A miniature stainless steel net dumbbell-shaped stir-bar for the extraction of phthalate esters in instant noodle and rice soup samples.

This work reports the development of a very-simple-to-construct stir-bar extraction device so called "a dumbbell-shaped stainless steel stir-bar." The extraction device was assembled from a rolled up stainless steel net filled with an XAD-2 sorbent and a metal rod to allow the use of a magnetic stirrer during extraction. The dumbbell-shaped stainless steel stir-bar was used to extract diethyl phthalate (DEP), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP) before analysis by a gas chromatograph equipped with an electron capture detector (GD-ECD). Under the optimal conditions, the developed method provided a good linearity from 10.0 to 1,000.0 ng mL-1 for all three compounds. Limits of detection and limits of quantification were 9.37 ± 0.29 ng mL-1 and 31.22 ± 0.95 ng mL-1 for DEP, 5.73 ± 0.31 ng mL-1 and 19.1 ± 1.0 ng mL-1 for DBP and 3.30 ± 0.06 ng mL-1 and 11.0 ± 0.19 ng mL-1 for DEHP, respectively. Good recoveries in the range of 81.89 ± 0.17 to 109.5 ± 2.0% were achieved when the method was used to extract phthalate esters in five instant noodle and two rice soup samples.

Bioassay-guided isolation of an active compound with protein tyrosine phosphatase 1B inhibitory activity from Sargassum fusiforme by high-speed counter-current chromatography.

A rapid and efficient method using high-speed counter-current chromatography was established for the bioassay-guided separation of an active compound with protein tyrosine phosphatase 1B inhibitory activity from Sargassum fusiforme. Under the bioassay guidance, the ethyl acetate extract with the best IC50 value of 0.37 ± 0.07 µg/mL exhibited a potential protein tyrosine phosphatase 1B inhibitory activity, which was further separated by high-speed counter-current chromatography. The separation was performed with a two-phase solvent system composed of n-hexane/methanol/water (5:4:1, v/v). As a result, dibutyl phthalate (19.7 mg) with the purity of 95.3% was obtained from 200 mg of the ethyl acetate extract. Its IC50 was 14.05 ± 0.06 µM, which was further explained by molecular docking. The result of molecular docking showed that dibutyl phthalate enfolded in the catalytic site of protein tyrosine phosphatase 1B. The main force between dibutyl phthalate and protein tyrosine phosphatase 1B was the hydrogen bond interaction with Gln266. In addition, hydrogen bond, van der Waals force and hydrophobic interaction with the amino acids (Ala217, Ile219, and Gly220) were also responsible for the stable protein-ligand complex.

Toxicity study of dibutyl phthalate of Rubia cordifolia fruits: in vivo and in silico analysis.

Natural toxins from plant sources with wide ranges of biological activities reflect the upswing of drug design in the pharmaceutical industry. Rubia cordifolia L. is one of the most important red dye yielding plants. Most of the former researches have focused on the bioactive compounds from the roots of R. cordifolia, while no attention was paid towards the fruits. For the first time, here we report the presence of dibutyl phthalate in the fruits of R. cordifolia. Structural characterization was carried out using Ultraviolet-Visible spectrophotometer (UV-Vis), Fourier transform infrared (FTIR), gas chromatography-mass spectrophotometer (GC-MS), Nuclear magnetic resonance (NMR). Acute toxicity of the crude ethanolic extracts of the R. cordifolia fruits was examined in Swiss albino mice. No mortality was observed in all treated mice with 100, 500, 1000 mg/kg body weight of crude extract of R. cordifolia fruit and it indicates that the LD50 value is higher than 1000 mg/kg body weight. This study exhibited a significant change in the body weight. Alanine transaminase (ALT), total protein, triglycerides, glucose, and also the histopathological analysis of liver for all treated mice showed difference from the control group. The dibutyl phthalate was further evaluated for the toxicity study through in silico analysis. Together, the results highlighted that the toxic potential of R. cordifolia fruits extracts and also the toxicity profile of the fruit should be essential for the future studies dealing with the long term effect in animals. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1059-1067, 2016.

Ortho-phthalic acid esters in lipophilic extract from the cell culture of Aconitum baicalense Turcz ex Rapaics 1907.

Optically active bis-2R(-)ethylhexyl o-phthalate was obtained with 0.18% yield from dry cultured cells of Aconitum baicalense Turcz ex Rapaics 1907 by extraction with petroleum ether followed by silica gel column chromatography. Its structure was confirmed by the analysis of 13C and 1H NMR spectra. Seasonal fluctuations of quantitative phthalate content in A. baicalense cells were identified. The tests were performed under conditions excluding the presence of phthalates in reagents, materials, and laboratory dishes. The same substance was shown to be produced by cultivated cells of other plants. Biosynthesis of esters of ortho-phthalic acid by cultivated plant cells was discovered for the first time.

Nanostructured copper-coated solid-phase microextraction fiber for gas chromatographic analysis of dibutyl phthalate and diethylhexyl phthalate environmental estrogens.

A novel nanostructured copper-based solid-phase microextraction fiber was developed and applied for determining the two most common types of phthalate environmental estrogens (dibutyl phthalate and diethylhexyl phthalate) in aqueous samples, coupled to gas chromatography with flame ionization detection. The copper film was coated onto a stainless-steel wire via an electroless plating process, which involved a surface activation process to improve the surface properties of the fiber. Several parameters affecting extraction efficiency such as extraction time, extraction temperature, ionic strength, desorption temperature, and desorption time were optimized by a factor-by-factor procedure to obtain the highest extraction efficiency. The as-established method showed wide linear ranges (0.05-250 µg/L). Precision of single fiber repeatability was <7.0%, and fiber-to-fiber repeatability was <10%. Limits of detection were 0.01 µg/L. The proposed method exhibited better or comparable extraction performance compared with commercial and other lab-made fibers, and excellent thermal stability and durability. The proposed method was applied successfully for the determination of model analytes in plastic soaking water.

[A new phthalide from angelicae sinensis radix].

Angelicae Sinensis Radix, dried roots of Angelicae sinensis, is a well-known traditional Chinese medicine. Six compounds were isolated and purified by silica gel and preparative HPLC. According to physicochemical properties and spectral data, the compounds were identified as senkyunolide H-7-acetate (1), o-phthalic acid (2), diisobutyl phthalate (3), p-hydroxyphenylethanol ferulate (4), ferulic acid (5) and coniferylferulate (6). Compound 1 was a new one.

A dibutyl phthalate sensor based on a nanofiber polyaniline coated quartz crystal monitor.

Dibutyl phthalate (DBP) is a commonly used plasticizer and additive to adhesives, printing inks and nail polishes. Because it has been found to be a powerful reproductive and developmental toxicant, a sensor to monitor DBP in some working spaces and the environment is required. In this work polyaniline nanofibers were deposited on the electrode of a quartz crystal oscillator to form a Quartz Crystal Microbalance gas sensor. The coated quartz crystal and a non-coated quartz crystal were mounted in a sealed chamber, and their frequency difference was monitored. When DBP vapor was injected into the chamber, gas adsorption decreased the frequency of the coated quartz crystal oscillator and thereby caused an increase in the frequency difference between the two crystals. The change of the frequency difference was recorded as the sensor response. The sensor was extremely sensitive to DBP and could be easily recovered by N2 purging. A low measurement limit of 20 ppb was achieved. The morphologies of the polyaniline films prepared by different approaches have been studied by SEM and BET. How the nanofiber-structure can improve the sensitivity and stability is discussed, while its selectivity and long-term stability were investigated.

[Study on constituents of the aerial parts of Pogostemon cablin].

OBJECTIVE: To investigate the chemical constituents of the aerial parts of Pogostemon cablin. METHODS: The constituents were isolated by column chromatography over silica gel, Sephadex LH-20 and C8. Structures were identified by spectroscopic data analysis. RESULTS: Thirteen compounds were obtained and elucidated as patchouli alcohol (1), pogostone (2), friedelin (3), epifriedelinol (4), oleanolic acid (5), methyl oleanolate (6), 5alpha-stigmast-3,6-dione (7), stigmast-4-ene-3-one (8), beta-sitosterol (9), pachypodol (10), retusin (11), (-)-guaiacylglycerol (12) and dibutyl phthalate (13). CONCLUSION: Compounds 6, 7, 8, 12 and 13 are isolated from this genus for the first time.

[Study on the chemical constituents of the roots of Dendropanax chevalieri].

OBJECTIVE: To study the chemical constituents of the roots of Dendropanax chevalieri. METHODS: The constituents were isolated by column chromatography with silica gel, Sephadex LH-20 gel and RP-18. Their structures were elucidated by analysis of spectral data and physicochemical properties. RESULTS: Eight compounds were isolated and identified as palmitic acid (1), dibutylphthalate (2), beta-sitosterol (3), coniferaldehyde (4), scopoletin (5), beta-hydroxypropiovanillone (6), (+)-pinoresinol (7), (+)-syringaresinol (8). CONCLUSION: Compounds 1-2, 4-8 are obtained from this genus for the first time.

[Study on the chemical constituents of Elephantopus mollis].

OBJECTIVE: To investigate the chemical constituents of Elephantopus mollis. METHODS: Compounds were separated and purified by various column chromatographies including macroporous resin, ODS, Sephadex LH-20 and silica gel columns. The structures were identified by their physicochemical properties and spectroscopic data. RESULTS: Nine compounds were identified as 2beta-deethoxy-2-hydroxyphantomolin (1), 2beta-methoxy-2-deethoxyphantomolin (2), 2beta-methoxy-2-deethoxy-8-O-deacylphantomolin-8-O-tigli-nate (3), molephantinin (4), betulinic acid (5), magnolol (6), honokiol (7), dibutly phthalate (8) and tricin (9). CONCLUSION: Compounds 5-9 are isolated from this plant for the first time.

[Study on chemical composition of ethylacetate fraction from Polygonum amplexicaule var. sinense].

OBJECTIVE: To study chemical composition of ethylacetate fraction from Polygonoum amplexicaule D. Don var. sinense Forb. METHODS: TLC, Normal-phase silica gel column, reveres-phase silica gel column, Sephadex-LH, semi-preparative HPLC column were used to isolate chemical compositions of ethylacetate fraction from Polygonoum var. sinense. RESULTS: Eight compounds were identified as: 1. P-Hydroxybenzoic acid, 2. P-Hydroxybenzoic ethanol, 3. Diisobutyl phthalate, 4. Vanillin, 5. Isovanillic acid, 6.3,4,5-trihydroxy-benzoic acid-butyl ester, 7. 4-hydroxy-3-methoxycinnamic acid, 8. 7-hydroxy-6-methoxycoumarin. CONCLUSION: Except of Diisobutyl phthalate, the others are isolated for the first from this plant, moreover, Vanillin, Isovanillic acid and P-hydro -xyphenethyl alcohol are gained from genus for the first time.

[Study on chemical constituents of the ethyl acetate extract from Blumea aromatica].

OBJECTIVE: To study the chemical constituents of the ethyl acetate extract from Blumea aromatica. METHODS: Column chromatographic techniques were used for the isolation and purification. Spectroscopic techniques were used for the identification of structures. RESULTS: Seven compounds were isolated from the ethyl acetate extract of 80% alcohol extract of the whole plant, and their structures were identified as xanthoxylin(1), dibutyl phthalate(2), luteolin-3',4',7-trimethyl ether(3), rubiadin(4), eriodictyol(5), kaempherol(6), luteolin 7,3'-dimethyl ether(7). CONCLUSION: All the compounds are isolated from this plant for the first time. Among them, compounds 2,4 and 7 are isolated from this genus for the first time.

[Study on chemical constituents from leaves of Tripterygium wilfordii].

In order to study the chemical constituents of the leaves of Tripterygium wilfordii and provide references for the bio-active study, we isolated nine compounds from the dried leaves of Tripterygium wilfordii. Their structures were determined by application of spectroscopic (NMR, MS) and chemical methods. These compounds were isolated and identified as (+)-lyoniresinol (1), (+)-isolariciresinol (2), burselignan (3), dibutyl phthalate (4), cyclo-(S-Pro-R-Phe) (5), cyclo-(S-Pro-R-Leu) (6), cyclo-(S-Pro-S-Ile) (7), 3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone (8) and daucosterol (9). Compounds 1-3, 5-8 were isolated from this plant for the first time.

Dual amplified ratiometric fluorescence ELISA based on G-quadruplex/hemin DNAzyme using tetrahedral DNA nanostructure as scaffold for ultrasensitive detection of dibutyl phthalate in aquatic system.

Dibutyl phthalate (DBP) is considered as one of the most widely used phthalate esters (PAEs), which has attracted worldwide concerns because of its potential threats to eco-environments and human health. Systematic investigations of DBP environmental occurrence contribute to the further risk assessment, which depends on effective and available analytical methods. In this study, an amplified ratiometric fluorescence ELISA was established for sensitive and high-throughput detection of DBP in the aquatic system based on a novel tetrahedral DNA nanostructure (TDN)-scaffolded-DNAzyme (Tetrazyme). Wherein, Tetrazyme was prepared by the precise folding of G-quadruplex sequence on three vertex angles of the TDN, together with hemin as the horseradish peroxidase (HRP)-mimicking enzyme. The rigid TDN avoided the local overcrowding effect to provide a reasonable spatial spacing on the interface for G-quadruplex sequence, increasing the collision chance between DNAzyme and substrates, improving the catalytic ability of DNAzyme effectively. Besides, streptavidin (SA) and biotin (bio) were used to anchor TDN and antibody, in which the specific binding of SA/bio could make more Tetrazyme conjugate on each signal element, resulting in the dual signal amplification. Meanwhile, the accuracy and precision were enhanced owing to the inherent built-in rectification to the environment from the dual output ratiometric fluorescence assay. Under the optimized conditions, the detection limit of this proposed method was 0.17 ng/mL (16 times lower than that of conventional ELISA using the same antibody) with a satisfactory accuracy (recoveries, 79.0%- 116.2%; CV, 2.1-6.5%). Overall, this platform provides a promising way for accurate, sensitive and rapid determination of DBP from environmental waters.

Overexpression of Capsular Polysaccharide Biosynthesis Protein in Lactobacillus plantarum P1 to Enhance Capsular Polysaccharide Production for Di-n-butyl Phthalate Adsorption.

Exopolysaccharides (EPSs) such as capsular polysaccharide (CPS) are important bioactive carbohydrate compounds and are often used as bioenrichment agents and bioabsorbers to remove environmental pollutants like di-n-butyl phthalate (DBP). Among the EPS-producing bacteria, lactic acid bacteria (LAB) have gained the most attention. As generally recognized as safe (GRAS) microorganisms, LAB can produce EPSs having many different structures and no health risks. However, EPS production by LAB does not meet the needs of large-scale application on an industrial scale. Here, the capA gene (encoding CPS biosynthesis protein) was overexpressed in Lactobacillus plantarum P1 to improve the production of EPSs and further enhance the DBP adsorption capability. Compared with P1, the CPS production in capA overexpressed strain was increased by 11.3 mg/l, and the EPS thickness was increased from 0.0786 ± 0.0224 µm in P1 to 0.1160 ± 0.0480 µm in P1-capA. These increases caused the DBP adsorption ratio of P1-capA to be doubled. Overall, the findings in this study provide a safe method for the adsorption and removal of DBP.

Simultaneous determination of four phthalate esters in bottled water using ultrasound-assisted dispersive liquid-liquid microextraction followed by GC-FID detection.

A simple and rapid sample pretreatment procedure based on ultrasound-assisted dispersive liquid-liquid microextraction is proposed for the determination of four phthalate esters (dibutyl phthalate, butyl benzyl phthalate, diisooctyl phthalate, dioctyl phthalate) in bottled water samples using gas chromatography-flame ionization detection. An ultrasound-assisted process was applied to accelerate the formation of the fine cloudy solution using less disperser solvent, which markedly increased the extraction efficiency and reduced the equilibrium time. Under optimum conditions, the enrichment factor of the four analytes ranged from 490- to 530-fold and the recovery ranged from 84.8%∼104.7%. A good linear relationship between the peak area and the concentration of analytes was obtained in the range of 6.9∼444 µg L(-1). Intra-assay and inter-assay precision expressed as relative standard deviation (RSD) were in the range of 1.4∼2.0% and 3.0∼3.7%, respectively. This method offers a good alternative for routine analysis due to its simplicity and reliability.

Dibutyl phthalate contributes to the thyroid receptor antagonistic activity in drinking water processes.

It has long been recognized that thyroid hormone (TH) is essential for normal brain development in both humans and animals, and there is growing evidence that environmental chemicals can disrupt the thyroid system. In the present work, we used a two-hybrid yeast assay to screen for agonistic or antagonistic thyroid receptor (TR) mediated effects in drinking waters. We found no TR agonistic, but TR antagonistic activities in all samples from the drinking water processes. The TR antagonistic activities in organic extracts of water samples were then calibrated regarding to a known TR-inhibitor, NH3, and were expressed as the NH3 equivalents (TEQbio). The observed TEQbio in waters ranged from 180.8+/-24.8 to 280.2+/-48.2 microg/L NH3. To identify the specific compounds responsible for TR disrupting activities, the concentrations of potentially thyroid-disrupting chemicals including organochlorine pesticides (OCPs), phenols, and phthalates in organic extracts were quantitatively determined and their toxic equivalents with respect to NH3 (TEQcal) were estimated from their concentration-dependent relationships, respectively, using the same set of bioassays. Based on the TEQ approach, it was revealed that dibutyl phthalate (DBP) accounted for 53.7+/-8.2% to 105.5+/-16.7% of TEQbio. There was no effective removal of these potential thyroid disrupting substances throughout drinking water treatment processes.

[Studies on the chemical constituents from pine needles of Cedrus deodara (II)].

OBJECTIVE: To study the chemical constituents from pine needles of Cedrus deodara. METHODS: Chemical constituents were isolated from 95% ethanol extract by silica gel and Sephadex LH-20 column chromatography. The structures were elucidated through spectroscopic analysis. RESULTS: The compounds were identified as 10-nonacosanol (1), dibutyl phthalate (2), protocatechuic acid (3), phthalic acid bis-(2-ethylhexyl) ester (4), (E)-1-O-p-coumaroyl-beta-D-glucopyranoside (5), 5-p-trans-coumaroylguinic acid (6). CONCLUSIONS: Compounds 1- 6 are obtained from this genus for the first time.

[Study on the constituents of petroleum ether fraction of Buxus microphylla].

OBJECTIVE: To study the chemical constituents from the petroleum ether fraction of Buxus microphylla. METHODS: The petroleum ether fraction of Buxus microphylla was isolated and identified by silica gel column chromatography. And the anticancer activity of different chemical constituents was measured by MTT reduction test. RESULTS: Eight compounds were isolated and identified as lupeol (1), butulin (3), beta-sitosterol (4), stigmasterol (5), dibutyl phthalate (6), 3beta, 30-dihydroxy-lup-20 (29) ene (7), daucosterol (8). Compound 7 inhibited KB cells' proliferation in a dose-dependent manner. CONCLUSION: Compounds 2 - 5, 7, 8 are isolated from this genus for the first time. Compound 7 has certainly anticancer effects.

Nanomaterials as alternative dispersants for the multiresidue analysis of phthalates in soil samples using matrix solid phase dispersion prior to ultra-high performance liquid chromatography tandem mass spectrometry.

In this study, the application of different nanomaterials as dispersants in matrix solid phase dispersion has been evaluated for the extraction of fifteen phthalates from different environmental samples prior to their separation and quantification by ultra-high performance liquid chromatography coupled to triple quadrupole mass spectrometry. Within the evaluated nanomaterials, including graphene oxide, multi-walled carbon nanotubes and iron 1,3,5-benzenetricarboxylate metal-organic framework, the last one showed the best results in terms of extraction capacity and sample clean-up. The effects of the different parameters affecting the sample pretreatment efficiency were exhaustively evaluated. The whole methodology was validated for agricultural soil and sand, using dibutyl phthalate-3,4,5,6-d4 as surrogate. Recovery values ranged from 70 to 120% for both matrices with RSD values lower than 20% and the limits of quantification of the method achieved were in the range 0.14-2.7 µg/kg dry weight. Finally, the analysis of soil samples from different locations of Tenerife (Canary Islands, Spain) was carried out finding the presence of BBP, DIBP and DBP in the range 5-52 µg/kg dry weight in agricultural soils, and DIPP, DNOP and DINP in the range 2-101 µg/kg dry weight in sand samples.