Neonectria ditissima is the fungal cause of costly European Canker (EC) in apple trees. A range of secondary metabolites were found at higher concentrations in infected twigs than in disease free twigs. Apple trees were then experimentally inoculated with N. ditissima and analyzed periodically until EC symptoms were visible at 12-13 weeks post-inoculation. Established destructive detection methods used were microscopy, which showed extensive hyphal penetration by 8 weeks post inoculation, and qPCR analyses, which confirmed the presence of N. ditissima. Headspace solid-phase microextraction GC-MS data showed significantly higher concentrations of styrene in apple twigs at six weeks after inoculation, and LC-MS data showed phloretin, triterpene acids, and 1-benzoyl β-d-glucose at raised concentrations after this time. Therefore, these compounds could be useful indicators of N. ditissima infection prior to visible canker formation, suitable for nondestructive disease detection development after further research on apple variety, pathogen specificity, and on field detection technology.
The potential of cannabinoids to address public health challenges has stimulated exploration into alternative sources and production technologies. Radula marginata, an endemic Aotearoa/New Zealand liverwort, produces the bibenzyl cannabinoid perrottetinene (PET), analogous to Cannabis psychoactive tetrahydrocannabinol (THC). Structural differences between PET and THC could alter therapeutic interactions and mitigate adverse side effects. To understand the cannabinoid production potential of R. marginata, we analyzed 75 collections from three locations across several seasons, collaborating with kaitiaki M & amacr;ori (indigenous guardians). Metabolic plasticity of the phytocannabinoids and plant growth was assessed under controlled growth conditions, and in in vitro culture. Perrottetinene diol (trans-PTD), analogous to cannabidiol (trans-CBD), and its acid precursor (PTDA), were identified and fully characterized from nature for the first time. Bibenzyl-4-geranyl (BB4G), analogous to cannabigerol (CBG), and its corresponding acid (BB4GA), were also isolated. Radula marginata showed chemotypes dominated by PET, PTD, or BB4G, in striking analogy to the main Cannabis chemotypes. These site-selective chemotypes persisted after growth under artificial lighting and in in vitro progeny, suggesting genetic control. These results expand phytocannabinoid knowledge through the discovery of PTD analogous to CBD. They add a new dimension to liverwort cannabinoids and suggest convergent evolution of biosynthesis in two distant plant lineages.
Plant & Food Research (PFR) is a biologically orientated multi-disciplinary research institute with the goal of improving the value of New Zealand's horticultural products. Within PFR, the practice of chemistry is both widespread and the focus of specialist chemists. To improve safety in the handling of laboratory chemicals, we sought to understand the state of chemical practice and knowledge, the awareness of risk, and how chemical knowledge was acquired and authenticated. A collaborative inquiry approach was chosen so that the social interactions and practice of the research process would itself serve to exchange knowledge and improve communication and laboratory safety. A "survey-small group meeting" model for interaction with users of chemicals was developed and rolled out across PFR. Survey responses were received from 346 respondents who reported their usage of laboratory chemicals, and this was followed by interactive small group meetings with 38 biology-focused research teams located across 12 sites. While the survey provided a generally positive view of practice and perceptions of risk, the team visits provided more site-specific, granular, and informative insights into the handling of chemicals and functioning of laboratories. Textual analysis of contemporaneous notes identified six interconnecting themes associated with risk in the handling of chemicals: lack of knowledge resulting in uncertainty and unrecognized risks; practical difficulties in effecting structural changes to laboratories; poor engagement by a few key individuals; feelings of lack of support by safety managers; the presence of students, visitors, and new graduates needing extensive training; and work pressures resulting in poor decision-making. This research demonstrates the use of collaborative inquiry to provide the granular knowledge needed to improve safety in handling chemicals in biological laboratories.
The methyl-migrated bicyclic skeleton of the halimane diterpenes has been found in a wide range of organisms, including flowering plants, liverworts, marine animals, and bacteria. The discovery of halima-1(10),14-dien-13-ol (3) from the Aotearoa New Zealand endemic alpine daisy Celmisia viscosa is now reported. The full configuration was assigned for the first time by X-ray crystallography, enantiomeric to that of a liverwort isolate. The absolute configuration at C-5 of the halimane is opposite to that at C-5 of the labdane epimanool (1) found in some C. viscosa specimens. Two new 2,6-dideoxyhexopyran-3-uloside halimane derivatives (4 and 5) were also found, and the absolute configuration of 5 was determined by 1H NMR analysis of the Mosher esters. Line broadening in the 13C NMR spectra of these halim-1(10)-enes was due to conformational exchange in the decalin ring A, as shown by molecular modeling and DFT calculations. 1H NMR and GC analyses of leaf extracts of individual plants from across the full geographic range of C. viscosa revealed intraspecific variation of diterpenes: 37 samples had halimadienol as the main diterpene in large amounts and 2 specimens had predominantly epimanool, again in large amounts. Three other viscid (sticky leaved) Celmisia species also contained diterpenes, but none was detectable in four nonviscid Celmisia species.
Flavonoids acylated on their core phenolic groups are rare. The Aotearoa New Zealand endemic alpine daisy Celmisia viscosa is widespread, but its flavonoids have not previously been identified. Leaf extracts yielded a series of 8-O-acylated flavones with combinations of 3-methylbutanoate, 2-methylbutanoate, and 2-methylpropanoate groups and one, two, or three O-methyls, all previously unreported. Regiochemistries of 8-(3″-methylbutanoyl)-5-hydroxy-6,7,4'-trimethoxyflavone (5) and 8-(2″-methylbutanoyl)-5,7,4'-trihydroxy-6-methoxyflavone (10) were defined by X-ray crystallography. LC analyses of leaf extracts from the full geographic range of C. viscosa showed intraspecific variation of these flavones: most had high concentrations of trimethoxy 8-O-acylated flavones, but dimethoxy 8-O-acylated flavones were the most abundant flavonoids in two individuals. Three other viscid (sticky leaved) Celmisa species also contained these rare flavones, but four nonviscid Celmisa had none detectable.
Introduction Hydrogen is the most efficient and economical carrier gas for gas chromatography (GC). However, there are rare reports of artefact formation by hydrogenation of unsaturated compounds on GC. Head space solid-phase microextraction (HS-SPME) GC conditions for hydrogenation were studied. Methodology HS-SPME-GC-mass spectrometry (MS) analyses of common classes of plant volatiles were carried out using hydrogen (H-2) and helium (He) carrier gases with different SPME fibre coatings, GC inlet temperatures, and desorption times. Results Common phenylpropanoids, monoterpenes, and green leaf volatiles were hydrogenated to varying degrees on HS-SPME-GC with H-2 carrier gas and SPME fibres coated with polydimethylsiloxane (PDMS)/Carboxen (CAR), PDMS/divinylbenzene (DVB), and PDMS/CAR/DVB. No artefacts were detected using PDMS-only coated fibres or He carrier gas. Conclusion Unsaturated plant volatiles may be hydrogenated on HS-SPME-GC when using H-2 carrier gas with SPME fibre coatings containing DVB polymer or CAR porous particles. Parallel analyses with He and H-2 carrier gases are recommended when developing HS-SPME-GC methods for plant volatiles, or use of PDMS-only coated fibres.
SummaryCarrots are a good source of essential nutrients and bioactive phytochemicals including carotenoids, phenolic compounds and polyacetylenes such as falcarinol. In this study, we investigated the inhibitory effect of a carrot extract on blood platelet aggregation in vitro and the effect of raw diced or juiced carrots on platelet aggregation in a human study. Carrot extract significantly reduced the platelet aggregation in vitro in blood obtained from healthy donors. In a randomised crossover human study, healthy volunteers consumed either 100 g of freshly diced carrots or 100 mL of freshly juiced carrots (with pulp). There was no significant effect on blood platelet aggregation in the participants at 2, 5, 8 and 24 h after the carrot meal due to wide interindividual variations. Further research is required to understand diet, genetics and lifestyle factors that may impact the physiological effects of falcarinol on platelet aggregation and blood flow.
ABSTRACT Knowledge about the behaviour of passive dispensers used to release semiochemicals for insect pest management is essential to ensure the efficacy of monitoring and control methods based on the use of the semiochemicals. The release characteristics of different passive dispenser types (commercial sachet, altered commercial sachet, polyethylene bags and cotton rolls) were investigated in the laboratory under various conditions. Using the volatile compound methyl isonicotinate (MI), a known lure for western flower thrips Frankliniella occidentalis (Pergande) and two additional homologues ethyl and n-propyl isonicotinate the effect of loading amount (0.5, 1.0 or 2.5 ml), temperatures (15°C, 25°C or 35°C) and air flow (0.1–0.15 m/s or 0.25–0.3 m/s) were tested in a low-speed laminar-flow wind tunnel. The results showed zero-order release kinetics for all tested dispenser types. Release rate kinetics relies on the type of molecule, dispenser type, and the climatic conditions with temperature being a major determinant of release rate. The results of the release characteristics of the different dispensers are discussed in regards to their practical use under greenhouse and field conditions.
ABSTRACT Leptospermum scoparium J. R. et G. Forst. (Myrtaceae), called mānuka or kahikātoa by Māori, shows distinct foliage chemotypes in different regions of Aotearoa New Zealand, including one with rare antimicrobial triketones. To extend knowledge of mānuka chemotypes geographically and historically, we have developed a miniaturised method for analyses of herbarium samples needing just a few small leaves analysed by headspace solid phase microextraction gas chromatography (HS-SPME-GC). This method was validated on herbarium samples of known chemotypes. Geographical knowledge was extended by analysing herbarium samples collected on New Zealand's offshore islands, ranging from the Manawa/Three Kings in the North to Rakiura/Stewart Island in the South. The chemotypes were generally similar to the nearest populations on the main North or South islands. Historically, volatiles were identified from herbarium samples collected by the first botanists from Europe in 1769, showing that the oil glands in mānuka leaves act as ‘chemical time capsules’.
© 2017 Manuka honey (MH), α-cyclodextrin (C) and a formulation containing these two components (MH + C) were subjected to simulated gastrointestinal digestion followed by fermentation with human faecal microbiota. The honey monosaccharides, glucose and fructose were 9- and 3-fold higher respectively in the digesta of MH + C compared with MH. Methylglyoxal (MGO), characteristic of MH was absent after gastric digestion. The precursor of MGO, 1,3-dihydroxyacetone was found to be at a higher concentration in MH + C, compared with MH, after digestion. The MH + C fermenta were more acidic (pH 4.6, p < 0.05), with a higher lactate concentration (p < 0.005). Compared with water control, MH + C fermenta significantly inhibited Salmonella enterica Typhimurium (p = 0.041) and enhanced Lactobacillus reuteri (p = 0.016). These findings suggest that complexation with α-cyclodextrin protects some MH components during digestion. This increases the availability of substrates to faecal bacteria resulting in the generation of metabolites that favour gut health.
Leptospermum scoparium or mānuka is a New Zealand native medicinal plant that produces essential oils with antimicrobial properties. This study investigated the arbuscular mycorrhizal fungi (AMF) community in mānuka by culture dependent (trap culture) and independent (denaturing gradient gel electrophoresis) approaches. Furthermore, to assess whether mycorrhizal inoculation could alter growth and essential oil composition of mānuka, plants of a single regional chemotype were grown in unsterilized soil and inoculated with five AMF isolates. Leaf essential oil compositions and yields were determined by microscale solvent extraction and gas chromatography-mass spectrometry (GC-MS) analysis. AMF inoculation significantly increased growth compared to uninoculated plants. Qualitative i.e. different relative proportions of compounds, which are distinctive in chemotypes and quantitative (i.e. absolute concentrations of compounds, expressed as mg/g of dry leaf or equivalent) effects of AMF inoculation on mānuka essential oil composition depended on the isolate. AMF inoculation modified the Gammaproteobacterial community on roots and this may have contributed to changes in essential oil composition. Overall, these results demonstrated that AMF can improve the growth of mānuka and affect plant secondary metabolites in leaves, which would be valuable in commercial essential oil production from plantation-grown mānuka.
INTRODUCTION The valuable secondary metabolites in hops (bitter acids, xanthohumol, volatile monoterpenes and sesquiterpenes) are sequestered in lupulin glands (extracellular trichomes) which can be collected and analysed with little or no sample preparation. OBJECTIVES To determine whether high throughput screening of lupulin glands composition, by fast analyses and chemometrics, could be used for breeder selection of hops with key flavour attributes. METHODS Lupulin glands from 139 plants (39 cultivars/advanced selections) were analysed by Raman and 1 H NMR spectroscopy, and head-space solid-phase microextraction (HS-SPME) GC-FID. The digital X,Y-data were subjected to principal component analysis (PCA) and the results compared with conventional analyses of extracts of whole hops from the same plants. Quantitative 1 H NMR analyses were also done for the bitter acids. RESULTS Raman spectroscopy rapidly identified hops cultivars with high xanthohumol concentrations and high α:β bitter acid ratios. 1 H NMR spectroscopy was slower, requiring a solvent extraction, but distinguished cultivars by cohumulone content as well as α:β acid ratios. HS-SPME-GC rapidly distinguished aroma hops with high myrcene and farnesene contents, and pinpointed a novel selection with unusual sesquiterpenes. The quantitative NMR analyses showed correlations between bitter acid concentrations related to biosynthetic pathways. CONCLUSIONS Analysis of lupulin glands gave reliable results for the main quality indicators used by hops breeders, potentially avoiding harvesting, drying and solvent extracting whole hops. PCA of digital X,Y-data rapidly discriminated different hops chemotypes, and highlighted plants with potential for new flavourcultivars. Copyright © 2016 John Wiley & Sons, Ltd.
The traditionally consumed New Zealand native plant nau, Cook's scurvy grass, Lepidium oleraceum, has a pungent wasabi-like taste, with potential for development as a flavor ingredient. The main glucosinolate in this Brassicaceae was identified by LC-MS and NMR spectroscopy as 3-butenyl glucosinolate (gluconapin, 7-22 mg/g DM in leaves). The leaves were treated to mimic chewing, and the headspace was analyzed by solid-phase microextraction and GC-MS. This showed that 3-butenyl isothiocyanate, with a wasabi-like flavor, was produced by the endogenous myrosinase. Different postharvest treatments were used to create leaf powders as potential flavor products, which were tasted and analyzed for gluconapin and release of 3-butenyl isothiocyanate. A high drying temperature (75 °C) did not give major glucosinolate degradation, but did largely inactivate the myrosinase, resulting in no wasabi-like flavor release. Drying at 45 °C produced more pungent flavor than freeze-drying. Seven other Lepidium species endemic to New Zealand were also analyzed to determine their flavor potential and also whether glucosinolates were taxonomic markers. Six contained mostly gluconapin, but the critically endangered Lepidium banksii had a distinct composition including isopropyl glucosinolate, not detected in the other species.
Alkaloid contents of leaf and seed samples of eight species of Sophora native to New Zealand, plus Sophora cassioides from Chile are reported. Fifty-six leaf and forty-two seed samples were analysed for alkaloid content by proton nuclear magnetic resonance spectroscopy, which showed major alkaloids as cytisine, N-methyl cytisine and matrine. GC analyses quantified these and identified further alkaloid components. The alkaloids identified were cytisine, sparteine, and matrine-types common to Sophora from other regions of the world. Cytisine, N-methyl cytisine, and matrine were generally the most abundant alkaloids across all species with seeds containing the highest concentrations of alkaloids. However, there was no clear taxonomic grouping based on alkaloid composition. A quantitative analysis of various parts of two Sophora microphylla trees showed that the seeds were the richest source of alkaloids (total 0.4-0.5% DM), followed by leaf and twig (0.1-0.3%) and then bark (0.04-0.06%), with only low amounts (<0.02%) found in the roots. This study represents the most comprehensive phytochemical investigation of New Zealand Sophora species to date and presents data for three species of Sophora for which no prior chemistry has been reported.
Poisonings due to consumption of honeys containing plant toxins have been reported widely. One cause is the neurotoxin tutin, an oxygenated sesquiterpene picrotoxane, traced back to honeybees (Apis mellifera) collecting honeydew produced by passionvine hoppers (Scolypopa australis) feeding on sap of the poisonous shrub tutu (Coriaria spp.). However, a pharmacokinetic study suggested that unidentified conjugates of tutin were also present in such honeys. We now report the discovery, using ion trap LC-MS, of two tutin glycosides and their purification and structure determination as 2-(β-d-glucopyranosyl)tutin (4) and 2-[6'-(α-d-glucopyranosyl)-β-d-glucopyranosyl]tutin (5). These compounds were used to develop a quantitative triple quadrupole LC-MS method for honey analysis, which showed the presence of tutin (3.6 ± 0.1 μg/g honey), hyenanchin (19.3 ± 0.5), tutin glycoside (4) (4.9 ± 0.4), and tutin diglycoside (5) (4.9 ± 0.1) in one toxic honey. The ratios of 4 and 5 to tutin varied widely in other tutin-containing honeys. The glycosidation of tutin may represent detoxification by one or both of the insects involved in the food chain from plant to honey.
Two glasshouse trials in a capsicum crop near Warkworth New Zealand in January 2011 and two field trials in a nectarine orchard near Lleida Spain in July 2013 were undertaken to determine if trap capture of Frankliniella occidentalis (western flower thrips WFT) and Thrips tabaci (onion thrips OT) could be increased by alternative volatile compounds beyond the known thrips attractant methyl isonicotinate (MI) On blue sticky board traps in the crop in New Zealand none of six alternative compounds tested caught more thrips (mostly WFT OT and two other species) than the Control traps In contrast to MI catches with the alternative lures were mostly significantly lower For both trials in the orchard in Spain using white water traps the highest numbers of WFT and OT were caught higher than most of the nine alternative odour compounds tested
Bactericera cockerelli (tomato potato psyllid; TPP) is an important pest of solanaceous crops in New Zealand and North America A volatile compound that alters the behaviour of TPP could be developed into a component of an integrated pest management strategy for solanaceous crops One compound 2undecanone was found to increase the percentages of female and male TPP (65 P
The leave volatiles of six Gingidia species from New Zealand and Australia and the seed volatiles of G. grisea were characterized by solid‐phase microextraction (SPME)‐GC/MS analysis. This technique, using a small quantity of samples and automated extraction, gave repeatable results, with maximum sensitivity for medium volatility compounds. The major monoterpenes among the volatiles, i.e. , β ‐phellandrene ( 4 ), limonene ( 6 ), and γ ‐terpinene ( 5 ), and phenylpropanoids, i.e. , estragole ( 3 ), ( E ) ‐ anethole ( 7 ), and myristicin ( 1 ), showed to be useful chemotaxonomic markers. For G. grisea leaves and seeds, similar compositions were detected, characterized by high contents of 4 . As leaves were more readily available for study than seeds, they were used for further investigations. The G. grisea leaf volatiles showed infraspecific variation in the ratio of 4 / 5 between and within sites of collection. The G. montana leaf volatiles also showed infraspecific variation, with high contents of 3 at one site and high contents of 7 at another. The SPME‐GC/MS analysis of G. montana herbarium voucher specimens resulted in the identification of further chemotypes for this species. The volatiles of the G. amphistoma samples were all dominated by 7 and those of the G. haematitica samples were rich in 5 . Moreover, single plants of two Australian Gingidia species were analyzed; the volatiles of G. harveyana showed high concentrations of 5 and 7 , whereas those of G. rupicola were dominated by 5 and 1 .
Rapid quantitative near-infrared Fourier transform Raman analyses of the key phytonutrients in carrots, polyacetylenes and carotenoids, are reported here for the first time. Solvent extracts of 31 carrot lines were analyzed for these phytonutrients by conventional methods, polyacetylenes by GC-FID and carotenoids by visible spectrophotometry. Carotenoid concentrations were 0-5586 μg g(-1) dry weight (DW). Polyacetylene concentrations were 74-4846 μg g(-1) DW, highest in wild carrots. The polyacetylenes were falcarinol, 6-1237 μg g(-1) DW; falcarindiol, 42-3475 μg g(-1) DW; and falcarindiol 3-acetate, 27-649 μg g(-1) DW. Strong Raman bands for carotenoids gave good correlation to results by visible spectrophotometry. A chemometric model capable of quantitating carotenoids from Raman data was developed. A classification model for rapidly distinguishing carrots with high and low polyacetylene (limit of detection = 1400 μg g(-1)) concentrations based on Raman spectral intensity in the region of 2250 cm(-1) was produced.
Root and rhizome production of goldenseal (Hydrastis canadensis) was measured annually from 1996 to 2002 under shade in Waikato, New Zealand. Root and rhizome production increased annually to 60-70 g dry matter (DM)/plant after 6 years, giving a root:rhizome DM yield of 5500 kg/ha. Initial growth was dominated by the roots but by the fifth and sixth year, the root:rhizome ratio remained constant at 1.2. After 6 years, approximately 84% of the root and rhizome mass was in the first 50 mm of soil, with very few roots below 100 mm. The berberine concentration in the roots and rhizomes was always above the US Pharmacopeia's quality threshold of 2.5%. The hydrastine content was only above the US quality threshold of 2% in the rhizomes and in the roots in 1999. In the 2001 and 2002 analyses, hydrastine concentrations dropped markedly in both roots and rhizomes with the hydrastine levels in the roots being below the quality threshold.