Spectroscopic characterization of environmentally relevant C10-chloroterpenes from a photochemically modified toxaphene standard

Twenty-five pure environmentally relevant toxaphene components have been isolated from photochemically modified technical toxaphene by means of a combination of column chromatography on silica gel and preparative high resolution liquid chromatography. These compounds are 6 chlorinated camphenes (1–3, 5, 7, and 11) and 19 chlorinated bornanes (4, 6, 8–10, 12–16, 18–24, 26, and 27 according to Table 1). Two further chlorobornanes (17 and 25) have been isolated from a highly chlorinated mixture obtained by the excess chlorination of 2-exo,10-dichlorobornane. The structural elucidation of the isolated compounds has been carried out with spectroscopical methods.     

Polybrominated diphenyl ether congeners and toxaphene in selected marine standard reference materials

Polybrominated diphenyl ether (PBDE) congeners and components of the complex mixture toxaphene are stable in the environment and readily bioaccumulated into wildlife and human tissues. PBDEs are presently used in large quantities worldwide as flame retardants in textiles, furniture, computer equipment, and cables. Toxaphene is a complex mixture of chlorinated bornanes and bornenes that was the most heavily used pesticide in the United States until it was banned in 1982; however, some countries continue to use toxaphene. The National Institute of Standards and Technology has quantified PBDE congeners and toxaphene in several available Standard Reference Materials (SRMs) using methods of gas chromatography with electron impact mass spectrometry (GC-EI-MS) and GC negative chemical ionization (NCI) MS, respectively. SRM 1588a Organics in Cod Liver Oil and SRM 1945 Organics in Whale Blubber were examined for PBDE congeners 47, 99, 100, 153, and 154, total toxaphene, and toxaphene congeners 26, 50, and 62. SRM 1946 Lake Superior Fish Tissue was also examined for total toxaphene and toxaphene congeners. The sum of the PBDE congeners (mean, (1 SD) wet basis) for SRM 1945 was 150 ng g^–1 (7 ng g^–1). The concentration of PBDE 47 in SRM 1588a was 82.7 ng g^–1 (2.8 ng g^–1). Other PBDEs were detected in SRM 1588a but were not quantified due their low levels. The total toxaphene (wet mass basis) was 1,210 ng g^–1 (127 ng g^–1), 1,960 ng g^–1 (133 ng g^–1), and 3,980 ng g^–1 (248 ng g^–1) in SRMs 1945, 1946, and 1588a, respectively. The values for PBDEs and toxaphene determined in the SRMs, while not certified, indicate that the SRMs will be suitable control materials for PBDE and toxaphene analyses.     

Preparation and structure of high-chlorinated bornane derivatives for the quantification of toxaphene residues in environmental samples

Summary The HRGC-determination of Taxophene® residues in the presence of other chlorinated hydrocarbons with similar retention times is often difficult. This problem can satisfactorily be overcome by using purely isolated high-chlorinated bornane derivatives (7–17) as standard. The method is highly selective for measuring toxaphene in complex environmental matrices, such as fish, and can also be used for evaluating the changes in the relative distribution that may have resulted from bioaccumulation and environmental transformation.Dedicated to Professor Dr. Wilhelm Fresenius on the occasion of his 80th birthday     

Congener specific determination of compounds of technical toxaphene (CTTs) in different antarctic seal species

Summary Gas chromatography and electron-capture, negative-ionization, mass spectrometry (GC-ECNI-MS) in combination with a non-polar stationary phase (CP-Sil 2) was applied to study the composition of residues of the multicomponent toxaphene mixture in seal blubber from the Antarctic. In samples of the five Antarctic seal species eleven compounds of technical toxaphene (CTTs) were detected and six of them quantified by application of single standard compounds. Five abundant CTTs in seal blubber were included in the “Parlar 22 components standard” (commercially available) and one further was isolated and quantified for the first time. Finally, high levels of toxaphene were determined in Weddell seals and crabeaters confirming that toxaphene is a major organochlorine pollutant in the Antarctic.     

Isolation and characterization of methoxylated flavones in the flowers of Primula veris by liquid chromatography and mass spectrometry

Characterization of six flavones, which were named substances G1, G2, G3, G4, G5 and G6 according to their R_F values in normal-phase thin-layer chromatography, is reported. The pure flavones were purified after maceration with methanol by normal-phase solid-phase extraction, normal-phase medium-pressure liquid chromatography, normal-phase preparative thin-layer chromatography and preparative reversed-phase high-performance liquid chromatography (RP-HPLC). The collected fractions of several isolation steps were analyzed by normal-phase (NP) and RP-HPLC. Detection and identification of the substances G was accomplished by UV detection at 213–216 nm, diode array UV detection, or fluorescence detection (λ_ex=330 nm; λ_em=440 nm). The molecular mass, the elementary composition, and the structure of the six components was determined by electron-impact high-resolution mass spectrometry (EI-HRMS). Substance G4 was identified as 3′,4′,5′-trimethoxyflavone. The substances G1–G6 were shown to be mono-, di- tri- and pentamethoxyflavones. HPLC–electrospray ionization tandem mass spectrometry (ESI-MS–MS) of the flavones was carried out employing a 150×2 mm I.D. column packed with a 3 μm/100 Å octadecylsilica stationary phase and a mobile phase comprising 1.0% acetic acid in water–acetonitrile (50:50). Comparative RP-HPLC–ESI-MS of the raw methanol extract and the isolated substances G1–G6 proved that the isolated compounds were pure and were not artifacts. Finally, RP-HPLC–ESI-MS–MS was used to identify substances G1–G6 in phytopharmaceutical drugs.     

Analysis of Toxaphene

Abstract

Toxaphene, a widely and chlorinated hydrocarbon insecticide produced by chlorination of camphene, consists of a poorly defined mixture of at least 180–190 substances. Most of these conform the formulars C₁₀H₁₈-_nCl_n and C₁₀H₁₆-_nCl_n, where n is 6–10. Although the chromatographic behaviour of the toxaphene components is extremely similar, seven components have been isolated up to now, six of which are hepta- to decachlor derivatives of bornane. In the following work, isolation and identification of these compounds with the help of spectroscopical methods are described and their behaviour under biotic and abiotic conditions are studied. The experiments shown, that toxaphene is slowly to rapidly degraded in various environmental systems.     

Analysis of nitrosamines in water by automated SPE and isotope dilution GC/HRMS Occurrence in the different steps of a drinking water treatment plant, and in chlorinated samples from a reservoir and a sewage treatment plant effluent

A method based on automated solid-phase extraction (SPE) and isotope dilution gas chromatography/high resolution mass spectrometry (GC/HRMS) has been developed for the analysis of nine nitrosamines in water samples. The combination of automated SPE and GC/HRMS for the analysis of nitrosamines has not been reported previously. The method shows as advantages the selectivity and sensitivity of GC/HRMS analysis and the high efficiency of automated SPE with coconut charcoal EPA 521 cartridges. Low method detection limits (MDLs) were achieved, along with a greater facility of the procedure and less dependance on the operator with regard to the methods based on manual SPE. Quality requirements for isotope dilution-based methods were accomplished for most analysed nitrosamines, regarding to trueness (80–120%), method precision (<15%) and MDLs (0.08–1.7 ng/L).Nineteen water samples (16 samples from a drinking water treatment plant {DWTP}, 2 chlorinated samples from a sewage treatment plant {STP} effluent, and 1 chlorinated sample from a reservoir) were analysed. Concentrations of nitrosamines in the STP effluent were 309.4 and 730.2 ng/L, being higher when higher doses of chlorine were applied. N-Nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) were the main compounds identified in the STP effluent, and NDEA was detected above 200 ng/L, regulatory level for NDMA in effluents stated in Ontario (Canada). Lower concentrations of nitrosamines were found in the reservoir (20.3 ng/L) and in the DWTP samples (n.d. −28.6 ng/L). NDMA and NDEA were respectively found in the reservoir and in treated and highly chlorinated DWTP samples at concentrations above 10 ng/L (guide value established in different countries). The highest concentrations of nitrosamines were found after chlorination and ozonation processes (ozonated, treated and highly chlorinated water) in DWTP samples.     

A fiber optic evanescent field absorption sensor for monitoring organic contaminants in water

Summary A fiber optic chemical sensor for determination of organic compounds in aqueous solution has been developed. Based on the evanescent field principle, a quartz glass fiber with a polysiloxane cladding is used as in-situ measuring probe. A compact sensor built from a 6-m coiled fiber has been connected to a commercially available fast scanning dispersive NIR spectrometer. The siloxane cladding fulfils two functions: on the one hand, it acts as protecting layer of the fragile silica fiber core, and on the other hand, it is selective with respect to non-polar organic compounds due to its organophilic properties. Hence, interactions of the evanescent field at the core/cladding interface with organic species penetrating into the cladding can be measured without interferences from broad water OH absorption bands. Aqueous solutions of chlorinated hydrocarbon solvents (CHS) have been used to test the sensor response. NIR evanescent field absorbance spectra of methylene chloride, chloroform and trichloroethylene diffused into the fiber cladding are shown in the 900–2100 nm spectral range. Different amounts of CHCl₃ dissolved in water have been determined in order to evaluate the quantitative sensor response. A linear absorbance/concentration relationship has been found for solutions between 80–6800 mg l^–1. Kinetic experiments performed with CHCl₃ solutions resulted in sensor response times of 5–10 min. The sensor seems to be promising for the remote monitoring of organic contaminants, e.g. CHS, in drainage waters of contaminated areas.     

New sesquiterpenoids from the oleoresin of Abies alba

The structures of four new sesquiterpenoids from the oleoresin ofAbies alba have been studied. On the basis of various spectral characteristics, the structures of (10S, 11S)-himachala-2,4-diene, (10S, 11S)-himachala-3(12), 4-diene, humula-4,9-dien-8-ol, and (4S, 5S, 10S)-selina-6-en-4-ol have been proposed for the compounds isolated. The stereochemistry of the asymmetric centers was determined by the conversion of these compounds into known sesquiterpenes and also by analysis of PMR spectra with a shift reagent.Novosibirsk Institute of Organic Chemistry, Siberian Branch, USSR Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 712–718, September–October, 1988.     

Supported liquid membrane work-up in combination with liquid chromatography and electrochemical detection for the determination of chlorinated phenols in natural water samples

Summary A sample preparation method has been developed for the determination of chlorinated phenols in water. The method is based on a supported liquid membrane extraction system connected on-line to liquid chromatography with electrochemical detection. The supported liquid membrane technique utilizes a porous PTFE membrane. The membrane is impregnated with an organic solvent which forms a barrier between two aqueous phases and enables selective extraction. The technique can easily be coupled in a flow system. In this investigation five chlorinated phenols (1–5 chlorine atoms) were extracted from natural water samples. Extraction for 30 minutes resulted in detection limits of approximately 25 ng L^–1.     

Lipolytic enzymes of cotton seeds V. Triacetinase

Summary A triacetinase has been isolated from cotton seeds by the methods of gel filtration and ion-exchange chromatography. The homogeneity of the enzyme was shown by rechromatography, electrophoresis, ultracentrifugation, and a determination of the terminal amino acid. The molecular weight of the triacetinase obtained by four different methods (column gel filtration, thin-layer chromatography, ultracentrifugation, and amino-acid composition) is 18,000±1200. The amino-acid composition and the N-terminal amino-acid residue — methionine — have determined.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 767–770, November–December, 1974.     

An investigation by gas liquid chromatography into the composition of the essential oils of some Siberian conifers

Summary Eighteen monoterpene hydrocarbons have been isolated from the essential oils of Siberian species of cedar, larch, and fir. Fourteen components have been identified by gas-liquid chromatography.Khimiya Prirodnykh Soedinenii, Vol. 1, No. 6, pp. 382–384, 1965.     

Berberis alkaloids. XXXVII. Investigation of the alkaloids ofB. oblongata andB. integerrima. Crystal structure of 8-trichloromethyldihydroberberine

Two species of Berberis have yielded 10 isoquinoline alkaloids. In addition to known bases, two artifacts have been isolated — 8-trichloromethyldihydroberberine (I) and 8-trichloromethyldihydropalmatine. An x-ray structural analysis has been made of (1).Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 889–893, November–December, 1996. Original article submitted April 15, 1996.     

Cembrenolides of a soft coral Lobophytum sp. (coelenterata, octocorallia, alcyonacea)

The known cembrenolide sarcophin and its new acetoxy derivative — 13-acetoxy-7,8-epoxycembra-1(15),3,11-trien-2,16-olide — have been isolated from the soft coralLobophytum sp.. The compounds isolated are inhibitors of the activity of Na⁺K⁺-ATPase and are membranotropic agents. The structures of the compounds have been shown on the basis of the results of NMR spectroscopy.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 762–765, November–December, 1990.     

New Carbonic Anhydrase-II Inhibitors from Marine Macro Brown Alga Dictyopteris hoytii Supported by In Silico Studies

In continuation of phytochemical investigations of the methanolic extract of Dictyopteris hoytii, we have obtained twelve compounds (1–12) through column chromatography. Herein, three compounds, namely, dimethyl 2-bromoterepthalate (3), dimethyl 2,6-dibromoterepthalate (4), and (E)-3-(4-(dimethoxymethyl)phenyl) acrylic acid (5) are isolated for the first time as a natural product, while the rest of the compounds (1, 2, 6–12) are known and isolated for the first time from this source. The structures of the isolated compounds were elucidated by advanced spectroscopic 1D and 2D NMR techniques including ¹H, ¹³C, DEPT, HSQC, HMBC, COSY, NEOSY, and HR-MS and comparison with the reported literature. Furthermore, eight compounds (13–20) previously isolated by our group from the same source along with the currently isolated compounds (1–12) were screened against the CA-II enzyme. All compounds, except 6, 8, 14, and 17, were evaluated for in vitro bovine carbonic anhydrase-II (CA-II) inhibitory activity. Eventually, eleven compounds (1, 4, 5, 7, 9, 10, 12, 13, 15, 18, and 19) exhibited significant inhibitory activity against CA-II with IC₅₀ values ranging from 13.4 to 71.6 μM. Additionally, the active molecules were subjected to molecular docking studies to predict the binding behavior of those compounds. It was observed that the compounds exhibit the inhibitory potential by specifically interacting with the ZN ion present in the active site of CA-II. In addition to ZN ion, two residues (His94 and Thr199) play an important role in binding with the compounds that possess a carboxylate group in their structure.     

Preparation and testing for homogeneity of spiked strawberry and cabbage candidate reference materials

Strawberry and cabbage candidate reference materials (RMs) have been prepared by our laboratory during 1992–1993. Fresh materials have been homogenized and spiked with known concentrations of pesticides representing compounds commonly used for strawberries and cabbages. The candidate RMs have been then freeze-dried, homogenized, bottled under a stream of nitrogen and stored frozen at –20°C. Homogeneity and stability of the candidate RMs have been studied during the storage period. Homogeneity of the candidate RMs for 5 g samples has been within 10%. Homogeneity and stability studies have been carried out using the conventional multiresidue method of Luke et al. [1]. Instrumental analysis have been performed by gas chromatography mass spectrometry (GC-MS) employing selected ion monitoring (SIM).     

The polybuffer separation of the alkaloids of Vinca erecta

Summary By separating the total alkaloids ofV.erecta according to their basicities in an APS, in addition to bases known previously we have isolated ervincidine, apovincamine, (+)-quebrachamine, dl-eburnamine, (–)-1,2-dehydroaspidospermidine, and kopsanone. This is the first time that these alkaloids have been obtained from this plant. Thin-layer chromatography showed the presence of another 10–12 uncharacterized alkaloids.The region of the passage into the buffer solutions of some alkaloids has also been established.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 713–717, November–December, 1970.     

Purification of nerve growth factor from the venom of the Central Asian cobraNaja oxiana

A highly purified electrophoreticaly homogeneous protein with a NGF activity of 10·10⁵ BU/mg of protein have been isolated from the venom of the Central Asian cobra by gel-filtration and ion-exchange chromatography followed by preparative isolectric focusing in a thin layer of Sephadex. It has been shown that the NGF isolated is characterized by a molecular weight in the range of 20–30 kD and a pI value of about 7.0.Institute of Biochemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii. No. 4, pp. 546–551, July–August, 1985.     

Determination of fat-soluble chlorinated compounds in fish

Summary The level of chlorinated non-polar compounds in samples of sprat (Clupea sprattus) has been determined. The total amounts of chlorine, bromine and iodine in the lipid phase were determined by neutron activation analysis prior to and after treatment of the lipid phase with concentrated sulfuric acid. In sprat samples from a contaminated area the following chlorinated hydrocarbons have been identified and quantified by means of gas chromatography and mass spectrometry: pentachlorobenzene, hexachlorobenzene, heptachlorostyrene and octachlorostyrene. In addition, the following compounds have been detected by gas chromatography using standards: dichlorobenzene, trichlorobenzene, tetrachlorobenzene and polychlorinated biphenyls. A gradual reduction of the level of individual components and total level of chemically persistent chlorinated hydrocarbons in the samples is observed with increasing distance from the source of contamination (Frierfjorden). The same tendency is not seen for the PCB. It has been found that highly chlorinated compounds are distinctly enriched in the sprat oil relative to compounds with lower contents of chlorine.

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Bestimmung von fettlöslichen chlorierten Verbindungen in Fisch

Zusammenfassung Chlorierte unpolare Verbindungen wurden in Fischproben (Sprotten, Clupea sprattus) bestimmt. Der Gesamtgehalt an Chlor, Brom und Jod in der Fettphase wurde vor und nach deren Behandlung mit konz. Schwefelsäure mit Hilfe der Neutronenaktivierungsanalyse erfaßt. In Proben aus einem kontaminierten Gebiet wurden folgende Verbindungen durch Gas-Chromatographie/ Massenspektrometrie identifiziert und quantitativ bestimmt: Pentachlorbenzol, Hexachlorbenzol, Heptachlorstyrol und Octachlorstyrol. Zusätzlich wurden die folgenden Verbindungen durch GC mit Hilfe von Standards erfaßt: Dichlorbenzol, Trichlorbenzol, Tetrachlorbenzol, polychlorierte Biphenyle. Eine allmähliche Abnahme des Gehaltes an einzelnen Verbindungen sowie des Gesamtgehaltes an beständigen chlorierten Kohlenwasserstoffen wurde mit zunehmender Entfernung vom Ursprung der Verschmutzung (Frierfjorden) beobachtet. Dies konnte jedoch im Falle von PCBs nicht festgestellt werden. Hochchlorierte Verbindungen werden im Sprottenöl im Gegensatz zu solchen mit niederen Chlorgehalten deutlich angereichert.

Presented at the 6th Annual Symposium on Recent Advances in the Analytical Chemistry of Pollutants, April 21–23, 1976; Vienna, Austria.     

Synthesis of tritium-labeled components of nucleic acids of the hypoxanthine series

The synthesis of [8-³H] and [2,8-³H]hypoxanthine, inosine, inosine 5-mono-, -di-and -triphosphates, and also of 2-deoxy[2,2-8-³H]inosine from the corresponding labeled compounds of the adenine series with the aid of the de-amination reaction is described. De-amination was carried out with sodium nitrite in the presence of acetic acid. In the case of bases and nucleosides, the separation of the reaction mixtures with simultaneous desalting of the final products was achieved by column chromatography on Sephadex G-10 or SE C-25 with elution by water. For nucleotides, the isolation process included chromatography on DEAE-Sephadex A-25 (HCOO^– or Cl^–) and Dowex 1×8 (Cl^–) followed by desalting with the aid of reprecipitation or adsorption on Carboraffin activated carbon. The molar radioactivities of the compounds synthesized amounted to 370–2220 TBq/mole (10–60 kCi/mole) and corresponded to the molar radioactivities of the initial compounds of the adenine series.V. G. Khlopin Radium Institute, Leningrad. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 128–131, January–February, 1987.