Showing papers by "Valery M. Dembitsky published in 2003"
TL;DR: Biological systems have evolved haloperoxidase (HaloPO) enzymes to catalyze the oxidation of chloride, bromide and iodide by hydrogenperoxide by hydrogen peroxide.
152 citations
TL;DR: This review focuses primarily on the presence and distribution of organoarsenic compounds in vascular plants, marine and freshwater algal species, lichens, fungi, and microorganisms.
148 citations
74 citations
TL;DR: A review of the use of partly geminated boranes (BCB), and also bisdiborane reagents (BCCB, BCCB, and BCCB) can be found in this paper.
Abstract: An overview of the development of new strategies in organic synthesis with a minimum of chemical steps is becoming increasingly necessary for the efficient assembly of complex molecular structures Therefore, the combination of multiple reactions in a single operation represents a particularly efficient approach Among these strategies, the synthesis and reactivity of bisdiboranes has never been reviewed although its popularity for the synthesis of complex architectural molecules has been steadily increasing during the last decade This review is intended to highlight the use of partly geminated boranes (BCB), and also bisdiborane reagents (BCCB, BCCB, BCCB) Copyright © 2003 John Wiley & Sons, Ltd
63 citations
TL;DR: The structures, biogenesis, synthesis and bioactivity of some lipid compounds of freshwater sponge species are reviewed.
59 citations
TL;DR: Hydroxy,n-saturated, branched, dioic, and unsaturated fatty acids in six freshwater wild cyanobacteria collected from different lakes and springs of Israel have been identified by gas chromatography-mass spectrometry (GC-MS).
Abstract: Hydroxy, n-saturated, branched, dioic, and unsaturated fatty acids in six freshwater wild cyanobacteria (Chroococcus minutus, Lyngbya ceylanica, Merismopedia glauca, Nodularia sphaerocarpa, Nostoc linckia, and Synechococcus aeruginosus) collected from different lakes and springs of Israel have been identified by gas chromatography-mass spectrometry (GC-MS).
53 citations
TL;DR: Analysis of fatty acids by gas chromatography-mass spectrometry using serially coupled capillary columns with different polarity of stationary phases is reported, finding large variations in individual fatty acid contents according to species, season and location of the genus Codium.
34 citations
TL;DR: Nonphosphorus betaine-containing lipid,viz.
Abstract: The occurrence of n-saturated, branched, and unsaturated fatty acids of 3 wild terrestrial strains of the genus Chroococcidiopsis (Order Chroococcales): C. supralittoralis, C. umbratilis, and C. ver- satilis collected from Lake Kinneret, Dead Sea, and Ein Kerem (Jerusalem) was investigated and individual compounds identified by gas chromatography-mass spectrometry. Polar lipids also were examined. Among polar lipids (studied using two-dimensional thin-layer chromatography) were as major glycolipids isolated: monogalactosyl-diacylglycerols, digalactosyl-diacylglycerols, 6-sulfoquinovosyl-diacylglycerols and phos- phatidylglycerol. Nonphosphorus betaine-containing lipid, viz. N,N,N-trimethylhomoserin-4-O-yl-diacylgly- cerol, was found for the first time in cyanobacterial species.
33 citations
TL;DR: Two new compounds isolated from an extract of a Central Asian lichen are glucosides with mono- and di-prenylated xanthones as the aglycones and a saccharide moiety from two glucoses linked at C-7.
33 citations
TL;DR: A new method of synthesis of 3-amino-1-alkenylphosphonates is described, which involves the addition of imines to the alkynylPhosphonate titanium(II) complexes 2, which are prepared in situ from 1-alkynylph phosphonates and Ti(O-i-Pr)(4)/2 equiv of i-PrMgCl.
31 citations
TL;DR: The occurrence of different amounts of n-alkanes and fatty acids in the photobiont and mycobionts of X. parietina was shown for the first time and dehydroabietic acid was found in both lichen and myCobionT.
Abstract: Surface alkanes and fatty acids from the thalli of the lichen Xanthoria parietina, its photobiont Trebouxia sp., and its mycobiont were analysed by GC-MS. The green alga Trebouxia sp. synthesized mainly unsaturated fatty acids such as (Z,Z,Z)-9,12,15-18 : 3 (Z,Z)-9,12-18 : 2 and (Z)-9-18 : 1, and light alkanes C8-C15 (up to 83% of total n-alkanes). However, the mycobiont contained mainly saturated fatty acids such as hexadecanoic (16 : 0) and octadecanoic acid (18 : 0), and also very long-chain n-alkanes C22–C34. Dehydroabietic acid was found in both lichen and mycobiont. The occurrence of different amounts of n-alkanes and fatty acids in the photobionts and mycobionts of X. parietina was shown for the first time. Lichens collected from different locations in the Jerusalem hills contained n-alkanes ranging in concentration from 187 to 211 mg·(g dry wt)−1; n-alkane concentrations in the photobiont and mycobiont were 17–24 and 215–262 mg·(g dry wt)−1, respectively.
TL;DR: Chagosensine, a sixteen-membered chlorinated macrolide, was isolated from the Red Sea calcareous sponge Leucettachagosensis and its structure was elucidated mainly on the basis of NMR spectroscopic data.
TL;DR: In this paper, eight new brominated oxylipins 1−8, including two glycosides, were isolated from the Red Sea invertebrates Dendrophyllia sp., Dendronephthya sp. and Tubipora musica.
TL;DR: The xanthoside composition of the crude extract of Umbilicaria proboscidea (L.) Schrader was characterized using LC-UV diode array detection and LC-atmospheric pressure chemical ionization (APCI) MS methods and the effect of different ionization energy on fragmentation was studied using APCI.
TL;DR: A new trinorsesterterpene glycoside was isolated from the ethanol extract of the American fern Woodwardia virginica having a 3-hydroxypropionic acid moiety as the aglycone and a saccharide moiety linked at C-4 to glucoses, xylose or arabinofuranose.
TL;DR: In this article, two novel glycosides, latrunculinosides A and B, containing substituted 2-oxecanones (decalactones) were isolated from Latrunculia corticata collected in the Gulf of Aqaba, Israel.
TL;DR: Thirteen unsaturated sterols were identified by gas chromatography-mass spectrometry using serially-coupled capillary columns from the filamentous nitrogen-fixing terrestrial cyanobacteriumScytonema sp.
Abstract: Thirteen unsaturated sterols were identified by gas chromatography-mass spectrometry using serially-coupled capillary columns from the filamentous nitrogen-fixing terrestrial cyanobacteriumScytonema sp. isolated from the microbial community of cyanobacterial on ‘Black Cover’ biofilms lime-stone walls in Jerusalem. The dominant sterols were cholest-5-en-3β-ol (18.9 %), 3β-methoxycholest-5-ene (16.2 %) and 3β-acetoxycholest-5-ene (11.2 %).
01 Jan 2003
TL;DR: Structures of more than 230 natural halogenated (chlorine-, bromine- and iodine-containing) alkaloids isolated from cyanobacteria, plants, fungi, sea algae and invertebrates, and data on their biological activity are presented.
Abstract: Structures of more than 230 natural halogenated (chlorine-, bromine- and iodine-containing) alkaloids isolated from cyanobacteria, plants, fungi, sea algae and invertebrates, and data on their biological activity are presented.
TL;DR: New glycosides having multisubstituted cyclohex-2-enones as aglycones and saccharide moieties consisting of three and four glucoses, respectively were isolated from the ethanol extract of the American fern Woodwardia virginica.
01 Jan 2003
TL;DR: In this paper, the structures of a hundred compounds of phenol, quinones and cyclitol types, their metabolism and data on their biological activity are considered in a review.
Abstract: Mononuclear halogenated simple phenol compounds and their derivatives formed from mono- and polyhydroxybenzenes are represented in nature by metabolites of insects, fungi, plants and microorganisms living on land and in water. The structures of a hundred compounds of phenol, quinones and cyclitol types, their metabolism and data on their biological activity are considered in the review.
01 Jan 2003
TL;DR: Halogenated non-terpenic C15-acetogenins of sea organisms make up a large group of natural compounds and data on their biological activity are presented.
Abstract: Halogenated non-terpenic C15-acetogenins of sea organisms make up a large group of natural compounds. Structures of more than 130 compounds are considered and data on their biological activity are presented.
01 Jan 2003
TL;DR: In this article, simple halogenated alkanes and their derivatives comprise a relatively large group of natural compounds which were discovered in cyanobacteria, algae, phytoplankton, fungi and plants.
Abstract: Simple halogenated alkanes and their derivatives comprise relatively large group of natural compounds which were discovered in cyanobacteria, algae, phytoplankton, fungi and plants. The structures of more than 100 compounds are considered.
01 Jan 2003
TL;DR: In this paper, a review is dedicated to a group of natural compounds of a new type - halogenated polyacetylenides. But these compounds are synthesized mainly by plants and by some sea organisms.
Abstract: The review is dedicated to a group of natural compounds of a new type – halogenated polyacetylenides. These compounds are synthesized mainly by plants and by some sea organisms. Structures of 71 compounds are considered. Data on the biological activity of some of their representatives are discussed.
01 Jan 2003
TL;DR: In this paper, the structures of about 86 compounds are considered and the data on their biological activity are described, including halogenated macrolides, tetracyclines and quinones.
Abstract: Natural halogenated macrolides, tetracyclines and quinones comprise three small groups of natural antibiotics which were isolated from microorganisms, plants, fungi and marine organisms. The structures of about 86 compounds are considered and the data on their biological activity are described.
01 Jan 2003
TL;DR: In this article, natural halogenated furanones, higher terpenes and steroids comprising three relatively small groups of natural compounds were isolated mainly from sea organisms, as well as from some plant species.
Abstract: Natural halogenated furanones, higher terpenes and steroids comprising three relatively small groups of natural compounds were isolated mainly from sea organisms, as well as from some plant species. The structures of about 90 compounds are considered and the data on the biological activity of some of them are presented. Contents