Comparative assessment of soil microbial community in crude oil contaminated sites.

Petroleum refineries generate oily sludge that contains hazardous polycyclic aromatic hydrocarbons (PAH), and hence, its proper disposal is of foremost concern. Analysis of the physicochemical properties and functions of indigenous microbes of the contaminated sites are essential in deciding the strategy for bioremediation. This study analyses both parameters at two geographically distant sites, with different crude oil sources, and compares the metabolic capability of soil bacteria with reference to different contamination sources and the age of the contaminated site. The results indicate that organic carbon and total nitrogen derived from petroleum hydrocarbon negatively affect microbial diversity. Contamination levels vary widely on site, with levels of PAHs ranging from 5.04 to 1.66 × 103 µg kg-1 and 6.20 to 5.64 × 103 µg kg-1 in Assam and Gujarat sites respectively, covering a higher proportion of low molecular weight (LMW) PAHs (fluorene, phenanthrene, pyrene, and anthracene). Functional diversity values were observed to be positively correlated (p < 0.05) with acenaphthylene, fluorene, anthracene, and phenanthrene. Microbial diversity was the highest in fresh oily sludge which decreased upon storage, indicating that immediate bioremediation, soon after its generation, would be beneficial. Improvement in the bio-accessibility of hydrocarbon compounds by the treatment of biosurfactant produced by a (soil isolate/isolate) was demonstrated., with respect to substrate utilization.

Correlation of soil microbiome with crude oil contamination drives detection of hydrocarbon degrading genes which are independent to quantity and type of contaminants.

The impacts of crude oil contamination on soil microbial populations were explored in seven different polluted areas near oil and gas drilling sites and refineries of Assam, India. Using high-throughput sequencing techniques, the functional genes and metabolic pathways involved in the bioconversion of crude oil contaminants by the indigenous microbial community were explored. Total petroleum hydrocarbon (TPH) concentrations in soil samples ranged from 1109.47 to 75,725.33 mg/kg, while total polyaromatic hydrocarbon (PAH) concentrations ranged from 0.780 to 560.05 mg/kg. Pyrene, benzo[a]anthracene, naphthalene, phenanthrene, and anthracene had greater quantities than the maximum permitted limits, suggesting a greater ecological risk, in comparison to other polyaromatic hydrocarbons. According to the metagenomic data analysis, the bacterial phyla Proteobacteria, Actinobacteria, Acidobacteria, and Bacteroides were the most prevalent among all polluted areas. The most prominent hydrocarbon degraders in the contaminated sites included Burkholderia, Mycobacterium, Polaromonas, and Pseudomonas. However, the kinds of pollutants and their concentrations did not correlate with the abundances of respective degrading genes for all polluted locations, as some of the sites with little to low PAH contamination had significant abundances of corresponding functional genes for degradation. Thus, the findings of this study imply that the microbiome of hydrocarbon-contaminated areas, which are biologically involved in the degradation process, has various genes, operons and catabolic pathways that are independent of the presence of a specific kind of contaminant.

Aloe gel-base food products: Chemical, toxicological, and regulatory aspects.

Aloe products are increasingly valued as ingredients in food supplements and flavoring agents. In early March 2020, the European Commission drafted a ban on the use of Aloe products that contain hydroxyanthracene derivatives (HADs) in food, following the opinion on concerns about the toxicity of vegetable extracts containing HADs carried out by the European Food Safety Authority (EFSA). Aloe gel preparation is characterized by minimal amounts of HADs, only present as contaminants during extraction, compared to other sold Aloe preparations such as Aloe latex and Aloe whole leaf extract. This review provides a comprehensive account of the toxicological aspects of Aloe gel, and briefly discusses the chemical profile of other Aloe preparations. Unlike these other preparations, pure Aloe gel shows no toxic effects. However, further toxicological studies remain necessary to establish the maximum permissible limit of HAD contaminants in Aloe gel, considering daily doses and maximum duration of treatments. Finally, officially validated analytical methods for determination of HADs are required, in the form of tools for use by Companies and Competent Authorities to ensure the absence of HAD contamination in raw materials or in finished products.

Polycyclic aromatic hydrocarbons in edible oils and fatty foods: Occurrence, formation, analysis, change and control.

Numerous studies have demonstrated that dozens of polycyclic aromatic hydrocarbons (PAHs) are mutagenic, genotoxic and strongly carcinogenic. PAHs are found to be widely present in foods contaminated through multiple paths. Due to their lipophilic nature, these compounds easily accumulate in edible oils and fatty foods where they can range from no detection to over 2000µg/kg. Compared to precursor PAHs, researchers have seldom studied the presence of PAH derivatives, especially in food matrices. This chapter includes the physical and chemical characteristics of PAHs and their types, occurrence, sample pretreatment and instrumental determination methods, and their formation, change and control in edible oils and fatty foods. The occurrence and formation of PAH derivatives in foods are much less investigated compared to those of their precursor PAHs. Although the removal of matrix effects and accuracy remain difficult for current rapid determination methods, a prospective research direction of PAH analysis for large-scale screening is in demand. To date, physical absorption, chemical oxidation and biodegradation have been widely used in PAH removal techniques. Specific types of bacteria, fungi, and algae have also been used to degrade PAHs into harmless compounds. However, most of them can only degrade a range of LPAHs, such as naphthalene, anthracene and phenanthrene. Their ability to degrade HPAHs requires further study. Moreover, it is still a great challenge to maintain food nutrition and flavor during the PAH removal process using these methods.

Biological activity and stability analyses of knipholone anthrone, a phenyl anthraquinone derivative isolated from Kniphofia foliosa Hochst.

Knipholone (1) and knipholone anthrone (2), isolated from the Ethiopian medicinal plant Kniphofia foliosa Hochst. are two phenyl anthraquinone derivatives, a compound class known for biological activity. In the present study, we describe the activity of both 1 and 2 in several biological assays including cytotoxicity against four human cell lines (Jurkat, HEK293, SH-SY5Y and HT-29), antiplasmodial activity against Plasmodium falciparum 3D7 strain, anthelmintic activity against the model organism Caenorhabditis elegans, antibacterial activity against Aliivibrio fischeri and Mycobacterium tuberculosis and anti-HIV-1 activity in peripheral blood mononuclear cells (PBMCs) infected with HIV-1c. In parallel, we investigated the stability of knipholone (2) in solution and in culture media. Compound 1 displays strong cytotoxicity against Jurkat, HEK293 and SH-SY5Y cells with growth inhibition ranging from approximately 62-95% when added to cells at 50 µM, whereas KA (2) exhibits weak to strong activity with 26, 48 and 70% inhibition of cell growth, respectively. Both 1 and 2 possess significant antiplasmodial activity against Plasmodium falciparum 3D7 strain with IC50 values of 1.9 and 0.7 µM, respectively. These results complement previously reported data on the cytotoxicity and antiplasmodial activity of 1 and 2. Furthermore, compound 2 showed HIV-1c replication inhibition (growth inhibition higher than 60% at tested concentrations 0.5, 5, 15 and 50 µg/ml and an EC50 value of 4.3 µM) associated with cytotoxicity against uninfected PBMCs. The stability study based on preincubation, HPLC and APCI-MS (atmospheric-pressure chemical ionization mass spectrometry) analysis indicates that compound 2 is unstable in culture media and readily oxidizes to form compound 1. Therefore, the biological activity attributed to 2 might be influenced by its degradation products in media including 1 and other possible dimers. Hence, bioactivity results previously reported from this compound should be taken with caution and checked if they differ from those of its degradation products. To the best of our knowledge, this is the first report on the anti-HIV activity and stability analysis of compound 2.

Characterization and identification of the chemical constituents of Polygonum multiflorum Thunb. by high-performance liquid chromatography coupled with ultraviolet detection and linear ion trap FT-ICR hybrid mass spectrometry.

Dianthrone derivatives are minor constituents of Polygonum multiflorum Thunb. (PM). These derivatives are potential hepatotoxic components in PM. Fraction D6 contains many dianthrone derivatives and was successfully enriched using an efficient three-step approach. An effective and reliable high-performance liquid chromatography (HPLC) technique coupled with ultraviolet detection (UV) and a linear ion trap FT-ICR hybrid mass spectrometry (HPLC-UV/LTQ-FT-ICR-MS) method were successfully developed to separate and identify the dianthrones of the fraction D6. The characteristic diagnostic fragment ions and characteristic fragmentation pathway of the seven dianthrone standards, namely, Polygonumnolide B1 (S1), Polygonumnolide C3 (S2), Polygonumnolide C2 (S3), Polygonumnolide E (S4), Polygonumnolide A1 (S5), Polygonumnolide A2 (S6) and cis-emodin dianthrones (S7), were compared with unknown compounds in fraction D6, and 45 dianthrone derivatives were characterized or tentatively identified. Of these derivatives, 32 new dianthrone derivatives were tentatively characterized in PM. Therefore, LTQ-FT-ICR-MS combined with a selective enrichment method provided a powerful means for analyzing dianthrone derivatives. This study provides a meaningful basis for correcting some mistakes in previous studies, as well as further quality control and pharmacological and toxicological research.

The effect of soil pollution with petroleum-derived substances on Porcellio scaber Latr. (Crustacea, Isopoda).

Presented research aimed at investigating the effect of short-term contact with petroleum-derived substances (PDSs) on life parameters of Porcellio scaber Latr. (Isopoda) and accumulation of polycyclic aromatic hydrocarbons (PAHs) in its body. The influence of presence of P. scaber on the total petroleum hydrocarbons (TPH) content in soil was also determined. The following objects were established: control-unpolluted soil; soil polluted with petrol; soil polluted with diesel fuel and soil polluted with used engine oil. Every pollutant was used in the amounts equal to 6000 mg of fuel/kg d.m. of soil 15 months earlier. In the laboratory, survival and body mass change of P. scaber reared in investigated soils were observed. The delivered food was not contaminated with PDSs. P. scaber reveals a considerable resistance in a short (4 weeks) contact with PDSs, evidenced as high survivability (from 68% on the soil polluted with engine oil to 77% on the soil polluted with diesel fuel) and undisturbed increase in body mass (on the level similar to control). It indicates the potential usefulness of this animal as a monitoring organism. No positive correlation was observed between TPH depletion in the soils contaminated with PDSs and P. scaber presence during 4 weeks of the experiment. PAH level in P. scaber bodies was generally very low (with the highest level of anthracene 0.40 µg/g of wet mass-after 4 weeks of rearing on the diesel fuel-contaminated soil), which may confirm the thesis about considerable abilities of isopods for biotransformation of these pollutants and low susceptibility to these xenobiotic penetration through integuments. However, a tendency for accumulation for phenanthrene and anthracene in conditions of soil polluted with diesel fuel was observed respectively 0.07 and 0.21 µg/g of wet mass for phenanthrene and 0.22 and 0.40 µg/g of wet mass for anthracene, observed successively in the 2nd and 4th week of rearing.

Polycyclic aromatic hydrocarbons in surface sediments of the mid-Adriatic and along the Croatian coast: Levels, distributions and sources.

This study provides contamination levels, distributions and source apportionment of PAHs in surface sediments in the mid-Adriatic and along the Croatian coast. Median summed concentrations of parent and alkyl-PAHs are circa 10 times lower in the off-shore transect stations of the mid-Adriatic (22.3 and 18.2 µg.kg-1 d.w.) than the ranges determined at the coastal stations, including those of Kastela bay (227-331 and 11.7-197 µg.kg-1 d.w., respectively). The highest levels, circa 20 times higher, were found in Sibenik bay (median 6603 and 3051 µg.kg-1). The overall range of PAH concentrations spans more than 2000 times between the lowest and the highest contamination level. The geographical distributions reflect the presence of strong gradients at local and regional scales. A major factor influencing sedimentary PAH distributions at local scale appears to be the distance from their known continental and coastal upstream emission sites (urban, industrial, harbour …), whereas at regional scale, this distribution depends more on the routes of entry of PAHs into the study area. Two combustion and one petroleum model source profiles of PAHs were determined by alternative least square analysis. Benzo[b+j]fluoranthenes and fluoranthene/pyrene are compounds characterizing two pyrogenic sources respectively, while signatures of alkyl-substituted homologues (phenanthrenes/anthracenes, fluranthenes/pyrenes, chrysenes and dibenzothiophenes) delineate a petrogenic source profile. The quantitative apportionment of source contributions shows significant geographical differences, with a dominant petrogenic source found along the mid-Adriatic transect (approximately 74%) and in Kastela bay (61%). In the coastal sediments about a fifty-fifty contamination mix is assigned to a petrogenic/pyrogenic source of PAHs (47% and 53% respectively), whereas in Sibenik bay a strong predominance is apportioned to the combustion compounds (81%).

[Genotype, environment and their interactions of functional components in Rheum palmatum].

Eight kinds of provenance of Rheum palmatum collected from 4 provinces Sichuan, Ningxia, Gansu, Shannxi as test materials, which were transplanted under 3 different environments by using complete randomized block design with three replicates. The contents of the chemical components was determined by HPLC. This study aimed at analyzing the effect of genotype, environment and their interactions on the 4 kinds of functional components (phenolic acids, bianthrone, free anthraquinones and combined anthraquinones) in 14 kinds of active components of R. palmatum, in order to provide a theoretical basis for the selection of cultivated R. palmatum in high quality producing area and excellent provenance. The functional components of R. palmatum were influenced by genotype and environment. The content of phenolic acids was mainly influenced by environment, and the other three kinds of functional components were affected by environment and their interactions. The proportion of environment was larger. The cultivation quality of R. palmatum should give priority to environment, then choose a provenance. Sichuan may be beneficial in accumulation of free anthraquinones in R. palmatum, Gansu may facilitate the binding of combined anthraquinone, phenolic acids and bianthrone content. Preliminary inference based on the content and proportion of efficacy components, P2 could be potential special medicinal germplasm that have function of heat-clearing and detoxifying drugs. P6 could be potential special medicinal germplasm that activate blood circulation to dissipate blood stasis. P7 and P1 could all be potential specialmedicinal germplasms that exist diarrhea attack characters. The results of this study have important guiding significance for the production of rhubarb precision medicinal materials.

[Genotype, environment and their interactions of functional components in Rheum tanguticum].

Six kinds of provenance of Rheum tanguticum collected from Qinghai province as the test materials, which were transplanted under 3 different environments by using complete randomized block design with three replicates. The contents of the chemical components was determined by HPLC. This study aimed at analyzing the effect of genotype, environment and their interactions on the 4 kinds of functional components (phenolic acids, bianthrone, free anthraquinones and combined anthraquinones) in 14 kinds of active components of Rh. tanguticum, in order to provide a theoretical basis for the selection of cultivated Rh. tanguticum in high quality producing area and excellent provenance. The provenance trial showed that the genotype and environment influence on the effect of all kinds of functional components in Rh. tanguticum were significant (P<0.05). The content of phenolic acids was mainly influenced by environment, and the other three kinds of functional components were affected by environment and their interactions. The proportion of environment was larger. The cultivation quality of Rh. tanguticum should give priority to environment, then choose a provenance. Sichuan may be beneficial in accumulation of combined anthraquinones in Rh. tanguticum, Gansu may facilitate the binding of free anthraquinone, phenolic acids and bianthrone content. Preliminary inference based on the content and proportion of efficacy components, T4 could be potential special medicinal germplasm that have function of heat-clearing and detoxifying drugs and activate blood circulation to dissipate blood stasis; T3 and T6 could all be potential specialmedicinal germplasms that exist diarrhea attack characters. The results of this study have certain guiding significance for the production of rhubarb precision medicinal materials.

Optimization and validation of a method using UHPLC-fluorescence for the analysis of polycyclic aromatic hydrocarbons in cold-pressed vegetable oils.

Among the different food categories, the oils and fats are important sources of exposure to polycyclic aromatic hydrocarbons (PAHs), a group of organic chemical contaminants. The use of a validated method is essential to obtain reliable analytical results since the legislation establishes maximum limits in different foods. The objective of this study was to optimize and validate a method for the quantification of four PAHs [benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(a)pyrene] in vegetable oils. The samples were submitted to liquid-liquid extraction, followed by solid-phase extraction, and analyzed by ultra-high performance liquid chromatography. Under the optimized conditions, the validation parameters were evaluated according to the INMETRO Guidelines: linearity (r2 >0.99), selectivity (no matrix interference), limits of detection (0.08-0.30µgkg-1) and quantification (0.25-1.00µgkg-1), recovery (80.13-100.04%), repeatability and intermediate precision (<10% RSD). The method was found to be adequate for routine analysis of PAHs in the vegetable oils evaluated.

Active matrix-based collection of airborne analytes: an analyte recording chip providing exposure history and finger print.

In the field of sensors that target the detection of airborne analytes, Corona/lens-based-collection provides a new path to achieve a high sensitivity. An active-matrix-based analyte collection approach referred to as "airborne analyte memory chip/recorder" is demonstrated, which takes and stores airborne analytes in a matrix to provide an exposure history for off-site analysis.

Biodegradation of anthracene by Aspergillus fumigatus.

An anthracene-degrading strain, identified as Aspergillus fumigatus, showed a favorable ability in degradation of anthracene. The degradation efficiency could be maintained at about 60% after 5d with initial pH of the medium kept between 5 and 7.5, and the optimal temperature of 30 °C. The activity of this strain was not affected significantly by high salinity. Exploration on co-metabolism showed that the highest degradation efficiency was reached at equal concentration of lactose and anthracene. Excessive carbon source would actually hamper the degradation efficiency. Meanwhile, the strain could utilize some aromatic hydrocarbons such as benzene, toluene, phenol etc. as sole source of carbon and energy, indicating its degradation diversity. Experiments on enzymatic degradation indicated that extracellular enzymes secreted by A. fumigatus could metabolize anthracene effectively, in which the lignin peroxidase may be the most important constituent. Analysis of ion chromatography showed that the release of anions of A. fumigatus was not affected by addition of anthracene. GC-MS analysis revealed that the molecular structure of anthracene changed with the action of the microbe, generating a series of intermediate compounds such as phthalic anhydride, anthrone and anthraquinone by ring-cleavage reactions.

Surveillance and source diagnostic investigation of hydrocarbon residues in sediments.

The nature and seasonal distribution of hydrocarbons were studied in Ondo coastal region in Western Nigeria. The petroleum hydrocarbons were screened by gas chromatography with flame ionization detector (GC/FID) and gas chromatography-mass spectrometry (GC-MS). Complex series of compounds were identified. The overall molecular compositions obtained were characteristic of petrogenic origin with very little biogenic input. The concentrations of two important polycyclic aromatic hydrocarbons (PAHs); phenanthrene and anthracene exceeded the threshold level where adverse effects on biota would occasionally occur; a conclusion suggested to be clarified by site-specific studies on resident organisms. The study is useful for ecological risk assessment in the context of contaminant input, nature, pattern and trend.

Chromatographic quantitation of some bioactive minor components in oils of wheat germ and grape seeds produced as by-products.

The objective of this work was to determine some beneficial and bioactive minor lipid components in wheat germ and grape seeds as a result of milling industry of wheat and pressing of grapes in wineries. Sterylglycosides (SG's) were isolated and fractionate into free and acylated SG's by TLC and were determine as their1-anthroylnitriles (1-AN) by HPLC. Moreover, 4-desmethylsterols were isolated, derivatized into their trimethyl silyl derivatives and analyzed by GLC. Tocopherols and tocotrienols were directly analyzed by HPLC. In addition, fatty acids composition by GLC was accomplished. The results were compared to three conventional edible oils, namely, corn, sunflower and cottonseed. It was found that the wheat germ oil (WGO) and grape seed oil (GSO) contained reasonable amounts of whole sterols. Sterylglycosides fraction (SG), which have not been evaluated, it was found that the two by-products contained high amounts of SG's and they were rich in free and acylated campe/stigma SG as well as free and acylated beta-sito SG. Total tocopherols and tocotrienols components were found in very high amounts in WGO (1300 ppm) and GSO (380 ppm). It is noteworthy to mention that GSO contained significant amounts of alpha- and gamma-tocotrienols which prevent cardiovascular diseases and contained reasonable amounts of alpha- and gamma-tocopherols. On the other side, it was found that WG and GS oils were enrich in linoleic acid (omega-6), while linolenic acid (omega-3) was present in higher quantity in WGO.

Study of active naphtodianthrone St John's Wort compounds by electrospray ionization Fourier transform ion cyclotron resonance and multi-stage mass spectrometry in sustained off-resonance irradiation collision-induced dissociation and infrared multiphoton dissociation modes.

Five well-known active naphtodianthrone constituents of Hypericum perforatum (St John's Wort) extracts have been investigated by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICRMS) and ESI-FTICRMSn. The studied compounds were hypericin, pseudohypericin, protohypericin, protopseudohypericin (biosynthetic precursors of the two former compounds, respectively) and isopseudohypericin (alkaline degradation product of pseudohypericin). Dissociation mass spectrometry measurements performed on the [M-H]- ion presented a variable efficiency as a function of the used activation mode. Sustained off-resonance irradiation collision-induced dissociation (SORI-CID) only led to a restricted number of fragment ions. In contrast, IRMPD ensured the detection of numerous product ions. Ions detected in ESI-FTICRMS and ESI-FTICRMSn experiments were measured with a very high mass accuracy (typically mass error is lower than 0.5 mDa at m/z close to 500) that allowed unambiguous formulae to be assigned to each signal observed in a mass spectrum. In spite of similar structures, specific fragmentation patterns were observed for the different compounds investigated. This study may be useful in the future to characterize in natural extracts these compounds (or derivatives of these compounds) by liquid chromatography/tandem mass spectrometry (LC/MS/MS) experiments by considering the MS/MS transitions highlighted in this paper.

Using acetone as solvent to study removal of anthracene in soil inhibits microbial activity and alters nitrogen dynamics.

Acetone is often used as a carrier to contaminate soil with polycyclic aromatic hydrocarbons (PAHs) and then to study the factors that control their removal. Acetone is an organic solvent that might affect soil processes. An alkaline saline (Texcoco soil) and an agricultural soil (Acolman soil) were amended with or without acetone, nitrogen + phosphorus (NP), and contaminated with anthracene at 520 mg/kg soil while emissions of CO2 and N2O and concentrations of NH4+, NO2(-) and NO3(-) were monitored. The CO2 emission rate decreased greater than 10 times in the soils amended with acetone. Emission of N2O decreased 70 times in the Acolman soil amended with acetone and NP and 5 times in the Texcoco soil. The concentration of NH4+ decreased in the unamended Acolman and Texcoco soil but increased when acetone was added in the first and remained constant in the latter. Acetone inhibited the increase in the amount of NO3(-) in the Acolman soil but not in the Texcoco soil. It was found that microbial activity as evidenced by the emission of CO2, nitrification, and production of N2O were inhibited by acetone. The amount of acetone used as solvent should thus be kept to a minimum, but it can be assumed that its effect on soil processes will be temporary, as microorganisms are known to repopulate soil quickly.

Micellar electrokinetic chromatography for separation of a mixture of coptis alkaloids, scute flavonoids, and rhubarb anthraquinones and bianthrones.

Coptidis Rhizoma, Scutellariae Radix, and Rhei Rhizoma are three common Chinese herbs. There are many herbal formulas which contain either two or all three of the herbs mentioned above. Their bioactive components have already been identified, respectively. However, there is no report about separation of the 13 bioactive constituents of the three herbs at the same time. In order to assess these constituents of related Chinese herbal preparations, a micellar electrokinetic chromatography method was developed. While buffer pH and surfactant concentration affected the resolution of separation, acetonitrile percentage was found to significantly influence the resolution, peak shape, and elution window. Optimum separation of 13 compounds was achieved at pH 7.3 using a buffer mixture of 70% (v/v) 3 mM di-sodium tetraborate, 10 mM sodium dihydrogen phosphate, and 50 mM sodium deoxycholate with 30% (v/v) acetonitrile. When applying the developed method to analyze a model preparation, San-huang-xie-xin-tang, which contains all three herbs, 8 of the 13 bioactive constituents, could be determined. The present study proposed a method to assess San-huang-xie-xin-tang within short analysis time and also provided a possible starting point to evaluate related herbal preparations containing Coptidis Rhizoma, Scutellariae Radix, and Rhei Rhizoma.

Preparative isolation and purification of five compounds from the Chinese medicinal herb Polygonum cuspidatum Sieb. et Zucc by high-speed counter-current chromatography.

High-speed counter-current chromatography (HSCCC) was applied to the separation and purification of five compounds from the Chinese medicinal herb Polygonum cuspidatum Sieb. et Zucc. The crude extracts from P. cuspidatum Sieb. et Zucc were treated with light petroleum-ethyl acetate-methanol-water (2:5:4:6, v/v). Sample 1 was obtained from the lower phase and sample 2 from the upper phase. The sample 1 was separated with light petroleum-ethyl acetate-water (1:5:5, v/v) and yielded 19.3mg of piceid, 17.6 mg of anthraglycoside B from 200mg of sample 1. The sample 2 was separated with light petroleum-ethyl acetate-methanol-water (3:5:4:6, v/v) and light petroleum-ethyl acetate-methanol-water (3:5:7:3, v/v) in a gradient elution and yielded 18.5mg of resveratrol, 35.3mg of emodin and 8.2mg of physcion from 220 mg of sample 2. The purity of each compound is over 95% as determined by HPLC. The chemical structures of these components were identified by (1)H NMR and (13)C NMR.

Analysis of rhubarb anthraquinones and bianthrones by microemulsion electrokinetic chromatography.

In this work a method of microemulsion electrokinetic chromatography (MEEKC) has been developed for the analysis of nine anthraquinones and bianthrones in rhubarb. This study employed di-n-butyl tartrate as oil substance to make up the microemulsion. The composition of the microemulsion was 0.5% (w/w) di-n-butyl tartrate, 0.6% (w/w) SDS, 1.2% (w/w) 1-butanol and 97.7% (w/w) 10 mM sodium borate buffer, pH of the buffer being 9.2. Acetonitrile was added to the emulsion to improve the separation. The volume ratio between the emulsion solution and acetonitrile of an optimized separation was 70:30. With the optimized conditions all of the nine analytes were baseline-separated in peaks of good shapes within 20 min. After validation the method was used to analyze the components in a rhubarb sample. A solid-phase extraction procedure was employed. Five anthraquinones and two bianthrones had been detected in the sample and their amounts were determined. The method should be able to be used for the quantitative analysis of the main active components of rhubarb crude drugs.