Identification, quantification, and synthesis of a novel dimethoxylated polybrominated biphenyl in marine mammals caught off the coast of Japan

Bioaccumulation of persistent organic compounds can eventually lead to concentrations in wildlife and humans that are deleterious to health. The present paper documents the identification, quantification, and synthesis of a novel compound, 2,2'-dimethoxy-3,3',5,5'-tetrabromobiphenyl (2,2'-diMeO-BB80), present in the marine mammals Striped dolphin (Stenella coeruleoalba), Bottlenose dolphin (Tursiops truncatus), Minke whale (Balaenoptera acutorostrata), and Baird's beaked whale (Berardius bairdii) caught in the Pacific Ocean. Identification was based on comparison of the relative retention times of the compound on two gas chromatographic columns of different polarities to those of an authentic standard. Furthermore, this identification was also supported by comparison of the full scan mass spectrometric data collected employing electron ionization (El), positive ion chemical ionization (PICI), and electron capture negative ionization (ECNI). The concentrations of 2,2'-diMeO-BB80 in the samples ranged from 12 to 800 ng/g lipid, making this consistently one of the most abundant compounds among those analyzed, including polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD), and methoxylated PBDEs. The known occurrence of 3,3',5,5'-tetrabromo-2,2'-biphenyldiol (2,2'-diOH-BB80) in the marine environment as a natural product suggests that its methylated derivative, 2,2'-diMeO-BB80, is also of natural origin. To obtain the necessary authentic standards, synthesis was performed of 2,2'-diMeO-BB80 and the known natural product 2',6-dimethoxy-2,3',4,5'-tetrabromodiphenyl ether (2',6-diMeO-BDE68).     

Concentrations of polybrominated diphenyl ethers, polychlonnated biphenyls, and polychlorobiphenylols in serum from pregnant Faroese women and their children 7 years later

The objective of this study was to assess blood concentrations of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs), and their polychlorobiphenylol (OH-PCB) metabolites in humans with a high seafood intake. Samples were obtained from pregnant women in the Faroe Islands in 1994-1995 and from their children at 7 years of age to examine maternal transfer of the compounds to their child, age-dependent metabolism, and temporal changes. Maternal serum was dominated by 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), while 2,2',4,4',5,5'-hexabromodiphenyl ether (BDE-153) prevailed in the children's serum seven years later. DecaBDE was present in both mothers and children up to 3 and 6 ng/g lipid weight, respectively. The sigmaPCB concentration in the children averaged about 60% of the concentrations in their mothers, with median levels for both above 1 microg/g lipid weight and .with similar PCB congener patterns. sigmaOH-PCB serum concentrations from the mothers and their children showed ranges of 1.8-36 ng/g wet weight (ww) and 0.49-22 ng/g ww, respectively, with all OH-PCB congener concentrations being lower in the children, except for 2,3,3',4',5-pentachloro-4-biphenylol (4-OH-CB107). Children at 7 years of age are exposed to PCBs at levels only slightly below those of their mothers, and the increased 4-OH-CB107 concentrations in children could be due to age-related differences in PCB metabolism. The PBDE concentrations were similar in both mothers and their children. The main persistent organic pollutant concentrations in the children are most probably due to other environmental exposure than maternal transfer.     

Synthesis of octabrominated diphenyl ethers from aminodiphenyl ethers

Polybrominated diphenyl ethers (PBDEs) are additive brominated flame retardants (BFRs), which have become widespread pollutants in abiotic and biotic environments including man. Tetra- to hexaBDEs and decaBDE are the most common environmental PBDE contaminants. Congeners of octabromodiphenyl ethers (octaBDEs) originate from used industrial OctaBDE mixtures and from transformation products of the high-volume industrial BFR mixture "DecaBDE", which most exclusively consists of perbrominated diphenyl ether (BDE-209). The objective of the present work was to develop methods for the synthesis of authentic octaBDE congeners in order to make them available as standards for analytical, toxicological, and stability studies, as well as studies concerning physical-chemical properties. The syntheses of six octaBDEs, 2,2',3,3',4,4',5,5'-octabromodiphenyl ether (BDE-194), 2,2',3,3',4,4',5,6'-octabromodiphenyl ether (BDE-196), 2,2',3,3',4,5,5',6-octabromodiphenyl ether (BDE-198), 2,2',3,3',4,5',6,6'-octabromodiphenyl ether (BDE-201), 2,2',3,3',5,5',6,6'-octabromodiphenyl ether (BDE-202), and 2,2',3,4,4',5,6,6'-octabromdipheny ether (BDE-204), are described, of which BDE-204 was prepared via two different pathways. Syntheses of BDE-198, BDE-201, BDE-202, and BDE-204 are based on octabromination of mono- or diaminodiphenyl ethers followed by diazotization and reduction of the amino group(s). BDE-194 and BDE-196 were prepared by bromination of 3,3',4,4',5,5'-hexabromodiphenyl ether (BDE-169) and 2,3,3',4,4',5',6-heptabromodiphenyl ether (BDE-191), respectively, and BDE-169 and BDE-191 were prepared from 4,4'-diaminodiphenyl ether and 3,4'-diamiodiphenyl ether, respectively. The synthesized PBDE congeners are described by 1H NMR, 13C NMR, electron ionization mass spectra, and their melting points.     

Radiocarbon evidence for a naturally produced, bioaccumulating halogenated organic compound

Halogenated organic compounds (HOCs) such as 1,1'-dimethyl-3,3',4,4'-tetrabromo-5,5'-dichloro-2,2'-bipyrrole (DBP-Br4Cl2) and heptachloro-1'-methyl-1,2'-bipyrrole (Q1) have been detected worldwide, sometimes at high levels in Antarctic air, seabird eggs, the blubber of marine mammals, and, most notably, even human milk. To date, it has been difficult to determine whether these compounds are natural products or derived from industrial synthesis. Molecular-level 14C analysis of these compounds is particularly appealing because most industrial compounds are manufactured from petrochemicals (14C-free) and natural compounds should have "modern" or "contemporary" 14C levels. To investigate the source of DBP-Br4Cl2, we isolated 600 microg of this compound (150 microg of carbon) from marine animal extracts by employing gel permeation chromatography, Florisil column chromatography, and two-dimensional preparative capillary gas chromatography. The purified DBP-Br4Cl2 was split into two samples (75 microg of carbon each) and analyzed by accelerator mass spectrometry for 14C content. The delta14C values were -449 percent per thousand and -467 percent per thousand, corresponding to conventional 14C ages of 4740 and 5000 years before present (BP), respectively. The presence of detectable 14C in the DBP-Br4Cl2 strongly points to at least a natural or biogenic source. However, these delta14C values for DBP-Br4Cl2 are more depleted than expected for a recently synthesized natural product. Several explanations are discussed, but additional samples     

The epigenetic toxicity of pyrene and related ozonation byproducts containing an aldehyde functional group

Gap junction intercellular communication (GJIC) was used to assess the epigenetic toxicity of pyrene, pure byproducts of pyrene ozonation, and other compounds similar in chemical structure. Byproduct mixtures collected from HPLC were also evaluated using GJIC. Of the 11 pure compounds studied, five inhibited GJIC completely. Two inhibiting compounds contained four rings and were the only compounds studied with greater than three rings. The remaining three compounds contained either two or three rings, and all three contained an aldehyde group. Toxicological evaluation and GC/MS of impure byproduct mixtures showed that two common compounds were found in inhibiting fractions. These common compounds contained both a bay region and at least one aldehyde group.     

Polybrominated diphenyl ethers and polychlorinated biphenyls in human adipose tissue from New York

Human adipose tissue samples (n=52) collected in New York City during 2003-2004 were analyzed for the presence of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs). Concentrations of PBDEs in adipose tissues ranged from 17 to 9630 ng/g, lipid wt (median: 77; mean: 399 ng/g, lipid wt; sum all di- through hexaBDE congeners). Average PBDE concentrations in human adipose tissues from New York City were 10- to 100-times greater than those reported for European countries. A concentration of 9630 ng/g, lipid wt, found in a sample of adipose tissue, is one of the highest concentrations reported to date. PBDE 47 (2,2',4,4'-tetraBDE) was the major congener detected in human tissues, followed by PBDE congeners #99 (2,2',4,4',5-penta BDE), 100 (2,2',4,4',6-pentaBDE), and 153 (2,2',4,4',5,5'-hexaBDE). A few individuals contained PBDE 153 as the predominant congener in total PBDE concentrations, suggesting alternative exposure sources, possibly occupational. Principal component analysis of PBDE congener composition in human adipose tissues revealed the presence of five clusters, each characterized by varying composition. No significant difference was found in the concentrations of PBDEs between gender. Concentrations of PBDEs were, on average, similar to those for PCBs in human adipose tissues, and substantially higher when PBDE outliers were retained. PBDE and PCB concentrations were not correlated. PBDE concentrations did not increase with increasing age of the subjects, whereas concentrations of PCBs increased with increasing age in males but not in females in this study. These results suggest differences between PBDEs and PCBs in their sources or time course of exposure and disposition. The presence of comparable or greater concentrations of PBDEs, relative to PCBs, highlights the importance of recentvoluntary and regulatory effortsto cease production of commercial penta- and octa-BDE in North America, although these efforts do not address continuing emissions from existing sources, such as polyurethane foams.     

Ozonation of chrysene: evaluation of byproduct mixtures and identification of toxic constituent

The effects of chrysene and the ozonated byproducts on in vitro gap junctional intercellular communication (GJIC) were evaluated using the scrape loading/dye transfer (SL/DT) technique. A 1 mM solution of chrysene was ozonated at dosages of 1.75, 3, 4.25, and 5 mol O3/mol chrysene (Chr). The early ozonation mixture, 1.75 mol O3/mol Chr, exhibited greater inhibition to GJIC than chrysene and irreversible damage to cells leading to cell death. To determine the compounds potentially responsible for the increase in toxicity, the byproducts formed upon treatment with 1.44 mol O3/mol Chr were separated into 14 fractions using RP-HPLC. The major compounds identified in the fractions were 2-(2'-formyl) phenyl-1-naphthaldehyde, 2-(2'formyl) phenyl-1-naphthoic acid, and 2-2-carboxyphenyl-1-naphthoic acid. 2-(2'-Formyl) phenyl-1-naphthaldehyde was determined to be the compound causing GJIC inhibition in sample fractions and byproduct mixtures.     

Organochlorine pesticides and polychlorinated biphenyls in 12 edible marine organisms from the Adriatic Sea, Italy, Spring 1997.

Edible portions of 12 marine organisms from several areas of the Adriatic Sea, Italy, were collected during Spring 1997 and analysed for 32 organochlorine pesticides residues and 27 polychlorobiphenyl congeners. Only eight organochlorine pesticides - hexachlorobenzene (HCB), hexachlorocyclohexane (HCH) isomers, diphenyl-dichloro-trichloroethane (DDT) group, dieldrin - were determined at levels in the range <0.01-19.88 ng g(-1) wet weight, with 1,1'-dichloro-2,2'-bis(4-chlorophenyl)ethylene (DDE) being the more relevant single organochlorine. The contamination by organochlorine pesticides was comparable in organisms from the North, Centre and South Adriatic. Polychlorinated biphenyls (PCBs) were determined at levels in the range <0.05-14.46 ng g(-1), with CB 101, 118, 138, 153, 180 and 187 being more relevant (penta-, hexa- and hepta-chlorinated congeners). The sum of PCBs congeners determined were in the range 1.18-69.05 ng g(-1). The contamination by PCBs is more relevant in organisms from the North Adriatic Sea owing to the antropic discharge from major rivers such as Po and Adige that flow through highly industrialized and densely populated areas.     

Cytotoxicity of carbon nanomaterials: single-wall nanotube, multi-wall nanotube, and fullerene

A cytotoxicity test protocol for single-wall nanotubes (SWNTs), multi-wall nanotubes (with diameters ranging from 10 to 20 nm, MWNT10), and fullerene (C60) was tested. Profound cytotoxicity of SWNTs was observed in alveolar macrophage (AM) after a 6-h exposure in vitro. The cytotoxicity increases by as high as approximately 35% when the dosage of SWNTs was increased by 11.30 microg/cm2. No significant toxicity was observed for C60 up to a dose of 226.00 microg/cm2. The cytotoxicity apparently follows a sequence order on a mass basis: SWNTs > MWNT10 > quartz > C60. SWNTs significantly impaired phagocytosis of AM at the low dose of 0.38 microg/cm2, whereas MWNT10 and C60 induced injury only at the high dose of 3.06 microg/cm2. The macrophages exposed to SWNTs or MWNT10 of 3.06 microg/cm2 showed characteristic features of necrosis and degeneration. A sign of apoptotic cell death likely existed. Carbon nanomaterials with different geometric structures exhibit quite different cytotoxicity and bioactivity in vitro, although they may not be accurately reflected in the comparative toxicity in vivo.     

Role of hydroxylamine intermediates in the phytotransformation of 2,4,6-trinitrotoluene by Myriophyllum aquaticum

Phytotransformation studies of 2,4,6-trinitrotoluene (TNT) were conducted using Myriophyllum aquaticum to clarify the role of initial intermediates of TNT transformation in the complex product distributions reported previously. 2-Hydroxylamino-4,6-dinitrotoluene (2HA46DNT) and 4-hydroxylamino-2,6-dinitrotoluene (4HA26DNT) were the initial intermediates of TNT phytotransformation. 2HA46DNT and 4HA26DNT were both abiotically transformed to 4,4',6,6'-tetranitro-2,2'-azoxytoluene (2,2'azoxy) and 2,2',6,6'-tetranitro-4,4'-azoxytoluene (4,4'azoxy) and also phytoreduced to the related amines 2-amino-4,6-dinitrotoluene (2A46DNT) and 4-amino-2,6-dinitrotoluene (4A26DNT). To further elucidate the initial steps of this TNT phytotransformation pathway, the transformations of known intermediates (including 2HA46DNT, 4HA26DNT, 2A46DNT, 4A26DNT, 2,2'azoxy, and 4,4'azoxy) were monitored in plant systems. The transformation rates were measured, and kinetic analysis using pseudo-first-order models was used to evaluate the relative rates of competing reactions. The formation of the azoxy products was determined to be more rapid than the formation of the amine products. Both the azoxy and amine products were subject to uptake and further transformation by the plant.     

Isolation and Biological Activities of Decanal,Linalool, Valencene,and Octanal from Sweet Orange Oil

Abstract: Product 1 (82.25% valencene), product 2 (73.36% decanal), product 3 (78.12% octanal), and product 4 (90.61% linalool) were isolated from sweet orange oil by combined usage of molecular distillation and column chromatography. The antioxidant activity of sweet orange oil and these products was investigated using 2,2‐diphenyl‐1‐picrylhydrazyl and reducing power assays. In this test, product 1 (82.25% valencene), product 2 (73.36% decanal), and product 4 (90.61% linalool) had antioxidant activity, but lower than sweet orange oil. The antimicrobial activity was investigated in order to evaluate their efficacy against 5 microorganisms. The results showed that sweet orange oil, product 2 (73.36% decanal), product 3 (78.12% octanal), and product 4 (90.61% linalool) had inhibitory and bactericidal effect on the test microorganisms (except Penicillium citrinum). Valencene did not show any inhibitory effect. Saccharomyces cerivisiae was more susceptible, especially to the crude sweet orange oil (minimal inhibitory concentration 6.25 μL/mL). The cytotoxicity was evaluated on Hela cells using the 3‐(4,5‐dimethyl‐thiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide assay. All test samples showed significant cytotoxicity on the cell lines with IC₅₀ values much less than 20 μg/mL.     

Brominated flame retardants in serum from U.S. blood donors

Serum samples collected in 1988 from U.S. blood donors were analyzed for polybrominated diphenyl ethers (PBDEs) and polychlorinated and polybrominated biphenyls (PCBs and PBBs). The levels of the PBDEs are reported for the first time in serum from the U.S. population. The median concentrations and range of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47); 2,2',4,4',5,5'-hexabromodiphenyl ether (BDE-153); 2,2',3,4,4',5',6-heptabromodiphenyl ether (BDE-183); and decabromodiphenyl ether (BDE-209) were 1.3 (<0.8-49); 0.54 (0.13-3.1); 0.24 (0.12-1.8); and <1 (<1-35) pmol/g lipid weight (l.w.), respectively. In addition we also measured detectable levels of nine additional PBDE congeners in many of the serum samples. The median concentrations and ranges of 2,2',4,4',5,5'-hexachloro- and hexabromobiphenyl (CB-153 and BB-153) were 190 (21-2600) and 19 (4.2-84) pmol/g l.w. The levels of PBDEs and CB-153 found in the U.S. samples were similar to background levels reported in the serum of Swedish hospital cleaners collected 10 years later, i.e., 1997. The BB-153 congener measured in the U.S. samples was not found in the Swedish samples. The difference in exposure to this congener could not be assessed in this study, although might be related to the 1973 BB-153 (FireMaster BP-6) animal and human contamination incident in the State of Michigan.     

Polybrominated diphenyl ethers and polychlorinated biphenyls in a marine foodweb of coastal Florida

Nine species of marine fish, including teleost fishes, sharks, and stingrays, and two species of marine mammals (dolphins) collected from Florida coastal waters were analyzed for polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) to evaluate biomagnification factors (BMF) of these contaminants in a coastal foodweb. In addition, bottlenose dolphins and bull sharks collected from the Florida coast during the 1990s and the 2000s were analyzed for evaluation of temporal trends in PBDE and PCB levels in coastal ecosystems. Mean concentrations of PBDEs in muscle tissues of teleost fishes ranged from 8.0 ng/g, lipid wt (in silver perch), to 88 ng/g, lipid wt (in hardhead catfish), with an overall mean concentration of 43 +/- 30 ng/g, lipid wt. Mean concentrations of PBDEs in muscle of sharks ranged from 37.8 ng/g, lipid wt, in spiny dogfish to 1630 ng/g, lipid wt, in bull sharks. Mean concentrations of PBDEs in the blubber of bottlenose dolphins and striped dolphins were 1190 +/- 1580 and 660 ng/g, lipid wt, respectively. Tetra-BDE 47 (2,2',4,4'-) was the major congener detected in teleost fishes and dolphin samples, followed by BDE-99, BDE-153, BDE-100, and BDE-154. In contrast, BDE-209 was the most abundant congener in sharks. Concentrations of PBDEs and PCBs in dolphins and sharks were 1-2 orders of magnitude greater than those in lower trophic-level fish species, indicating biomagnification of both of these contaminants in the marine foodweb. Based on the analysis of sharks and dolphins collected over a 10-year period, an exponential increase in the concentrations of PBDEs and PCBs has occurred in these marine predators. The doubling time of PBDE and PCB concentrations was estimated to be 2-3 years for bull sharks and 3-4 years for bottlenose dolphin.     

Toxicity Study of Ethanolic Extract of Chrysanthemum morifolium in Rats

Abstract: Chrysanthemum morifolium extract (CME) has many pharmacological effects, and the effective components of CME are luteolin and apigenin which have been reported with cytotoxicity in vitro. The purpose of this study was to evaluate the safety of CME in Sprague–Dawley (S–D) rats. In the acute toxicity study, a single oral dose of 15 g/kg body weight (bw) CME was administered to rats, then the rats were observed for 14 d. No treatment-related death was observed, and the maximal tolerance dose estimated was greater than 15 g/kg bw in rats. In the long-term toxicity study, the rats were administered daily by gavage at dose levels of 320, 640, and 1280 mg/kg bw/d for consecutive 26 wk followed by 4 wk recovery period. The results showed that no toxicological changes in body weight, food, and water consumption, hematologic examination, blood biochemical examination, organ weight, and microscopic histopathologic examination were found in any treatment group. Therefore, CME is considered to be safe in general in rats at the limited dose level.     

聚乙二醇1000维生素E琥珀酸酯-皂皮皂素微乳液的制备、表征及活性

选用毒性小、刺激性低且有P-糖蛋白抑制剂作用的聚乙二醇1000维生素E琥珀酸酯（D-α-tocopheryl polyethylene glycol 1000 succinate,TPGS）和乳化效果强的天然植物化合物皂皮皂素（quillaja saponin,QS）,与聚氧乙烯氢化蓖麻油（RH40）复配为乳化剂,再以油酸乙酯为油相,异丙醇为助乳化剂,配制TPGS-QS微乳液。利用普通光学显微镜、透射电子显微镜和激光粒度测定仪观察微乳液液滴形貌、粒径分布和Zeta电位。结果：TPGS-QS微乳液具体配制方法为m（油酸乙酯）∶m（质量分数0.02%?TPGS溶液）∶m（质量分数1.5%?QS溶液）∶m（RH40）∶m（异丙醇）＝30∶6.6∶6.6∶39.4∶17.5,所用溶液均以纯水配制。该微乳液外观淡黄、澄清、透明,流动性强,液滴呈均一规则的圆球形,为O/W型乳液,微乳液平均粒径为（48.89±0.08）nm,Zeta电位为（－4.513±0.564）mV。为验证TPGS-QS微乳液是否具有生物活性,测定其α-葡萄糖苷酶抑制活性、1,1-二苯基-2-三硝基苯肼自由基清除能力、2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除能力、铁离子还原能力,及其对HepG2和Caco-2细胞的毒性作用,发现该微乳液对α-葡萄糖苷酶活性的半抑制质量浓度为67.15?mg/mL,具有一定的抗氧化活性,并且几乎不会影响细胞的正常生长,甚至在一定质量浓度范围对细胞有增殖效果。     

Antioxidant, antihypertensive and antimicrobial properties of ovine milk caseinate hydrolyzed with a microbial protease

BACKGROUND: Bioactive peptides might be released from precursor proteins through enzymatic hydrolysis. These molecules could be potentially employed in health and food products. In this investigation, ovine milk caseinate hydrolysates obtained with a novel microbial protease derived from Bacillus sp. P7 were evaluated for antioxidant, antimicrobial, and angiotensin I‐converting enzyme (ACE)‐inhibitory activities. RESULTS: Antioxidant activity measured by the 2,2′‐azino‐bis‐(3‐ethylbenzothiazoline)‐6‐sulfonic acid method increased with hydrolysis time up to 2 h, remaining stable for up to 4 h. Hydrolysates showed low 2,2‐diphenyl‐1‐picrylhydrazyl radical‐scavenging abilities, with higher activity (31%) reached after 1 h of hydrolysis. Fe²⁺‐chelating ability was maximum for 0.5 h hydrolysates (83.3%), decreasing thereafter; and the higher reducing power was observed after 1 h of hydrolysis. ACE‐inhibitory activity was observed to increase up to 2 h of hydrolysis (94% of inhibition), declining afterwards. 3 h hydrolysates were shown to inhibit the growth of Bacillus cereus, Corynebacterium fimi, Aspergillus fumigatus, and Penicillium expansum. CONCLUSION: Ovine caseinate hydrolyzed with Bacillus sp. P7 protease presented antioxidant, antihypertensive, and antimicrobial activities. Hydrolysis time was observed to affect the evaluated bioactivities. Such hydrolysates might have potential applications in the food industry. Copyright © 2011 Society of Chemical Industry     

Biological activities and physicochemical properties of Maillard reaction products in sugar–bovine casein peptide model systems

The purpose of this study was to evaluate the biological activities and physicochemical properties of Maillard reaction products (MRPs), derived from aqueous reducing sugar (ribose, galactose and lactose) and bovine casein peptide (BCP) model systems. The fluorescence intensity of ribose-BCP MRPs reached the maximum value within 1 h, while it took 3 h for galactose-BCP MRPs. Size exclusion chromatography of all the MRPs indicated molecular rearrangements and production of new smaller molecules, as a function of the heating time. The consumption of ribose and amino groups was the highest in the ribose-BCP MRPs. BCP lost its known angiotensin-I-converting enzyme (ACE) inhibitory activity by the Maillard reaction with reducing sugars. Ribose–BCP MRPs had the lowest ACE inhibitory activity, but they showed the highest 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging activity and ferrous reducing power among all the MRPs. Galactose-BCP MRPs inhibited, slightly the growth of Caco-2 cells, while ribose-BCPand lactose-BCP MRPs had no cytotoxicity.     

Grayanotoxin-III Detection and Antioxidant Activity of Mad Honey

“Mad honey” is a complex mixture of numerous chemicals produced by honeybees from Rhododendron flowers. Consumption of mad honey leads to diarrhea, perspiration, dizziness, changes in consciousness, syncope, diplopia, as well as blurred vision, hypotension, and bradycardia due to the presence of grayanotoxins (GTXs). Therefore, it is important to detect the level grayanotoxins in mad honey. Besides its toxicity, mad honey also has antioxidant activity. This study was designed to determine the level of grayanotoxin-III toxin and antioxidant activity of ten different mad honey samples collected from the Black Sea region of Turkey. Liquid chromatography-tandem mass spectrometry was used for the quantitation of grayanotoxin-III. Antioxidant activity was evaluated using total phenolic contents, total ferric reducing antioxidant power, scavenging of 2,2-diphenyl-1-picrylhydrazyl and 3-(2-pyridyl)-5, 6-diphenyl-1,2,4-triazine-4’,4’’-disulfonic acid radicals. Quantities of grayanotoxin-III levels ranged from 68.754 to 0.701 µg grayanotoxin-III/g honey. Mad honey MH7 from Artvin/Hopa had the highest grayanotoxin-III level. Although there were varying levels of grayanotoxin-III, mad honey samples were outstanding in terms of antioxidant activity. MH₃ had the highest antioxidant potential. Although toxicity effect comprises, a metered dose of mad honey might also be explored as a potential source in clinical trials due to high bioactivity levels.     

Predatory bird species show different patterns of hydroxylated polychlorinated biphenyls (HO-PCBs) and polychlorinated biphenyls (PCBs)

Hydroxylated metabolites of polychlorinated biphenyls (HO-PCBs) have previously been associated with endocrine disrupting effects. Since metabolic capacity may differ among species, we investigated the levels and profiles of HO-PCBs and PCBs in livers of four predatory bird species from Belgium. Maximum concentrations for sum HO-PCBs were found in the common buzzard (Buteo buteo) up to 13 700 pg/g wet weight (ww). The most prominent HO-PCB congener in all bird species was 4-HO-CB 187 (up to 6420 pg/g ww in buzzard liver), followed by 4-HO-CB148 in the buzzard (up to 1820 pg/g ww), sparrowhawk (Accipiter nisus), and grey heron (Ardea cinerea), and by 3'-HO-CB138 in long eared owl (Asio otus) and in one grey heron (up to 985 pg/g ww and 3450 pg/g ww, respectively). The mean profile of the grey heron differed from the other species with 3'-HO-CB138 and 4-HO-CB163 contributing more to the sum HO-PCBs. This indicates that aquatic and terrestrial predatory bird species may show differences in their HO-PCBs profiles. Variation in the diet and species-specific accumulation and metabolism of PCBs are probably the most important causes for these differences. Correlations between HO-PCBs and their parent PCBs were only found significant for buzzards.     

Chiral PCB methyl sulfones in rat tissues after exposure to technical PCBs

PCB methyl sulfones (MeSO2-PCBs) are lipophilic PCB metabolites known to exhibit selective tissue retention properties in wildlife and humans. The aim of this study was to investigate the presence of atropisomers of MeSO2-PCB congeners in tissues of rats exposed to a technical PCB product, Clophen A50. Changes in the enantiomer fractions (EFs) of the MeSO2-PCB atropisomers after exposure were also determined. Liver, lung, and adipose tissue from rats dosed with Clophen A50 were analyzed for the MeSO2-PCB atropisomers of 3-methylsulfonyl-2,2',4',5,6-pentachlorobiphenyl (5-MeSO2-CB91), 4-methylsulfonyl-2,2',3,4',6-pentachlorobiphenyl (4-MeSO2-CB91), 3-methylsulfonyl-2,2',3',4',5,6-hexachlorobiphenyl (5'-MeSO2-CB132), 4-methylsulfonyl-2,2',3,3',4',6-hexachlorobiphenyl (4'-MeSO2-CB132), 3-methylsulfonyl-2,2',4',5,5',6-hexachlorobiphenyl (5-MeSO2-CB149), and 4-methylsulfonyl-2,2',3,4',5',6-hexachlorobiphenyl (4-MeSO2-CB149). In all tissues analyzed, especially lung, the para-MeSO2-PCBs were more abundant than the meta-MeSO2-PCBs. The concentration ratio was higher for 4-MeSO2-CB149 versus 5-MeSO2-CB149 than for the corresponding ratio 4-/5-MeSO2-CB91 and 4'-/5'-MeSO2-CB132. Enantioselective MeSO2-PCB analysis of the lung samples showed an excess and dominance of the second eluting atropisomer of 4-MeSO2-CB149. In both lung and adipose tissues, small amounts of the first eluting atropisomer of 5-MeSO2-CB149 was present, but this atropisomer was not detected in the liver. No significant time-dependent changes in the EFs of 4-MeSO2-CB91, 5'-MeSO2-CB132, 4'-MeSO2-CB132, 5-MeSO2-CB149, and 4-MeSO2-CB149 atropisomers were found for either lung, liver, or adipose tissue. The results of the present study suggest that enantioselective formation occur for both meta- and para-MeSO2-PCBs.