RESUMEN

Alkylamides, as the representative hemp flavor and active ingredients, can reflect the quality of Zanthoxylum bungeanum Maxim. However, conjugated triene structure exists in alkylamides, which is easy to be oxidized and decomposed in air, making it difficult to quantify. In this study, a method for the quantitative determination of alkylamides by 1 H-NMR technology was developed with 85% ethanol as the best extraction solvent, CDCl3 as the best deuterium dissolution reagent, pyrazine as the internal standard, and triple peaks of hydrogen protons on the amide bond at δ 6.33 ppm as the quantitative signal peak. Meanwhile, methodological verification was carried out to prove the reliability and effectiveness of the method. On this basis, the contents of alkylamides in nine germplasms of Zanthoxylum with monthly dynamics were obtained. The results showed that the alkylamides of Hancheng stingless Z. bungeanum (HC) exhibited the highest content in August (51.92 ± 0.96 mg/g), while the lowest was FG in June (1.23 ± 0.21 mg/g). The results of 1 H-NMR corresponded to those of HPLC, and the effectiveness of this method was verified. Accumulation dynamic results show that the best harvest period of Z. bungeanum is July and August. Moreover, the quality of nine varieties of Zanthoxylum bungeanum from a common garden was evaluated by the established 1 H-NMR fingerprint and chemometric analyses. The results showed that Hancheng stingless Z. bungeanum was the best germplasm. This study provides a new strategy for the quantitative determination of alkylamides in Z. bungeanum and improves the quality evaluation system of Z. bungeanum. PRACTICAL APPLICATION: The results provide a new research idea for the analysis of important chemical components of Z. bungeanum. Meanwhile, the study provides a scientific basis for the quality evaluation and high-quality germplasm resources of Z. bungeanum.

Asunto(s)

RESUMEN

Honey is the natural sweet substance produced by honeybee from nectar or honeydew, exhibiting several nutritional and health benefits. It contains a complex mixture of compounds in different proportions, with sugars being the main component. The physicochemical characteristics of ten honeys were evaluated; represented by five, three, and two from South Africa, Slovakia, and Zambia, respectively. The range of values for the pH (3.75-4.38), electrical conductivity (99-659 µS/cm), and moisture content (14.2-17.7%) are within the recommended limits for quality honeys. ¹H-NMR (Nuclear Magnetic Resonance) profiling of the honeys in D2O was determined, and the data were analysed by chemometrics. This method is fast, reproducible, and sample pre-treatment is not necessary. The ¹H-NMR fingerprints of various chemical shift regions showed similarity or dissimilarity across geographical origins that are useful for identification, detection of adulteration, and quality control. The principal component analysis PCA and partial linear square discriminant analysis PLS-DA of the ¹H-NMR profiles successively categorises the honeys into two chemically related groups. The R² values are higher than the corresponding Q² values for all samples, confirming the reliability of the model. Honeys in the same cluster contain similar metabolites and belong to the same botanic or floral origin.

Asunto(s)

RESUMEN

Generic and specific determination among the Laurencia complex is a challenging task. DNA barcoding combined with phenotypic investigations are mandatory for species differentiation. In this study, two morphologically different members of the Laurencia complex were investigated using untargeted 1 H-NMR-based metabolomics. Twenty-one population samples were collected in order to evaluate both temporal and geographical homogeneity. Data obtained from 1 H-NMR analysis followed by statistical analysis allowed a clear separation of all the samples into two groups. DNA mitochondrial tests confirmed this pattern and identified the two species as Laurenciella sp. and Laurencia obtusa. In addition, metabolites responsible of this discrimination were investigated directly in crude extracts by 13 C-NMR using an in-house computer-assisted method. The combination of both untargeted (1 H) and targeted (13 C) NMR-based metabolomic approaches proves to be a powerful and complementary approach to discriminate species from the Laurencia complex.

Asunto(s)

RESUMEN

BACKGROUND AND OBJECTIVE: Even though herbal medicines have played an important role in disease management and health for many centuries, their present frequent use is challenged by the necessity to determine their complex composition and their multitarget mode of action. In the present study, modern methods were investigated towards their potential in the characterization of herbal substances. As a model the herbal substance Chelidonii herba was used, for which several reports on liver toxicities exist. Extracts of Chelidonii herba with different solvents were characterized phytochemically and functionally by experiments with HepG2 liver cells. METHODS: Chelidonii herba was extracted with four solvents of different polarity (dichloromethane, water, ethanol, and ethanol 50% (V/V); four replicates each). The different extracts were characterized metabolomically by (1)H-NMR fingerprinting analysis and principal component analysis (PCA). The content of alkaloids was additionally determined by RP-HPLC. Functional characterization was achieved by the determination of cell proliferation and by transcriptomics techniques (Whole Genome Gene Expression Microarrays v2, Agilent Technologies) in HepG2 cells after exposure to the different extracts (four experimental replicates each). RESULTS: Based on data from (1)H-NMR fingerprints and RP-HPLC analyses the different extracts showed a divergent composition of constituents depending on the solvent used. HepG2 liver cells responded differentially to the four extracts. Microarray analysis revealed a significant regulation of genes and signal cascades related to biotransformation. Also liver-toxic signal cascades were activated. Neither the activated genes nor the proliferation response could be clearly related to the differing alkaloid content of the extracts. CONCLUSION: Different manufacturing processes lead to different herbal preparations. A systems biology approach combining a metabolomic plant analysis with a functional characterization by gene expression profiling in HepG2 cells is an appropriate strategy to characterize variations in plant extracts. Safety assessments of herbal substances may benefit from such complementary analyses.

Asunto(s)

RESUMEN

Brazil is currently the largest exporter of concentrated orange juice and, unlike the other exporter countries, the domestic consumption is mainly based on the fresh orange juice. The quality control by evaluating the major chemical constituents under the influence of the most important factors, such as temperature and storage time of the product, is very important in this context. Therefore, the objective of this study was to evaluate the influence of temperature and time on the degradation of fresh orange juice for 24h, by using (1)H NMR technique and chemometric tools for data mining. The storage conditions at 24h led to the production of the formic, fumaric and acetic acids; and an increase of succinic and lactic acids and ethanol, which were observed at low concentration at the initial time. Furthermore, analysis by PCA has successfully distinguished the juice of different species/varieties as well as the metabolites responsible for their separation.

Asunto(s)

RESUMEN

INTRODUCTION: The fruits of Vaccinium vitis-idaea L. are a valuable source of biologically active flavonoid derivatives. For studies focused on the purification of its quercetin glycosides (QGs) and related glycosides from plants and for the purpose of biological studies, the availability of numeric datasets from computer-assisted ¹H iterative full spin analysis (HiFSA), that is, ¹H-NMR fingerprinting, can replace and assist the repetitive and tedious two-dimensional NMR identification protocol required for both known and new compounds, respectively. OBJECTIVE: To fully interpret the complex ¹H-NMR fingerprints of eight QGs obtained from the berries of V. vitis-idaea and provide complete and unambiguous signal assignments. METHODS: Vaccinium vitis-idaea QGs were purified in a single run by long-bed gel permeation chromatography and identified by comparison with commercially available compounds using LC-MS combining ion-trap and time-of-flight detection and one- or two-dimensional NMR. The HiFSA analysis yielded full sets of ¹H chemical shifts and proton-proton coupling constants, allowing for field-independent spectral simulation. RESULTS: Signal assignments were achieved for the reference standards and the QGs that dominated in purified fractions. However, even mixtures of two to three QGs could be fitted using the HiFSA approach. In the case of the overlapped sugar resonances, the initial fitting of the ¹H spectra of reference compounds, together with values extracted from the two-dimensional NMR data and literature data, assisted in the process. CONCLUSION: The HiFSA method revealed for the first time the presence of Q-3-O-ß-glucopyranoside and Q-3-O-ß-glucuronopyranoside in the berries of V. vitis-idaea, and unambiguously confirmed the structures of Q-3-O-[4″-(3-hydroxy-3-methylglutaroyl)]-α-rhamnopyranoside, Q-3-O-α-rhamnopyranoside, Q-3-O-ß-galactopyranoside, Q-3-O-α-arabinofuranoside, Q-3-O-ß-xylopyranoside and Q-3-O-α-arabinopyranoside.

Asunto(s)

RESUMEN

AIM: To establish ()~1H NMR fingerprint of Radix Daphne genkwa to disclose its chemical composition of the secondary metabolites and provide a quick and credible assay for the detoxicated extraction of the active constituents. METHODS: The ()~1H NMR spectrum of petrol-acetone-methanol extract from Radix Dephne genkwa was detected using CDCl_3/DMSO-d_6(1∶1) as the deuterium reagent. The resonance intensity of the proton in the spectrum was indicated in relative integral area of peaks referenced by the resonance intensity of methyl signal in DMSO. The ()~1H NMR of cascade extraction of Radix Dephne genkwa by the reagent in sequence of petrol→acetone→methanol or chloroform→aether→acetyl acetate→methanol was utilized for observing the variation on their chemical compositions. RESULTS: The ()~1H NMR of Radix Dephne genkwa clearly expressed the information of the protons from long chain aliphatics or genkwadaphnin derivatives, aromatic coumarins or flavonoids as well as glycosides with moiety(ies) of pyran saccharide, symbolizing the existence of aliphatics, genkwadaphnin derivatives, coumarins and flavonoids. Remarkable difference was observed in ()~1H NMR spectrum of the extract by different cascade reagent. As the increase in the polarity of reagent, the intensity of the proton signals in upper field was quickly reduced concomitantly with the rapid enhancement of active proton signals from hydroxyls and saccharides in glycosides in down field. CONCLUSION: The ()~1H NMR fingerprint of Radix Dephne genkwa possesses its own characteristics and can be used as a reliable assay for studying the extraction of active constituents with minimum content of toxic diterpenoids. (Key