Important Chemical Markers Research Articles

Component analysis using UPLC-Q-TOF/MS and quality evaluation using fingerprinting and chemometrics for hops

Hops, extensively cultivated in China for their food and medicinal applications, currently lack well-defined chemical markers to evaluate variations in their quality. The study aimed to explore variations in the quality of Chinese hops by the chemical characteristics of hops, employing UPLC-Q-TOF/MS, integrated with chemical fingerprinting and chemometrics. The results indicated that Chinese hops are abundant in polyphenols and bitter acids. The integration of UPLC-Q-TOF/MS, Chemical fingerprinting, and chemometrics revealed to be an accurate and effective approach for assessing the quality of Chinese hops. In this study, ten important chemical markers were found to be useful in differentiating various hop varieties. Moreover, the support vector machine showed a prediction accuracy of 92.3077% in identifying Chinese hop varieties. The strategy of the study lays the groundwork for classifying Chinese hop varieties and serves as a prerequisite for future quality control studies, particularly focusing on chemical compositions.

A comprehensive quality evaluation method of different medicinal parts of Physalis Calyx seu Fructus by fingerprints, chemometrics, antioxidant activity, network pharmacology and molecular docking.

Physalis Calyx seu Fructus (PCF) is a herb widely used in China for its function of clearing heat and detoxifying, benefitting the pharynx and reducing phlegm, both in health care and in tea drinking. However, the quality of its fruit and calyx is uneven and the storage period is short. Therefore, it is crucial to develop other parts of PCF with longer storage periods and obvious medicinal effects. Firstly, high-performance liquid chromatography was used to develop the fingerprint of different parts of PCF, and various chemometric analyses were conducted to screen out chemical markers. The calyxes of PCF were found to cluster together, distinct from the fruits, roots, stems and leaves. The active components of PCF were concentrated in the persistent calyxes, and flavonoids were mainly found in the persistent calyxes and leaves. Secondly, the extraction of persistent calyxes showed the strongest scavenging ability of DPPH and ABTS. Finally, the important chemical markers were verified by network pharmacological analysis and molecular docking. It provides a reference for the clinical application of PCF, and the obtained chemical markers offer a scientific basis for quality evaluation.

Quality evaluation of compounds in leaves of six Taxus species based on UPLC-MS/MS and chemometrics.

Introduction: Taxus species are used as medicinal plants all over the world. The leaves of Taxus species are sustainable medicinal resources that are rich in taxoids and flavonoids. However, traditional identification methods cannot effectively identify Taxus species on the basis of leaces used as raw medicinal materials, because their appearance and morphological characteristics are almost the same, and the probability of error identification increases in accordance with the subjective consciousness of the experimenter. Moreover, although the leaves of different Taxus species have been widely used, their chemical components are similar and lack systematic comparative research. Such a situation is challenging for quality assessment. Materials and methods: In this study, ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry combined with chemometrics was applied for the simultaneous determination of eight taxoids, four flavanols, five flavonols, two dihydroflavones, and five biflavones in the leaves of six Taxus species, namely, T. mairei, T. chinensis, T. yunnanensis, T. wallichiana, T. cuspidata, and T. media. Chemometric methods, including hierarchical cluster analysis, principal component analysis, orthogonal partial least squares-discriminate analysis, random forest iterative modeling, and fisher linear discriminant analysis, were utilized to differentiate and evaluate the six Taxus species. Results: This proposed method exhibited good linearity (R 2 = 0.9999-0.9972) with a lower quantification limits of 0.94-3.05ng/mL for all analytes. The intra- and inter-day precisions were within 6.83%. Six compounds, namely, 7-xylosyl-10-deacetyltaxol, ginkgetin, rutin, aromadendrin, 10-deacetyl baccatin III, and epigallocatechin, were identified through chemometrics for the first time. These compounds can be used as important chemical markers to distinguish the above six Taxus species rapidly. Conclusion: This study established a method for determination of the leaves of six Taxus species, and revealing the differences in the chemical components of these six Taxus species.

Sinapis Semen: A review on phytochemistry, pharmacology, toxicity, analytical methods and pharmacokinetics.

Sinapis Semen (SS), the dried mature seed of Sinapis alba L. and Brassica juncea (L.) Czern. et Coss., is one of the traditional Chinese medicinal materials with a wide range of pharmacological effects being used for asthma, cough and many other ailments. SS is also widely used in food agriculture, medicine and other industries in North America and South Asia. More recently, the research on SS has gradually intensified and increased. However, there is no systematic review of SS. In this review, through literature exploration and analysis, the research advance on phytochemistry, pharmacology, toxicity, analytical methods and pharmacokinetics of SS was aggregated initially. Total 144 compounds have been isolated and identified from SS. Among them, glucosinolates and their hydrolysates and volatile oils are the main active ingredients and important chemical classification markers. SS has a wide range of pharmacological effects, especially in cough suppressing, asthma calming, anti-inflammatory, neuroprotective, cardiovascular protective, inhibiting androgenic effects, anti-tumor, and skin permeation promoting effects. Sinapine and sinapic acid are the main active ingredients of SS for its medicinal effects. However, SS has a strong skin irritation, presumably related to the time of application, the method of processing, and original medicinal plants. This review will provide useful data for the follow-up research and safe and reasonable clinical application of SS.

Phytochemical standardization of Eucalyptus tereticornis Smith (Myrtaceae) used in Green Pharmacy from Northeastern Brazil

IntroductionEucalyptus tereticornis Smith. is used in the Green Pharmacies Project in the state of Ceará, Brazil, for the treatment of respiratory ailments. Its major essential oil content is 1,8-cineole. Until the present time, there is no phytochemical standardization. Therefore, the present study was aimed at standardization by phytochemical studies and comparison of the leaves of E. tereticornis Smith. (Myrtaceae) used in the Green Pharmacies (Programa Farmácia Viva) of the Northeast Brazilian region, Ceará at different seasons. Material and methodsThe leaves were collected from the matrix plant and its clones located in Fortaleza, Ceará. Preliminary phytochemical analysis, extraction and analysis of essential oils using Gas Chromatography coupled to Mass Spectrometry (GCMS) were carried out. The mass spectra obtained was compared with that from the late Professor Francisco José de Abreu Matos' scientific collection. The fluid extract was prepared and analysed using HPLC. ResultsPhytochemical studies on the fresh leaves of E. tereticornis demonstrated the presence of coumarins, flavonoids, saponins and tannins in all the accessions. The essential oils presented 1,8-cineole as the major compound, in addition α-pinene, β-pinene, p-cymene, limonene, γ-terpinene, α-terpineol and aromadendrene were identified. The fluid extract presented 1,8-cineole (7.68 %) and coumarin (6.2 ×10−3%), both can serve as important chemical markers. ConclusionThe percentage of 1,8-cineole of essential oil in the accessions of E. tereticnornis studied is in accordance with the Brazilian pharmacopeia. The phytochemical profile of the matrix plant has remained relatively stable since 1994. Coumarin presence is reported for the first time in this species.

PREPARATION AND STANDARDIZATION OF CHITRAKADI VATI

The present work deals with the preparation and standardization of chitrakadi vati. All the parameters of both market formulation (MF1 & MF2) and Laboratory formulation (LF) were found to be within the limit prescribed in pharmacopoeia. Average weight and weigh variation of LF was 2057 mg and 0.2±0.1 %, disintegration time was 8±2 min, hardness was 4.6±0.2 Kg/cm2 , friability was 0.9722±0.2 %, ash values were 2.4 % (acid insoluble ash) and 2.15 % (water soluble ash), extractive values were 5.6 % (acid insoluble extractive) and 7.25 % (water soluble extractive). In order to ensure quality and stability of final product, some of the important chemical markers has been separated from the mixture and for analysis by high performance thin layer chromatography was selected for qualitative and quantitative purpose. The results of standardization parameters showed marked difference among three, which fingers to authenticity of market formulations. Even HPTLC fingerprinting showed some ingredients in market formulations were taken adulterated or inferior in quality. The HPTLC method for fingerprinting was found to be precise and accurate to quantify three chemical markers plumbagin (0.84%), piperine (0.92%), zingiberene (0.71%), and it further characterized by IR, NMR, Mass spectra.

Anticomplement and antitussive activities of major compound extracted from Chimonanthus nitens Oliv. leaf.

Chimonanthus nitens Oliv. leaf (CNOL), as a traditional Chinese medicine, has been widely used for the treatment of influenza and colds over a long history. However, the mechanism of colds related to the effects of CNOL have been little studied. In this study, the anticomplement and antitussive activities of different polarity extracts of CNOL were evaluated. Ethyl acetate extract (EAE) among different extracts not only significantly decreased cough times by 21-58% (P < 0.01), but also had anticomplement effects demonstrated by the CH50 values of 0.100 mg/ml. A total of 28 constituents (10 coumarins, 13 flavonoids and five phenolics) were identified in EAE based on the ultra-high-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry technique. Eight compounds in EAE were evaluated by an ammonia-induced cough model to reveal the antitussive mechanisms and classical anticomplement pathway. The results indicated that the antitussive effects of scopoletin, kaempferol-3-O-rutinoside and kaempferol may depend on central mechanisms and that flavonoids such as compounds of kaempferol-3-O-rutinoside and kaempferol have better anticomplementary activity than coumarins like compounds of scopolin, scopoletin and isofraxidin. Taken together, kaempferol-3-O-rutinoside and kaempferol could be important chemical markers in the present study that might be used to evaluate the quality and biological activity of CNOL.

Determination of the metabolic profile of Solidago canadensis using UFLC-PDA-ESI-TOF

Abstract Species in the Solidago genus are used worldwide due to the therapeutic activities of their flavonoids and terpenoids. Its anti-inflammatory, antirheumatic, analgesic, diuretic, aquaretic, wound-healing properties as well as its ability to relieve burn and insect bites allow use in a variety of situations. This study was carried out to determine the metabolic profile of Solidago canadensis inflorescences (SCAI) to identify the species commercialized in Rio de Janeiro, RJ, Brazil, and evaluate the medicinal potential compared to S. chilensis and SCAI, which is used in North America and Europe. The UFLC-PDA-ESI-TOF revealed the metabolic profile of SCAI, finding the pseudo-molecular ions and characteristic fragments, mainly flavonols (10) such as quercetin, kaempferol, isorhamnetin, and its glycosides, as well as chlorogenic acid (CA). Eleven substances were identified, confirming the compatibility of the metabolic profile presented in varieties canadensis and scabra of european S. canadensis. The both contain the same flavonoid aglycones, and their glycosides are important chemical and biological markers for extracts and products based on species of the genus Solidago. UFLC-PDA-ESI-TOF characterized the extracts, which can help with quality control of raw plant materials and commercialized phytotherapeutics as well as for development of new products and phytomedicines.

Discovery of chemical markers for identifying species, growth mode and production area of Astragali Radix by using ultra-high-performance liquid chromatography coupled to triple quadrupole mass spectrometry

BackgroundAstragali Radix (AR) is a well-known Chinese herbal medicine. The quality of AR can be affected by many factors such as species, growth mode and production area, but there are still no chemical markers to distinguish it. PurposeTo explore chemical markers for improving the quality assessment of AR and discover chemical markers for identifying species, growth mode and production area of AR. MethodsA highly sensitive, efficient and accurate method based on ultra-high performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-QQQ-MS/MS) for simultaneous quantitative determination of 14 major chemical components (five flavonoids and nine triterpene saponins) in 94 batches of AR from China, Republic of Korea and Germany was developed for the first time. To explore chemical markers and assess changes in the contents of 14 compounds in the 94 batches of AR samples from different regions, hierarchical clustering analysis (HCA) and principal component analysis (PCA) were performed. ResultsAstragaloside III was not only an important chemical marker for distinguishing two species of AR, i.e.: Astragalus mongholicus and A. membranaceus, but also a potential chemical marker for the classification of cultivated and semi-wild AR. In addition, in the batches of cultivated AR, the content of isoastragaloside II and cyclocephaloside II were greater in batches from the region of Shaanxi Province than that of other Provinces in China, but the content of calycosin-7-O-β-D-glucoside and astragaloside IV, which are the quality control markers of AR required by the Chinese Pharmacopoeia, were higher than that of other Provinces in China. In addition, the content of calycosin-7-O-β-D-glucoside, ononin, calycosin and astragaloside I could be used to identify samples of AR collected from China, Republic of Korea and Germany. ConclusionThis UHPLC-QQQ-MS/MS method could be applied to the quantitative evaluation of AR and could be an important and meaningful reference to develop chemical markers for quality control of AR.

Exploiting multi-wavelength aerosol absorption coefficients in a multi-time resolution source apportionment study to retrieve source-dependent absorption parameters

Abstract. In this paper, a new methodology coupling aerosol optical and chemical parameters in the same source apportionment study is reported. In addition to results on source contributions, this approach provides information such as estimates for the atmospheric absorption Ångström exponent (α) of the sources and mass absorption cross sections (MACs) for fossil fuel emissions at different wavelengths. A multi-time resolution source apportionment study using the Multilinear Engine (ME-2) was performed on a PM10 dataset with different time resolutions (24, 12, and 1 h) collected during two different seasons in Milan (Italy) in 2016. Samples were optically analysed by an in-house polar photometer to retrieve the aerosol absorption coefficient bap (in Mm−1) at four wavelengths (λ=405, 532, 635, and 780 nm) and were chemically characterized for elements, ions, levoglucosan, and carbonaceous components. The dataset joining chemically speciated and optical data was the input for the multi-time resolution receptor model; this approach was proven to strengthen the identification of sources, thus being particularly useful when important chemical markers (e.g. levoglucosan, elemental carbon) are not available. The final solution consisted of eight factors (nitrate, sulfate, resuspended dust, biomass burning, construction works, traffic, industry, aged sea salt); the implemented constraints led to a better physical description of factors and the bootstrap analysis supported the goodness of the solution. As for bap apportionment, consistent with what was expected, biomass burning and traffic were the main contributors to aerosol absorption in the atmosphere. A relevant feature of the approach proposed in this work is the possibility of retrieving a lot of other information about optical parameters; for example, in contrast to the more traditional approach used by optical source apportionment models, here we obtained source-dependent α values without any a priori assumption (α biomass burning =1.83 and α fossil fuels =0.80). In addition, the MACs estimated for fossil fuel emissions were consistent with literature values. It is worth noting that the approach presented here can also be applied using more common receptor models (e.g. EPA PMF instead of multi-time resolution ME-2) if the dataset comprises variables with the same time resolution as well as optical data retrieved by widespread instrumentation (e.g. an Aethalometer instead of in-house instrumentation).

Comparative Investigation for Rotten Xylem (kuqin) and Strip Types (tiaoqin) of Scutellaria baicalensis Georgi Based on Fingerprinting and Chemical Pattern Recognition

Scutellaria baicalensis Georgi (SBG) is not just as a traditional herbal medicine but also a popular functional food in China and other Asian countries. A sensitive simple strategy was developed for the first time to analyze SBG from eight different geographical sources using high-performance liquid chromatography (HPLC) coupled with multivariate chemometric methods. Two unsupervised pattern recognition models, hierarchical cluster analysis (HCA) and principal components analysis (PCA), and a supervised pattern recognition model, partial least squares discriminant analysis (PLS-DA), were used to analyze the chemical compositions and physical traits of SBG. The important chemical markers baicalin, baicalein, and wogonoside were analyzed quantitatively and with PLS-DA. These methods distinguished rotten xylem (kuqin) and strip types (tiaoqin) of SBG and found that the thickness of the slice had a significant impact on the classification of SBG. Two classes of strip types were identified: one as the uncut pharmaceutical, which was sectioned with a thickness >3 mm; the other as a thin-sectioned strip type, with a thickness of <2 mm. This fingerprinting technique coupled to a chemometric analysis was used for the simultaneous quantitation of three components (chemical markers) of SBG, and greatly simplified the complicated identification of the multiple components of this plant relative to traditional methods. The strategy can clearly distinguish between kuqin and tiaoqin of SBG, and suggests that the thickness of the slice can be used as the basis for evaluation of SBG. These data provide a theoretical basis and scientific evidence for the development and utilization of SBG.

Mass size distribution of major monosaccharide anhydrides and mass contribution of biomass burning

Aerosol samples were collected by a MOUDI cascade impactor in central Budapest in winter 2017, and were analysed by GC–MS and AAS methods for major monosaccharide anhydrides, i.e. levoglucosan (LVG), mannosan (MAN) and galactosan (GAN), and for K, which are important chemical markers for biomass burning (BB) emissions. Their median atmospheric concentrations were 0.36 μg m−3, 37 ng m−3, 10.9 ng m−3 and 0.32 μg m−3, respectively. Detailed mass size distributions were determined in an aerodynamic diameter range of 0.053–9.9 μm for all markers. There were 3 modes identified in the distributions of the monosaccharide anhydrides with typical mass median aerodynamic diameters (MMADs) and relative modal concentrations (RMCs) of 0.42 μm and 90%, 1.62 μm and up to 9%, and 0.11 μm and up to 9%, respectively. The modes were assigned to the condensation and droplet submodes (formed by splitting) of a dominant accumulation mode and to a minor accumulation mode, respectively. The former 2 modes were generated by BB, while the latter mode was explained by another source type with higher burning temperature than BB, which is likely lignite combustion. The size distributions of K also contained 3 modes with mean MMADs and RMCs of 0.40 μm and 78%, 0.16 μm and 12%, and 5.8 μm and 10%, respectively. The former 2 modes were assigned to a major and a minor accumulation mode similarly to the monosaccharide anhydrides, while the latter peak is a coarse mode. Levoglucosan was further utilised to estimate the PM10 mass originating from BB, which yielded a mean relative contribution of 18%. This implies that BB represents a considerable or substantial source for particulate mass in the area. Concentration ratios among the monosaccharide anhydrides suggested that it is the wood burning that is the major form of BB, and that the relative share of softwood burnt to hardwood is around 46%.

Quality Evaluation of Phellodendri Chinensis Cortex by Fingerprint⁻Chemical Pattern Recognition.

Phellodendri Chinensis Cortex (PCC) and Phellodendri Amurensis Cortex (PAC) are increasingly being used as traditional herbal medicines, but they are often mistaken for each other. In this study, the fingerprints of PCC from six different geographical sources were obtained by high-performance liquid chromatography, and multivariate chemometric methods were used for comprehensive analysis. Two unsupervised pattern recognition models (principal component analysis and hierarchical cluster analysis) and a supervised pattern recognition model (partial least squares discriminant analysis) were established on the basis of the chemical composition and physical traits of PCC and PAC. PCC and PAC were found to be distinguishable by these methods. The PCC category was divisible into two categories, one with more crude cork and a maximum thickness of ~1.5 mm, and the other with less net crude cork and a maximum thickness of 0.5 mm. According to the model established by partial least squares discriminant analysis (PLS-DA), the important chemical marker berberine hydrochloride was obtained and analyzed quantitatively. From these results combined with chemometric and content analyses, the preliminary classification standards for phellodendron were established as three grades: superior, first-order and mixed. Compared with the traditional identification methods of thin layer chromatography identification and microscopic identification, our method for quality evaluation is relatively simple. It provides a basis and reference for identification of PCC and enables establishment of grade standards. It also could be applied in quality control for compound preparations containing PCC.

Chemical profiling and quantification of XueBiJing injection, a systematic quality control strategy using UHPLC-Q Exactive hybrid quadrupole-orbitrap high-resolution mass spectrometry

To clarify and quantify the chemical profiling of XueBiJing injection (XBJ) rapidly, a feasible and accurate strategy was developed by applying ultra high performance liquid chromatography-Q Exactive hybrid quadrupole-orbitrap high resolution accurate mass spectrometry (UHPLC-Q-Orbitrap HRMS). A total of 162 components were characterized, including 19 phenanthrenequinones, 33 lactones, 28 flavonoids and 12 phenolic acids and 51 other compounds. Among them, 38 major compounds were unambiguously quantified by comparing with reference standards. Meanwhile, 38 representative compounds were simultaneously detected in XBJ samples by Q-Orbitrap HRMS. Satisfactory linearity and correlation coefficient were achieved with wide linear range. The precisions, repeatability, stability and recovery were meeting requirements. The validated method was successfully applied for simultaneous determination of 38 bioactive compounds in 10 batches XBJ samples. In addition, the similarity evaluation of fingerprintings was applied to assess the quality of XBJ. And the results were evaluated by multiple statistical strategies and five compounds might be the most important chemical markers for chemical quality control of XBJ. Finally, a rapid and simple UPLC-MS/MS method was developed for determination of five markers in XBJ sample. This research established a high sensitive and efficient strategy for integrating quality control, including identification and quantification of XBJ.

Electrochemical Biosensors Using Multi-Enzyme Cascade Reactions

In this work, we demonstrate the development of reliable biosensing methods using multi-enzyme cascade reactions. The cascade reactions result in the generation of an amperometric signal that could be attributed to the selective interaction of the analyte with the enzyme biosensing platform. An example of such a multi-enzyme cascade based amperometric biosensor is an enzymatic methyl salicylate biosensor. Methyl salicylate is an important chemical marker for biotic stress in plants. Here we report the detection of methyl salicylate by three different methods. First two methods involve two enzyme cascade reactions for indirect detection of methyl salicylate through alcohol oxidase/horse radish peroxidase enzyme couple or salicylate hydroxylase/tyrosinase enzyme couple. The third method involves the use of 3 enzyme system that additionally includes an esterase for direct hydrolysis of methyl salicylate for subsequent reactions. The presentation will discuss the mechanisms behind the amperometric detection in each of the above biosensing methods

Rapid determination of 30 bioactive constituents in XueBiJing injection using ultra high performance liquid chromatography-high resolution hybrid quadrupole-orbitrap mass spectrometry coupled with principal component analysis

Xuebijing injection (XBJ) is a traditional Chinese herbal prescription widely used in the treatment of sepsis. Extensive chemical studies revealed that XBJ injection contains amino acids, phenolic acids, flavonoid glycosides, terpeneglycosides and phthalides. In this study, the applicability of ultra high performance liquid chromatography coupled with high resolution hybrid quadruple-orbitrap mass spectrometry (UHPLC-Q-Orbitrap MS) for the simultaneous quantitative analysis of 30 bioactive constituents in XueBiJing injection (XBJ) was investigated. The mass spectrometer was operated in full MS scan mode. The use of 70,000FWHM mass resolution and narrow mass windows (5ppm) could effectively improve the selectivity of the method. Separation was achieved on a Waters ACQUITY UPLC® HSS C18 column (2.1mm×100mm, 1.8μm) with a gradient mobile phase consisting of acetonitrile-water (containing 10mM ammonium acetate) at a flow rate of 0.2mL/min. Satisfactory linearity was achieved within wide linear range and all correlation coefficients (r) of analytes were more than 0.9996. The limits of detection (LODs) were in the range of 0.1180–27.82ng/mL for different analytes. The relative standard deviations (RSDs) of inter- and intra-day precisions were less than 3.0% and the recoveries of the assay were in the range of 98.5%–101.5%. The validated method was successfully applied for simultaneous determination of 30 bioactive compounds in XueBiJing injection from 10 batches samples by UHPLC-Q-Orbitrap MS within 10min. Moreover, the results were evaluated principal component analysis and two compounds might be the most important chemical markers for chemical quality control of XBJ injection. The novel Q-Orbitrap mass spectrometry has been proved to be a very promising and powerful tool for routine screening of bioactive compounds in traditional Chinese medicine injection, ensuring drug safety and public health.

Compositional and Electronic Discrimination Analyses of Taste and Aroma Profiles of Non-Centrifugal Cane Brown Sugars

Eight non-centrifugal cane brown sugars were compositionally differentiated by their sugar, amino acid, mineral, phenolic, and volatile aroma components. Their taste and aroma profiles were generated using two electronic sensing techniques, namely, a potentiometric electronic tongue (e-tongue) and a mass spectrometry (MS)-based electronic nose (e-nose). The nutritional and phenolic contents varied in brown sugars and influenced relative taste values for sweetness, umami, astringency, and bitterness. Various composition–taste correlations, including both contributive and negative associations, were discovered, whereas minerals and phenolics had a positive effect on astringency and bitterness. Brown sugars were also composed of different formations of volatile aroma components, predominantly acetaldehyde, ethanol, acetic acid, butanoic acid, 2,5-dimethyl pyrazine, and 2,6-dimethyl pyrazine. Hyphenated MS-based e-nose sensing differentiated brown sugars in more detail and generated important discriminant chemical markers for those aroma compounds in the multivariate PCA statistical model, viz., m/z 42 and 43 (acetaldehyde), 46 (ethanol), 55 and 73 (butanoic acid), 60 (acetic acid), and 94, 108, and 122 (pyrazines).

Two new hopane-type triterpenes from the aerial part of Chelidonium majus

Two new hopane-type triterpenes, 1-oxo-3α-hydroxy-22(30)-hopen-29-oic acid (1) and 3α-hydroxy-22(30)-hopen-29-oic acid (2), and the known compounds dihydrosanguinarine (3), dl-stylopine (4), dihydrochelirubine (5), dihydromacarpine (6), dihydrochelerythrine (7), dihydrochelilutine (8), and norsanguinarine (9) were isolated from the aerial part of Chelidonium majus. The structures of the new compounds were elucidated based on extensive spectroscopic evidence, especially from 1D and 2D NMR and HRESIMS experiments. The shared structure features of the hopane-type triterpenes are the presence of a mono-hydroxyl substitution at the 3-position and an acrylic acid-2-yl moiety, as a manifestation of the isopropyl group connected to C-21 of the hopane skeleton. Phytotaxonomically, the hopane-type triterpenes might be another important chemical marker in addition to the benzophenanthridine alkaloids of C. majus.

Comparative analysis of volatile oils in the stems and roots of Ephedra sinica via GC-MS-based plant metabolomics

With a great difference in therapeutic effects of Mahuang (MH, the stems of Ephedra sinica) and Mahuanggen (MHG, the roots of Ephedra sinica), chemical differences between MH and MHG should be investigated. In the present study, gas chromatography-mass spectrometry (GC-MS)-based plant metabolomics was employed to compare volatile oil profiles of MH and MHG. The antioxidant activities of volatile oils from MH and MHG were also compared. 32 differential chemical markers were identified according to the variable importance in the projection (VIP) value of orthogonal partial least squares discriminant analysis (OPLS-DA) and P value of Mann-Whitney test. Among them, chemical markers of tetramethylpyrazine (TMP) and α-terpineol were quantified. Their contents were much higher in most MH samples compared with MHG. The antioxidant assay demonstrated that MH had significantly higher free radical-scavenging activity than MHG. Although MH and MHG derived from the same medicinal plant, there was much difference in their volatile oil profiles. MH samples had significantly higher content of two reported pharmacologically important chemical markers of TMP and α-terpineol, which may account for their different antioxidant activities.

Chemical and fruit skin colour markers for simple quality control of tomato fruits

Summary The orientation of this research was to evaluate the classic parameters regarding the external and internal quality of tomato fruits cv. 'Brilliant' at different stages of maturity and to define the dynamics of their changes during the ripening in storage at 18 C. Principal component analysis (PCA) and multivariate canonical discriminant analysis (DA) were used to classify tomato samples according to quality (internal and external) and nutritional value based on fruit mass, fruit skin colour, contents of soluble solids (SS), total titratable acids (TTA), ascorbic acid (AA), and total antioxidant potential (TAP). Several methods are usedfor determining AA content and TAP in plant samples. A simple routine method, direct redox titration with iodate solution and spectrophotometric determination of TAPSP, as described by Singleton and Rossi, also called total phenols, were used respectively. The results show that the stage of maturity (based on fruit skin colour) strongly determines the quality and nutritional value of the tomato fruit. Tomatoes harvested at table maturity (red colour, index a*/b* ≥ 0.85) have a significantly higher nutritional value (in terms of antioxidants - TAPSP and AA content) and overall quality than those harvested at an earlier maturity stage and then ripened in storage. This brings out the importance of short food supply chains and, from the viewpoint of overall fruit quality, it raises doubt about harvesting before reaching table maturity. On the other hand, it is necessary to be extremely attentive when determining optimal maturity, because when the plant becomes over-ripe or when stored, the nutritional value and overall quality decrease drastically. Besides the colour parameters, AA content is the most important chemical marker for a simple quality control. By using a simple and reliable analytical method for determining AA content, such as direct redox titratiation, the monitoring of tomato fruit quality could also be easily performed in situ.