. Phospholipid and fatty acid compositions of the amphipod crustacean of the genus Eulimnogammarus

Comparative biochemistry and physiology. B. Comparative biochemistry, Feb 1, 1994

Lipid and phospholipid compositions of an endemic deep-water freshwater gammarid, belonging to th... more Lipid and phospholipid compositions of an endemic deep-water freshwater gammarid, belonging to the subphylum Crustacea, Acanthogammarus grewingkii was studied. Content of aikenylacyl, alkylacyl and diacyi forms in the main phospholipid classes (phosphatidylethanolamine and phosphatydilcholine) were established using reaction micro-thin-layer chromatography. The fatty acids compositions of total lipids, neutral, glycoand phospholipid fractions were investigated by capillary gas chromatography-mass spectrometry. Seventy-nine fatty acids were identified: 26 saturated (iso-, anteiso-and cyclo-)

Research paper thumbnail of Comparative study of the endemic freshwater fauna of Lake Baikal—V. Phospholipid and fatty acid composition of the deep-water amphipod crustacean Acanthogammarus (Brachyuropus) grewingkii

Comparative biochemistry and physiology. B. Comparative biochemistry, Aug 1, 1994

Lipid and phospholipid compositions of an endemic deep-water freshwater gammarid, belonging to th... more Lipid and phospholipid compositions of an endemic deep-water freshwater gammarid, belonging to the subphylum Crustacea, Acanthogammarus grewingkii was studied. Content of aikenylacyl, alkylacyl and diacyi forms in the main phospholipid classes (phosphatidylethanolamine and phosphatydilcholine) were established using reaction micro-thin-layer chromatography. The fatty acids compositions of total lipids, neutral, glycoand phospholipid fractions were investigated by capillary gas chromatography-mass spectrometry. Seventy-nine fatty acids were identified: 26 saturated (iso-, anteiso-and cyclo-)

Research paper thumbnail of Comparative study of the endemic freshwater fauna of Lake Baikal—IV. Phospholipid and fatty acid compositions of two gastropod molluscs of the genus Valvata

Comparative biochemistry and physiology. B. Comparative biochemistry, Feb 1, 1994

Lipid and phospholipid compositions of an endemic deep-water freshwater gammarid, belonging to th... more Lipid and phospholipid compositions of an endemic deep-water freshwater gammarid, belonging to the subphylum Crustacea, Acanthogammarus grewingkii was studied. Content of aikenylacyl, alkylacyl and diacyi forms in the main phospholipid classes (phosphatidylethanolamine and phosphatydilcholine) were established using reaction micro-thin-layer chromatography. The fatty acids compositions of total lipids, neutral, glycoand phospholipid fractions were investigated by capillary gas chromatography-mass spectrometry. Seventy-nine fatty acids were identified: 26 saturated (iso-, anteiso-and cyclo-)

Research paper thumbnail of Comparative study of the endemic freshwater fauna of Lake Baikal-VII. Carotenoid composition of the deep-water amphipod crustaceanAcanthogammarus (Brachyuropus)grewingkii

Comparative study of the endemic freshwater fauna of Lake Baikal-VII. Carotenoid composition of the deep-water amphipod crustaceanAcanthogammarus (Brachyuropus)grewingkii

Comparative Biochemistry and Physiology B, Aug 1, 1996

Abstract The carotenoid composition of the deep-water gammaride is reported. Astaxanthin and thei... more Abstract The carotenoid composition of the deep-water gammaride is reported. Astaxanthin and their derivatives were determined to be major components of the carotenoids (58.4%). Astaxanthin-glycoside-esters comprised 21.6% of total carotenoids. A new carotenoid glycoside ester (CGE) was isolated from the deep-water gammarideAcanthogammarus (Brachyuropus)grewingkii and its structure was elucidated. The structures were determined from spectra (1H-NMR,13C-NMR, MS, IR) after their isolation and quantification by means of semipreparative RP-HPLC and capillary GC-MS.

Research paper thumbnail of Knowledge Updates 2020/2

Knowledge Updates 2020/2

Science of Synthesis

Research paper thumbnail of Fatty acid amides from freshwater green alga Rhizoclonium hieroglyphicum

Fatty acid amides from freshwater green alga Rhizoclonium hieroglyphicum

Phytochemistry, 2000

Freshwater green algae Rhizoclonium hieroglyphicum growing in the Ural Mountains were examined fo... more Freshwater green algae Rhizoclonium hieroglyphicum growing in the Ural Mountains were examined for their fatty acid amides using capillary gas chromatography-mass spectrometry (GC-MS). Eight fatty acid amides were identified by GC-MS. (Z)-9-octadecenamide was found to be the major component (2.26%).

Research paper thumbnail of Dicarboxylic and Fatty Acid Compositions of Cyanobacteria of the Genus Aphanizomenon

The occurrence of dioic, hydroxy, branched, and unsaturated fatty acids in cyanobacteria of the g... more The occurrence of dioic, hydroxy, branched, and unsaturated fatty acids in cyanobacteria of the genus Aphanizomenon growing in different freshwater lakes has been studied. Unusual dicarboxylic (from 4.52 to 7.14%) and other fatty acids were identified by gas chromatography/mass spectrometry (GC/MS).

Research paper thumbnail of Biological Activity and Structural Diversity of Steroids Containing Aromatic Rings, Phosphate Groups, or Halogen Atoms

Molecules

This review delves into the investigation of the biological activity and structural diversity of ... more This review delves into the investigation of the biological activity and structural diversity of steroids and related isoprenoid lipids. The study encompasses various natural compounds, such as steroids with aromatic ring(s), steroid phosphate esters derived from marine invertebrates, and steroids incorporating halogen atoms (I, Br, or Cl). These compounds are either produced by fungi or fungal endophytes or found in extracts of plants, algae, or marine invertebrates. To assess the biological activity of these natural compounds, an extensive examination of referenced literature sources was conducted. The evaluation encompassed in vivo and in vitro studies, as well as the utilization of the QSAR method. Numerous compounds exhibited notable properties such as strong anti-inflammatory, anti-neoplastic, anti-proliferative, anti-hypercholesterolemic, anti-Parkinsonian, diuretic, anti-eczematic, anti-psoriatic, and various other activities. Throughout the review, 3D graphs illustrating th...

Research paper thumbnail of Selective Synthesis of Unsymmetrical Peroxides: Transition-Metal-Catalyzed Oxidation of Malononitrile and Cyanoacetic Ester Derivatives by tert-Butyl Hydroperoxide at the α-Position

Selective Synthesis of Unsymmetrical Peroxides: Transition-Metal-Catalyzed Oxidation of Malononitrile and Cyanoacetic Ester Derivatives by tert-Butyl Hydroperoxide at the α-Position

Synthesis, May 5, 2011

ABSTRACT A novel method was developed for the selective oxidation of α-monosubstituted malononitr... more ABSTRACT A novel method was developed for the selective oxidation of α-monosubstituted malononitrile and cyanoacetic ester derivatives at the α-position based on transition-metal-catalyzed reaction (Cu, Fe, Mn, Co) with tert-butyl hydroperoxide giving unsymmetrical peroxides in 63-94% yields. The method is facile, does not require large excesses of reagents, and is amenable to gram-scale synthesis.

Research paper thumbnail of α-Alkyl Ketones by the Reaction of Trialkylboranes with α-Bromo Ketones

α-Alkyl Ketones by the Reaction of Trialkylboranes with α-Bromo Ketones

Boron Compounds, 2005

Research paper thumbnail of Synthesis of 5-(Dihydroxyboryl)uracil by Halogen–Metal Exchange

Synthesis of 5-(Dihydroxyboryl)uracil by Halogen–Metal Exchange

Research paper thumbnail of Addition of Thiols to Alkenylboranes

Addition of Thiols to Alkenylboranes

Boron Compounds, 2005

Research paper thumbnail of Addition of Halogens to Alkenylboranes and Alkenylboronates

Addition of Halogens to Alkenylboranes and Alkenylboronates

Boron Compounds, 2005

Research paper thumbnail of Diels–Alder Reaction of Alkenylboranes and Alkenylboronates

Diels–Alder Reaction of Alkenylboranes and Alkenylboronates

Boron Compounds, 2005

Research paper thumbnail of Addition of Hydrogen Halides to Vinylboronates

Addition of Hydrogen Halides to Vinylboronates

Boron Compounds, 2005

Research paper thumbnail of Boron Compounds

Research paper thumbnail of α-Halo-γ,γ,γ-trichloropropylborane Derivatives by Additions to Vinylboranes and Vinylboronates

α-Halo-γ,γ,γ-trichloropropylborane Derivatives by Additions to Vinylboranes and Vinylboronates

Boron Compounds, 2005

Research paper thumbnail of Metal-Exchange Reactions of Diazo Compounds

Metal-Exchange Reactions of Diazo Compounds

Boron Compounds, 2005

Research paper thumbnail of Synthesis of 1-Boraadamantane Derivatives via Hydroboration

Synthesis of 1-Boraadamantane Derivatives via Hydroboration

Boron Compounds, 2005

Research paper thumbnail of Thioboration of Ethoxyacetylene

Thioboration of Ethoxyacetylene

Boron Compounds, 2005

Research paper thumbnail of The evolutionary pathway to the biomembrane. The role of low molecular weight polyols in the formation of the protomembrane.

BOOK, 2023

The assumption that sea water is the cradle of the origin of primitive living organisms is beyond... more The assumption that sea water is the cradle of the origin of primitive living organisms is beyond doubt. No one
knows how this happened, but there are many assumptions, although the evidence base for all these assumptions
raises many questions. This book is an attempt to elucidate the origin of the protomembrane and its transformation
into a bilayer lipid membrane in an inanimate substance. Presumably, protomembranes consisting of fatty acids
and other amphiphiles were a simple type of membrane, but with the advent of polyols and, accordingly, complex
lipids, a new type of protomembranes appears. Perhaps this new type of protomembrane, consisting of complex
lipids, was the beginning of the emergence of the future biological membrane and all life on Earth. Coacervates
from the Oparin – Haldane hypothesis were used as a model to explain the formation of protomembranes. The
chemical model shows which polyols could spontaneously form in the primary broth, and the mathematical model
shows that ethylene glycol (40%), glycerol (33%), butane-1,2,3,4-tetraols (17%) account for 90% of all polyols
produced. This indicates the possible predominance of diol lipids in the primary primitive protomembranes. During
chemical evolution and with changes in temperature, pH, and environmental conditions, diol lipids were replaced
by glycerolipids, which have more suitable physicochemical characteristics for the formation of biological
membranes of all living organisms. The book presents polyols as part of complex lipids that are found in modern
biological membranes.