Variation In Chemical Profiles Research Articles

Comprehensive Evaluation of the Quality of Tripterygium Glycosides Tablets Based on Multi-Component Quantification Combined with an In Vitro Biological Assay.

Tripterygium glycosides tablets (TGTs) are widely used in clinical practice to treat rheumatoid arthritis and other autoimmune diseases, with significant beneficial effects but also high toxicity, necessitating rigorous quality evaluation and control. In current study, a rapid resolution liquid chromatography tandem electrospray ionization triple quadrupole mass spectrometry (RRLC–ESI–MS/MS) method was developed and validated for the quantitative analysis of 14 components of ten batches of TGTs produced by different manufacturers, including four diterpenoids, three triterpenoids, and seven sesquiterpene alkaloids. Meanwhile, the NO inhibition effects of these TGTs were evaluated in LPS-induced RAW264.7 cells for their downstream anti-inflammatory activities, as well as their cytotoxicity. The results indicate that the TGTs from different manufacturers showed poor quality consistency, as evidenced by large variations in chemical profiles and biological effects, which may increase the risks associated with clinical use. To improve the quality status of TGTs, it is crucial to identify indicator components whose characterization can accurately reflect the efficacy and toxicity of TGTs from which they were derived. Our study reveals that triptolide, triptoquinone B, celastrol, and demethylzelaysteral considerably contributed to the anti-inflammatory activity and/or cytotoxicity of TGTs, implying that they should be further investigated as candidate indicator components for TGT quality control.

Ecological factors influence balancing selection on leaf chemical profiles of a wildflower.

Balancing selection is frequently invoked as a mechanism that maintains variation within and across populations. However, there are few examples of balancing selection operating on loci underpinning complex traits, which frequently display high levels of variation. We investigated mechanisms that may maintain variation in a focal polymorphism—leaf chemical profiles of a perennial wildflower (Boechera stricta, Brassicaceae)—explicitly interrogating multiple ecological and genetic processes including spatial variation in selection, antagonistic pleiotropy, and frequency-dependent selection. A suite of common garden and greenhouse experiments showed that the alleles underlying variation in chemical profile have contrasting fitness effects across environments, implicating two ecological drivers of selection on chemical profile: herbivory and drought. Phenotype-environment associations and molecular genetic analyses revealed additional evidence of past selection by these drivers. Together, these data are consistent with balancing selection on chemical profile, likely caused by pleiotropic effects of secondary chemical biosynthesis genes on herbivore defense and drought response.

Assessing the Role of Developmental and Environmental Factors in Chemical Defence Variation in Heliconiini Butterflies

Chemical defences in animals are both incredibly widespread and highly diverse. Yet despite the important role they play in mediating interactions between predators and prey, extensive differences in the amounts and types of chemical compounds can exist between individuals, even within species and populations. Here we investigate the potential role of environment and development on the chemical defences of warningly coloured butterfly species from the tribe Heliconiini, which can both synthesize and sequester cyanogenic glycosides (CGs). We reared 5 Heliconiini species in captivity, each on a single species-specific host plant as larvae, and compared them to individuals collected in the wild to ascertain whether the variation in CG content observed in the field might be the result of differences in host plant availability. Three of these species were reared as larvae on the same host plant, Passiflora riparia, to further test how species, sex, and age affected the type and amount of different defensive CGs, and how they affected the ratio of synthesized to sequestered compounds. Then, focusing on the generalist species Heliconius numata, we specifically explored variation in chemical profiles as a result of the host plant consumed by caterpillars and their brood line, using rearing experiments carried out on two naturally co-occurring host plants with differing CG profiles. Our results show significant differences in both the amount of synthesized and sequestered compounds between butterflies reared in captivity and those collected in the field. We also found a significant effect of species and an effect of sex in some, but not all, species. We show that chemical defences in H. numata continue to increase throughout their life, likely because of continued biosynthesis, and we suggest that variation in the amount of synthesized CGs in this species does not appear to stem from larval host plants, although this warrants further study. Interestingly, we detected a significant effect of brood lines, consistent with heritability influencing CG concentrations in H. numata. Altogether, our results point to multiple factors resulting in chemical defence variation in Heliconiini butterflies and highlight the overlooked effect of synthesis capabilities, which may be genetically determined to some extent.

Mass spectral studies on the human skin surface for mosquito vector control applications.

Human skin surface chemical cues comprise a complex mixture of compounds that mosquitoes use to locate and select their human host, based on inter- and intra-human variation in chemical profiles. The complexity of the skin surface matrix calls for advanced analytical techniques to enable separation and identification of biomarkers, which may be used as topical attractants and repellants in future mosquito vector control programmes. The perceived mosquito attractiveness between 20 volunteers and the preference of mosquitoes to bite certain regions, namely, ankle versus wrist, of the human host were investigated in this study, by comparing skin surface chemical profiles. Ion mobility was combined with high resolution mass spectrometry to provide additional confidence in biological marker discovery and identification of human skin surface compounds. This study employed a non-intrusive sampling scheme using a polydimethylsiloxane (PDMS) sampler and solvent desorption analysed with ultra-performance liquid chromatography with ion mobility high-resolution mass spectrometry (UPLC-IMS-HRMS). Statistical approaches guided the identification of 14 biological markers discerning difference in perceived mosquito attractiveness and 20 biomarkers associated with the different skin regions sampled. A broad range (m/z 96.0437 to 788.6095) of chemical compounds was detected from a variety of classes (including sugars, steroids, fatty acids, peptides and peptide derivatives, and compounds of food origin). Ten compounds were unequivocally identified on the human skin surface, and caffeine was reported on the human skin surface for the first time. Furthermore, 77 compounds, of which 64 to the authors' knowledge have not previously been reported, were detected on the human skin surface using accurate mass, collision cross section (CCS) values and fragmentation patterns. This approach enabled comprehensive human skin surface chemical profiling and provides an extensive list of tentatively identified skin surface compounds together with accurate mass values and adducts with their corresponding CCS values.

Variation in chemical profile of leaves essential oils from thirteen Tunisian Eucalyptus species and evaluation of their antioxidant and antibacterial properties

The aromatic medicinal plant Eucalyptus and its essential oils have been used since antiquity in folk medicine. The interest in this genus has increased remarkably over the last decade mostly because of their various biological activities. This study aimed to determine the chemical composition of essential oils of thirteen Eucalyptus species leaves and their antioxidant and antibacterial activities. Obtained results showed that E. maidenii had the highest essential oil yield (6.16 ± 1.55 %). Chemical composition (by GC/MS) was highly affected by the species factor (P < 0.001), with the abundance of the major compound 1,8-cineole (82.64 % in E. microcarpa) in most Eucalyptus species. Essential oils exhibited a moderate antioxidant activity, but an interesting bacteriostatic effect against all tested bacteria. Eucalyptus camaldulensis had the strongest bioactivities despite its major compound was spathulenol with efficacy concentration of 50 % EC50 = 2.96 ± 0.11 mg/mL for the reducing power assay and presented an important inhibition zone (25.33 ± 2.84) and lowest minimum inhibitory concentration (MIC = 0.93 mg/mL) against Serratia marcescens bacteria. This result demonstrated that biological activities could be explained by the synergistic effect between major and minor compounds.

Chemical profiling of Egyptian propolis and determination of its xanthine oxidase inhibitory properties using UPLC–MS/MS and chemometrics

In the current study, propolis samples from various geographical localities in Egypt were investigated by chemical profiling and xanthine oxidase (XO) inhibitory and radical scavenging activity testing. Metabolic fingerprints were attained using ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS), UHPLC-MS analysis in an untargeted holistic perspective followed by the subsequent annotation of 65 compounds in total. Variation in chemical profiles of samples was assessed by principle component analysis and orthogonal projection to latent structures discriminant analysis which was able to successfully classify Egyptian propolis samples into two main types (orange and blue) and one subtype (green or mixed) and rapidly screen type-specific markers. Further, propolis extracts were assessed for their antioxidant and xanthine oxidase inhibitory effects through in vitro assays coupled to orthogonal projection to latent structures in order to relate metabolite profiles to biological effects in Egyptian propolis and pick out the potential biomarkers pinocembrin, kaempferide, coumaroyl acetyl glycerol, galangin, palmitic acid and pinobanksin as likely mediators of antioxidant and XO inhibitory activity. To the best of our knowledge, this is the first comprehensive profiling of Egyptian propolis secondary metabolites that can present a chemical-based evidence for its efficacious consistency regarding its potential XO inhibitory activity.

Cannabis Chemovar Nomenclature Misrepresents Chemical and Genetic Diversity; Survey of Variations in Chemical Profiles and Genetic Markers in Nevada Medical Cannabis Samples

Introduction: Medical cannabis patients receive clinical benefits from the secondary metabolites of the plant, which contain a variety of cannabinoids and terpenoids in combinations that can be used to classify the chemovars. State-regulated medical cannabis programs rely on breeder-reported “strain” names both within diversion control systems and to describe the medical cannabis products that are sold to patients in medical cannabis dispensaries. In state-regulated medical cannabis programs, there is no conventional nomenclature system that correlates the breeder-reported names with their profiles of active ingredients, and these “strain” names are invalid as they refer to chemical differences properly referred to as to chemovars.Materials and Methods: To determine the actual levels of chemical diversity represented in 2662 samples of Cannabis flower collected between January 2016 and June of 2017 in Nevada, chemical profile data were measured from these samples by a state-qualified third-party testing laboratory. Principal component analysis (PCA) was used to define clusters in data sets representing both cannabinoids and terpenoids, cannabinoids only, or terpenoids only.Results: The PCA of the terpenoid only data set revealed three well-defined clusters. All three terpenoids only data clusters had high tetrahydrocannabinolic acid synthase, but the terpene profiles listed in reverse-order of abundance best defined these chemovars. The three chemovars in Nevada were labeled with 396 breeder-reported sample names, which overestimate the diversity and do not inform patients regarding chemical properties. Representative DNA samples were taken from each chemovar to determine whether the genetic diversity was greater than the chemical diversity. The limited genotyping experiment was based on DNA sequence polymorphisms. The genetic analysis revealed twelve distinct genetic clades, which still does not account for the entirety of the 396 reported sample names. The finite genotypes did not correlate with the chemotypes determined for the samples. This suggests that either the DNA-markers used were too narrowly restricted for factual separation or that environmental factors contributed more significantly to the chemical profiles of cannabis than genetics.Conclusion: The three chemovars and twelve genotypes reflect low medical diversity on the market in Nevada during its “medical use only” phase. Furthermore, the 396 breeder-reported sample names within this set imply a false sense of diversity of products in Nevada dispensaries.

Exploring feature selection of St John's wort grown under different light spectra using 1 H-NMR spectroscopy.

Nuclear magnetic resonance (NMR) spectroscopy combined with multivariate statistical analysis can provide tools to help detect differences in plant chemistry when grown under varying conditions. Hypericum perforatum, or Saint John's wort, plants are a suitable model to explore methods of discrimination between early stage plants grown in different conditions. The purpose of this work was to develop a method for identifying differences in chemical profiles between young Hypericum perforatum plants grown under different lighting conditions. Cuttings were grown for 3 weeks under different light conditions. Plant extracts were prepared in MeOD-d4 and analysed by 1 H-NMR. A multivariate analysis method of the NMR data was developed in an effort to determine variations in chemical profiles. The method identified specific metabolites as drivers of difference between the plants grown under different light conditions. STOCSY (statistical total correlation spectroscopy) and quantification of highlighted metabolites supported the findings of the multivariate analysis. Glutamine, sucrose and fructose were found to be chemical markers of light quality in this study. NMR metabolomics using a medium field instrument could find differences in plant chemistry when grown in different conditions. This method could easily be extended to benchtop instruments and be used for crop monitoring and growth condition optimisation.

Gas chromatography–mass spectrometry profile and antimicrobial activities of Ballota bullata Pomel and B. nigra L. subsp. uncinata (Fiori & Bég.): A comparative analysis

This study was carried out to compare for the first time, the chemical composition and antimicrobial activities of essential oils from two Ballota species growing wild in different regions of Tunisia. The volatile oils obtained by hydro-distillation of Ballota bullata Pomel and Ballota nigra L. subsp. uncinata (Fiori & Bég.) Patzak were analyzed by gas chromatography (GC) and gas chromatography mass spectrometry (GC/MS) to investigate the variations in chemical profiles. The results showed a significant difference in terms of essential oil yields and characteristic aroma. Valerianol (18.3%), α-muurolol (7.9%) and spathulenol (7.1%) were identified as the major odorants in B. bullata, while B. nigra subsp. uncinata oil was mainly composed of hexadecanoic acid (31.8%) and linoleic acid (17.9%). In addition, oxygenated sesquiterpenes were found to be the principal constituents of B. bullata essential oil (42.1%), whereas long chain oxygenated hydrocarbons form the main class in B. nigra (49.7%). Moreover, the antimicrobial activities were tested in vitro against five bacteria: Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Staphylococcus aureus and Bacillus subtilis and the yeast Candida albicans. B. bullata essential oil showed stronger antibacterial effects comparing to B. nigra oil. Consequently, B. bullata essential oil holds promising antimicrobial potential, confirming its traditional medical use.

Environmental and cultured cyanobacteria as sources of Aedes aegypti larvicides

In tropical countries, the control of the mosquito Aedes aegypti is a public health priority due to its role as a vector of important viral diseases. Marine cyanobacteria are recognized as abundant sources of bioactive compounds, and they constitute a potential source of insecticides useful for controlling mosquito populations and preventing epidemic outbreaks. We collected 30 benthic cyanobacterial mats in Providencia and Rosario islands (in the Colombian Caribbean) belonging to the genera Phormidium, Symploca, Oscillatoria, Lyngbya, Pseudoanabaena, Leptolyngbya, Moorea, and Dapis. Fractions of organic extracts from the most abundant environmental samples were evaluated in three bioassays, assessing (i) larvicidal activity against A. aegypti, (ii) toxicity against the brine shrimp (Artemia salina) nauplii, and (iii) acetylcholinesterase inhibition. Non-polar fractions exhibited larvicidal activity. The polar fraction from one Dapis pleuosa extract showed larvicidal activity without being toxic against A. salina nauplii. Extracts from Moorea producens exhibited the greatest toxicity against A. aegypti larvae and A. salina nauplii. From 23 cultured cyanobacterial samples, only five grew under laboratory conditions and produced enough biomass to yield organic extracts. Of these, three extracts showed strong larvicidal activity, but only the extract from Phormidium tenue showed reduced toxicity against A. salina nauplii. We detected variation among the chemical profiles and larvicidal activity of cyanobacterial consortia depending on sites and dates of collection. Our findings suggest that despite variation in chemical profiles, extracts of marine benthic cyanobacteria can be further developed as effective control agents against insect vectors, in their larval stages. The culture of marine benthic cyanobacteria needs to be further explored to provide enough biomass leading to the identification of bioactive compounds with public health applications.

Chemical profiles of cannabis sativa medicinal oil using different extraction and concentration methods

The present study shows the variability in chemical profiles of three different varieties of Cannabis sativa extracts used in medicinal cannabis oil when using two different extraction and evaporation methods. Procedures were compared by analyzing rate of total terpenoids to the principal cannabinoids, tetrahydrocannabinol (THC) and cannabidiol (CBD), using gas chromatography coupled to mass spectrometry (GC-MS). The extraction of inflorescences using soxhlet method showed the highest mass of final extract. Also, the use of heating and the presence of oxygen when evaporating the solvents, greatly modified the final profiles due to evaporation or chemical reactions. These variations in chemical profiles must be carefully taken into account and standardized in the elaboration of medicinal oils.

Analysis of the Seasonal Variation in Chemical Profile of Piper glabratum Kunth Essential Oils using GC×GC/qMS and Their Antioxidant and Antifungal Activities

Piper glabratum is a plant native from South America, which has been little studied, despite its use in folk medicine. In this study, chemical composition, antioxidant and antifungal activities of essential oils (EOs) from leaves of P. glabratum were investigated. The influence of seasonality on its chemical composition was also evaluated. The chemical characterization was performed by two-dimensional gas chromatography coupled with quadrupole mass spectrometry (GC×GC/qMS). Altogether, 199 compounds were identified in the EOs and their composition varied during the seasonal cycle. The main compounds found were sesquiterpenes and their oxygenated analogues. EOs showed antioxidant activity, measured by 2,2-diphenyl-1-picrylhydrazyl-DPPH (from 28.1 to 33.4 µg mL-1) and β-carotene assays (from 57.4 to 66.4%), and inhibitory action against C. albicans. The oils provided expressive properties; however, the yield of EO from winter was not enough for activities assays, remarking the influence of the seasonality on the biological activities of this plant.

Attraction of Culex pipiens to House Sparrows Is Influenced by Host Age but Not Uropygial Gland Secretions.

Culex pipiens serves as the endemic vector of West Nile virus (WNV) in eastern North America, where house sparrows (HOSP, Passer domesticus) serve as a reservoir host. We tested the hypotheses that: (1) Attraction of Cx. pipiens to HOSP is influenced by bird age and (2) that age-specific variation in chemical profiles of bird uropygial gland secretions informs this choice. We conducted mosquito choice trials in an olfactometer and found that Cx. pipiens were more often attracted to adult sparrows over nestlings, however, they demonstrated no preference for adults over fledglings. Using gas chromatography-mass spectrometry we observed age-specific differences in the semi-volatile chemical profiles of house sparrow uropygial gland secretions. Contrary to our hypothesis, we found no significant difference in mosquito feeding preference between the secretions of adults and those of either nestlings or fledglings. We suggest that other chemical cues influence the feeding preference of Cx. pipiens, either independently of uropygial gland secretions, or synergistically with them.

Variation in chemical profiles within large seizures of cocaine bricks

Cocaine is usually trafficked from South America throughout the world in packages of approximately one kilogram shaped as bricks and imprinted with a logo. Seizures consisting of multiple cocaine bricks gives the opportunity to examine the variation in the chemical profile within cocaine bricks assumed to originate from the same manufacturer and maybe even the same production batch. This knowledge may be important to the forensic investigator when chemical profiles from cocaine samples of unknown origin are compared.In the present study, the alkaloid and residual solvent profiles from three large cocaine seizures each containing identical cocaine bricks was examined. The three cases consisted of 36, 84 and 100 cocaine bricks, respectively. Each cocaine brick was profiled according to its cocaine alkaloid and residual solvent content using gas chromatography–mass spectrometry (GC–MS) and headspace GC–MS.The study showed that each of the three identical looking seizures consisted of up to four groups of cocaine bricks displaying the same cocaine alkaloid and residual solvent profile. The size of the groups varied from 2.4 to 63.3kg cocaine. The study also showed that the residual solvent profile within each of the three large seizures exhibited very little variation whereas the alkaloid profile varied considerably more. This finding suggest that the same organic solvent is used for the production of several batches of cocaine HCl. Therefore, the residual solvent profile may be a tool to link different production batches from the same manufacturer even though the alkaloid profile are different.

Investigation of association of chemical profiles with the tracheobronchial relaxant activity of Chinese medicinal herb Beimu derived from various Fritillaria species

Ethnopharmacological relevanceFritillariae Bulbus (Beimu in Chinese) is derived from the bulbus of many Fritillaria species (family Liliaceae), which has been used as an antitussive herb in traditional Chinese medicine for more than 2000 years. Due to the complexity of plant origins and significant variations in chemical profiles, the characterization of the profile of the major bioactive constituents and its association with pharmacological activity are important for the quality control of Beimu herbs from different origins. Aim of the studyThis study aims to investigate the distribution of major bioactive isosteroidal alkaloids in Beimu herbs of different origins and its correlation with the tracheobronchial relaxant activity. MethodsQuantification of 7 main bioactive 5α-cevanine isosteroidal alkaloids, including ebeiedine, ebeiedinone, hupehenine, isoverticine, verticine, verticinone and imperialine, in 23 Fritillaria species was performed using gas chromatography. The relaxant effect of different extracts of 4 commonly used Beimu herbs, namely Zhe-Beimu (F. thunbergii Miq.), Chuan-Beimu (F. cirrhosa D. Don), Hubei-Beimu (F. hupehensis Hsiao et K. C. Hsia) and Yi-Beimu (F. pallidiflora Schrenk), was evaluated using rat isolated tracheal and bronchial preparations pre-contracted with carbachol, the well established in vitro antitussive model. ResultsAmongst 23 Fritillaria species detected, significant variations of the types and quantities of 7 major isosteroidal alkaloids were determined, which served as an important indicator for the classification of different Beimu herbs with distinct geographic distributions. Based on the type and quantity of these alkaloids, different origins of Beimu could be clearly clustered into several subgroups by principal component analysis. Furthermore, both crude alkaloid and water extracts of all 4 Beimu herbs showed a dose-dependent tracheobronchial relaxation with different potencies. The total content of alkaloids (weight adjusted based on the activity of individual alkaloids) in Beimu extracts significantly correlated with their tracheobronchial relaxation effects (r2 > 0.9, p < 0.001). ConclusionsThe results demonstrated that the differences in chemical profile of major bioactive isosteroidal alkaloids and pharmacological activity of Beimu could be incorporated into a simple and unified method for quality control and potential prediction of activity of Beimu herbs from different origins.

Lock-picks: fungal infection facilitates the intrusion of strangers into ant colonies

Studies investigating host-parasite systems rarely deal with multispecies interactions, and mostly explore impacts on hosts as individuals. Much less is known about the effects at colony level, when parasitism involves host organisms that form societies. We surveyed the effect of an ectoparasitic fungus, Rickia wasmannii, on kin-discrimination abilities of its host ant, Myrmica scabrinodis, identifying potential consequences at social level and subsequent changes in colony infiltration success of other organisms. Analyses of cuticular hydrocarbons (CHCs), known to be involved in insects’ discrimination processes, revealed variations in chemical profiles correlated with the infection status of the ants, that could not be explained by genetic variation tested by microsatellites. In behavioural assays, fungus-infected workers were less aggressive towards both non-nestmates and unrelated queens, enhancing the probability of polygyny. Likewise, parasitic larvae of Maculinea butterflies had a higher chance of adoption by infected colonies. Our study indicates that pathogens can modify host recognition abilities, making the society more prone to accept both conspecific and allospecific organisms.

Metabolomics reveals constitutive metabolites that contribute resistance to fall webworm (Hyphantria cunea) in Populus deltoides

Constitutive chemical defenses play important roles in protecting trees against insects. Studying the constitutive chemical resistance of trees to insect would thus help control the pests and minimize the associated ecological and economic losses. Poplar is an ecologically and economically important tree species but has been greatly damaged by fall webworm (Hyphantria cunea) in China. Here we investigated H. cunea resistance in 7 poplar cultivars commonly planted in China by applying bioassays, and analyzed metabolic profiles of H. cunea -resistant and -susceptible cultivars. Substantial variation in chemical profiles between resistant and susceptible genotypes was detected. Ninety-two distinguishing metabolites were identified. Correlation analysis indicated that hydroxycinnamates, benzenoids and their derivatives significantly positively correlated with resistance against H. cunea, whereas sucrose, glutamic acid and myo-inositol showed negative correlations. Bioassays of H. cunea given an artificial diet supplemented with these compounds confirmed their effects but indicated that they each have different roles. Metabolite enrichment and gene expression analysis showed that phenylpropanoid biosynthesis in poplar is important for constitutive resistance against H. cunea. Induced experiment found that some of the constitutive resistance-related metabolites were induced by H. cunea indicating that these metabolites also play a role in induced resistance. This study provides further insight into the molecular mechanisms behind H. cunea resistance in poplar and suggests candidate metabolites that may serve as biomarkers for breeding of resistant poplar cultivars.

Passive Sampling and High Resolution Mass Spectrometry for Chemical Profiling of French Coastal Areas with a Focus on Marine Biotoxins.

Passive samplers (solid phase adsorption toxin tracking: SPATT) are able to accumulate biotoxins produced by microalgae directly from seawater, thus providing useful information for monitoring of the marine environment. SPATTs containing 0.3, 3, and 10 g of resin were deployed at four different coastal areas in France and analyzed using liquid chromatography coupled to high resolution mass spectrometry. Quantitative targeted screening provided insights into toxin profiles and showed that toxin concentrations and profiles in SPATTs were dependent on the amount of resin used. Between the three amounts of resin tested, SPATTs containing 3 g of resin appeared to be the best compromise, which is consistent with the use of 3 g of resin in SPATTs by previous studies. MassHunter and Mass Profiler Professional softwares were used for data reprocessing and statistical analyses. A differential profiling approach was developed to investigate and compare the overall chemical diversity of dissolved substances in different coastal water bodies. Principal component analysis (PCA) allowed for spatial differentiation between areas. Similarly, SPATTs retrieved from the same location at early, medium, and late deployment periods were also differentiated by PCA, reflecting seasonal variations in chemical profiles and in the microalgal community. This study used an untargeted metabolomic approach for spatial and temporal differentiation of marine environmental chemical profiles using SPATTs, and we propose this approach as a step forward in the discovery of chemical markers of short- or long-term changes in the microbial community structure.

Differences in males’ chemical signals between genetic lineages of the lizard Psammodromus algirus promote male intrasexual recognition and aggression but not female mate preferences

Interpopulational variation in sexual signals may lead to premating reproductive isolation and eventually may result in speciation. We explored the role of chemical cues secreted by the femoral glands of male lizards Psammdoromus algirus in chemosensory recognition between two distinct genetic lineages from Central Spain. We hypothesized that if there were differences in chemical sexual signals between lineages, these may result in differential recognition and mate preferences. This might lead to reproductive isolation, which would allow the observed morphological and genetic differences between lineages. Our results showed that males of each lineage secreted a singular mixture of compounds in their femoral secretions. However, females were apparently not able to discriminate the lineage of males by chemosensory cues or, alternatively, this discrimination may not be important for females. Moreover, females did not select or reject areas scent marked by males of their own vs. the other lineage. However, previous studies suggest that females might prefer scent of males with particular chemical characteristics that show interindividual variability but do not vary between lineages. Similarly, males did not discriminate between the scents of females of the two lineages, although they had greater chemosensory responses to scents of larger females. In contrast, males clearly discriminated the lineage of other males based on their scents alone, showing chemosensory and aggressive responses that were higher to scents of males of the other lineage. If males of the opposite lineage were more prone to be detected and excluded from a male territory due to their differences in chemical signals, this may probably impede the access of males of one lineage to females of the opposite lineage. This might result in reproductive isolation between lineages. We suggest that the current genetic divergence observed between lineages of P. algirus lizards may be mediated by intrasexual relationships among males, but not by female mate preferences. Significance statement Sexual signals often vary geographically to maximize their efficiency in communication under local conditions. Such variation may, however, affect recognition between individuals of different populations, resulting in reproductive isolation and speciation. We studied two populations (lineages) of a lizard with genetic and morphological differences. We found clear inter-lineage variation in chemical profiles of sexual signals of males. However, females did not recognize these differences by chemosensory cues and did not prefer or reject areas scent-marked by males of the two lineages. In contrast, males recognized and responded more aggressively toward scent of males of the opposite lineage. This might impede access of males of one lineage to females of the other. We suggest that the observed differences between lineages may result from partial reproductive isolation, which can be mediated by agonistic interactions between males rather than by female mate preferences.

Phytochemical variation: How to resolve the quality controversies of herbal medicinal products?

Plants and plant products possess therapeutic potential and are duly utilized for the production of traditional as well as modern medicines worldwide. It is evident that the chemical composition of a plant and possible synergy of its constituents impart therapeutic potential to a plant or plant product(s) (HMPs). However, genomic composition, developmental stage and ambient environmental conditions often cause spatio-temporal variation in the chemical profile of plants. Likewise, harvesting techniques, post-harvest processing, storage conditions, widespread use of pesticides, frequent adulteration and microbial contamination also cause a notable variation in chemical profile of medicinal plant material. The occurrence of phytochemical variation in plant material obtained from different geo-biological sources eventually induce discrepancies in its therapeutic profile. Consequently a variation in chemical composition and therapeutic profile of plant material causes routine complications for the validation of therapeutic efficiency and safety of HMPs.With the global upsurge in the usage of HMPs together with the concurrent reports on chemical variation, adulteration and safety concerns there is an urgent need to institute regulatory and diagnostic measures to meet the objectives of WHO Traditional Medicine Strategy 2014–2023. In this regard, DNA based diagnosis and quantitative profiling of chemical markers accompanied by conventional purity measurements should provide a complete set of quality assurance for medicinal plant material and HMPs. The implementation of an integrated approach of DNA barcoding and quantitative metabolomics has therefore become essential to ascertain potency, purity, consistency and safety of medicinal plants as well as HMPs practised in traditional medicine systems such as Ayurveda, Traditional Chinese Medicine, Kampo and other systems of traditional medicines worldwide.