A UFLC–MS/MS method for the simultaneous determination of eight bioactive constituents from red wine and dealcoholized red wine in rat plasma: Application to a comparative pharmacokinetic study

To explore whether alcohol has an effect on the pharmacokinetic behavior of phenolic acids, the main bioactive constituents in red wine, a highly sensitive and simple ultra‐fast liquid chromatography coupled with triple quadrupole mass spectrometry (UFLC–MS/MS) method was developed for simultaneous quantitation of eight phenolic acids in plasma samples. Plasma samples were extracted by liquid–liquid extraction and the chromatographic separation was achieved on a Zorbax SB‐C₁₈ column within 7.0 min. Results of the validated method revealed that all of the calibration curves displayed good linear regression (r > 0.99). The intra‐ and inter‐day precisions of the analytes were <14.0% and accuracies ranged from ?8.5 to 7.3%. The extraction recoveries of the analytes were from 71.2 to 110.2% and the matrix effects ranged from 86.2 to 105.5%. The stability of these compounds under various conditions satisfied the requirements of biological sample measurement. The method was successfully applied to a comparative pharmacokinetic study of phenolic acids in rat plasma. For gallic acid and gentisic acid, the parameters AUC_0–t and AUC_0–∞ increased remarkably (p < 0.05) after oral administration of red wine, which suggested that alcohol might enhance their absorption. This is the first report to compare the pharmacokinetic behavior of phenolic acids in red wine and dealcoholized red wine.     

Synthesis of 4‐Heteroaryl–Quinazoline Derivatives as Potential Anti‐breast Cancer Agents

4‐Heteroaryl or heteroalkyl–quinazoline derivatives were prepared as dual epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor‐2 (VEGFR‐2) inhibitors. The new compounds were tested for their dual enzyme inhibition as well as their cytotoxic activity on MCF7 cell line. The results indicated that almost all the compounds showed moderate dual inhibition of both enzymes. Compound 3 (methyl piperidine‐4‐carboxylate derivative) showed the highest inhibitory activity against both enzymes with IC₅₀ 97.6 and 64.0 µM against EGFR and VEGFR‐2 kinases, respectively. Most of the test compounds showed potent to moderate antitumor activity on MCF7 cell line. Five compounds ( 3 , 9c , 11 , 13 , and 15b ) showed potent cytotoxic activity with IC₅₀ values between 10 and 17 µM .     

A rapid assay for angiotensin‐converting enzyme activity using ultra‐performance liquid chromatography–mass spectrometry

Angiotensin‐converting enzyme (ACE) plays an important role in the renin–angiotensin system and ACE activity is usually assayed in vitro by monitoring the transformation from a substrate to the product catalyzed by ACE. A rapid and sensitive analysis method or ACE activity by quantifying simultaneously the substrate hippuryl–histidyl–leucine and its product hippuric acid using an ultra‐performance liquid chromatography coupled with electrospray ionization‐mass spectrometry (UPLC‐MS) was first developed and applied to assay the inhibitory activities against ACE of several natural phenolic compounds. The established UPLC‐MS method showed obvious advantages over the conventional HPLC analysis in shortened running time (3.5 min), lower limit of detection (5 pg) and limit of quantification (18 pg), and high selectivity aided by MS detection in selected ion monitoring (SIM) mode. Among the six natural products screened, five compounds, caffeic acid, caffeoyl acetate, ferulic acid, chlorogenic acid and resveratrol indicated potent in vitro ACE inhibitory activity with IC₅₀ values of 2.527 ± 0.032, 3.129 ± 0.016, 10.898 ± 0.430, 15.076 ± 1.211 and 6.359 ± 0.086 mm , respectively. A structure–activity relationship estimation suggested that the number and the situation of the hydroxyls on the benzene rings and the acrylic acid groups may play the most predominant role in their ACE inhibitory activity. Copyright © 2009 John Wiley & Sons, Ltd.     

Characterization of chemical constituents in Zhi–Zi–Da–Huang decoction by ultra high performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry

A sensitive and reliable ultra high performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry method was established to separate and identify the chemical constituents of Zhi–Zi–Da–Huang decoction, a classic traditional Chinese medicine formula. The chromatographic separation was achieved on a Shim‐pack XR‐ODS C₁₈ column (75  × 3.0 mm, 2.2 μm) using a gradient elution program. The detection was performed on a Waters Xevo G2 Q‐TOF mass spectrometer equipped with electrospray ionization source in both positive and negative modes. With the optimized conditions, a total of 82 compounds were identified or tentatively characterized. Of the 82 compounds, 21 compounds were identified by comparing the retention time and MS data with reference standards, the rest were characterized by analyzing MS data and retrieving the reference literature. In addition, 31 compounds were identified from Gardenia jasminoides Ellis, ten compounds were identified from Rheum palmatum L., 33 compounds were identified from Citrus aurantium L., and eight compounds were identified from Sojae Semen Praeparatum. Results indicated that iridoids, anthraquinones, flavonoids, isoflavonoids, coumarins, glycosides of crocetin, monoterpenoids, and organic acids were major constituents in Zhi–Zi–Da–Huang decoction. It is concluded that the developed ultra high performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry method with high sensitivity and resolution is suitable for identifying and characterizing the chemical constituents of Zhi–Zi–Da–Huang decoction, and the analysis provides a helpful chemical basis for further research on Zhi–Zi–Da–Huang decoction.     

Computational approach to structural identification of phospholipids using raw mass spectra from nanoflow liquid chromatography–electrospray ionization–tandem mass spectrometry

A qualitative analysis tool (LiPilot) for identifying phospholipids (PLs), including lysophospholipids (LPLs), from biological mixtures is introduced. The developed algorithm utilizes raw data obtained from nanoflow liquid chromatography–electrospray ionization–tandem mass spectrometry experiments of lipid mixture samples including retention time and m/z values of precursor and fragment ions from data‐dependent, collision‐induced dissociation. Library files based on typical fragmentation patterns of PLs generated with an LTQ‐Velos ion trap mass spectrometer are used to identify PL or LPL species by comparing experimental fragment ions with typical fragment ions in the library file. Identification is aided by calculating a confidence score developed in our laboratory to maximize identification efficiency. Analysis includes the influence of total ion intensities of matched and unmatched fragment ions, the difference in m/z values between observed and theoretical fragment ions, and a weighting factor used to differentiate regioisomers through data filtration. The present study focused on targeted identification of particular PL classes. The identification software was evaluated using a mixture of 24 PL and LPL standards. The software was further tested with a human urinary PL mixture sample, with 93 PLs and 22 LPLs identified. Copyright © 2012 John Wiley & Sons, Ltd.     

Validated LC–MS/MS method for simultaneous determination of doxorubicin and curcumin in polymeric micelles in subcellular compartments of MCF‐7/Adr cells by protein precipitation–ultrasonic breaking method

A specific and sensitive LC–MS/MS with protein precipitation– ultrasonic breaking method has been developed and validated for simultaneous determination of doxorubicin (DOX) and curcumin (Cur) in DOX and Cur co‐loaded hyaluronic acid–vitamin E succinatemicelles [(DOX + Cur)–polymeric micelles (PMs)] in subcellular compartments of resistant MCF‐7/Adr cells. Sequential extraction of four subcellular protein fractions (cytosolic, membrane/organelle, nucleic and cytoskeleton) was performed directly from MCF‐7/Adr cells after incubation with (DOX + Cur)–PMs. An ultrasonic breaking–methanol precipitation method was used for extraction of the fractions, and the micelle breaking efficiency with methanol was 98.1 and 97.6% for DOX and Cur, respectively. The analytes were analyzed using positive electrospray ionization coupled with multiple reaction monitoring. The calibration curves were linear over a concentration range of 0.5–400 ng/mL for DOX and 2–2000 ng/mL for Cur, and the recovery for the two analytes were >85% with negligible matrix effect. The intra‐day and inter‐day precision was <10.80% and relative error was within ±7.70%. The developed method was successfully applied for subcellular determination of DOX and Cur in MCF‐7/Adr cells. Moreover, Cur and (DOX + Cur)–PMs had a marked promoting effect on the distribution of DOX in the nucleic protein fraction.     

Chemical fingerprint analysis and metabolic profiling of 50% ethanol fraction of Lomatogonium rotatum by ultra‐performance liquid chromatography/quadrupole–time of flight mass spectrometry

Lomatogonium rotatum (L.) Fries ex Nym (L. rotatum), a member of Gentianaceae, is an important mongolian medicine in China used to treat febrile diseases in liver and gallbladder. The aim of present study was to investigate the chemical constituents and metabolites of the 50% ethanol fraction of L. rotatum (50EtLR). Firstly, the extract of L. rotatum was partitioned by macroporous resin to obtain the target fraction (50EtLR), then several compounds were isolated from 50EtLR to obtained the standards for further analysis of chemical constituents of 50EtLR. Secondly, the chemical constituents of 50EtLR were characterized using the ultra‐high performance liquid chromatography coupled with quadrupole–time‐of‐flight mass spectrometry (UHPLC–Q‐TOF–MS/MS). Finally, prototype constituents and related metabolites were analyzed after orally administerng 50EtLR to rats. As a result, a new compound, 6‐O‐[β‐d ‐xylopyranosyl‐(1 → 6)‐O‐β‐d ‐glucopyranosyl]‐1,4,8‐trimethoxyxanthone ( 6 ) along with seven known compounds ( 1–5 , 7 and 8 ) were isolated from the 50EtLR, 92 components were either unambiguously or tentatively identified. Additionally, 34 prototype constituents and 112 metabolites in rat plasma along with 32 prototype constituents and 53 metabolites in rat liver were tentatively identified. Therefore, xanthones and flavonoids were the main chemical constituents of 50EtLR and sulfation and glucuronidation are the main enzyme‐induced metabolic pathways involved post‐administration.     

Studies of proteasome inhibition and apoptosis induction in triple‐negative breast cancer cells by novel amino acid–polypyridine–copper complex

An innovative ternary copper(II) complex, [Cu(Cl‐PIP)(Tyr)Cl]_n, has been synthesized and characterized using infrared spectroscopy, elemental analysis and single‐crystal X‐ray diffraction analysis. X‐ray crystallography indicates that the Cu atom is five‐coordinated in a square‐pyramidal configuration. The unit forms a one‐dimensional chain along the crystallographic c‐axis. The complex was screened for cytotoxicity against a panel of eight human cancer cell lines, namely MDA‐MB‐231, CAL‐51, K562, HeLa, SGC‐7901, A549, MCF‐7 and SMMC‐7721. The best anticancer activity was obtained with triple‐negative breast cancer CAL‐51 and MDA‐MB‐231 cell lines, with IC₅₀ values in the range 0.035–0.10 μM, and this was better than using carboplatin. The complex inhibits proteasomal chymotrypsin‐like activity, and docking studies reveal its interaction with 20S proteasome. In addition, the complex causes accumulation of ubiquitinated proteins, induces apoptosis and inhibits cell proliferation, indicating its great potential as a novel therapy for triple‐negative breast cancer.     

Geographical discrimination of Glechomae Herba based on fifteen phenolic constituents determined by LC–MS/MS method combined with chemometric methods

Glechomae Herba (GH) is rich in bioactive phenolic constituents and is widely used for treatment of cholelithiasis, urolithiasis and dropsy. The simultaneous determination of phenolic constituents in GH from different geographical origins is significant for authentication and quality control purposes. In this study, we developed a strategy integrating targeted analysis and chemometric methods for quality evaluation and discrimination of GH from different geographical origins. Firstly, an accurate and reliable liquid chromatography–tandem mass spectrometry method was developed for simultaneous quantification of 15 phenolic constituents in GH from different geographical origins. The established method was well validated in terms of desirable specificity, linearity, precision and accuracy. Secondly, the quantitative data were subjected to principal component analysis and orthogonal partial least squares discriminant analysis. Thirdly, a heatmap visualization was employed for clarifying the distribution of 15 phenolic compounds in GH from different geographical origins. These results indicated that GH samples from Shandong province obviously differ from those from other provinces in the content of bioactive phenolic constituents. Collectively, the proposed platform might be a suitable tool for quality evaluation and discrimination of GH from different geographical origins, providing promising perspectives in tracking the formulation processes of traditional Chinese medicine products.     

Synthesis,characterization, antioxidant and anti‐diabetic activities of a novel protein–vanadium complex

The protein–vanadium complex was successfully synthesized and systematically characterized using electron paramagnetic resonance, Fourier transform‐infrared spectroscopy and thermogravimetric analysis. The antioxidant activity analysis indicated that it had better radical scavenging activity on 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH), 2,2′‐azinobis (3‐ethylbenzothiazoline)‐6‐sulfonic acid (ABTS) and O₂^? compared with the free protein and vanadate. Additionally, the complex exhibited high anti‐diabetic activity against Saccharomyces cerevisiae α‐glucosidase and rat intestinal maltase with IC₅₀ values of 258.53 and 72.41 μg/ml, respectively. Kinetics study showed that the complex was a mixed inhibition type against S. cerevisiae α‐glucosidase and uncompetitive inhibition type against rat intestinal maltase. These indicated that the complex with antioxidant and anti‐diabetic potential could be used for lowering blood glucose that might be caused by insufficient secretion of insulin in the body or excess fat storage. Our findings provide a new protein–vanadium complex for further use in diabetes mellitus or obesity.     

Simultaneous quantification of both triterpenoid and steroidal saponins in various Yunnan Baiyao preparations using HPLC–UV and HPLC–MS

Yunnan Baiyao (YNBY) is one of the best known traditional Chinese medicines. Saponins are considered to be its active components. In this study, an HPLC method was first developed for the simultaneous quantitative analysis of thirteen saponins, including five triterpenoid saponins and eight steroidal saponins, in a series of YNBY preparations, i. e., powder, capsules, aerosol, toothpaste, plaster, and adhesive bandage. The pre‐treatment methods for each dosage form were investigated and optimized. The HPLC separation was performed on a Shim‐pack C₁₈ reversed‐phase column in gradient mode with UV detection at 203 nm. All calibration curves showed good linear regression (r² ? 0.9981) within the test ranges. Precisions and repeatabilities of the methods were better than 4.22 and 4.78%, respectively. Recoveries were better than 90.5%, even in the analysis of the least abundant saponins in a complex YNBY plaster. HPLC–ESI‐TOF/MS was used for definite identification of compounds in the preparations. This proposed method was successfully applied to quantify the 13 bioactive constituents in 27 commercial samples to evaluate the quality of YNBY preparations. The overall results demonstrate that this method is simple, reliable, and suitable for the quality control of YNBY. Furthermore, the retention behavior of these saponins in reversed‐phase chromatography is described.     

Xylocosides A – G,Phenolic Glucosides from the Stems of Xylosma controversum

Seven new phenolic glucosides, xylocosides A–G ( 1 – 7 ), together with 18 known compounds were isolated from the stems of Xylosma controversum Clos . In compounds 3 – 6 , the glucose residue is esterified at C(6) by 2‐hydroxycyclopentanecarboxylic acid. These new structures were established by spectroscopic‐data interpretation and chemical methods.     

Eight New Cucurbitane Glycosides,Kuguaglycosides A – H,from the Root of Momordica charantia L.

Eight new cucurbitane glycosides, kuguaglycosides A–H ( 1 – 8 , resp.), together with five known analogues, 3β,23‐dihydroxycucurbita‐5,24‐dien‐7β‐yl β‐D ‐glucopyranoside ( 9 ), karaviloside III ( 10 ), karaviloside V ( 11 ), karaviloside XI ( 12 ), and momordicoside K ( 13 ), were isolated from the root of Momordica charantia L. The structures of the new compounds were determined on the basis of spectroscopic and chemical methods.     

Perturbations of an Acetone‐Based Briggs–Rauscher System by α‐Tocopherol (Vitamin E)

The malonic acid (MA)‐based oscillating Briggs–Rauscher reaction (BR) in batch mode has been shown to be sensitive to various hydrophilic polyphenol antioxidants. Several of these have been shown to cause cessation of oscillations for a period of time before a restart occurs. The length of time before oscillations restart is related to the type of antioxidant and its concentration. Procedures have been devised to use this method as a tool for measuring antioxidant activity from pure compounds and from extracts of natural sources. The antioxidant activity has been related to the reaction of the antioxidants with HOO^. radicals present in the oscillating system. Vitamin E (α‐tocopherol), a typical highly lipophilic antioxidant containing an phenolic OH group, is soluble in acetone that also is a suitable substrate for the BR reaction. Perturbations of a highly concentrated acetone‐based BR oscillator by acetonic solutions of vitamin E were studied. The inhibitory effects were found similar to those provoked by hydrophilic polyphenols in the MA‐based oscillator, but to obtain reasonable inhibition times, the concentration of vitamin E must be at the mM level instead μM . However, there is a region of concentrations where there is a nearly linear relation between concentration and inhibition time. A comparison with a hydrophilic diphenol (2,6‐dihydroxybenzoic acid) in the acetone‐based oscillator showed that the inhibitory reaction is much slower in this system than in the MA one. We were able to model the perturbations by vitamin E assuming its reaction with HOO^. radicals by using the FCA mechanism previously reported with some little modifications.     

Lewis Acid Catalyzed Enantioselective Desymmetrization of Donor–Acceptor meso‐Diaminocyclopropanes

The first Lewis acid catalyzed enantioselective ring‐opening desymmetrization of a donor–acceptor meso‐diaminocyclopropane is reported. The copper(II)‐catalyzed Friedel–Crafts alkylation of indoles and one pyrrole with an unprecedented meso‐diaminocyclopropane delivered enantioenriched, diastereomerically pure urea products, which are structurally related to natural and synthetic bioactive compounds. The development of a new ligand through the investigation of an underexplored subclass of bis(oxazoline) ligands was essential for achieving high enantioselectivities.     

Screening of analgesic and anti‐inflammatory active component in Fructus Alpiniae zerumbet based on spectrum–effect relationship and GC–MS

Fructus Alpiniae zerumbet is widely used in Guizhou province as a miao folk herb with anti‐inflammatory, analgesic, protection against cardiovascular diseases, antihypertension and antioxidant activities. To further investigate the chemical material basis, the spectrum–effect relationship was established using gray relational analysis between the chromatographic fingerprint and its bioactivities. Herein, the fingerprints of essential oils from Fructus Alpiniae zerumbet (EOFAZ) from various sources were determined by gas chromatography mass spectrometry, and the analgesic and anti‐inflammatory bioactivities were investigated using the mouse model of acetic acid‐induced writhing test and dimethylbenzene‐induced mouse ear edema test. Finally, 17 common peaks were identified from nine batches of A. zerumbet, by comparison with the standard mass spectra in Nist2005, Wiley275 library. Meanwhile, the results showed significant analgesic and anti‐inflammatory effects in all of the different sources of EOFAZ. In particularly, peak 1 (α‐pipene), peak 3 (β‐pinene), peak 9 (camphor) and peak 16 (α‐cadinol) might be the main bioactive ingredients for analgesic and anti‐inflammatory activities. The model of the spectrum–effect relationships of EOFAZ was successfully discovered, which provided a novel platform for finding the bioactive components, a theoretical foundation for its further study and helping to establish quality control of Fructus A. zerumbet.     

LC–QTOF–MS-based metabolite profiling and evaluation of α-glucosidase inhibitory kinetics of Coccinia grandis fruit

Coccinia grandis is an important food crop of the Cucurbitaceae family, widely used for culinary purposes in India. It is reported to possess hypoglycemic, hypolipidemic and antioxidant activities. The current study was aimed to explore the inhibition kinetics as well as major constituents of the active fraction of C. grandis against α-glucosidase. The kinetic study was performed through spectrophotometric assay, with p-nitrophenyl-α-d -glucopyranoside as a substrate with varying concentrations. An in vitro antioxidant study was performed by DPPH assay. In addition, UPLC–QTOF–MS analysis was carried out for metabolite profiling of the bioactive fraction of C. grandis. The results showed that the difference between the α-glucosidase inhibitory activity of the ethyl acetate fraction of C. grandis (EFCG) (IC₅₀ 2.43 ± 0.27 mg/ml), and standard inhibitor, acarbose (2.08 ± 0.19 mg/ml), was not statistically significant at a P-value of 0.05. The enzyme kinetics confirmed the inhibition mode in a mixed manner. The EFCG also showed the highest antioxidant activity (101.74 ± 1.95 μg/ml) among all of the fractions. A significant correlation between antioxidant and α-glucosidase inhibitory activity of EFCG was observed. The LC–QTOF–MS study of the EFCG putatively identified 35 metabolites, which may be responsible for its antioxidant and α-glucosidase inhibitory properties. Thus, C. grandis fruits can serve as a functional food to address diabetes-related disorders associated with α-glucosidase.     

Determination of phenolic compounds by MALDI–TOF and essential oil composition by GC–MS during three development stages of Origanum majorana L.

This study aimed to investigate the effect of the maturation process of sweet marjoram (Origanum majorana L.) on essential oil composition, the phenolic profile of ethanolic extract and their antioxidant capacities. The essential oil composition was studied at three stages of maturity by GC–MS. Thirty compounds were detected representing 100% of the total essential oil. p‐Menth‐1‐en‐4‐ol was the major compound (37.15–76.94%) followed by cyclohexanol‐3,3,5 trimethyl (5.41–15.99%) and α‐terpineol (0.94–11.34%). During the maturation process, an accumulation of oxygenated monoterpenes was observed. The phenolic composition was studied using matrix‐assisted laser desorption/ionization time of flight. The analysis showed the presence of short flavonoid monomers at all stages of maturation. The antioxidant capacity of ethanolic extracts and essential oils was evaluated using the DPPH assay, iron chelating power and reducing power assay. The highest phenolic content and antioxidant capacity were found at flowering stage. These findings on essential oil composition, phenolic profile and antioxidant capacity of O. majorana at three different stages of development provide more information on how these secondary metabolites are accumulated.     

Identification of cytochrome P450 isoforms involved in the metabolism of artocarpin and assessment of its drug–drug interaction

Artocarpin isolated from an agricultural plant Artocarpus communis has shows anti‐inflammation and anticancer activities. In this study, we utilized recombinant human UDP‐glucuronosyltransferasesupersomes (UGTs) and human liver microsomes to explore its inhibitory effect on UGTs and cytochrome p450 enzymes (CYPs). Chemical inhibition studies and screening assays with recombinant human CYPs were used to identify if CYP isoform is involved in artocarpin metabolism. Artocarpin showed strong inhibition against UGT1A3, UGT1A6, UGT1A7, UGT1A8, UGT1A9, UGT1A10, UGT2B7, CYP2C8 and CYP3A4. In particular, artocarpin exhibited competitive inhibition against CYP3A4 and noncompetitive inhibition against UGT1A3 and UGT1A7. The half inhibition concentration values for CYP3A4, UGT1A3 and UGT1A7 were 4.67, 3.82 and 4.82 μm , and the inhibition kinetic parameters for them were 0.78, 2.67 and 3.14 μm , respectively. After artocarpin was incubated in human liver microsomes and determined by HPLC, we observed its main metabolites (M1 and M2). In addition, we proved that CYP2D6 played the key role in the biotransformation of artocarpin in human liver microsomes. The result of molecular docking further confirmed that artocarpin interacted with CYP2D6, CYP2C8 and CYP3A4 through hydrogen bonds. This study provided preliminary results for further research on artocarpin or artocarpin‐containing herbs.     

Pharmacokinetic and tissue distribution studies of cassane diterpenoids,in rats through an ultra‐high‐performance liquid chromatography–Q exactive hybrid quadrupole–Orbitrap high‐resolution accurate mass spectrometry

Cassane diterpenoids (CA) are considered as the main active constituents of medicinal plants belonging to the Caesalpinia genus. Three cassane derivatives, bonducellpin G (BG), 7‐O‐acetyl‐bonducellpin C (7‐O‐AC) and caesalmin E (CE), isolated from Caesalpinia minax Hance seeds, showed strong anti‐inflammatory activity. In this paper, pharmacokinetics (BG, 7‐O‐AC, CE) and tissue distribution (7‐O‐AC, CE) properties were studied for the first time using a reliable, sensitive and rapid UHPLC–Q‐Orbitrap HR‐MS to develop new anti‐inflammatory agents. A novel quantitative method with full scan in positive ion mode was used to determine the contents of compounds. They were separated using acetonitrile–water (0.1% formic acid) as gradient mobile phase. The calibration curve displayed good linearity and the lower limit of quantitation was 0.005–0.02 μg/mL for all analytes. Meanwhile, the absorption, distribution, metabolism, excretion (ADME) property was predicted using PreADMET web. The pharmacokinetic parameters indicated that they were absorbed quickly, eliminated rapidly together with high blood concentration. The results of tissue distribution demonstrated that CE was distributed rapidly and widely among tissues, and stomach was the main tissue site of CE and 7‐O‐AC, followed by small intestine/liver. This study indicates that the structures and dosages of active CA should be modified to help improve the absorption rate and residence time, and the findings are helpful for the pharmaceutical design of CA derivatives.