Paul R. Shipley

A review of the chemistry of the genus Crataegus.

Since the 1800s, natural health products that contain hawthorn (Crataegus spp.) have been used in North America for the treatment of heart problems such as hypertension, angina, arrhythmia, and congestive heart failure. Traditionally, Native American tribes used hawthorn (Crataegus spp.) to treat gastrointestinal ailments and heart problems, and consumed the fruit as food. Hawthorn also has a long history of use in Europe and China for food, and in traditional medicine. Investigations of Crataegus spp. typically focus on the identification and quantification of flavonoids and anthocyanins, which have been shown to have pharmacological activity. The main flavonoids found in Crataegus spp. are hyperoside, vitexin, and additional glycosylated derivatives of these compounds. Reviewed herein are the botany, ethnobotany, and traditional use of hawthorn while focusing on the phytochemicals that have been reported in Crataegus species, and the variation in the described chemistry between individual species.

Phytochemical diversity of cranberry (Vaccinium macrocarpon Aiton) cultivars by anthocyanin determination and metabolomic profiling with chemometric analysis.

Originally native to the eastern United States, American cranberry ( Vaccinium macrocarpon Aiton, family Ericaceae) cultivation of native and hybrid varieties has spread across North America. Herein is reported the phytochemical diversity of five cranberry cultivars (Stevens, Ben Lear, Bergman, Pilgrim, and GH1) collected in the Greater Vancouver Regional District, by anthocyanin content and UPLC-TOF-MS metabolomic profiling. The anthocyanin content for biological replicates (n = 5) was determined as 7.98 ± 5.83, Ben Lear; 7.02 ± 1.75, Bergman; 6.05 ± 2.51, GH1; 3.28 ± 1.88, Pilgrim; and 2.81 ± 0.81, Stevens. Using subtractive metabonomic algorithms 6481 compounds were found conserved across all varietals, with 136 (Ben Lear), 84 (Bergman), 91 (GH1), 128 (Pilgrim), and 165 (Stevens) unique compounds observed. Principal component analysis (PCA) did not differentiate varieties, whereas partial least-squares discriminate analysis (PLS-DA) exhibited clustering patterns. Univariate statistical approaches were applied to the data set, establishing significance of values and assessing quality of the models. Metabolomic profiling with chemometric analysis proved to be useful for characterizing metabonomic changes across cranberry varieties.

Reactivity of β-Methylamino-l-alanine in Complex Sample Matrixes Complicating Detection and Quantification by Mass Spectrometry

β-methylamino-l-alanine (BMAA) is a naturally occurring nonprotein amino acid originally discovered in cycad seeds and traditional foods of the Chamorro people of Guam. Recent research has implicated BMAA as a potential factor in neurodegenerative disease and described the production of BMAA in cyanobacteria, but conflicting results have complicated the interpretation of data. We hypothesized that the reactivity of BMAA with metal ions in the sample matrix and the formation of metal adducts in electrospray ionization mass spectrometry (MS) analysis confound results. Dilute solutions of TCA, MgCl(2), NaCl, CuCl(2), ZnCl(2) (0.01 M), or artificial ocean water (Instant Ocean, 3.5 g/L) reduced the signal attributable to the BMAA M + H(+) peak by 78-99.7%. The degree of adduct formation was significantly affected by MS settings such as induction voltage. A number of the detected ion peaks in BMAA standards were consistent with the formation of metal-BMAA complexes in addition to the adduct formation. A standard of Zn(BMAA)(2) was synthesized, and the effects of sample preparation, derivatization, column chromatography, pH, and interactions with serine were determined. Together, these data demonstrate that sample matrix, formation of adducts, and mass spectrometry settings complicate analysis of BMAA, that analysis by detection of the parent ion and daughter ion fragmentation patterns are highly susceptible to false negative findings, and that failure to detect BMAA cannot be considered proof of absence of the compound.

Comparisons of large (Vaccinium macrocarpon ait.) and small (Vaccinium oxycoccos L., Vaccinium vitis-idaea L.) cranberry in British Columbia by phytochemical determination, antioxidant potential, and metabolomic profiling with chemometric analysis

There is a long history of use and modern commercial importance of large and small cranberries in North America. The central objective of the current research was to characterize and compare the chemical composition of 2 west coast small cranberry species traditionally used (Vaccinium oxycoccos L. and Vaccinium vitis-idaea L.) with the commercially cultivated large cranberry (Vaccinium macrocarpon Ait.) indigenous to the east coast of North America. V. oxycoccos and V. macrocarpon contained the 5 major anthocyanins known in cranberry; however, the ratio of glycosylated peonidins to cyanidins varied, and V. vitis-idaea did not contain measurable amounts of glycosylated peonidins. Extracts of all three berries were found to contain serotonin, melatonin, and ascorbic acid. Antioxidant activity was not found to correlate with indolamine levels while anthocyanin content showed a negative correlation, and vitamin C content positively correlated. From the metabolomics profiles, 4624 compounds were found conserved across V. macrocarpon, V. oxycoccoS, and V. vitis-idaea with a total of approximately 8000-10 000 phytochemicals detected in each species. From significance analysis, it was found that 2 compounds in V. macrocarpoN, 3 in V. oxycoccos, and 5 in V. vitis-idaea were key to the characterization and differentiation of these cranberry metabolomes. Through multivariate modeling, differentiation of the species was observed, and univariate statistical analysis was employed to provide a quality assessment of the models developed for the metabolomics data.

North American Artemisia species from the subgenus Tridentatae (Sagebrush): a phytochemical, botanical and pharmacological review.

The genus Artemisia consists of between 350 and 500 species with most of the North American endemic Artemisia species contained within the subgenus Tridentatae (Sagebrush). The reported uses of these species by Native American and First Nations peoples include analgesic, antiinflammatory, antiseptic, immunostimulation activity, as well as the treatment of afflictions from spiritual origins. Taxonomic revision for North American Sagebrush has created a number of synonyms that confuse the literature. The phytochemical diversity of the Tridentatae includes at least 220 distinct and important specialized metabolites. This manuscript reviews the current phytochemical, botanical and pharmacological understanding for the subgenus Tridentatae, and provides a foundation for future studies of the metabolomes of the Tridentatae. Modern approaches to phytochemical analysis and drug discovery are likely to provide interesting lead compounds in the near future.

Design of organoiron macromolecules based on upper rim functionalized calix[4]arenes.

The versatility of cationic cyclopentadienyliron complexes is demonstrated for the generation of calix[4]arene-based dendrimers and polymers. Dendrimers were prepared from a branched organoiron calix[4]arene through subsequent reactions of azo dyes and organoiron complexes. The resulting azo dye-containing metallocalix[4]arenes were soluble in polar organic solvents and displayed λ(max) ranging between 430 and 456 nm. Upon addition of various acids, the λ(max) shifted to higher wavelengths (513-535 nm). In the solid state and in solution, the azo dye-containing metallocalix[4]arenes reversibly changed colour in the presence of acid and base, indicating their potential use as acid sensors. Cyclic voltammetric studies showed that the iron centres of the metallocalix[4]arenes were reversibly reduced at E(1/2)  = -1.49 V. When non-branching organoiron-based calix[4]arene were reacted with dithiols, polymers containing calix[4]arenes either in their side chains or main chains were obtained. The polymers possessed weight average molecular weights between 35 000 and 53 000. The polymers were determined to be thermally stable with backbone decomposition occurring above 500 °C.

DNA barcodes from four loci provide poor resolution of taxonomic groups in the genus Crataegus

The leaves and fruits of some of the approximately 230 species of hawthorn (Crataegus) yield natural health products with significant therapeutic effects on symptoms of cardiovascular disease. DNA barcoding could be a valuable tool for authenticating these products, but only a small fraction of the 93 taxa that we examined were distinguished, even though all major clades and eight out of ten taxonomic sections of the genus were included. DNA barcoding as currently practised thus has limited utility in Crataegus. Hybridization, lineage sorting due to incomplete concerted evolution in ITS2, and limited variation in plastid loci are implicated.

Micro and nano-sized polysiloxanes containing organoiron moieties

Utilizing organoiron-mediated nucleophilic aromatic substitution, a number of allylamine-containing organoiron complexes were prepared. Amide formation between 1,1′-ferrocene dicarbonyl chloride and allylamine produced a similar ferrocene compound. These materials were subjected to hydrosilation with methyldiethoxyhydrosilane to generate cationic organoiron siloxanes and ferrocene-containing siloxane complexes. Electrochemical analysis of the allylamine and siloxane complexes showed redox couples characteristic of nitrogen-substituted arene-coordinated cyclopentadienyliron complexes. In situ cleavage of the ethoxy groups followed by the addition of H2SO4 resulted in the formation of polymeric materials. Thermal analysis revealed that the cationic organoiron moieties decomposed between 200 °C and 250 °C, whereas the ferrocene moiety decomposed at 110 °C and the backbones of the polymers began to decompose above 400 °C. The polymers displayed glass transition temperatures between 68 °C and 111 °C. Scanning electron microscopy showed that the polymers possessed very different morphologies, ranging from particulates to crystalline.

Comparison of computational approaches for identification and quantification of urinary metabolites in 1H NMR spectra

Nuclear magnetic resonance (NMR) spectroscopy is extensively used in analytical chemistry as a powerful, non-invasive, and non-destructive tool to elucidate detailed structures of small molecules in complex mixtures. A major initiative in NMR is the identification of metabolic changes in biological fluids, particularly urine, as potential biomarkers for specific diseases or occupational exposure. However, major challenges are encountered during data processing of complex NMR spectra, presenting obstacles in the use of NMR analysis in clinical applications. In this report, metabolite concentrations were determined using three different computational approaches with complex NMR spectra obtained using 33 replicates of quality control (QC) human urine samples. We have used a new computational method involving Monte Carlo (MC) simulation to automatically deconvolve and quantify metabolites in NMR spectra from human urine. MC simulation is independent of experimental bias or human error, and is recommended as the least biased approach to peak fitting for NMR spectra derived from human urine samples. We found that similar results could be obtained using MC simulation in urine samples compared with two previous approaches that are subject to experimental bias and/or human error.

Differentiation of Crataegus spp. guided by nuclear magnetic resonance spectrometry with chemometric analyses

For compliance with US Current Good Manufacturing Practice regulations for dietary supplements, manufacturers must provide identity of source plant material. Despite the popularity of hawthorn as a dietary supplement, relatively little is known about the comparative phytochemistry of different hawthorn species, and in particular North American hawthorns. The combination of NMR spectrometry with chemometric analyses offers an innovative approach to differentiating hawthorn species and exploring the phytochemistry. Two European and two North American species, harvested from a farm trial in late summer 2008, were analyzed by standard 1D 1H and J-resolved (JRES) experiments. The data were preprocessed and modelled by principal component analysis (PCA). A supervised model was then generated by partial least squares-discriminant analysis (PLS-DA) for classification and evaluated by cross validation. Supervised random forests models were constructed from the dataset to explore the potential of machine learning for identification of unique patterns across species. 1D 1H NMR data yielded increased differentiation over the JRES data. The random forests results correlated with PLS-DA results and outperformed PLS-DA in classification accuracy. In all of these analyses differentiation of the Crataegus spp. was best achieved by focusing on the NMR spectral region that contains signals unique to plant phenolic compounds. Identification of potentially significant metabolites for differentiation between species was approached using univariate techniques including significance analysis of microarrays and Kruskall-Wallis tests.