Characterization of effective phytochemicals in traditional Chinese medicine by mass spectrometry.

Traditional Chinese medicines (TCMs) have been widely used in clinical and healthcare applications around the world. The characterization of the phytochemical components in TCMs is very important for studying the therapeutic mechanism of TCMs. In the analysis process, sample preparation and instrument analysis are key steps to improve analysis performance and accuracy. In recent years, chromatography combined with mass spectrometry (MS) has been widely used for the separation and detection of trace components in complex TCM samples. This article reviews various sample preparation techniques and chromatography-MS techniques, including the application of gas chromatography-MS and liquid chromatography-MS and other MS techniques in the characterization of phytochemicals in TCM materials and Chinese medicine products. This article also describes a new ambient ionization MS method for rapid and high-throughput analysis of TCM components.

The relationship between exposure to polycyclic aromatic hydrocarbons and adult atopic dermatitis.

BACKGROUND: Polycyclic aromatic hydrocarbons are one of the major pathogenic components in air pollution. Previous studies have demonstrated an association between air pollution and atopic dermatitis. OBJECTIVE: We sought to explore the relationship between polycyclic aromatic hydrocarbons exposure and adult atopic dermatitis. METHODS: We prospectively recruited 23 adult patients with atopic dermatitis and 11 healthy controls. Plasma levels of inflammatory cytokines were determined using enzyme-linked immunosorbent assay. Expression levels of aryl hydrocarbon receptor, which mediates the effect of polycyclic aromatic hydrocarbons, and cytokines in peripheral blood nuclear cells (PBMCs) were measured using reverse transcription polymerase chain reaction. Urine levels of 16 polycyclic aromatic hydrocarbon metabolites were determined by gas chromatography- tandem mass spectrometry. RESULTS: Patients with atopic dermatitis had lower levels of interleukin (IL)-5 and IL-23, and lower PBMC messenger RNA expression levels of interferon-> than the healthy controls. Plasma levels of IL-22 were moderately and positively associated with the SCORAD index. Creatinine-corrected urine levels of 9-hydroxyfluorene and 2-hydroxyphenanthrene were elevated in the atopic dermatitis group. However the difference was not statistically significant after Bonferroni correction. CONCLUSIONS: Our results demonstrated that the polycyclic aromatic hydrocarbons fluorene and phenanthrene are potentially associated with the pathogenesis of atopic dermatitis in adults.

Therapeutic Potential of Tpl2 (Tumor Progression Locus 2) Inhibition on Diabetic Vasculopathy Through the Blockage of the Inflammasome Complex.

OBJECTIVE: Diabetic retinopathy, one of retinal vasculopathy, is characterized by retinal inflammation, vascular leakage, blood-retinal barrier breakdown, and neovascularization. However, the molecular mechanisms that contribute to diabetic retinopathy progression remain unclear. Approach and Results: Tpl2 (tumor progression locus 2) is a protein kinase implicated in inflammation and pathological vascular angiogenesis. Nε-carboxymethyllysine (CML) and inflammatory cytokines levels in human sera and in several diabetic murine models were detected by ELISA, whereas liquid chromatography-tandem mass spectrometry analysis was used for whole eye tissues. The CML and p-Tpl2 expressions on the human retinal pigment epithelium (RPE) cells were determined by immunofluorescence. Intravitreal injection of pharmacological inhibitor or NA (neutralizing antibody) was used in a diabetic rat model. Retinal leukostasis, optical coherence tomography, and H&E staining were used to observe pathological features. Sera of diabetic retinopathy patients had significantly increased CML levels that positively correlated with diabetic retinopathy severity and foveal thickness. CML and p-Tpl2 expressions also significantly increased in the RPE of both T1DM and T2DM diabetes animal models. Mechanistic studies on RPE revealed that CML-induced Tpl2 activation and NADPH oxidase, and inflammasome complex activation were all effectively attenuated by Tpl2 inhibition. Tpl2 inhibition by NA also effectively reduced inflammatory/angiogenic factors, retinal leukostasis in streptozotocin-induced diabetic rats, and RPE secretion of inflammatory cytokines. The attenuated release of angiogenic factors led to inhibited vascular abnormalities in the diabetic animal model. CONCLUSIONS: The inhibition of Tpl2 can block the inflammasome signaling pathway in RPE and has potential clinical and therapeutic implications in diabetes-associated retinal microvascular dysfunction.

Long, Noncoding RNA SRA Induces Apoptosis of ß-Cells by Promoting the IRAK1/LDHA/Lactate Pathway.

Long non-coding RNA steroid receptor RNA activators (LncRNA SRAs) are implicated in the ß-cell destruction of Type 1 diabetes mellitus (T1D), but functional association remains poorly understood. Here, we aimed to verify the role of LncRNA SRA regulation in ß-cells. LncRNA SRAs were highly expressed in plasma samples and peripheral blood mononuclear cells (PBMCs) from T1D patients. LncRNA SRA was strongly upregulated by high-glucose treatment. LncRNA SRA acts as a microRNA (miR)-146b sponge through direct sequence-structure interactions. Silencing of lncRNA SRA increased the functional genes of Tregs, resulting in metabolic reprogramming, such as decreased lactate levels, repressed lactate dehydrogenase A (LDHA)/phosphorylated LDHA (pLDHA at Tyr10) expression, decreased reactive oxygen species (ROS) production, increased ATP production, and finally, decreased ß-cell apoptosis in vitro. There was a positive association between lactate level and hemoglobin A1c (HbA1c) level in the plasma from patients with T1D. Recombinant human interleukin (IL)-2 treatment repressed lncRNA SRA expression and activity in ß-cells. Higher levels of lncRNA-SRA/lactate in the plasma are associated with poor regulation in T1D patients. LncRNA SRA contributed to T1D pathogenesis through the inhibition of miR-146b in ß-cells, with activating signaling transduction of interleukin-1 receptor-associated kinase 1 (IRAK1)/LDHA/pLDHA. Taken together, LncRNA SRA plays a critical role in the function of ß-cells.

Polyketide Synthase Gene Expression in Relation to Chloromonilicin and Melanin Production in Monilinia fructicola.

Monilinia fructicola is a fungal pathogen of worldwide significance that causes brown rot of stone fruits. There are only few reports related to the production of biologically active polyketides by this pathogen. In this study, we examined an atypical M. fructicola strain TW5-4 that shows strong antimicrobial activity against various plant pathogens. TW5-4 also displays sparse growth in culture, low virulence, and higher levels of melanin compared with its albino mutant, TW5-4WM, and a wild-type strain Mf13-81. Antifungal compounds were extracted from TW5-4 and purified by thin-layer chromatography following visualization with an on-the-chromatogram inhibition assay. The principal antifungal compound was identified by linear ion trap mass spectrometry, high-resolution electro-spray ionization mass spectrometry, and proton nuclear magnetic resonance analyses as the polyketide chloromonilicin. Multiple M. fructicola polyketide synthase (PKS) sequences were then cloned by degenerate PCR and inverse PCR. Sequence analyses support presence of a 10-member PKS gene family in the M. fructicola genome. Analyses of PKS gene expression found no strong correlation between chloromonilicin production in culture and transcript levels of any of the PKS gene family members in mycelium of strains TW5-4, TW5-4WM, and Mf13-81. However, MfPKS12, a homolog of BcPKS12 involved in biosynthesis of 1,8-dihydroxynaphthalene (DHN)-melanin in Botrytis cinerea, was strongly expressed in mycelia of TW5-4 and Mf13-81. An MfPKS12-silenced mutant accumulated significantly less melanin in mycelia, had lower resistance to polyethylene glycol-induced osmotic stress, and displayed reduced virulence on nectarine fruit. The results suggest that DHN-melanin is required for tolerance to osmotic stress and full virulence in M. fructicola.

Therapeutic Effects of Lithospermate B Complexed with Mg2+ or Zn2+ on Metabolic Syndrome Induced in Rats Fed with High-Fat Diet.

Excessive food consumption and insufficient exercise lead to the prevalence of metabolic syndrome in modern life, which consequently increases the risk of many chronic diseases. Magnesium lithospermate B (MLB) from Danshen has been demonstrated to improve metabolic changes in high-fat diet-fed rats with metabolic syndrome. In this study, Mg2+ in MLB was successfully replaced with Zn2+ to form zinc lithospermate B (ZLB) complex. MLB (10 mg/kg /day) and ZLB of various concentrations (1, 2.5, 5, and 10 mg/kg/day) were prepared and examined for their therapeutic effects on metabolic syndrome induced in rats fed with a high-fat diet. The results showed that both MLB and ZLB were able to recover or alleviate the abnormal physiological states of high-fat diet-fed rats including weight gain, epididymal fat accumulation, fatty liver, retarded blood lipid and glucose metabolism putatively caused by insulin resistance, and elevated levels of proinflammatory cytokine, leptin, and oxidative stress. In an overall view of the animal study, the effectiveness of ZLB supplementation seemed to be better than that of MLB supplementation for the recovery of high-fat-fed rats from metabolic syndrome.

TPL2 (Therapeutic Targeting Tumor Progression Locus-2)/ATF4 (Activating Transcription Factor-4)/SDF1α (Chemokine Stromal Cell-Derived Factor-α) Axis Suppresses Diabetic Retinopathy.

RATIONALE: Diabetic retinopathy is characterized by vasopermeability, vascular leakage, inflammation, blood-retinal barrier breakdown, capillary degeneration, and neovascularization. However, the mechanisms underlying the association between diabetes mellitus and progression retinopathy remain unclear. OBJECTIVE: TPL2 (tumor progression locus 2), a serine-threonine protein kinase, exerts a pathological effect on vascular angiogenesis. This study investigated the role of Nε-(carboxymethyl)lysine, a major advanced glycation end products, and the involved TPL2-related molecular signals in diabetic retinopathy using models of in vitro and in vivo and human samples. METHODS AND RESULTS: Serum Nε-(carboxymethyl)lysine levels and TPL2 kinase activity were significantly increased in clinical patients and experimental animals with diabetic retinopathy. Intravitreal administration of pharmacological blocker or neutralizing antibody inhibited TPL2 and effectively suppressed the pathological characteristics of retinopathy in streptozotocin-induced diabetic animal models. Intravitreal VEGF (vascular endothelial growth factor) neutralization also suppressed the diabetic retinopathy in diabetic animal models. Mechanistic studies in primary human umbilical vein endothelial cells and primary retinal microvascular endothelial cells from streptozotocin-diabetic rats, db/db mice, and samples from patients with diabetic retinopathy revealed a positive parallel correlation between Nε-(carboxymethyl)lysine and the TPL2/chemokine SDF1α (stromal cell-derived factor-α) axis that is dependent on endoplasmic reticulum stress-related molecules, especially ATF4 (activating transcription factor-4). CONCLUSIONS: This study demonstrates that inhibiting the Nε-(carboxymethyl)lysine-induced TPL2/ATF4/SDF1α axis can effectively prevent diabetes mellitus-mediated retinal microvascular dysfunction. This signaling axis may include the therapeutic potential for other diseases involving pathological neovascularization or macular edema.

Microwave-assisted-demulsification dispersive liquid-liquid microextraction for the determination of triazole fungicides in water by gas chromatography with mass spectrometry.

A novel microwave-assisted-demulsification dispersive liquid-liquid microextraction technique was established for determination of three triazole fungicides in environmental water samples by gas chromatography with mass spectrometry. Importantly, microwave irradiation has been applied in demulsification to achieve the phase separation and enrichment of triazole fungicides in water samples successfully with low-density toluene as extractant. The experimental variables, including microwave power, microwave time, ultrasonic time, type and volume of extraction solvent, and effect of salting out were investigated. Under the optimized conditions, the method showed good linearity for myclobutanil, tebuconazole, and difenoconazole in the range of 1-100 µg/L. The limits of detection and the limits of quantification were within the range of 0.14-0.27 and 0.47-0.90 µg/L, respectively. The suitable enrichment factors for three triazole pesticides were in the range of 425-636. The recoveries were between 89.3 and 108.7%, and the relative standard deviations were from 5.4 to 8.6%. Finally, environmental water samples were used to verify the applicability of the proposed method for analysis of triazole fungicides targets. It can be concluded that the developed microwave-assisted-demulsification dispersive liquid-liquid microextraction gas chromatography with mass spectrometry method was a rapid, efficient, reliable, and environmental friendly way for analysis of triazole fungicides in water.

Effect of teapot materials on the chemical composition of oolong tea infusions.

BACKGROUND: The flavor and quality of tea are widely believed to be associated with the pot in which the tea is made. However, this claim is mostly by experiences and lacks solid support from scientific evidence. The current study investigated and compared the chemical compositions of oolong tea made with six different teapot materials, namely Zisha, Zhuni, stainless steel, ceramic, glass and plastic. RESULTS: For each tea sample, polyphenols and caffeine were examined by HPLC-UV, volatile compounds by GC/MS, amino acids by LC/MS and minerals by ICP-MS. The results suggested that tea infusions from Zisha and Zhuni pots contain higher levels of EGC, EGCG and total catechins and less caffeine than those from ceramic, glass and plastic pots and tend to have the lowest total mineral contents, potassium and volatile compounds in tea soup. The statistical differences were not all significant among Zisha, Zhuni and stainless steel pots. CONCLUSION: Based on the overall chemical composition of the tea infusion, Yixing clay pots (Zisha and Zhuni) produce tea infusions that are presumably less bitter and more fragrant and tend to contain more healthful compounds than tea infusions from other pots. The results could partially explain why Yixing clay pots are among the most popular teapots. The beneficial effects of long-term repeated use of these teapots warrants further study. © 2017 Society of Chemical Industry.

Simultaneous determination of sulfonamides and metabolites in manure samples by one-step ultrasound/microwave-assisted solid-liquid-solid dispersive extraction and liquid chromatography-mass spectrometry.

An in-line matrix cleanup method was used for the simultaneous extraction of 15 sulfonamides and two metabolites from manure samples. The ultrasound/microwave-assisted extraction (UMAE) combined with solid-liquid-solid dispersive extraction (SLSDE) procedure provides a simple sample preparation approach for the processing of manure samples, in which the extraction and cleanup are integrated into one step. Ultrasonic irradiation power, extraction temperature, extraction time, and extraction solvent, which could influence the UMAE efficiency, were investigated. C18 was used as the adsorbent to reduce the effects of interfering components during the extraction procedure. The extracts were concentrated, and the analytes were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) without any further cleanup. The isotopically labeled compounds sulfamethoxazole-d 4, sulfamethazine-d 4, sulfamonomethoxine-d 4, and sulfadimethoxine-d 6 were selected as internal standards to minimize the matrix effect in this method. The recoveries of the antibiotics tested ranged from 71 to 118 % at the three spiking levels examined (20, 200, and 500 µg · kg(-1)). The limits of detections were 1.2-3.6 µg · kg(-1) and the limits of quantification were 4.0-12.3 µg · kg(-1) for the sulfonamides and their metabolites. The applicability of the method was demonstrated by analyzing 30 commercial manure samples. The results indicated that UMAE-SLSDE combined with LC-MS/MS is a simple, rapid, and environmentally friendly method for the analysis of sulfonamides and their metabolites in manure, and it could provide the basis for a risk assessment of the antibiotics in agricultural environments.

Observation of the intermediates of in-source aldolization reaction in electrospray ionization mass spectrometry analysis of heteroaromatic aldehydes.

Electrospray ionization mass spectrometry (ESI-MS) analyses of 2-(1,2,4-triazole-1-yl)-6-methyl-3- quinolinecarboxaldehyde were carried out by using an ion trap mass spectrometer in a positive-ion mode. Interestingly, several unusual [M + 15](+), [M + 33](+), and [M + 47](+) ions were observed with a high abundance in the ESI-MS spectrum when methanol was used as the ESI solvent. However, only the protonated molecule was obtained with acetonitrile as the ESI solvent. These unusual ions have been proposed as the intermediates of an aldolization reaction occurring in the ESI source, which have been validated by a tandem mass spectrometry experiment, high-performance liquid chromatography/mass spectrometry analysis, and theoretical calculations. A full understanding of this reaction can contribute to the avoidance of analysis errors in the ESI-MS analysis of unknown heteroaromatic aldehydes.

HPLC/QTOF-MS/MS application to investigate phenolic constituents from Ficus pandurata H. aerial roots.

Ficus pandurata H. aerial roots are used as a traditional Chinese medicine for the treatment of uarthritis, indigestion and hyperuricemia. However, the bioactive constituents responsible for the pharmacological effects of F. pandurata H. are unclear. A simple and efficient HPLC/QTOF-MS/MS (high-performance liquid chromatography/electrospray ionization with quadrupole time-of-flight tandem mass spectrometry) method was established to detect and identify active constituents in the n-butanol extract of F. pandurata H. aerial roots. Chemical constituents were separated and investigated by HPLC/QTOF-MS/MS in the negative-ion mode. Thirty-seven compounds, including hydroxycinnamic acid derivatives, hydroxybenzoic acid derivatives, hydroquinone glycosides, flavonoid glycosides, etc., were identified or tentatively characterized in the n-butanol extract of F. pandurata H. aerial roots by comparing the UV spectra, accurate mass spectra and fragmentation pathways and retrieving the reference literatures. Moreover, the flavonoid trisaccharides and hydroxybenzoic acid derivatives were tentatively characterized in F. pandurata H. for the first time. The analytical tool used here is very valuable in the rapid separation and identification of the multiple and minor constituents in the n-butanol extract of F. pandurata H. aerial roots.

Advanced glycation end product Nε-carboxymethyllysine induces endothelial cell injury: the involvement of SHP-1-regulated VEGFR-2 dephosphorylation.

N(ε)-carboxymethyllysine (CML), a major advanced glycation end product, plays a crucial role in diabetes-induced vascular injury. The roles of protein tyrosine phosphatases and vascular endothelial growth factor (VEGF) receptors in CML-related endothelial cell injury are still unclear. Human umbilical vein endothelial cells (HUVECs) are a commonly used human EC type. Here, we tested the hypothesis that NADPH oxidase/reactive oxygen species (ROS)-mediated SH2 domain-containing tyrosine phosphatase-1 (SHP-1) activation by CML inhibits the VEGF receptor-2 (VEGFR-2, KDR/Flk-1) activation, resulting in HUVEC injury. CML significantly inhibited cell proliferation and induced apoptosis and reduced VEGFR-2 activation in parallel with the increased SHP-1 protein expression and activity in HUVECs. Adding recombinant VEGF increased forward biological effects, which were attenuated by CML. The effects of CML on HUVECs were abolished by SHP-1 siRNA transfection. Exposure of HUVECs to CML also remarkably escalated the integration of SHP-1 with VEGFR-2. Consistently, SHP-1 siRNA transfection and pharmacological inhibitors could block this interaction and elevating [(3)H]thymidine incorporation. CML also markedly activated the NADPH oxidase and ROS production. The CML-increased SHP-1 activity in HUVECs was effectively attenuated by antioxidants. Moreover, the immunohistochemical staining of SHP-1 and CML was increased, but phospho-VEGFR-2 staining was decreased in the aortic endothelium of streptozotocin-induced and high-fat diet-induced diabetic mice. We conclude that a pathway of tyrosine phosphatase SHP-1-regulated VEGFR-2 dephosphorylation through NADPH oxidase-derived ROS is involved in the CML-triggered endothelial cell dysfunction/injury. These findings suggest new insights into the development of therapeutic approaches to reduce diabetic vascular complications.

Detecting metabolites of different transition metal-lithospermate B complexes after intravenous injection in rats.

AIM: Lithospermate B (LSB) isolated from the traditional Chinese medicine danshen (Salvia miltiorrhiza) is an effective Na(+)/K(+)-ATPase inhibitor and used to treat congestive heart failure. The inhibition of LSB on Na(+)/K(+)-ATPase is potentiated by forming complexes with transition metal ions. Here we investigated the safety and metabolites of different transition metal-LSB complexes in rats. METHODS: LSB complexed with six different transition metal ions (Mg(2+), Zn(2+), Cr(3+), Co(2+), Ni(2+) and Mn(2+)) were prepared. Adult male SD rats were injected with the different metal-LSB complexes (50 mg/kg, iv), and their bile and blood samples were collected. The metabolites of the metal-LSB complexes in the samples were analyzed using mass spectroscopy. RESULTS: In rats injected with LSB complexed with Mg(2+), Zn(2+), Cr(3+), Ni(2+) or Mn(2+), LSB and its four putative metabolites were equivalently detected in their bile samples. Mn(2+)-LSB exhibited distinct metabolite profiles compared with the other four metal-LSB complexes. The four putative metabolites were identified as 3-monomethyl-LSB, 3,3''-dimethyl-LSB, 3,3'''-dimethyl-LSB and 3,3'',3'''-trimethyl-LSB. The tracking of successive bile samples of rats injected with Mg(2+)-LSB, Zn(2+)-LSB and Mn(2+)-LSB concurrently demonstrated that LSB was firstly methylated at position 3, then at position 3'', and, finally, the 3''' hydroxyl group. All rats injected with Co(2+)-LSB died. CONCLUSION: Zn(2+)-LSB, Cr(3+)-LSB, Ni(2+)-LSB or Mn(2+)-LSB produces identical four methylated metabolites of LSB in rats, and seemed to be as safe as LSB or Mg(2+)-LSB.

Gramella planctonica sp. nov., a zeaxanthin-producing bacterium isolated from surface seawater, and emended descriptions of Gramella aestuarii and Gramella echinicola.

A Gram-stain negative, strictly aerobic, zeaxanthin-producing, rod-shaped, non-spore-forming bacterial strain which is motile by gliding, designated CC-AMWZ-3(T), was isolated from surface seawater off coastal Kending, Taiwan. Strain CC-AMWZ-3(T) was found to share 93.3 % and 96.0-92.4 % pairwise 16S rRNA gene sequence similarity to Gramella echinicola KMM 6050(T) and other Gramella species, respectively, and formed distinct phyletic lineage during phylogenetic analysis. The major fatty acids were identified as C16:0, iso-C15:0, anteiso-C15:0, C16:1 ω6c and/or C16:1 ω7c and iso-C17:1 ω9c and/or C16:0 10-methyl. Polar lipids were found to include phosphatidylethanolamine, six unidentified lipids and three unidentified aminolipids. The DNA G+C content was determined to be 40.6 mol%. Menaquinone-6 was the sole respiratory quinone identified and triamine-sym-homospermidine was the predominant polyamine. Based on the polyphasic characteristics that are in line with those of Gramella species, in addition to distinguishing phylogenetic and phenotypic features, strain CC-AMWZ-3(T) appears to represent a novel species of the genus Gramella, for which the name Gramella planctonica sp. nov. (type strain CC-AMWZ-3(T) = JCM 18807(T) = BCRC 80553(T)) is proposed. In addition, emended descriptions of the species Gramella aestuarii and Gramella echinicola are also proposed.

Sphingomicrobium astaxanthinifaciens sp. nov., an astaxanthin-producing glycolipid-rich bacterium isolated from surface seawater and emended description of the genus Sphingomicrobium.

A Gram-stain-negative, rod-shaped, strictly aerobic, flagellated and non-spore-forming marine bacterium designated strain CC-AMO-30B(T) was isolated from coastal surface seawater, Taiwan. Strain CC-AMO-30B(T) synthesized astaxanthin [40 µg (g dry weight)(-1)] and formed reddish-orange-coloured colonies on marine agar (Difco 2216). The strain showed highest pairwise 16S rRNA gene sequence similarity to Sphingomicrobium lutaoense CC-TBT-3(T) (96.4%) followed by other members of the family Sphingomonadaceae (<94%) and established a discrete phyletic lineage associated with the former. The polar lipid profile constituted a remarkable number of unidentified glycolipids (GL1-8), in addition to diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid and two unidentified lipids (L1-2). The major fatty acids (>5% of total fatty acids) were C(18:1)ω7c/C(18:1)ω6c (summed feature 8), C(16:1)ω7c/C(16:1)ω6c (summed feature 3), C(18:1) 2-OH, methyl C(18:1)ω7c, C(17:1)ω6c and C(16 : 0). DNA G+C content was 70.6%; major respiratory quinone was ubiquinone Q-10; predominant polyamine was the triamine sym-homospermidine. Chemotaxonomic evidence including characteristic glycolipid profile, presence of significant amounts of C(18:1) 2-OH and absence of typical hydroxylated fatty acids such as C(14:0) 2-OH, C(15:0) 2-OH and C(16:0) 2-OH in considerable amounts, accompanied by phylogenetic distinctiveness and several other phenotypic features support the classification of strain CC-AMO-30B(T) as a representative of a novel species within the genus Sphingomicrobium for which the name Sphingomicrobium astaxanthinifaciens sp. nov. is proposed; the type strain is CC-AMO-30B(T) ( =JCM 18551(T) =BCRC 80465(T)).

The determination of flavonoids in Wikstroemia indica C. A. Mey. by liquid chromatography with photo-diode array detection and negative electrospray ionization tandem mass spectrometry.

RATIONALE: Flavonoids in the medicinal plant Wikstroemia indica C. A. Mey. are present in trace amounts and found in complex matrices. An efficient and sensitive method is necessary for the rapid identification of such biomolecules. METHODS: Flavonoids were extracted with methanol via ultrasonic-assisted extraction and analyzed by liquid chromatography with photo-diode array detection and tandem mass spectrometry. The extract was analyzed and compounds were identified using negative electrospray ionization data-dependent tandem mass spectrometry. RESULTS: The results confirmed the presence of three flavonoid compounds, seven biflavonoid compounds, and one coumarin-like compound, daphnoretin, in the extracts of different plant parts of W. indica. The method detection limit was evaluated down to 5 µg/g using kaempfol as a reference standard. CONCLUSIONS: The proposed method offers a rapid and reliable analysis for the determination of flavonoids in medicinal plants.

Modulation of energy deficiency in Huntington's disease via activation of the peroxisome proliferator-activated receptor gamma.

Huntington's disease (HD) is a neurodegenerative disease caused by the expansion of a CAG trinucleotide repeat in exon 1 of the huntingtin (HTT) gene. Here, we report that the transcript of the peroxisome proliferator-activated receptor-γ (PPARγ), a transcription factor that is critical for energy homeostasis, was markedly downregulated in multiple tissues of a mouse model (R6/2) of HD and in lymphocytes of HD patients. Therefore, downregulation of PPARγ seems to be a pathomechanism of HD. Chronic treatment of R6/2 mice with an agonist of PPARγ (thiazolidinedione, TZD) rescued progressive weight loss, motor deterioration, formation of mutant Htt aggregates, jeopardized global ubiquitination profiles, reduced expression of two neuroprotective proteins (brain-derived neurotrophic factor and Bcl-2) and shortened life span exhibited by these mice. By reducing HTT aggregates and, thus, ameliorating the recruitment of PPARγ into HTT aggregates, chronic TZD treatment also elevated the availability of the PPARγ protein and subsequently normalized the expression of two of its downstream genes (the glucose transporter type 4 and PPARγ coactivator-1 alpha genes). The protective effects described above appear to have been exerted, at least partially, via direct activation of PPARγ in the brain, as TZD was detected in the brains of mice treated with TZD and because a PPARγ agonist (rosiglitazone) protected striatal cells from mHTT-evoked energy deficiency and toxicity. We demonstrated that the systematic downregulation of PPARγ seems to play a critical role in the dysregulation of energy homeostasis observed in HD, and that PPARγ is a potential therapeutic target for this disease.

Analysis of methyl-, chloro-, bromo- and trifluoromethyl-substituted 1,9-diphenyl-9H-fluorene and its isomers by gas chromatography-ion trap multistage tandem mass spectrometry.

This work presents a modified method to analyze methyL-, chloro-, bromo- and trifluoromethyl-substituted 1,9-diphenyt-9H-fluorene and their isomers by ion trap mass spectrometry with electron impact ionization (EI). Since MS spectra of 1,9-diphenyl-9H-fluorene with these four groups and their isomers are similar, it is difficult to distinguish them from its isomers. Multistage tandem mass spectrometry analysis involves selecting molecular ions obtained in MS spectra as precursor ions in the MS/MS process, and the fragment [C25H17]+ (m/z 317) obtained in MS/MS spectra as a precursor ion in MS3 processes. Collision-induced dissociation (CID) experiments at different activation energies were done to elucidate possible fragmentation pathways. Proposed fragmentation pathways including m/z 317 and structures of the product ions are acquired simultaneously. At a higher CID voltage, the isomers of C25H17-F3 can be distinguished in MS/MS, while the isomers of C25H17-CH3, C25H17-Cl and C25H17-Br can be distinguished in MS3. This work can provide new and valuable information needed for unambiguous characterization of such substances in complex sample matrices.

Liquid chromatography incorporating ultraviolet and electrochemical analyses for dual detection of zeranol and zearalenone metabolites in mouldy grains.

BACKGROUND: Zeranol (Z) is a semi-synthetic mycotoxin that is used in some countries as a growth-promoting agent in livestock. In view of the known oestrogenic actions by Z and certain Z analogues, significant concerns exist with regard to the presence of Z residues in human foods and the potential for untoward effects, including carcinogenicity within the reproductive system. In order to confirm that foods are free from harmful Z residues, regulators need a quick and reliable analytical method that can be used for routine confirmation of Z-positive samples identified by enzyme-linked immunosorbent assay (ELISA) screening. In this study the authors have developed and validated a simple and rapid high-performance liquid chromatography method incorporating ultraviolet (UV) absorbance (wavelength 274 nm) and electrochemical (EC) dual-mode detection for simultaneous determination of Z-related mycotoxins produced from mouldy grain matrices, including rice, soybean and corn flakes. RESULTS: Recoveries for all analytes were around 80% and the limits of detection ranged from 10 to 25 ng mL(-1) for UV and from 50 to 90 ng mL(-1) for EC detection with good accuracy and reproducibility. Differential profiles and occurrence rates of Z, ß-zearalenol, ß-zearalanol and α-zearalenol in naturally moulded grain matrices were observed, indicating different metabolite patterns and possibly grain-specific effects of mycotoxin exposure for humans and animals. The strength of this dual detection method lies in its selectivity characterised by a carbon screen-printed electrode such that aflatoxin interference is precluded. CONCLUSION: The combined dual detection technique affords quick and reliable semi-confirmative and quantitative information on multiple types of Z analogues in mouldy grains without the necessity of using expensive mass spectrometry. The method is considered a superior supplement to ELISA, which only screens total Z immunoreactivity.