Comparative pharmacokinetics of multi-components in normal and stomach cold syndrome rats after oral administration of Zingiberis Rhizoma - Jujubae Fructus herb pair and its single herb extracts by UHPLC-MS/MS

The Zingiberis Rhizoma - Jujubae Fructus herb pair (ZJHP) is a classic herb pair in traditional Chinese medicine. The herb pair shows the effect of dispelling cold, harmonizing the middle and improving gastrointestinal function, and is widely used for patients with stomach cold syndrome (SCS), stomachache and anemofrigid cold. The gingerols, shogaols, flavonoids and triterpenic acids are the important bioactive ingredients of ZJHP. However, few pharmacokinetic studies have been investigated in vivo for the above compounds. To comprehend the kinetics of active components and promote their curative application, a fast and sensitive ultra-high performance liquid chromatography coupled with mass spectrometry (UHPLC-MS/MS) method was established for simultaneous determination of 12 analytes in normal and SCS rats in this study. The results showed that the pharmacokinetic parameters (Cmax, Tmax, t1/2z, MRT0-t, AUC0-t and AUC0-∞) in SCS model were significantly different from those in normal rats. In addition, the pharmacokinetics of rats given ZJHP were also varied from single herb oral administration, especially in model condition. These results indicated that the in vivo processes of the above analytes changed under pathological conditions and the compatibility of the herb pair could significantly influence the absorption of active components, which might provide an insight and further supports for the clinical application of ZJHP.

Ziziphus spina-christi L. extract attenuates bleomycin-induced lung fibrosis in mice via regulating TGF-β1/SMAD pathway: LC-MS/MS Metabolic profiling, chemical composition, and histology studies

Ancient Egyptians (including Bedouins and Nubians) have long utilized Ziziphus spina-christi (L.), a traditional Arabian medicinal herb, to alleviate swellings and inflammatory disorders. It is also mentioned in Christian and Muslim traditions. Ziziphus spina-christi L. (Family: Rhamnaceae) is a plentiful source of polyphenols, revealing free radical scavenging, antioxidant, metal chelating, cytotoxic, and anti-inflammatory activities. Herein, different classes of the existing bioactive metabolites in Z. spina-christi L. were detected using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the first time. The study also aimed to assess the anti-inflammatory and antifibrotic properties of Z. spina-christi L. extract against bleomycin-induced lung fibrosis in an experimental mouse model. 32 male Swiss Albino mice were assigned into 4 groups; the first and second were the normal control group and the bleomycin positive control (single 2.5 U/kg bleomycin intratracheal dose). The third and fourth groups received 100 and 200 mg/kg/day Z. spina-christi L. extract orally for 3 weeks, 2 weeks before bleomycin, and 1 week after. The bioactive metabolites in Z. spina-christi L. extract were identified as phenolic acids, catechins, flavonoids, chalcones, stilbenes, triterpenoid acids, saponins, and sterols. The contents of total phenolic compounds and flavonoids were found to be 196.62 mg GAE/gm and 33.29 mg QE/gm, respectively. In the experimental study, histopathological examination revealed that lung fibrosis was attenuated in both Z. spina-christi L.- treated groups. Z. spina-christi L. extract downregulated the expression of nuclear factor kappa B (NF-κB) p65 and decreased levels of the inflammatory markers tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and c-Jun N-terminal kinase (JNK) in lung tissue. Z. spina-christi L. also downregulated the expression of the fibrotic parameters collagen-1, alpha-smooth muscle actin (α-SMA), transforming growth factor-beta 1 (TGF-β1), matrix metalloproteinase-9 (MMP-9) and SMAD3, with upregulation of the antifibrotic SMAD7 in lung tissue. Overall, the present study suggests a potential protective effect of Z. spina-christi L. extract against bleomycin-induced lung fibrosis through regulation of the TGF-β1/SMAD pathway.

Revealing the potential bioactive components and mechanism of Qianhua Gout Capsules in the treatment of gouty arthritis through network pharmacology, molecular docking and pharmacodynamic study strategies

Recent clinical studies have confirmed the effectiveness of Qianhua Gout Capsules (QGC) in the treatment of gouty arthritis (GA). However, the specific regulatory targets and mechanisms of action of QGC are still unclear. To address this gap, we utilized network pharmacology, molecular docking, and pharmacodynamic approaches to investigate the bioactive components and associated mechanisms of QGC in the treatment of GA. By employing UPLC-Q Exactive-MS, we identified the compounds present in QGC, with active ingredients defined as those with oral bioavailability ≥30 % and drug similarity ≥0.18. Subsequently, the targets of these active compounds were determined using the TCMSP database, while GA-related targets were identified from DisGeNET, GeneCards, TTD, OMIM, and DrugBank databases. Further analysis including PPI analysis, GO analysis, and KEGG pathway enrichment was conducted on the targets. Validation of the predicted results was performed using a GA rat model, evaluating pathological changes, inflammatory markers, and pathway protein expression. Our results revealed a total of 130 components, 44 active components, 16 potential shared targets, GO-enriched terms, and 47 signaling pathways related to disease targets. Key active ingredients included quercetin, kaempferol, β-sitosterol, luteolin, and wogonin. The PPI analysis highlighted five targets (PPARG, IL-6, MMP-9, IL-1β, CXCL-8) with the highest connectivity, predominantly enriched in the IL-17 signaling pathway. Molecular docking experiments demonstrated strong binding of CXCL8, IL-1β, IL-6, MMP9, and PPARG targets with the top five active compounds. Furthermore, animal experiments confirmed the efficacy of QGC in treating GA in rats, showing reductions in TNF-α, IL-6, and MDA levels, and increases in SOD levels in serum. In synovial tissues, QGC treatment upregulated CXCL8 and PPARG expression, while downregulating IL-1β, MMP9, and IL-6 expression. In conclusion, this study applied a network pharmacology approach to uncover the composition of QGC, predict its pharmacological interactions, and demonstrate its in vivo efficacy, providing insights into the anti-GA mechanisms of QGC. These findings pave the way for future investigations into the therapeutic mechanisms underlying QGC's effectiveness in the treatment of GA.

Analytical Methods for the Determination of Quercetin and Quercetin Glycosides in Pharmaceuticals and Biological Samples

Flavonoids are plant-derived compounds that have several health benefits, including antioxidative, anti-inflammatory, anti-mutagenic, and anti-carcinogenic effects. Quercetin is a flavonoid that is widely present in various fruits, vegetables, and drinks. Accurate determination of quercetin in different samples is of great importance for its potential health benefits. This review, is an overview of sample preparation and determination methods for quercetin in diverse matrices. Previous research on sample preparation and determination methods for quercetin are summarized, highlighting the advantages and disadvantages of each method and providing insights into recent developments in quercetin sample treatment. Various analytical techniques are discussed including spectroscopic, chromatographic, electrophoretic, and electrochemical methods for the determination of quercetin and its derivatives in different samples. UV-Vis (Ultraviolet-visible) spectrophotometry is simple and inexpensive but lacks selectivity. Chromatographic techniques (HPLC, GC) offer selectivity and sensitivity, while electrophoretic and electrochemical methods provide high resolution and low detection limits, respectively. The aim of this review is to comprehensively explore the determination methods for quercetin and quercetin glycosides in diverse matrices, with emphasis on pharmaceutical and biological samples. The review also provides a theoretical basis for method development and application for the analysis of quercetin and quercetin glycosides in real samples.

Bioanalysis by LC-MS/MS and preclinical pharmacokinetic interaction study of ribociclib and oleanolic acid

Background: Ribociclib (RIBO), approved in 2017 for HR-positive and HER-2-negative metastatic breast cancer treatment is reported to have the potential to induce hepatobiliary toxicity in patients. Oleanolic acid (OLA) has hepatoprotective potential that can be beneficial if coadministered with RIBO. Methodology & results: The primary scope of this study was to develop quantitative bioanalytical methods for RIBO and OLA. Two methods (for +ve electrospray ionization [ESI] and -ve ESI) were developed and validated according to USFDA bioanalytical guidelines. Discussion/conclusion: A single and simple sample preparation method was developed with >75% recovery. The accuracy and precision for RIBO and OLA were within acceptable limits over the calibration range of 5-500 ng/ml. This work reports, for the first time, the drug-drug interaction potential between RIBO and OLA.

An UHPLC/LC-MS illustrated the dynamic profiling of balanophorin B, gallic acid, and 4-hydroxycinnamic acid in rat as 3 molecular entities from Balanophora simaoensis

An UHPLC/LC-MS was founded to detect balanophorin B (B), gallic acid (GA), 4-hydroxycinnamic acid (HC), and their in vivo profiling in rats, after oral administration of the ethanol extract of Balanophora simaoensis S. Y. Chang et Tam. The in vivo dynamic existence of 3 molecular entities in rats and the multistep biotransformation of GA were elucidated by their sensitive mass spectrometry response after efficient UHPLC and/or HPLC separation, through analyzing the bio-samples of rat plasma, bile, liver, kidneys, and excreta. The method was validated with satisfactory calibration curves having correlation coefficients r from 0.996 to 0.999 for concentration scaled from 0.100 nM to 0.100 μM, internal standard normalized matrix factors ranged from 0.923 to 0.993, sextuplicate recoveries valued from 95.0% to 103.6%, as well as accuracy and precision varied from 95.6% to 103.7%. The content of B, GA, and HC in the whole herb was of 4.66, 63.5, and 10.4 μmol/kg in dry weight, respectively. The Cmax for B, GA, and HC in rat systemic circulation was of 76.0 nM, 2.30 μM, and 51.0 μM, with tmax at 3, 2, and 2 h, respectively. B and GA stayed in rat liver over 4 hs to present a material base for the pharmacology and pharmacodynamics of the whole herb. The biotransformation of GA indicated a complicated scheme in rats. As a final metabolite from GA with total biotransformation conversion over 20%, 4-hydroxybenzaldehyde resourced from two steps of dehydroxylation and one step of reduction of GA, but not concerned with HC.

A Sensitive Liquid Chromatography-Mass Spectrometry Method for Determination of Toosendanin in Rat Plasma and its Application to Pharmacokinetic Study

A simple, rapid and sensitive analytical method was developed for the determination of toosendanin in rat plasma using liquid chromatography tandem mass spectrometry (LC-MS/MS). Andrographolide was selected as the internal standard, and the plasma samples were extracted by liquid-liquid extraction with diethyl ether. Chromatographic separation was performed on a Dikma Spursil C18, 3.5 μm (150 × 2.1 mm i.d) analytical column with 85% methanol:water (v/v) containing 0.025% formic acid (pH = 3.9) as mobile phase. The flow rate was 0.25 mL/min, and the total run time was 3 min. Detection was performed with a triple-quadrupole tandem mass spectrometer using negative ion mode electrospray ionization (ESI) in the multiple reaction monitoring (MRM) mode. The MS/MS ion transitions monitored were m/z 573.1 → 531.1 and 349.0 → 287.0 for toosendanin and andrographolide, respectively. Good linearity was observed over the concentration range of 3.125-500 ng/mL in 100 μL of rat plasma with a correlation coefficient ˃0.9997. Intra- and inter-assay variabilities were ˂8.5% in plasma. The recovery and the matrix effect were in the range 71.8-73.5% and 96.4-103.8%, respectively. The analyte was stable under various conditions (at room temperature, during freeze-thaw settings, in the autosampler, and under deep-freeze conditions). The method was successfully applied to a pharmacokinetic study of toosendanin after its oral administration in rats at a dose of 10 mg/kg.

Identification and Characterization of Chemical Constituents in HuaTanJiangQi Capsules by UPLC-QTOF-MS Method

BACKGROUND

HuaTanJiangQi (HTJQ) is a classical Chinese medicine compound preparation, mainly used for clinically treating and improving chronic obstructive pulmonary disease (COPD) in China.

OBJECTIVE

To establish a rapid and efficient analytical method for the identification and characterization of chemical constituents in HTJQ based on ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS).

METHOD

UPLC-QTOF-MS was used to rapidly separate and identify the chemical constituents of HTJQ via a gradient elution system. The accurate mass data of the protonated and deprotonated molecules and fragment ions were detected in positive and negative ion modes. Compounds of HTJQ can be identified and assigned by analyzing accurate mass measurements and ion fragmentation mechanisms and comparing them with a chemical compositions database.

RESULTS

A total of 61 compounds in HTJQ were separated and identified, including 14 flavonoids, 16 organic acids, four isothiocyanic acids, eight butyl phthalides, two alkaloids, 10 terpenoids, four methoxyphenols and furanocoumarins, and three other compounds. The chemical compounds of HTJQ were identified and elucidated comprehensively for the first time.

CONCLUSIONS

A rapid, accurate, and efficient UPLC-QTOF-MS method has been developed for the identification of chemical components and applied to simultaneously evaluate the quality and effectiveness of HTJQ.

HIGHLIGHTS

Systematic identification of chemical constituents in HTJQ can provide a scientific and reasonable basis for the application of HTJQ in the clinical treatment of COPD.

Analysis of bioactive components and pharmacokinetics of Caulophyllum robustum in rat plasma after oral administration by UPLC-ESI-MS/MS

A UPLC-MS/MS method was developed and validated the determination and pharmacokinetic study of magnoflorine, cauloside C, hederagenin, and oleanolic acid from Caulophyllum robustum. Digoxin was used as the internal standard. The pretreated plasma samples were carried out on a Waters ACQUITYUPLC HSS T3 column at 35 °C with a mobile phase of acetonitrile-water (90:10, v/v) at a flow rate of 0.2 mL/min. This article describes the most simple, sensitive, and validated UPLC-MS/MS method to date for the simultaneous successful determination of four compounds in rat plasma after oral administration of the extract of C. robustum and their pharmacokinetic studies.

Identification of the Myogenetic Oligodeoxynucleotides (myoDNs) That Promote Differentiation of Skeletal Muscle Myoblasts by Targeting Nucleolin

Herein we report that the 18-base telomeric oligodeoxynucleotides (ODNs) designed from the Lactobacillus rhamnosus GG genome promote differentiation of skeletal muscle myoblasts which are myogenic precursor cells. We termed these myogenetic ODNs (myoDNs). The activity of one of the myoDNs, iSN04, was independent of Toll-like receptors, but dependent on its conformational state. Molecular simulation and iSN04 mutants revealed stacking of the 13-15th guanines as a core structure for iSN04. The alkaloid berberine bound to the guanine stack and enhanced iSN04 activity, probably by stabilizing and optimizing iSN04 conformation. We further identified nucleolin as an iSN04-binding protein. Results showed that iSN04 antagonizes nucleolin, increases the levels of p53 protein translationally suppressed by nucleolin, and eventually induces myotube formation by modulating the expression of genes involved in myogenic differentiation and cell cycle arrest. This study shows that bacterial-derived myoDNs serve as aptamers and are potential nucleic acid drugs directly targeting myoblasts.

Analysis of phenolic acids and flavonoids in leaves of Lycium barbarum from different habitats by ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry

The leaves of Lycium barbarum (LLB) have been utilized as crude drugs and functional tea for human health in China and Southeast Asia for thousands of years. To control its quality, a rapid and sensitive ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry method was established and validated for the first time for simultaneous determination of 10 phenolic acids and flavonoids (including neochlorogenic acid, protocatechuic aldehyde, p-hydroxybenzoic acid, chlorogenic acid, cryptochlorogenic acid, caffeic acid, p-coumaric acid, ferulic acid, rutin and kaempferol-3-O-rutinoside) in LLB. The separation was performed on an Acquity UPLC C₁₈ chromatographic column (100 × 2.1 mm internal diameter, 1.7 μm particle size) with 0.1% formic acid in water (A)-acetonitrile (B) as the mobile phase under gradient elution. Multiple reaction monitoring mode was adopted to simultaneously monitor the target components. The developed method was fully validated in terms of linearity (r²  ≥ 0.9860), precision (RSD ≤ 6.58%), repeatability (RSD ≤ 6.60%), stability (RSD ≤ 6.17%), recovery (95.56-108.06%, RSD ≤ 4.64%) and limit of detection (0.021-0.664 ng/mL) and limit of quantitation (0.069-2.210 ng/mL), and then successfully applied to evaluate the quality of 64 batches of LLB collected from 41 producing areas in four different provinces of China. The results showed that the LLB, especially collected from Inner Mongolia regions, were rich in the phenolic acids and flavonoids. Rutin, kaempferol-3-O-rutinoside and chlorogenic acid are the predominant compounds contained in LLB. The above findings will provide helpful information for the effective utilization of LLB.

A UPLC-MS/MS Method for Simultaneous Determination of Six Bioactive Compounds in Rat Plasma, and its Application to Pharmacokinetic Studies of Naoshuantong Granule in Rats

Background:

It is urgently needed to clarify the pharmacokinetic mechanism for the multibioactive constituents in Traditional Chinese Medicines for its clinical applications. A rapid, sensitive and reliable ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous determination of Danshensu, Ferulic acid, Astragaloside IV, Naringin, Neohesperidin and Puerarin after oral administration of Naoshuantong Granule using Carbamazepine as internal standard (IS).

Methods:

The plasma samples were pretreated by liquid-liquid extraction method using ethyl acetate after acidification, and separated on a Waters ACQUITY UPLC® BEH C18 column (50×2.1 mm, i.d., 1.7 µm) by gradient elution with a mobile phase composing of water (containing 0.1% formic acid) and acetonitrile at a flow rate of 0.2 mL/min. Multiple reaction monitoring (MRM) mode with both positive and negative ion mode was operated using an electrospray ionization (ESI) to detect the six compounds.

Result:

All calibration curves showed good linearity (r>0.99) over a wide concentration range. The intra- and inter-day precision (RSD%) was below 8.4% and the accuracy (RE%) ranged from 91.1% to 107.5%. The extraction recoveries of the six analytes and IS in the plasma were more than 77.9% and no severe matrix effect was observed.

Conclusion:

The fully validated method was successfully applied to the pharmacokinetics of Naoshuantong Granule.

Simultaneous Determination of Kirenol, Rosmarinic Acid and Caffeic Acid in Rat Plasma and Pharmacokinetic Study After Oral Administration of the Extract of Manxingshizhen Preparation by UPLC-MS/MS

Introduction:

A rapid, sensitive and convenient ultra-performance liquid chromatography with tandem mass spectrometric detection (UPLC-MS/MS) method has been validated and applied to the simultaneous determination of kirenol, rosmarinic acid and caffeic acid after oral administration of the extract of Manxingshizhen preparation in rat plasma.

Materials and Methods:

Puerarin was selected as the internal standard (IS). The plasma sample preparation was pretreated by liquid-liquid extraction of the mixture with ethyl acetate. All analytes were simultaneously detected in multiple reaction monitoring (MRM) mode via both the positive electrospray ionization (ESI+) and negative electrospray ionization (ESI). In the experiment, all calibration curves revealed good linearity (r > 0.999). The LLOQ were between 0.80-2.00 ng/mL, respectively.

Besides, the intra-day and inter-day precision ranged from 6.4 to 13.8%, respectively. Moreover, the accuracy was within - 11.4% and 12.8% for all the QC levels of all analytes. The extraction recoveries of the analytes and IS in plasma at three concentration levels ranged from 88.5 to 103.2%, moreover, the matrix effects of all the analytes and the IS were found to be satisfied with the acceptable range of 89.8%-101.7%. Meanwhile, the RSD values of stability met the requirement of not more than 15%. Furthermore, the pharmacokinetic parameters of three compounds were analyzed using concentrationtime profiles.

Conclusion and Results:

Plasma concentrations of the three compounds were determined up to 24 h after oral administration, and their pharmacokinetic parameters were in agreement with previous studies. The validated method was successfully applied in a pharmacokinetic study in rat plasma after oral administration of Manxingshizhen preparation.

A Review of Analytical Methods for p-Coumaric Acid in Plant-Based Products, Beverages, and Biological Matrices

p-Coumaric acid (p-CA), also known as 4-hydroxycinnamic acid, is a phenolic acid, which has been widely studied due to its beneficial effects against several diseases and its wide distribution in the plant kingdom. This phenolic compound can be found in the free form or conjugated with other molecules; therefore, its bioavailability and the pathways via which it is metabolized change according to its chemical structure. p-CA has potential pharmacological effects because it has high free radical scavenging, anti-inflammatory, antineoplastic, and antimicrobial activities, among other biological properties. It is therefore essential to choose the most appropriate and effective analytical method for qualitative and quantitative determination of p-CA in different matrices, such as plasma, urine, plant extracts, and drug delivery systems. The most-reported analytical method for this purpose is high-performance liquid chromatography, which is mostly coupled with some type of detectors, such as UV/Vis detector. However, other analytical techniques are also used to evaluate this compound. This review presents a summary of p-CA in terms of its chemical and pharmacokinetic properties, pharmacological effects, drug delivery systems, and the analytical methods described in the literature that are suitable for its quantification.

Microcrystalline cellulose based matrix solid phase dispersion microextration for isomeric triterpenoid acids in loquat leaves by ultrahigh-performance liquid chromatography and quadrupole time-of-flight mass spectrometry

An analytical procedure based on matrix solid phase dispersion (MSPD) microextration and ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry was developed for the determination of isomeric triterpenoid acids (maslinic acid, corosolic acid, oleanolic acid and ursolic acid) in loquat leaves. Microcrystalline cellulose was used for the first time as a solid sorbent in MSPD microextration. Compared with the traditional extraction methods, the proposed method possessed the advantages of shorter extraction time, and lower consumption of sample, sorbent and organic solvent. The MSPD parameters that influenced the extraction efficiency of isomeric analytes were investigated and optimized in detail. Under the optimized conditions, good linearity was obtained with correlation coefficients higher than 0.9990. The limits of detection and quantification were 19.6-51.6μg/kg and 65.3-171.8μg/kg, respectively. Meanwhile, the recoveries obtained for all the analytes were ranging from 90.1% to 107.5%. Finally, the optimized method was successfully applied for analyzing these isomeric acids in loquat leaves samples obtained from different cultivated areas.

Simultaneous Determination of Oleanolic and Ursolic Acids in Rat Plasma by HPLC-MS: Application to a Pharmacokinetic Study After Oral Administration of Different Combinations of QingGanSanJie Decoction Extracts

A liquid chromatography-mass spectrometry method has been developed and validated for rapid simultaneous determination of the oleanolic and ursolic acid contents in rat plasma with betulinic acid as the internal standard (IS). The plasma samples were prepared by a liquid-liquid extraction procedure. Chromatographic separation was performed with a Chromasil-C18 column (250 mm × 4.6 mm, i.d. 5 μm) with methanol-water as mobile phase at 1 mL/min. The detection was accomplished under selected-ion-monitoring mode with a negative electrospray ionization interface. Linear calibration curves were obtained between the range of 0.86-421.2 and 0.94-462.0 ng/mL for oleanolic and ursolic acids, with lower limits of quantification at 0.43 and 0.47 ng/mL, respectively. The extraction recovery exceeded 70% in plasma. The intra- and interday precision values were <9.8% with the accuracy as -7.0 to 9.9% at three different QC levels in both cases. The pharmacokinetic behaviors of oral dosage of QingGanSanJie decoctions were then studied in rats following the developed approach. The t1/2 values of the oleanolic and ursolic acids after oral administration of the monarch medicine extract were significantly different (P < 0.05) from other prescription extracts containing different herb pieces with different compatibilities. Bimodal phenomena appeared in every concentration-time curve for the oleanolic and ursolic acids at 3-8 h after administration. The minister, assistant and guide medicines in the formula could prolong the metabolism of the oleanolic and ursolic acids in vivo, providing an experimental basis for the slow onset and long action of the Traditional Chinese Medicine compound.

Qualitative and quantitative analysis of the major constituents in Chinese medical preparation Lianhua-Qingwen capsule by UPLC-DAD-QTOF-MS

Lianhua-Qingwen capsule (LQC) is a commonly used Chinese medical preparation to treat viral influenza and especially played a very important role in the fight against severe acute respiratory syndrome (SARS) in 2002-2003 in China. In this paper, a rapid ultraperformance liquid chromatography coupled with diode-array detector and quadrupole time-of-flight mass spectrometry (UPLC-DAD-QTOF-MS) method was established for qualitative and quantitative analysis of the major constituents of LQC. A total of 61 compounds including flavonoids, phenylpropanoids, anthraquinones, triterpenoids, iridoids, and other types of compounds were unambiguously or tentatively identified by comparing the retention times and accurate mass measurement with reference compounds or literature data. Among them, twelve representative compounds were further quantified as chemical markers in quantitative analysis, including salidroside, chlorogenic acid, forsythoside E, cryptochlorogenic acid, amygdalin, sweroside, hyperin, rutin, forsythoside A, phillyrin, rhein, and glycyrrhizic acid. The UPLC-DAD method was evaluated with linearity, limit of detection (LOD), limit of quantification (LOQ), precision, stability, repeatability, and recovery tests. The results showed that the developed quantitative method was linear, sensitive, and precise for the quality control of LQC.

Olean-12-eno[2,3-c] [1,2,5]oxadiazol-28-oic acid (OEOA) induces G1 cell cycle arrest and differentiation in human leukemia cell lines

Oleanolic acid (3β-hydroxy-olea-12-en-28-oic acid) is a natural pentacyclic triterpenoic acid found in many fruits, herbs and medicinal plants. In the past decade, increasing evidence has suggested that oleanolic acid exhibits inhibitory activities against different types of cancer including skin cancer and colon cancer, but not leukemia. We report here that a derivative of oleanolic acid, olean-12-eno[2,3-c] [1], [2], [5]oxadiazol-28-oic acid (designated OEOA) effectively blocks the proliferation of human leukemia cells. OEOA significantly reduces cell proliferation without inducing cell death in three types of leukemia cell lines, including K562, HEL and Jurket. Moreover, exposure of K562 cells to OEOA results in G1 cell cycle arrest, with a concomitant induction of cyclin-dependent kinase inhibitor p27 and downregulation of cyclins and Cdks that are essential for cell cycle progression. Interestingly, OEOA also enhances erythroid differentiation in K562 cells through suppressing the expression of Bcr-Abl and phosphorylation of Erk1/2. These findings identify a novel chemical entity for further development as therapeutics against leukemia.