Quality evaluation of Evodia rutaecarpa (Juss.) Benth by high performance liquid chromatography with photodiode-array detection

Three Novel Quinoline Alkaloids From Tetradium glabrifolium and Their Antibacterial Activities

Three novel quinoline alkaloids, tetradiunitiside A (1), tetradiunitiside B (2), and glycohaplopine-6-O-α-l-rhamnopyranoside (3), along with eight known ones (4-11), were isolated from the fruits of Tetradium glabrifolium. Their structures were inferred by IR, 1D NMR and 2D NMR, and HR-ESI-MS spectra. All the isolated compounds were evaluated for their antibacterial activities. Compounds 1-11 had potential antibacterial activities against Bacillus gasoformans, Bacillus subtilis, Pseudomonas solanacearum, and Pseudomonas aeruginosa, with minimum inhibitory concentration (MIC) values ranging from 100 to 3.125 µg/mL. Among them, compound 6 showed the most significant antibacterial activity against four strains of bacteria. These findings elucidated the pharmacological substance basis for the antibacterial activity of T. glabrifolium to some extent.

Traditional Chinese medicine Euodiae Fructus: botany, traditional use, phytochemistry, pharmacology, toxicity and quality control

Euodiae Fructus, referred to as "Wuzhuyu" in Chinese, has been used as local and traditional herbal medicines in many regions, especially in China, Japan and Korea, for the treatment of gastrointestinal disorders, headache, emesis, aphtha, dermatophytosis, dysentery, etc. Substantial investigations into their chemical and pharmacological properties have been performed. Recently, interest in this plant has been focused on the different structural types of alkaloids like evodiamine, rutaecarpine, dehydroevodiamine and 1-methyl-2-undecyl-4(1H)-quinolone, which exhibit a wide range of pharmacological activities in preclinical models, such as anticancer, antibacterial, anti-inflammatory, anti-cardiovascular disease, etc. This review summarizes the up-to-date and comprehensive information concerning the botany, traditional uses, phytochemistry, pharmacology of Euodiae Fructus together with the toxicology and quality control, and discusses the possible direction and scope for future research on this plant.

Chromatographic and mass spectrometric technologies for chemical analysis of Euodiae fructus: A review

INTRODUCTION

Euodiae fructus, also known as Evodiae fructus, is a popular Chinese herbal medicine derived from the dried, nearly ripe fruits of Tetradium ruticarpum (A. Juss.) T. G. Hartley. The main bioactive constituents of Euodiae fructus are alkaloids, limonoids, flavonoids, and anthraquinones. The contents of these compounds vary greatly between different plant species, geographic locations, and harvest times, which thus affect the therapeutic effects.

OBJECTIVES

We aimed to summarize the chromatographic and mass spectrometric technologies applied for chemical analysis and quality evaluation of Euodiae fructus. Moreover, we aimed to emphasize the diverse soft ionization techniques and mass analyzers of LC-MS methods for assessment of Euodiae fructus.

METHODOLOGY

A literature study was carried out by retrieving articles published between January 1988 and December 2021 from well-known databases, including PubMed, ASC, Elsevier, ScienceDirect, J·STAGE, Thieme, Taylor & Francis, Springer Link, Wiley Online Library, and CNKI. The chemical analysis methods were described in several categories in accordance with the used analytical techniques, including thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), high-performance liquid chromatography-mass spectrometry (HPLC-MS), gas chromatography-mass spectrometry (GC-MS), capillary electrophoresis (CE), and counter-current chromatography (CCC).

RESULTS

This review systematically summarizes the achievements in chemical analysis and quality evaluation of Euodiae fructus published in over three decades, covering the various chromatographic and mass spectrometric technologies applied for identification and quantification of phytochemical constituents.

CONCLUSION

The summary serves as an important basis for future phytochemical research and implementation of quality control methods in order to ensure the efficacy and safety of Euodiae fructus.

Evodiamine and Rutaecarpine as Potential Anticancer Compounds: A Combined Computational Study

Evodiamine (EVO) and rutaecarpine (RUT) are the main active compounds of the traditional Chinese medicinal herb Evodia rutaecarpa. Here, we fully optimized the molecular geometries of EVO and RUT at the B3LYP/6-311++G (d, p) level of density functional theory. The natural population analysis (NPA) charges, frontier molecular orbitals, molecular electrostatic potentials, and the chemical reactivity descriptors for EVO and RUT were also investigated. Furthermore, molecular docking, molecular dynamics simulations, and the analysis of the binding free energies of EVO and RUT were carried out against the anticancer target topoisomerase 1 (TOP1) to clarify their anticancer mechanisms. The docking results indicated that they could inhibit TOP1 by intercalating into the cleaved DNA-binding site to form a TOP1−DNA−ligand ternary complex, suggesting that they may be potential TOP1 inhibitors. Molecular dynamics (MD) simulations evaluated the binding stability of the TOP1−DNA−ligand ternary complex. The calculation of binding free energy showed that the binding ability of EVO with TOP1 was stronger than that of RUT. These results elucidated the structure−activity relationship and the antitumor mechanism of EVO and RUT at the molecular level. It is suggested that EVO and RUT may be potential compounds for the development of new anticancer drugs.

Analysis of Evodiae Fructus by capillary electrochromatography-mass spectrometry with methyl-vinylimidazole functionalized organic polymer monolilth as stationary phases

Evodiae Fructus is used as a traditional Chinese medicine for the treatment of several kinds of diseases with its bioactive constituents. In this study, a capillary electrochromatography-mass spectrometry (CEC-MS) method was developed to determine three bioactive compounds including evodiamine, rutaecarpine and limonin in Evodiae Fructus fruit. Home-developed monolithic columns with methyl-vinylimidazole functionalized organic polymer monolilth as stationary phases were used in CEC-MS with excellent separation selectivity and high efficiency. The CEC-MS methods provided 4-16 folds improvement of LODs when compared with CEC-UV method. The conditions, which could affect separation efficiency and detection sensitivity, were optimized. Under optimum conditions, baseline separation with high detection sensitivity was obtained. The method showed good linearity (R² >0.99) of 0.8-160 μg mL^-1 with low limits of detection of 0.15-0.31 μg mL^-1. Relative standard deviations of migration time and relative peak areas were <13.89%. Recoveries of evodiamine, rutaecarpine and limonin in Evodiae Fructus fruit were tested and calculated, which ranged from 102% to 113%. Finally, the three bioactive compounds in Evodiae Fructus herb samples from different regions were analyzed and studied. It has been demonstrated that the developed method has great potential for quality control of Evodiae Fructus herb.

Genus Tetradium L.: A comprehensive review on traditional uses, phytochemistry, and pharmacological activities

ETHNOPHARMACOLOGICAL RELEVANCE

The dried fruit of Tetradium ruticarpum is frequently utilized as a common traditional medicine in China, Japan and Korea. It has been widely used for the treatment of various diseases such as headache, menorrhalgia, dermatophytosis, celialgia, emesis and aphtha and so on.

AIM OF THIS REVIEW

Despite the wide biological activities of Tetradium plants, there is no current review summarizing medicinal properties of the genus of plants; thus, this review aims to systematically summarize studies on botanical characteristics, traditional uses, phytochemical ingredients, quality control, pharmacokinetics, pharmacological activities and toxicity of Tetradium species to demonstrate their therapeutic capacity.

MATERIALS AND METHODS

Information and materials related to Tetradium species were obtained from scientific databases such as Google Scholar, Wikipedia, Web of Science, PubMed, ScienceDirect, ACS Publications, SciFinder. Information was also gathered from International Plant Names Index, Global Biodiversity Information Facility, Chinese Pharmacopoeia and Traditional Chinese Medicine classics, etc. All studies of this genus were included in this review until July 2018.

RESULTS

Tetradium is widely assessed regarding its phytochemistry and biological activities. Approximately 131 chemical compounds, including alkaloids, saponins, phenols and other compounds, have been isolated from Tetradium plants. Among these components, alkaloid evodiamine is the most representative active ingredients of Tetradium plants. These compounds isolated from Tetradium plants exhibit a wide range of biological activities in vitro and in vivo including antitumor, antibacterial, anti-inflammatory, insecticide, cardioprotective and lipid-lowering, treating CNS disorders, digestive system regulation and endocrine system improving activities. Furthermore, alkaloids could be used as markers for quality identification and evaluation of medicinal materials and their preparations. Information on evaluating the safety and pharmacokinetics of Tetradium often focuses on the alkaloids, thus further study and clinical data are required to enable the drug safety of the utilization of Tetradium plants.

CONCLUSIONS

Phytochemical and pharmacological studies of Tetradium plants have proved Tetradium plants are important medicinal herb resource. However, well-designed randomized clinical trials are necessary to confirm the therapeutic benefits of this genus in clinical settings.

Effect of Sunlight Radiation on the Growth and Chemical Constituents of Salvia plebeia R.Br

This study investigated the chemical composition changes of Salvia plebeia R.Br. cultivated under different light sources, including florescent light and sunlight. The plants were exposed to fluorescent light for four months and sunlight and then examined for the next 5-7 months. Plants were harvested monthly during the seven months, and we examined whether the difference in light source affected the phenolic and flavonoid contents and antioxidant activity. A simple and reliable HPLC method using a PAH C18 column was applied for the quantitative analysis of two triterpenoids from the S. plebeia groups. Oleanolic acid (OA) and ursolic acid (UA) showed good linearity (R² > 0.9999) within the test ranges (0.005-0.05 mg/mL), and the average percentage recoveries of the OA and UA were 95.1-104.8% and 97.2-107.1%, respectively. The intra- and inter-day relative standard deviations (RSDs) were less than 2.0%. After exposure to sunlight, the phenolic contents, including rosmarinic acid, showed a reduced tendency, whereas the flavonoid contents, including homoplantaginin and luteolin 7-glucoside, were increased. The content of the triterpenoids also showed an increased tendency under sunlight irradiation, but the variance was not larger than those of the phenolic and flavonoid contents. Among experimental groups, the group harvested at six months, having been exposed to sunlight for two months, showed the most potent antioxidant activity. Therefore, these results showed that the chemical composition and antioxidant activities of S. plebeia R.Br. was affected from environmental culture conditions, such as light source. Our studies will be useful for the development of functional materials using S. plebeia R.Br.

Review: DNA Barcoding and Chromatography Fingerprints for the Authentication of Botanicals in Herbal Medicinal Products

In the last two decades, there has been a tremendous increase in the global use of herbal medicinal products (HMPs) due to their claimed health benefits. This has led to increase in their demand and consequently, also, resulted in massive adulteration. This is due to the fact that most of the traditional methods cannot identify closely related species in a process product form. Therefore the urgent need for simple and rapid identification methods resulted in the discovery of a novel technique. DNA barcoding is a process that uses short DNA sequence from the standard genome for species identification. This technique is reliable and is not affected by external factors such as climates, age, or plant part. The difficulties in isolation of DNA of high quality in addition to other factors are among the challenges encountered using the DNA barcoding in the authentication of HMP. These limitations indicated that using DNA barcoding alone may ineffectively authenticate the HMP. Therefore, the combination of DNA barcoding with chromatographic fingerprint, a popular and generally accepted technique for the assessment and quality control of HMP, will offer an efficient solution to effectively evaluate the authenticity and quality consistency of HMP. Detailed and quality information about the main composition of the HMPs will help to ascertain their efficacy and safety as these are very important for quality control.

Analysis of E. rutaecarpa Alkaloids Constituents In Vitro and In Vivo by UPLC-Q-TOF-MS Combined with Diagnostic Fragment

Evodia rutaecarpa (Juss.) Benth. (Rutaceae) dried ripe fruit is used for dispelling colds, soothing liver, and analgesia. Pharmacological research has proved that alkaloids are the main active ingredients of E. rutaecarpa. This study aimed to rapidly classify and identify the alkaloids constituents of E. rutaecarpa by using UPLC-Q-TOF-MS coupled with diagnostic fragments. Furthermore, the effects of the material base of E. rutaecarpa bioactive ingredients in vivo were examined such that the transitional components in the blood of rats intragastrically given E. rutaecarpa were analyzed and identified. In this study, the type of alcohol extraction of E. rutaecarpa and the corresponding blood sample were used for the analysis by UPLC-Q-TOF-MS in positive ion mode. After reviewing much of the literature and collected information on the fragments, we obtained some diagnostic fragments of the alkaloids. Combining the diagnostic fragments with the technology of UPLC-Q-TOF-MS, we identified the compounds of E. rutaecarpa and blood samples and compared the ion fragment information with that of the alkaloids in E. rutaecarpa. A total of 17 alkaloids components and 6 blood components were identified. The proposed method was rapid, accurate, and sensitive. Therefore, this technique can reliably and practically analyze the chemical constituents in traditional Chinese medicine (TCM).

A study of the geo-herbalism of evodiae fructus based on a flow-injection mass spectrometric fingerprinting method combined with chemometrics

A flow-injection mass spectrometric (FIMS) fingerprinting method in combination with principal component analysis (PCA) was used to study the geo-herbalism of Evodiae Fructus (EF) samples. Twenty four EF samples from different regions in China were collected and analyzed. The PCA scores plot showed that the samples from Guizhou Province were scattered in different groups, however, most of the samples from other provinces were basically scattered in the same group. Nine characteristic compounds responsible for the classification of the samples were tentatively characterized. These nine compounds might help differentiating EF samples from different regions.

Development and validation of an UPLC-ESI-MS/MS method for determination of dehydroevodiamine, limonin, evodiamine, and rutaecarpine in Evodiae Fructus

Objective:

Evodiae Fructus (EF), one of the most widely used traditional Chinese medicines, mainly consists of alkaloids, is widely used for the treatments of headache and gastrointestinal disorders. In this study, a sensitive and reliable UPLC-ESI-MS/MS method was developed for qualitative determination of dehydroevodiamine, limonin, evodiamine, and rutaecarpine.

Materials and Methods:

Chromatographic separations were accomplished on a Phenomenex Kinetex XB-C18 column (2.1 × 150 mm, 1.7 μm) by using a gradient elution profile with a mobile phase consisting of 0.5% formic acid in water (A) and acetonitrile (B). Detection was performed using multiple reactions monitoring mode under ESI in the positive ion mode.

Results:

The results showed good linearity over the investigated concentration ranges (R²>0.9900) for the analytes. The limit of quantitations (LOQs) were 6.88 ng/mL for dehydroevodiamine, 18.6 ng/mL for limonin, 6.24 ng/mL for evodiamine, and 2.56 ng/mL for rutaecarpine, respectively. Intraday and interday precisions (relative standard deviations, %) were <5% and accuracies ranged from 92% to 106%.

Conclusion:

The validated method was successfully applied to assay the contents of the four compounds in EF samples from different regions, with which just 10 min was needed to analyze each sample.

Simultaneous Quantification of Limonin, Two Indolequinazoline Alkaloids, and Four Quinolone Alkaloids in Evodia rutaecarpa (Juss.) Benth by HPLC-DAD Method

A simple and efficient HPLC-DAD (225 nm) method was developed and validated for the simultaneous determination of limonin and six key alkaloids (evodiamine, rutaecarpine, 1-methyl-2-undecyl-4(1H)-quinolone, evocarpine, 1-methy-2-[(6Z,9Z)]-6,9-pentadecadienyl-4-(1H)-quinolone, and dihydroevocarpine) in Evodia rutaecarpa (Juss.) Benth, which has been widely used as one of the Traditional Chinese Medicines. The chromatographic separation was carried out on a Hypersil BDS C18 column, and gradient elution was employed with a mobile phase containing acetonitrile and water. Contents of the analytes in 18 batches of samples were analyzed by ultrasonic extraction with ethanol and water mixture (80 : 20, v/v) followed by HPLC analysis. Separation of the seven analytes was achieved within 60 min with good linearity (r > 0.999). The RSD of both the intraday and interday precision was below 1.85%. The accuracy at different concentrations was within the range of 97.91 to 100.49%. Hierarchical clustering analysis was performed to differentiate and classify the samples based on the contents of the seven constituents. This study indicated that the quality control of E. rutaecarpa could be simplified to the measurement of four constituents, and that limonin, 1-methyl-2-undecyl-4(1H)-quinolone, and dihydroevocarpine should also be served as the chemical markers together with evodiamine for the quality control of Evodia rutaecarpa (Juss.) Benth.

Simultaneous determination of evodiamine and evodine in Beagle dog plasma using liquid chromatography tandem mass spectrometry

A sensitive, rapid, and specific liquid chromatography/tandem mass spectrometry assay has been established and validated for the quantitation of evodiamine and evodine in Beagle dog plasma. Plasma samples of 0.2 ml were processed by liquid-liquid extraction with n-hexane/ethyl acetate (2:1, v/v). Chromatographic separations were done on a Symmetry C18 column (100 mm × 4.6 mm, ID, 5 μm) at 35°C with a linear gradient of methanol and 20 mM ammonium formate containing 0.2% formic acid. Evodiamine, evodine, and glibenclamide [internal standard (IS)] were ionized with an electrospray ionization source operated in positive ion mode. The MS/MS transitions were m/z 304.1 → 161.1 for evodiamine, m/z 471.2 → 425.1 for evodine, and m/z 494.1 → 369.1 for IS. Calibration curves were linear over the concentration range of 0.1-100 ng/ml for evodiamine and 0.5-500 ng/ml for evodine. The mean extraction recoveries were 88.10 ± 3.21% for evodiamine and 81.24 ± 4.07% for evodine. The intra- and inter-day precisions were less than 11.10% and 12.81%, and the accuracy was within ± 11.76% for both analytes. Evodiamine and evodine were stable during storage and analytical periods. The validated method has been successfully applied to a pharmacokinetic study of evodiamine and evodine in beagle dogs after oral administration.

Enhanced transdermal delivery of evodiamine and rutaecarpine using microemulsion

Objective

The purpose of this study was to improve skin permeation of evodiamine and rutaecarpine for transdermal delivery with microemulsion as vehicle and investigate real-time cutaneous absorption of the drugs via in vivo microdialysis.

Methods

Pseudoternary phase diagrams were constructed to evaluate microemulsion regions with various surfactants and cosurfactants. Nine formulations of oil in water microemulsions were selected as vehicles for assessing skin permeation of evodiamine and rutaecarpine in ex vivo transdermal experiments. With a microdialysis hollow fiber membrane implanted in the skin beneath the site of topical drug administration, dialysis sampling was maintained for 10 hours and the samples were detected directly by high performance liquid chromatography. Real-time concentrations of the drugs in rat skin were investigated and compared with those of conventional formulations, such as ointment and tincture. Furthermore, the drugs were applied to various regions of the skin using microemulsion as vehicle.

Results

In ex vivo transdermal experiments, cutaneous fluxes of evodiamine and rutaecarpine microemulsions were 2.55-fold to 11.36-fold and 1.17-fold to 6.33-fold higher, respectively, than those of aqueous suspensions. Different drug loadings, microemulsion water content, and transdermal enhancers markedly influenced the permeation of evodiamine and rutaecarpine. In microemulsion application with in vivo microdialysis, the maximum concentration of the drugs (evodiamine: 18.23 ± 1.54 ng/mL; rutaecarpine: 16.04 ± 0.69 ng/mL) were the highest, and the area under the curve_0–t of evodiamine and rutaecarpine was 1.52-fold and 2.27-fold higher than ointment and 3.06-fold and 4.23-fold higher than tincture, respectively. A greater amount of drugs penetrated through and was absorbed by rat abdominal skin than shoulder and chest, and a reservoir in the skin was found to supply drugs even after the microemulsion was withdrawn.

Conclusion

Compared to conventional formulations, higher cutaneous fluxes of evodiamine and rutaecarpine were achieved with microemulsion. Based on this novel transdermal delivery, the transdermal route was effective for the administration of the two active alkaloids.

Chromatographic fingerprint study on Evodia rutaecarpa (Juss.) Benth by HPLC/DAD/ESI-MS(n) technique

The LC-ESI-MS(n) method was developed for the analysis and characterization of alkaloids in the extract of E. rutaecarpa (called Wuzhuyu in Chinese). Thirty-six batches of Wuzhuyu from different locations of China were investigated and the common fingerprinting profile was established with a professional analytical software recommended by the State Food and Drug Administration. Fifteen chemical components of the common peaks were identified by multi-stage MS. The effects on the chromatographic profile resulting from different collecting locations, harvesting times or storage times were studied. Hierarchical clustering analysis and principal components analysis were also performed to classify and differentiate the 36 batches of the samples. As a result, those which had same chemical properties were sorted into one cluster, which was very useful in evaluating and controlling the quality of Wuzhuyu.

Determination of dehydroevodiamine in Evodia rutaecarpa (Juss.) Benth by high performance liquid chromatography and classification of the samples by using hierarchical clustering analysis

A simple, sensitive and accurate liquid chromatographic method with photodiode-array detection was developed for determination of dehydroevodiamine with detection wavelength at 368 nm and column temperature at 30 degrees C. The separation was carried out on an Agilent Zorbax SB-C(18) column (250 mm x 4.6 mm, 5 microm) together with a C(18) guard column. The mobile phase was acetonitrile-water (containing 30 mM sodium acetate trihydrate and 0.15% acetic acid) in the ratio of 30:70 (v/v) delivered at a flow rate of 1 mL/min. Excellent linear behavior was observed over the concentration range investigated, with correlation coefficient (R(2))=0.9998. This validated method was applied to determine the contents of dehydroevodiamine in 36 samples from different regions of China, and hierarchical clustering analysis was firstly used to classify and differentiate Evodia rutaecarpa samples. The analysis is specific and can be successfully applied to analyze E. rutaecarpa which is helpful for quality control of the herb.