Structurally Diverse Coumarins from Peucedanum praeruptorum and their Anti-Inflammatory Activities via NF-κB Signaling Pathway.

The phytochemical study of Peucedanum praeruptorum led to the isolation of twenty-five coumarins (1-25). Of which, (±) praeruptol A (±1), one pair of previous undescribed seco-coumarin enantiomers were obtained. Their structures were established according to HR-ESI-MS, NMR, X-ray single crystal diffraction analysis, as well as ECD calculation. All compounds were tested for anti-inflammatory activity in the RAW264.7 macrophage model, and eight compounds (7-10, and 13-16) exhibited significant inhibitory effects with IC50 values ranging from 9.48 to 34.66 µM. Among them, compound 7 showed the strongest inhibitory effect, which significantly suppressed the production of IL-6, IL-1ß, and TNF-α, as well as iNOS and COX-2 in a concentration-dependent manner. Further investigated results showed that compound 7 exerted an anti-inflammatory effect via the NF-κB signaling pathway.

Triterpenoid and Coumarin Isolated from Astilbe grandis with Anti-Inflammatory Effects through Inhibiting the NF-κB Pathway in LPS-Induced RAW264.7 Cells.

The roots of Astilbe grandis, known as "Ma sang gou bang", are used as a Miao traditional medicine with anti-inflammatory and analgesic properties. However, the active components and mechanism of action of this plant remain mostly uncharacterized. The aim of this study was to identify its active components and verify their pharmacological activity. The extract of A. grandis root was separated using various chromatographic methods. As a result, we obtained one novel triterpenoid, named astigranlactone (1), which has an unusual lactone moiety formed between C-7 and C-27. Additionally, a known coumarin compound, 11-O-galloyl bergenin (2) was isolated from this plant. The structures of these two compounds were elucidated by extensive NMR experiments in conjunction with HR-ESI-MS data. To the best of our knowledge, both compounds were isolated from this species for the first time. Moreover, we tested the anti-inflammation effect of the two compounds by establishing a cellular inflammation model induced by LPS in RAW264.7 cells. The effect of different concentrations of these compounds on the activity of RAW264.7 cells was assessed using a CCK8 assay. The levels of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1ß (IL-1ß) in the supernatant of each group were evaluated using the Griess method and an enzyme-linked immunosorbent assay (ELISA). Western blot and quantitative real-time PCR (qRT-RCR) were used to measure the levels of cyclooxygenase 2 (COX-2) and nitric oxide synthase (iNOS) gene expression. Our findings revealed that these two compounds inhibited the high levels of NO, TNF-α, IL-6, IL-1ß, COX-2, and iNOS (induced by LPS). Mechanistic studies demonstrated that these two compounds reduced the activation of the nuclear transcription factor-B (NF-κB) signaling pathway by inhibiting the phosphorylation of p65. Therefore, our study indicates that compounds 1 and 2 can exert a definite anti-inflammatory effect by inhibiting the NF-κB signaling pathway.

Biosynthesis of the Plant Coumarin Osthole by Engineered Saccharomyces cerevisiae.

Osthole is a coumarin compound found in the traditional Chinese medicine Cnidium monnieri. Extensive studies have shown that osthole exhibits many medicinal properties, and recently, researchers have found that it possesses potent airway-relaxation activity by inhibiting phosphodiesterase 4D activity, making it a potential novel bronchodilator that does not target ß2-adrenoceptors for asthma treatment. Here, we report the complete biosynthesis of osthole in engineered yeast. We created an umbelliferone (UMB)-producing strain by reconstituting the complete UMB pathway in yeast. We found that coumarin synthase (COSY) is essential for the conversion of 2',4'-dihydroxycinnamoyl-CoA into UMB in yeast; this conversion has been treated as a spontaneous step in previously reported UMB-producing microbials. By introducing downstream prenyltransferase and methyltransferase genes and addressing problems such as protein expression and cofactor supply to fulfill the downstream steps, complete biosynthesis of osthole was achieved. Finally, through metabolic engineering, to ensure precursor supply, and the debugging of rate-limited steps, the osthole titer reached 108.10 mg/L in shake flasks and 255.1 mg/L in fed-batch fermentation. Our study is the first to produce osthole using engineered microbes, providing a blueprint for the supply of plant-derived osthole via microbial fermentation, which will remove the barriers of resource limitations for osthole-based drug development.

Osthole Alleviates D-Galactose-Induced Liver Injury In Vivo via the TLR4/MAPK/NF-κB Pathways.

Osthole, a coumarin derivative, is found in several medicinal herbs. However, the protective effects of osthole against D-galactose (D-Gal)-induced liver injury still remain unclear. In this study, osthole treatment effectively reversed D-Gal-induced liver injury, according to the results of liver HE staining, and improved ALT and AST activities. Feeding with D-Gal significantly increased MDA content, and reduced the level or activity of SOD, CAT and GSH-Px, which were all alleviated by osthole intervention. Meanwhile, osthole treatment significantly inhibited the D-Gal-induced secretion of pro-inflammatory cytokines, such as TNF-α, IL-1ß and IL-6, in both serum and liver tissue. Investigations revealed that osthole ameliorated the D-Gal-induced activation of TLR4, MYD88 and its downstream signaling pathways of MAPK (p38 and JNK) and NF-κB (nucleus p65). Therefore, osthole mediates a protective effect against D-Gal-induced liver injury via the TLR4/MAPK/NF-κB pathways, and this coumarin derivative could be developed as a candidate bioactive component for functional food.

Two O-Methyltransferases Mediate Multiple Methylation Steps in the Biosynthesis of Coumarins in Cnidium monnieri.

Coumarins with methoxy groups such as osthole (1), xanthotoxin (2), bergapten (3), and isopimpinellin (4) are typical bioactive ingredients of many medicinal plants. The methylation steps remain widely unknown. Herein, we report the discovery of two methyltransferases in the biosynthesis of O-methyl coumarins in Cnidium monnieri by transcriptome mining, heterologous expression, and in vitro enzymatic assays. The results reveal that (i) CmOMT1 catalyzes the methylation of osthenol (8) as the final step in the biosynthesis of 1, (ii) CmOMT2 shows the highest efficiency and preference for methylating xanthotoxol (11) to form 2, and (iii) CmOMT1 and CmOMT2 also efficiently transform bergaptol (10) and 8-hydroxybergapten (13) into 3 or 4, suggesting the CmOMTs mediate multistep methylations in the biosynthesis of linear furanocoumarins in C. monnieri.

Deciphering the AChE-binding mechanism with multifunctional tricyclic coumarin anti-Alzheimer's agents using biophysical and bioinformatics approaches and evaluation of their modulating effect on Amyloidogenic peptide assembly.

Investigating the drug-AChE binding mechanism is vital in understanding its cogent use in medical practice against Alzheimer's disease (AD). The production and accumulation of oligomers of ß-amyloid is a central event in the neuropathology of AD. Beside the inhibition of assembly process, modulation of the aggregation process of these proteins towards minimally toxic pathways may be a possible therapeutic strategy for AD. Hence, the present study aims to examine the effect of multifunctional fused tricyclic 7-hydroxy 4-methyl coumarin analogs (HMC1-5) on the self-induced aggregation of ß-amyloid using Thioflavin T (ThT) assay, scanning electron microscopic study, AlamarBlue and immune blotting assays and also the binding mechanism with AChE by fluorescence emission, conformational, molecular docking and molecular dynamic simulation studies under physiological pH 7.4. The ThT assay, FE-SEM study, cell line and western blots establish that the HMC1-5 molecules could irreversibly disrupt preformed Aß42 fibrils, accelerate the aggregates into micro size co-assembled structures, and effectively eliminate the cytotoxicity of Aß1-42. Fluorescence emission studies indicating a strong binding affinity between HMC1-5 and AChE with the binding constants of 1.04 × 105, 3.57 × 104, 1.97 × 104, 3.07 × 104 and 2.95 × 104 M-1, respectively and binding sites number found to be 1. CD studies disclosed a partial unfolding in the secondary structure of AChE upon binding with HMC1-5. Docking analysis inferred that the HMC1-5 were bound through hydrophobic and hydrophilic interactions to the AChE active site. Molecular dynamics simulations emphasized the stability of AChE-HMC1-5 complexes throughout the 100 ns simulations, and the local conformational changes of the residues of AChE validate the stability of complexes. These results provide new and unique complementary approach for modulating the biological effects of the Aß aggregates by coumarin analogs and new insights for further in vivo investigations as novel anti AD agents.

Metabolic Profile of C-Prenyl Coumarins Using Mass Spectrometry-Based Metabolomics.

C-prenyl coumarins (C-PYCs) are compounds with similar structures and various bioactivities, which are widely distributed in medicinal plants. Until now, the metabolic characterizations of C-PYCs and the relationship between metabolism and bioactivities remain unclear. In this study, ultra-performance chromatography electrospray ionization quadrupole time-of-flight mass spectrometry-based metabolomics (UPLC-ESI-QTOF-MS) was firstly used to determine the metabolic characterizations of three C-PYCs, including meranzin hydrate (MH), isomeranzin (ISM), and meranzin (MER). In total, 52 metabolites were identified, and all of them were found to be novel metabolites. Among these metabolites, 10 were from MH, 22 were from ISM, and 20 were from MER. The major metabolic pathways of these C-PYCs were hydroxylation, dehydrogenation, demethylation, and conjugation with cysteine, N-acetylcysteine, and glucuronide. The metabolic rate of MH was much lower than ISM and MER, which was only 27.1% in MLM and 8.7% in HLM, respectively. Additionally, recombinant cytochrome P450 (CYP) screening showed that CYP1A1, 2B6, 3A4, and 3A5 were the major metabolic enzymes involved in the formation of metabolites. Further bioactivity assays indicated that all of these three C-PYCs exhibited anti-inflammatory activity, but the effects of ISM and MER were slightly higher than MH, accompanied by a significant decrease in inflammatory cytokines transcription induced by lipopolysaccharide (LPS) in macrophages RAW 264.7. Taken together, the metabolic characterizations of the three C-PYCs suggested that the side chain of the prenyl group may impact the metabolism and biological activity of C-PYCs.

In silico bimolecular characterization of anticancer phytochemicals from Fagonia indica.

The in silico molecular dynamics and structure-based site-specific drug design of indigenous plant biomolecules and selected proteins have remarkable potential for cancer therapy. A set of five proteins included for this research were epidermal growth factor protein (PDB ID; 1M17), crystal structure of mutated EGFR kinase (PDB ID; 2EB3), crystal structure of Bcl-xl (PDB ID; 2YXJ), apoptosis regulator protein MCL-1 BH3 (PDB ID; 3MK8) and apoptosis proteins (PDB ID; 5C3H). The present study on in silico investigation of fifteen indigenous medicinal plants were selected there one hundred thirty four ligands available literature were docked against five proteins involved in carcinogenesis. The highest scoring in silico plant, Fagonia indica was subjected to in vitro cytotoxic effects on HCT116, HepG-2 and HeLa human carcinoma cell lines. Molecular dynamics showed best ligand-protein inhibition interaction between Coumarin-2xyj and Kaempferol-2eb3 with promising binding affinities. Whereas, on HeLa human cervical cancer cell line IC50 was 28.3±0.102/ml. Fagonia indica could be potential source from natural products that have cytotoxic properties against cervical cancer cells by blocking mutant epidermal growth factor tyrosine or peroxisome proliferators activated receptor proteins.

Natural Coumarins: Exploring the Pharmacological Complexity and Underlying Molecular Mechanisms.

Coumarins belong to the benzopyrone family commonly found in many medicinal plants. Natural coumarins demonstrated a wide spectrum of pharmacological activities, including anti-inflammatory, anticoagulant, anticancer, antibacterial, antimalarial, casein kinase-2 (CK2) inhibitory, antifungal, antiviral, Alzheimer's disease inhibition, neuroprotective, anticonvulsant, phytoalexins, ulcerogenic, and antihypertensive. There are very few studies on the bioavailability of coumarins; therefore, further investigations are necessitated to study the bioavailability of different coumarins which already showed good biological activities in previous studies. On the evidence of varied pharmacological properties, the present work presents an overall review of the derivation, availability, and biological capacities of coumarins with further consideration of the essential mode of their therapeutic actions. In conclusion, a wide variety of coumarins are available, and their pharmacological activities are of current interest thanks to their synthetic accessibility and riches in medicinal plants. Coumarins perform the valuable function as therapeutic agents in a range of medical fields.

Structural mechanism of TRPV3 channel inhibition by the plant-derived coumarin osthole.

TRPV3, a representative of the vanilloid subfamily of TRP channels, is predominantly expressed in skin keratinocytes and has been implicated in cutaneous sensation and associated with numerous skin pathologies and cancers. TRPV3 is inhibited by the natural coumarin derivative osthole, an active ingredient of Cnidium monnieri, which has been used in traditional Chinese medicine for the treatment of a variety of human diseases. However, the structural basis of channel inhibition by osthole has remained elusive. Here we present cryo-EM structures of TRPV3 in complex with osthole, revealing two types of osthole binding sites in the transmembrane region of TRPV3 that coincide with the binding sites of agonist 2-APB. Osthole binding converts the channel pore into a previously unidentified conformation with a widely open selectivity filter and closed intracellular gate. Our structures provide insight into competitive inhibition of TRPV3 by osthole and can serve as a template for the design of osthole chemistry-inspired drugs targeting TRPV3-associated diseases.

Permeation, stability and acute dermal irritation of miroestrol and deoxymiroestrol from Pueraria candollei var. mirifica crude extract loaded transdermal gels.

In this study, permeation behaviors and chemical stability of miroestrol and deoxymiroestrol from Pueraria candollei var. mirifica (PM), Thai traditional medicine, crude extract containing transdermal gels were firstly evaluated. Three different PM extract containing gels were formulated, including hydroalcoholic and microemulsion gels using carbomer, and silicone gel using silicone elastomer. In vitro permeation through porcine ear skin demonstrated that the flux and 24 h cumulative permeation of miroestrol and deoxymiroestrol were in the order of hydroalcoholic > silicone > microemulsion gels. Hydroalcoholic gel provided the highest partition coefficient from gel onto skin, and thus the skin permeability coefficient. After 24 h permeation, no miroestrol and deoxymiroestrol remained deposited in the skin. Accelerated study using heating-cooling revealed insignificant difference between the remaining percentages of miroestrol and deoxymiroestrol in aqueous and non-aqueous based gels. Long-term stability study showed that miroestrol contents remained constant for 90 d and 30 d under 5 ± 3 °C and 30 ± 2 °C, 75 ± 5%RH, respectively; whereas the percentage of deoxymiroestrol decreased significantly after 30 d storage, irrespective of storage conditions. Acute dermal irritation test on New Zealand White rabbits showed that PM hydroalcoholic gels were non-irritant, with no signs of erythema or oedema.[Figure: see text].

Design, synthesis and biological evaluation of selective hybrid coumarin-thiazolidinedione aldose reductase-II inhibitors as potential antidiabetics.

Thiazolidinediones (TZD), benzopyrans are the proven scaffolds for inhibiting Aldose reductase (ALR2) activity and their structural confluence with the retention of necessary fragments helped in designing a series of hybrid compounds 2-(5-cycloalkylidene-2,4-dioxothiazolidin-3-yl)-N-(2-oxo-2H-chromen-3-yl)acetamide (10a-n) for better ALR2 inhibition. The compounds were synthesized by treating substituted 3-(N-bromoacetyl amino)coumarins (9a-d) with potassium salt of 5-cyclo alkylidene-1,3-thiazolidine-2,4-diones (4a-d). The inhibition activity against ALR2 with IC50 values range from 0.012 ± 0.001 to 0.056 ± 0.007 µM. N-[(6-Bromo-3-coumarinyl)-2-(5-cyclopentylidene-2,4-dioxothiazolidin-3-yl)] acetamide (10c) with cyclopentylidene group on one end and the 6-bromo group on the other end showed better inhibitory property (IC50 = 0.012 µM) and selectivity index (324.166) against the ALR2, a forty fold superiority over sorbinil, a better molecule over epalrestat and rest of the analogues exhibited a far superior response over sorbinil and slightly better as compared with epalrestat. It was further confirmed by the insilico studies that compound 10c showed best inhibition activity among the synthesized compounds with a high selectivity index against the ALR2. In invivo experiments, supplementation of compound 10c to STZ induced rats delayed the progression of cataract in a dose-dependent manner warranting its further development as a potential agent to treat thediabetic secondary complications especially cataract.

Identification and Quantification of Coumarins by UHPLC-MS in Arabidopsis thaliana Natural Populations.

Coumarins are phytochemicals occurring in the plant kingdom, which biosynthesis is induced under various stress factors. They belong to the wide class of specialized metabolites well known for their beneficial properties. Due to their high and wide biological activities, coumarins are important not only for the survival of plants in changing environmental conditions, but are of great importance in the pharmaceutical industry and are an active source for drug development. The identification of coumarins from natural sources has been reported for different plant species including a model plant Arabidopsis thaliana. In our previous work, we demonstrated a presence of naturally occurring intraspecies variation in the concentrations of scopoletin and its glycoside, scopolin, the major coumarins accumulating in Arabidopsis roots. Here, we expanded this work by examining a larger group of 28 Arabidopsis natural populations (called accessions) and by extracting and analysing coumarins from two different types of tissues-roots and leaves. In the current work, by quantifying the coumarin content in plant extracts with ultra-high-performance liquid chromatography coupled with a mass spectrometry analysis (UHPLC-MS), we detected a significant natural variation in the content of simple coumarins like scopoletin, umbelliferone and esculetin together with their glycosides: scopolin, skimmin and esculin, respectively. Increasing our knowledge of coumarin accumulation in Arabidopsis natural populations, might be beneficial for the future discovery of physiological mechanisms of action of various alleles involved in their biosynthesis. A better understanding of biosynthetic pathways of biologically active compounds is the prerequisite step in undertaking a metabolic engineering research.

Screening the Q-markers of TCMs from RA rat plasma using UHPLC-QTOF/MS technique for the comprehensive evaluation of Wu-Wei-Wen-Tong Capsule.

The appropriate selection of quality marker (Q-marker) for performing the comprehensive quality evaluation of traditional Chinese medicines (TCMs) has much more significance. Wu-Wei-Wen-Tong Capsule (WWWTC), a TCMs prescription, is mainly utilized to treat rheumatoid arthritis (RA) in China. However, the comprehensive quality control for WWWTC has not been achieved because of lacking system analysis for the Q-marker. In this study, a dual wavelength, 203 and 270 nm, was selected based on the feature of 15 Q-markers, and a reliable UHPLC-UV fingerprinting approach was established, achieving the comprehensive quality evaluation of WWWTC. First, we identified 91 prototypes in rat plasma after administering a set amount of WWWTC by using UHPLC-QTOF/MS technique and selected them as the candidate Q-markers. Next, based on the "five principles" of Q-marker selection, 15 absorbed components among them including coumarin, cinnamic acid, cinnamaldehyde, cinnamic alcohol, and 2-methoxycinnamaldehyde derived from Monarch medicine of Cmnamomi Mmulus; epimedin C, icariin, baohuoside I, and anhydroicaritin derived from Monarch medicine Epimedii Folium; germacrone, the sesquiterpene compound in Minister medicine Rhizoma Wenyujin Concisum; pachymic acid, the tetracyclic triterpenoid acids in Assistant medicine Poria; baicalin, baicalein, wogonin, and wogonoside in Guide medicine Scutellariae Radix, respectively, were seriously chosen as the Q-markers, indicating preferable pharmacological effect on RA, characterization of transitivity and traceability as well as measurable components in WWWTC. The effective and meaningful strategy displayed a unique perspective for the exploration of Q-markers in the quality evaluation and further ensured efficacy and safety of the TCMs.

7-Isopentenyloxycoumarin: What Is New across the Last Decade.

7-Isopentenyloxycoumarin is among the most widespread naturally occurring prenyloxy umbelliferone derivatives. This secondary metabolite of mixed biosynthetic origin has been typically isolated from plants belonging to several genera of the Rutaceae and Apiaceae families, comprising widely used medicinal plants and in general plants with beneficial effects on human welfare, as well as edible fruits and vegetables. Although known for quite a long time (more than 50 years), only in the last two decades has this natural compound been revealed to exert powerful and promising pharmacological properties, such as active cancer chemopreventive, antibacterial, antiprotozoal, antifungal, anti-inflammatory, neuroprotective, and antioxidant properties, among the activities best outlined in the recent literature. The aim of this comprehensive miniature review article is to detail the novel natural sources and the effects described during the last decade for 7-isopentenyloxycoumarin and what has been reported on the mechanisms of action underlying the observed biological activities of this oxyprenylated secondary metabolite. In view of the herein described data, suggestions on how to address future research on the abovementioned natural product and structurally related derivatives in the best ways according to the authors will be also provided.

Airway relaxation mechanisms and structural basis of osthole for improving lung function in asthma.

Overuse of ß2-adrenoceptor agonist bronchodilators evokes receptor desensitization, decreased efficacy, and an increased risk of death in asthma patients. Bronchodilators that do not target ß2-adrenoceptors represent a critical unmet need for asthma management. Here, we characterize the utility of osthole, a coumarin derived from a traditional Chinese medicine, in preclinical models of asthma. In mouse precision-cut lung slices, osthole relaxed preconstricted airways, irrespective of ß2-adrenoceptor desensitization. Osthole administered in murine asthma models attenuated airway hyperresponsiveness, a hallmark of asthma. Osthole inhibited phosphodiesterase 4D (PDE4D) activity to amplify autocrine prostaglandin E2 signaling in airway smooth muscle cells that eventually triggered cAMP/PKA-dependent relaxation of airways. The crystal structure of the PDE4D complexed with osthole revealed that osthole bound to the catalytic site to prevent cAMP binding and hydrolysis. Together, our studies elucidate a specific molecular target and mechanism by which osthole induces airway relaxation. Identification of osthole binding sites on PDE4D will guide further development of bronchodilators that are not subject to tachyphylaxis and would thus avoid ß2-adrenoceptor agonist resistance.

Two CYP71AJ enzymes function as psoralen synthase and angelicin synthase in the biosynthesis of furanocoumarins in Peucedanum praeruptorum Dunn.

KEY MESSAGE: Psoralen synthase and angelicin synthase responsible for the formation of psoralen and angelicin in Peucedanum praeruptorum Dunn were identified and functionally characterized, respectively. Furanocoumarins were reported to possess several activities such as anticancer, anti-inflammatory and neuroprotective, and function as phytotoxin and allelochemical in plants. Furanocoumarins are the main bioactive ingredient in P. praeruptorum which is a commonly used traditional Chinese medicine. Phenylalanine ammonia lyase (PAL), 4-coumarate: CoA ligase (4CL), p-coumaroyl CoA 2'-hyfroxylase (C2'H) were cloned previously to elucidate the biosynthetic mechanism of coumarin lactone ring. However, the genes involved in complex coumarins in P. praeruptorum have not been explored. Herein, putative psoralen synthase CYP71AJ49 and angelicin synthase CYP71AJ51 were cloned from P. praeruptorum. In vivo and in vitro yeast assays were conducted to confirm their activities. Furthermore, the results of High Performance Liquid Chromatography-Electrospray Ionization Mass Spectrometry (HPLC-ESI-MS) verified that CYP71AJ49 catalyzed the conversion of marmesin to psoralen, and CYP71AJ51 catalyzed columbianetin to angelicin. Subsequently, the expression profile showed that CYP71AJ49 and CYP71AJ51 were easily affected by environmental conditions, especially UV and temperature. The genes tissue-specific expression and compounds tissue-specific distribution pattern indicated the existence of substance transport in P. praeruptorum. Phylogenetic analysis was conducted with 27 CYP71AJs, CYP71AJ49 and CYP71AJ51 were classified in I-4 and I-2, respectively. These results provide further insight to understand the biosynthetic mechanism of complex coumarins.

Direct Infusion-Three-Dimensional-Mass Spectrometry Enables Rapid Chemome Comparison among Herbal Medicines.

Direct infusion-mass spectrometry (DI-MS) currently serves as an alternative analytical tool for metabolomics owing to the unique high-throughput advantage. Except the inherent shortcoming at a significant matrix effect, there are two other primary technical obstacles dampening its wide applications, such as data alignment and structural annotation. To address these two obstacles, a novel strategy termed as DI-three-dimensional-MS (DI-3D-MS) was proposed here, and chemome comparison among several confusing herbal medicines (HMs) belonging to the Umbelliferae family was conducted as a proof-of-concept. Each test sample was directly infused into Qtrap-MS. In the first dimension, stepwise multiple ion monitoring (MIM) program was implemented to universally acquire the quantitative information on all HMs and to generate aligned data files. In the second dimension, MS2 spectra were universally recorded by enhanced product ion (EPI) experiments that were triggered by MIM via an information-dependent acquisition algorithm. In the third dimension, online energy-resolved MS (ER-MS) was programmed to yield breakdown graphs for all MIM items. Moreover, a data library was built to aid structural identification by involving MS2 and CE50 features that were obtained by well-developed LC-MS methods. Qualitative and quantitative potentials of DI-3D-MS were validated toward metabolomics study. Significant species differences were observed, and all materials were grouped into three clusters. After matching MS2 spectra and breakdown graphs between DI-3D-MS and those in the data library, coumarins ubiquitously existed in each HM, and angular-type pyranocoumarins, linear-type pyranocoumarins, angular-type furanocoumarins, along with ligustilide derivatives offered primary contributions for the classification pattern. Above all, DI-3D-MS is an eligible choice for rapid metabolomics of HMs and other matrices as well.

Phytochemical composition profile and space-time accumulation of secondary metabolites for Dracocephalum moldavica Linn. via UPLC-Q/TOF-MS and HPLC-DAD method.

The aerial parts of Dracocephalum moldavica L. are extensively used in traditional ethnic medicines in China as a remedy for cardiovascular and cerebrovascular damage. However, the chemical composition and the accumulation of main secondary metabolites of D. moldavica in different natural environments remain unclear. This study aimed to conduct a qualitative and quantitative analysis of the main secondary metabolites to explore the quality variation of D. moldavica in markets. The evaluation of space-time accumulation of main secondary metabolites in D. moldavica was carried out during different growth periods and in different geographical locations. A total of 35 ingredients were detected and 24 identified, including 21 flavonoids, two phenolic acids and one coumarin by UPLC-QTOF-MS method. Furthermore, a simple and convenient HPLC method was successfully developed for the simultaneous determination of lutelin-7-O-glucuronide and tilianin and rosmarinic acid in D. moldavica. The results of space-time accumulation analysis showed the distinct variation of secondary metabolites of D. moldavica with the growth period and geographical location. Finally, the current study provided a meaningful and useful approach for comprehensively evaluating the quality of D. moldavica.

Mechanism-based inactivation of cytochrome P450 2D6 by Notopterol.

Notopterol (NOT) is a major bioactive ingredient extracted from the rhizomes of either Notopterygium incisum Ting ex H. T. Chang or N. forbesii Boiss (Qianghuo in Chinese), a botanical drug that was adopted as a traditional Chinese medicine. NOT is suggested to show analgesic and anti-inflammatory effects in clinical practice. The inhibitory effects of NOT on human cytochrome P450 enzymes were investigated in the present study. Our results indicate that NOT inhibited the activity of CYP2D6 in a time-, concentration- and NADPH-dependent manner. The values of KI and kinact were 10.8 µM and 0.62 min-1, respectively. The calculated kobs at 10 µM was 0.29 min-1, above the 0.02 min-1 risk level. After incubation with NOT at 10 µM for 9 min, approximately 92% of CYP2D6 activity was inhibited. Such loss of enzyme activity was not restored through dialysis, which indicates that the observed enzyme inhibition was irreversible. Partition ratio of the inactivation was approximately 29. Quinidine, a competitive CYP2D6 inhibitor, demonstrated protection on enzymes against the NOT-induced inactivation, but such protection was not found in incubation systems fortified with glutathione or catalase/superoxide dismutase. Additionally, CYP3A4 was observed to function as an enzyme mainly involved in the biotransformation of NOT. Taken together, these findings indicate that NOT served as a mechanism-based inactivator of CYP2D6, meanwhile, those observed effects may induce the latent drug-drug interactions. The metabolic activation of NOT may be the key to trigger the inactivation of the enzyme.