Determination of adulteration, geographical origins, and species of food by mass spectrometry.

Food adulteration, mislabeling, and fraud, are rising global issues. Therefore, a number of precise and reliable analytical instruments and approaches have been proposed to ensure the authenticity and accurate labeling of food and food products by confirming that the constituents of foodstuffs are of the kind and quality claimed by the seller and manufacturer. Traditional techniques (e.g., genomics-based methods) are still in use; however, emerging approaches like mass spectrometry (MS)-based technologies are being actively developed to supplement or supersede current methods for authentication of a variety of food commodities and products. This review provides a critical assessment of recent advances in food authentication, including MS-based metabolomics, proteomics and other approaches.

Rating System for Phytophthora Root Rot Influences Quantitative Trait Locus Detection and Reveals Incomplete Dominance and Duplicative Recessive Epistatic Gene Action in Capsicum annuum.

Phytophthora capsici is one of the most devastating pathogens facing pepper (Capsicum annuum) producers worldwide. Numerous factors, such as the race of the pathogen, the growing environment, and the source of resistance, have resulted in an overall lack of widely applicable molecular markers associated with resistance. Our objective was to determine the effect of the rating system on quantitative trait locus (QTL) detection and understand inheritance patterns of host resistance that can influence selection and molecular marker accuracy. We evaluated an F2:11 recombinant inbred line population screened against the highly virulent strain (Pc134) and scored using two widely used methods, developed by Bosland and Lindsey and by Black. The rating system developed by Bosland and Lindsey resulted in slightly higher logarithm of odds for the QTL on chromosome 5, and we detected a QTL on chromosome 12 uniquely using this rating system. A QTL on chromosome 10 was detected using both rating systems, but Black resulted in considerably higher logarithm of odds for this QTL compared with the Bosland and Lindsey system. Molecular markers developed were nominally better at accurately predicting the phenotype than previously published molecular markers but did not completely explain resistance in our validation populations. The inheritance pattern of resistance in one of our F2 populations did not significantly deviate from a 7:9 segregation ratio, indicating duplicative recessive epistasis. However, these results could be confounded by the presence of incomplete gene action, which was found through the improved selection accuracy when the phenotypes of heterozygous individuals were grouped with those with susceptible alleles.

The Configuration-Dependent Anti-Leukemic Effect of Manoalide Stereoisomers: Reignite Research Interest in these Sponge-Derived Sesterterpenoids.

Manoalide was studied as a potential anti-inflammatory agent for the last forty years and more than 200 publications and 180 patents were reported on this compound. However, the configurations at positions 24 and 25 and configuration-dependent bioactivity were not yet studied. In the current report, ten manoalide-like sesterterpenoids were isolated from Luffariella sp. (1-10). These stereoisomers were identified and separated for the first time since 1980 and their configurations at positions 24 and 25 were determined by analyzing their spectroscopic spectra. The configuration-dependent anti-proliferative activity of manoalide derivatives was examined by evaluating their effect on four leukemic cancer cell lines (Molt 4, K562, Sup-T1, and U937). The 24R,25S-isomers exhibited the most potent activity (IC50 0.50-7.67 µM). The anti-proliferative mechanism of action of 24R,25S-manoalide (7) was further studied on Molt 4 cells. Compound 7 exhibited apoptotic activity on Molt 4 cells through the disruption of mitochondrial membrane potential (MMP) and the generation of intracellular reactive oxygen species (ROS). It also inhibited the activity of human topoisomerase I and II. The apoptotic-inducing effect of 7 was further supported by the in vivo experiment by suppressing the volume of xenograft tumor growth (66.11%) compared with the control.

Development of analytical method of melamine in placenta from pregnant women by isotope-dilution liquid chromatography/tandem mass spectrometry.

RATIONALE: Melamine is ubiquitously present in our daily life. It has a known effect on the kidneys, but it may also adversely affect the reproduction system. We have developed an analytical method for measuring melamine levels in maternal placenta and correlated these levels with melamine concentrations in urine, a necessary step in finding out if melamine might cross the placenta and enter the circulation of the fetus. METHODS: We used liquid-liquid extraction, clean up by solid-phase extraction (SPE), and isotope-dilution liquid chromatography/tandem mass spectrometry (LC/MS/MS) to measure melamine in placenta specimens. The results of this method were assessed for linearity, limits of quantitation (LOQs), and intra- and inter-assay precision as well as accuracy, matrix effect, and recovery rate. RESULTS: Calibration curves indicated good linearity (r >0.995) over concentrations ranging from 5 to 500 ng/mL in placenta specimens, intra- and inter-assay precision from 0.89% to 27.07%, and accuracy from 92.4% to123.5%. Recovery ranged from 63.9 to 83.9%, and the LOQ was 5 ng/mL in placenta (0.2 g). Placental melamine levels ranged from 7.87 to19.64 ng/mL, all detectable (n = 8). Pregnant women with higher levels of urinary melamine had higher placenta melamine levels than those with non-detectable urinary melamine, though the results were not significantly different (p = 0.149, n = 4 in each group). CONCLUSIONS: The results of this study suggest that pregnant women were exposed to low doses of melamine in their daily lives as measured in urine samples and placenta specimens. It is unclear whether placenta melamine concentrations can better represent long-term exposure than urine or whether melamine in the uterus can enter the fetus via this route.

The Antioxidant from Ethanolic Extract of Rosa cymosa Fruits Activates Phosphatase and Tensin Homolog In Vitro and In Vivo: A New Insight on Its Antileukemic Effect.

Rosa cymosa Tratt is a Chinese herbal remedy that is used in the treatment of diarrhea, burns, rheumatoid arthritis, and hemorrhage. Despite its use in Asian folk medicine, there are limited reports on the biological activity of R. cymosa fruits. This study focused on the investigation of the antitumor effect of the antioxidative ethanolic extract of R. cymosa fruits (RCE) along with its underlying mechanism of action. RCE showed a potent cytotoxic effect against Sup-T1 and Molt-4 lymphoblastic leukemia cells. In the xenograft animal model, the tumor size was significantly reduced to about 59.42% in the RCE-treated group in comparison with the control group. The use of RCE (37.5, 75, or 150 µg/mL) triggered apoptosis by 26.52-83.49%, disrupted mitochondrial membrane potential (MMP) by 10.44-58.60%, and promoted calcium release by 1.29-, 1.44-, and 1.71-fold compared with the control group. The extract induced redox oxygen species (ROS) generation through the elimination of Nrf2/Keap1/P62-mediated oxidative stress response. The loss of phosphatase and tensin homolog (PTEN) activation by RCE impaired PI3K/Akt/Foxo and Jak/Stat activation pathways, which contributed to tumorigenesis. These multiple targets of R. cymosa against hematologic cancer cells suggested its potential application as an antileukemic dietary supplement.

Breaking down Leukemia Walls: Heteronemin, a Sesterterpene Derivative, Induces Apoptosis in Leukemia Molt4 Cells through Oxidative Stress, Mitochondrial Dysfunction and Induction of Talin Expression.

Heteronemin, the most abundant secondary metabolite in the sponge Hippospongia sp., exhibited potent cytotoxic activity against several cancer cell lines. It increased the percentage of apoptotic cells and reactive oxygen species (ROS) in Molt4 cells. The use of ROS scavenger, N-acetyl cysteine (NAC), suppressed both the production of ROS from mitochondria and cell apoptosis that were induced by heteronemin treatment. Heteronemin upregulated talin and phosphorylated talin expression in Molt4 cells but it only upregulated the expression of phosphorylated talin in HEK293 cells. However, pretreatment with NAC reversed these effects. Talin siRNA reversed the activation of pro-apoptotic cleaved caspases 3 and 9. On the other hand, the downstream proteins including FAK and NF-κB (p65) were not affected. In addition, we confirmed that heteronemin directly modulated phosphorylated talin expression through ROS generation resulting in cell apoptosis, but it did not affect talin/FAK complex. Furthermore, heteronemin interfered with actin microfilament and caused morphology changes. Taken together, these findings suggest that the cytotoxic effect of heteronemin is associated with oxidative stress and induction of phosphorylated talin expression. Our results suggest that heteronemin represents an interesting candidate which can be further developed as a drug lead against leukemia.

Novel 11-norbetaenone isolated from an entomopathogenic fungus Lecanicillium antillanum.

A novel nor-betaenone compound, 11-norbetaenone (1), was isolated from the culture broth of an entomopathogenic fungus Lecanicillium antillanum. The structure was determined on the basis of 1D and 2D NMR spectroscopic data. The absolute stereochemistry of 1 was further confirmed by X-ray single crystallography analysis. It is the first secondary metabolite reported from the species Lecanicillium antillanum. And it is also the first time that a betaenone-type compound was isolated from the genus Lecanicillium. Furthermore, 11-norbetaenone (1) displayed significant anti-angiogenic effect by suppressing tube formation.

Inflammation Modulatory Phorbol Esters from the Seeds of Aquilaria malaccensis.

The tree Aquilaria malaccensis is a valuable source of agarwood, which is used in herbal medicinal preparations. Phytochemical research on A. malaccensis seeds has led to the isolation of four new phorbol esters (1-4), two known phorbol esters (5, isolated from Nature for the first time, and 6), and two known glycerides (7 and 8). The structures of these isolates were elucidated by means of spectroscopic data interpretation. The inflammation-modulatory activities of the isolates on elastase release and superoxide anion generation in human neutrophils were evaluated. Interestingly, phorbol esters 1, 5, and 6 showed potent inhibitory activity on elastase release in human neutrophils, with IC50 values of 2.7, 0.8, and 2.1 µM, respectively. All isolated phorbol esters exerted enhancing activity on superoxide anion generation. The results indicated that phorbol esters may play a bilateral modulatory role in the processes of inflammation. In addition, the compounds were evaluated for their cytotoxic properties against HepG2 (hepatoma), MDA-MB-231 (breast), and A549 (lung) cancer cells, but all compounds were inactive for all cell lines used (IC50 > 10 µM).

Zoanthamine-Type Alkaloids from the Zoanthid Zoanthus kuroshio Collected in Taiwan and Their Effects on Inflammation.

Zoanthus kuroshio is a colorful zoanthid with a fluorescent pink oral disc and brown tentacles, which dominates certain parts of the Taiwanese and Japanese coasts. This sea anemone is a rich source of biologically active alkaloids. In the current investigation, two novel halogenated zoanthamines [5α-iodozoanthenamine (1) and 11ß-chloro-11-deoxykuroshine A (2)], along with four new zoanthamines [18-epi-kuroshine A (3), 7α-hydroxykuroshine E (4), 5α-methoxykuroshine E (5), and 18-epi-kuroshine E (6)], and six known compounds were isolated from Z. kuroshio. Compounds 1 and 2 are the first examples of halogenated zoanthamine-type alkaloids isolated from nature. Compounds 3 and 6 are the first zoanthamine stereoisomers with a cis-junction of the A/B rings. All isolated compounds were evaluated for their anti-inflammatory activities by measuring their effects on superoxide anion generation and elastase release by human neutrophils in response to fMLP.

Cytotoxic Lanostanoids from Poria cocos.

Six new and 16 known lanostanoids were isolated from the sclerotia of Poria cocos. The structures of the new isolates were elucidated to be 16α-hydroxy-3-oxo-24-methyllanosta-5,7,9(11),24(31)-tetraen-21-oic acid (1), 3ß,16α,29-trihydroxy-24-methyllanosta-7,9(11),24(31)-trien-21-oic acid (2), 3ß,16α,30-trihydroxy-24-methyllanosta-7,9(11),24(31)-trien-21-oic acid (3), 3ß-acetoxy-16α,24ß-dihydroxylanosta-7,9(11),25-trien-21-oic acid (4), 3ß,16α-dihydroxy-7-oxo-24-methyllanosta-8,24(31)-dien-21-oic acid (5), and 3α,16α-dihydroxy-7-oxo-24-methyllanosta-8,24(31)-dien-21-oic acid (6), based on extensive spectroscopic analyses. The absolute configuration of 4 was determined using Mosher's method. The antiproliferative activity of the isolated compounds (except 3 and 4) was evaluated against four leukemic cell lines (Molt 4, CCRF-CEM, HL 60, and K562). Dehydropachymic acid (9), dehydroeburicoic acid (12), pachymic acid (14), and lanosta-7,9(11),24-trien-21-oic acid (20) exhibited an antiproliferative effect on the CCRF-CEM cancer cell line with IC50 values of 2.7, 6.3, 4.9, and 13.1 µM, respectively. Both dehydropachymic acid (9) and dehydroeburicoic acid (12) showed antiproliferative effects against Molt 4 (IC50 13.8 and 14.3 µM) and HL 60 (IC50 7.3 and 6.0 µM) leukemic cell lines. Primary computational analysis using a chemical global positioning system for natural products (ChemGPS-NP) on the active lanostanoids from P. cocos suggested that targets other than topoisomerases may be involved in the antiproliferative activity.

Antiallergic Phorbol Ester from the Seeds of Aquilaria malaccensis.

The Aquilaria malaccensis (Thymelaeaceae) tree is a source of precious fragrant resin, called agarwood, which is widely used in traditional medicines in East Asia against diseases such as asthma. In our continuous search for active natural products, A. malaccensis seeds ethanolic extract demonstrated antiallergic effect with an IC50 value less than 1 µg/mL. Therefore, the present research aimed to purify and identify the antiallergic principle of A. malaccensis through a bioactivity-guided fractionation approach. We found that phorbol ester-rich fraction was responsible for the antiallergic activity of A. malaccensis seeds. One new active phorbol ester, 12-O-(2Z,4E,6E)-tetradeca-2,4,6-trienoylphorbol-13-acetate, aquimavitalin (1) was isolated. The structure of 1 was assigned by means of 1D and 2D NMR data and high-resolution mass spectrometry (HR-MS). Aquimavitalin (1) showed strong inhibitory activity in A23187- and antigen-induced degranulation assay with IC50 values of 1.7 and 11 nM, respectively, with a therapeutic index up to 71,000. The antiallergic activities of A. malaccensis seeds and aquimavitalin (1) have never been revealed before. The results indicated that A. malaccensis seeds and the pure compound have the potential for use in the treatment of allergy.

Nitroxidative chemistry interferes with fluorescent probe chemistry: implications for nitric oxide detection using 2,3-diaminonaphthalene.

Simultaneous production of nitric oxide (NO) and superoxide generates peroxynitrite and causes nitroxidative stress. The fluorometric method for NO detection is based on the formation of a fluorescent product from the reaction of a nonfluorescent probe molecule with NO-derived nitrosating species. Here, we present an example of how nitroxidative chemistry could interact with fluorescent probe chemistry. 2,3-Naphthotriazole (NAT) is the NO-derived fluorescent product of 2,3-diaminonaphthalene (DAN), a commonly used NO-detecting molecule. We show that NO/superoxide cogeneration, and particularly peroxynitrite, mediates the chemical decomposition of NAT. Moreover, the extent of NAT decomposition depends on the relative fluxes of NO and superoxide; the maximum effect being reached at almost equivalent generation rates for both radicals. The rate constant for the reaction of NAT with peroxynitrite was determined to be 2.2×10(3)M(-1)s(-1). Further, various peroxynitrite scavengers were shown to effectively inhibit NO/superoxide- and peroxynitrite-mediated decomposition of NAT. Taken together, the present study suggests that the interference of a fluorometric NO assay can be originated from the interaction between the final fluorescent product and the formed reactive nitrogen and oxygen species.

Characterization of the biochemical effects of naphthalene on the mouse respiratory system using NMR-based metabolomics.

Naphthalene is a ubiquitous environmental pollutant to which humans are exposed. Previous studies have demonstrated that naphthalene causes bronchiolar epithelial necrosis in the mouse distal airway, after parenteral administration. In this study, metabolic variations in the bronchoalveolar lavage fluid (BALF) and the lung tissues of naphthalene-treated mice and controls were examined using nuclear magnetic resonance (NMR)-based metabolomics to identify the toxic mechanism. Male ICR mice were treated with naphthalene [0, 50, 100 and 200 mg kg(-1), intraperitoneally (i.p.)]. After 24 h, BALF and lung tissues were collected and prepared for (1)H and J-resolved (JRES) NMR analysis after principal component analysis (PCA). PCA modeling of p-JRES spectra from the BALF, as well as hydrophilic and hydrophobic lung metabolites, enabled the high-dose group to be discriminated from the control group; increased levels of isopropanol, ethane, and acetone and lower levels of ethanol, acetate, formate, and glycerophosphocholine were detected in the BALF of mice treated with higher doses of naphthalene. Furthermore, increased isopropanol and phosphorylcholine-containing lipid levels and decreased succinate and glutamine levels were discovered in the lungs of naphthalene-exposed mice. These metabolic changes may be related to lipid peroxidation, disruptions of membrane components and imbalanced energy supply, and these results may partially explain the loss of cell membrane integrity in the airway epithelial cells of naphthalene-treated mice. We conclude that NMR-based metabolomic studies on BALF and lung tissues are a powerful tool to understand the mechanisms underlying respiratory toxicity.

Chemical constituents and bioactivities of Clinacanthus nutans aerial parts.

Four new sulfur-containing compounds, named clinamides A-C (1-3), and 2-cis-entadamide A (4), were isolated together with three known compounds from the bioactive ethanol extract of the aerial parts of Clinacanthus nutans. These secondary metabolites possess sulfur atoms and acrylamide functionalities. The structures of the isolated components were established by interpretation of their spectroscopic data, especially 1D and 2D NMR.

Direct Identification of Intact Proteins Using a Low-Resolution Mass Spectrometer with CIDn/ETnoD.

Over the past decades, proteomics has become increasingly important and a heavily discussed topic. The identification of intact proteins remains a major focus in this field. While most intact proteins are analyzed using high-resolution mass spectrometry, identifying them through low-resolution mass spectrometry continues to pose challenges. In our study, we investigated the capability of identifying various intact proteins using collision-induced dissociation (CID) and electron transfer without dissociation (ETnoD). Using myoglobin as our test protein, stable product ions were generated with CID, and the identities of the product ions were identified with ETnoD. ETnoD uses a short activation time (AcT, 5 ms) to create sequential charge-reduced precursor ion (CRI). The charges of the fragments and their sequences were determined with corresponding CRI. The product ions can be selected for subsequent CID (termed CIDn) combined with ETnoD for further sequence identification and validation. We refer to this method as CIDn/ETnoD. The use of a multistage CID activation (CIDn) and ETnoD protocol has been applied to several intact proteins to obtain multiple sequence identifications.

The identification of soy sauce adulterated with bean species and the origin using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry.

Soy sauce is one of the significant seasonings in Asia but is often mislabeled in ingredients or substituted with geographical information. With no adequate methods to distinguish the bean sources and the origins of soy sauce, our study designed a seamless headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS) for analyzing unique volatile components of different soy sauces. Over 400 volatile flavor compounds were identified and the assistance of chemometric analysis successfully discriminated different bean sources (black bean and soybean) and producing regions (Taiwan and Japan). The chemometric models can also perfectly evaluate real samples together with adulterated samples. In brief, these soy sauce volatile signatures can solve the problem of authentication and assist the whole industry in preventing adulteration and producing countries' counterfeit.

Quantitative modelling of fine-scale variations in the Arabidopsis thaliana crossover landscape.

In, essentially, all species where meiotic crossovers (COs) have been studied, they occur preferentially in open chromatin, typically near gene promoters and to a lesser extent, at the end of genes. Here, in the case of Arabidopsis thaliana, we unveil further trends arising when one considers contextual information, namely summarised epigenetic status, gene or intergenic region size, and degree of divergence between homologs. For instance, we find that intergenic recombination rate is reduced if those regions are less than 1.5 kb in size. Furthermore, we propose that the presence of single nucleotide polymorphisms enhances the rate of CO formation compared to when homologous sequences are identical, in agreement with previous works comparing rates in adjacent homozygous and heterozygous blocks. Lastly, by integrating these different effects, we produce a quantitative and predictive model of the recombination landscape that reproduces much of the experimental variation.

Assessment of genetic diversity and SNP marker development within peanut germplasm in Taiwan by RAD-seq.

The cultivated peanut (Arachis hypogaea L.) is an important oil crop but has a narrow genetic diversity. Molecular markers can be used to probe the genetic diversity of various germplasm. In this study, the restriction site associated DNA (RAD) approach was utilized to sequence 31 accessions of Taiwanese peanut germplasm, leading to the identification of a total of 17,610 single nucleotide polymorphisms (SNPs). When we grouped these 31 accessions into two subsets according to origin, we found that the "global" subset (n = 17) was more genetically diverse than the "local" subset (n = 14). Concerning botanical varieties, the var. fastigiata subset had greater genetic diversity than the other two subsets of var. vulgaris and var. hypogaea, suggesting that novel genetic resources should be introduced into breeding programs to enhance genetic diversity. Principal component analysis (PCA) of genotyping data separated the 31 accessions into three clusters largely according to the botanical varieties, consistent with the PCA result for 282 accessions genotyped by 14 kompetitive allele-specific PCR (KASP) markers developed in this study. The SNP markers identified in this work not only revealed the genetic relationship and population structure of current germplasm in Taiwan, but also offer an efficient tool for breeding and further genetic applications.

Avatar-like body imaging of dermal exposure to melamine in factory workers analyzed by ambient mass spectrometry.

Ambient mass spectrometry thermal desorption-electrospray ionization/mass spectrometry (TD-ESI/MS) can rapidly identify chemicals without pretreatment of biological samples. This study used a rapid semi-quantitative TD-ESI/MS screening technique for the probe skin sampling of melamine workers occupationally exposed to different ambient melamine concentrations to create avatar-like body images, which were then used to study temporal and dynamic changes in nephrotoxic melamine exposure. We enrolled four voluntary melamine workers from one factory, each from one of four worksites. Melamine exposure was highest in manufacturing and molding, followed by grinding and polishing, packing, and administration, the lowest. Skin samples were collected Friday (end-of-shift) and Monday (pre-shift). Early morning one-spot urine samples were also collected right after skin sampling. 2198 probe skin samples were collected and subjected to semi-quantitative TD-ESI/MS analyses of melamine chemical within 40 h. After normalization, converted body image scores revealed exposure to be highest in the manufacturing worker on Friday and lowest in the administrative worker on Monday. The absolute differences (Friday minus Monday) of normalized body image scores were all significantly positive in each individual worker and across all four workers (permutation test, all p-values < 0.002). The slope estimates of the linear regression line between body image scores and urinary melamine levels were 0.81 (p-value = 0.008). We concluded that this fast and non-invasive technique can potentially be used to study temporal and dynamic changes in exposure to occupational hazards. A future study of developing an automatic and reproducible TD-ESI/MS sampling platform is needed.

Whole genome resequencing and complementation tests reveal candidate loci contributing to bacterial wilt (Ralstonia sp.) resistance in tomato.

Tomato (Solanum lycopersicum) is one of the most economically important vegetable crops worldwide. Bacterial wilt (BW), caused by the Ralstonia solanacearum species complex, has been reported as the second most important plant pathogenic bacteria worldwide, and likely the most destructive. Extensive research has identified two major loci, Bwr-6 and Bwr-12, that contribute to resistance to BW in tomato; however, these loci do not completely explain resistance. Segregation of resistance in two populations that were homozygous dominant or heterozygous for all Bwr-6 and Bwr-12 associated molecular markers suggested the action of one or two resistance loci in addition to these two major QTLs. We utilized whole genome sequence data analysis and pairwise comparison of six BW resistant and nine BW susceptible tomato lines to identify candidate genes that, in addition to Bwr-6 and Bwr-12, contributed to resistance. Through this approach we found 27,046 SNPs and 5975 indels specific to the six resistant lines, affecting 385 genes. One sequence variant on chromosome 3 captured by marker Bwr3.2dCAPS located in the Asc (Solyc03g114600.4.1) gene had significant association with resistance, but it did not completely explain the resistance phenotype. The SNP associated with Bwr3.2dCAPS was located within the resistance gene Asc which was inside the previously identified Bwr-3 locus. This study provides a foundation for further investigations into new loci distributed throughout the tomato genome that could contribute to BW resistance and into the role of resistance genes that may act against multiple pathogens.