Five new sesquiterpenoids isolated from Dictamnus dasycarpus Turcz.

Five new sesquiterpenoids, dictamtrinorguaianols E and F (1-2), and dictameudesmnosides F, G, and H (3-5), along with seven known sesquiterpenoids (6-12) were isolated from Dictamnus dasycarpus Turcz. The structures of all new compounds were characterized by spectroscopic methods, including UV, IR, HR-ESI-MS, and 1D and 2D NMR. The In-vitro anti-proliferative activities of all the compounds against two human cancer cell lines (SW982 and A549) were evaluated by CCK-8 assay. Compounds 1 and 4 showed medium anti-proliferative activity against SW982 cells, with IC50 values of 3.49 ± 0.10 and 6.42 ± 1.23 µM, respectively. Additionally, compounds 2, 7, and 8 exhibited medium anti-proliferative activity against A549 cells, with IC50 values ranging from 0.80 ± 0.05 to 6.60 ± 0.46 µM.

Dictamnus dasycarpus Turcz. attenuates airway inflammation and mucus hypersecretion by modulating the STAT6-STAT3/FOXA2 pathway.

BACKGROUND: Effects of Dictamnus dasycarpus Turcz. on allergic asthma and their underlying mechanisms remain unclarified. Thus, we investigated the effects of D. dasycarpus Turcz. water extract (DDW) on mucus hypersecretion in mice with ovalbumin (OVA)-induced asthma and human bronchial epithelial cells. METHODS: BALB/c mice were used to establish an OVA-induced allergic asthma model. Mice were grouped into the OVA sensitization/challenge, 100 and 300 mg/kg DDW treatment, and dexamethasone groups. In mice, cell counts in bronchoalveolar lavage fluid (BALF), serum and BALF analyses, and histopathological lung tissue analyses were performed. Furthermore, we confirmed the basic mechanism in interleukin (IL)-4/IL-13-treated human bronchial epithelial cells through western blotting. RESULTS: In OVA-induced asthma mice, DDW treatment reduced inflammatory cell number and airway hyperresponsiveness and ameliorated histological changes (immune cell infiltration, mucus secretion, and collagen deposition) in lung tissues and serum total immunoglobulin E levels. DDW treatment lowered BALF IL-4, IL-5, and IL-13 levels; reduced levels of inflammatory mediators, such as thymus- and activation-regulated chemokine, macrophage-derived chemokine, and interferon gamma-induced protein; decreased mucin 5AC (MUC5AC) production; decreased signal transducer and activator of transcription (STAT) 6 and STAT3 expression; and restored forkhead box protein A2 (FOXA2) expression. In IL-4/IL-13-treated human bronchial epithelial cells, DDW treatment inhibited MUC5AC production, suppressed STAT6 and STAT3 expression (related to mucus hypersecretion), and increased FOXA2 expression. CONCLUSIONS: DDW treatment modulates MUC5AC expression and mucus hypersecretion by downregulating STAT6 and STAT3 expression and upregulating FOXA2 expression. These findings provide a novel approach to manage mucus hypersecretion in asthma using DDW.

Two new alkaloids isolated from Dictamnus dasycarpus Turcz.

Two new quinoline alkaloids (1-2) together with twenty-two known alkaloids (3-24) were isolated and identified from Dictamnus dasycarpus Turcz. Compounds 6-7, 9, 11, 15-16, 19 and 24 were isolated from D. dasycarpus for the first time. The structures of all compounds were characterised by spectroscopic methods (1D, 2D NMR and HRESIMS). The anti-proliferative activity was mediated by the arrest of three human cancer cell lines (SW982, HepG2 and A549) of all the compounds that were evaluated by CCK-8 assay.

Exploring the Mechanism of Hepatotoxicity Induced by Dictamnus dasycarpus Based on Network Pharmacology, Molecular Docking and Experimental Pharmacology.

The root bark of Dictamnus dasycarpus Turcz is a traditional Chinese medicine, Dictamni Cortex (DC), which is mainly used in the clinical treatment of skin inflammation, eczema, rubella, rheumatism, and gynecological inflammation. Unexpectedly, there are some cases of liver injury after the administration of DC. However, the mechanism of hepatotoxicity remains ambiguous. The aim of this study was to explore the mechanism and substance bases of DC hepatotoxicity based on network pharmacology and molecular docking, verified through pharmacological experiments. Partial prototype components and metabolites in vivo of quinoline alkaloids from DC were selected as candidate compounds, whose targets were collected from databases. Network pharmacology was applied to study the potential hepatotoxic mechanism after correlating the targets of candidate compounds with the targets of hepatotoxicity. Molecular docking was simulated to uncover the molecular mechanism. Furthermore, the hepatotoxicity of the extract and its constituents from DC was evaluated in vivo and in vitro. We constructed the "potential toxic components-toxic target-toxic pathway" network. Our results showed that the targets of DC included CYP1A2 and GSR, participating in heterologous steroid metabolism, REDOX metabolism, drug metabolism, heterocyclic metabolic processes, the synthesis of steroid hormone, cytochrome P450 metabolism, chemical carcinogens and bile secretion pathways. In vitro and in vivo experiments displayed that DC could result in a decrease in GSH-Px and oxidative stress, simultaneously inhibiting the expression of CYP1A2 and inducing hepatotoxicity. These results further indicated the mechanism of hepatotoxicity induced by Dictamnus dasycarpus, providing a basic theory to explore and prevent hepatotoxicity in the clinical usage of Dictamnus dasycarpus.

Developmental Programmed Cell Death Involved in Ontogenesis of Dictamnus dasycarpus Capitate Glandular Hairs.

Plant glandular trichomes have received much attention due to their commercial and biological value. Recent studies have focused on the development of various glands in plants, suggesting that programmed cell death (PCD) may play an important role during the development of plant secretory structures. However, the development processes and cytological characteristics in different types of plant secretory structures differed significantly. This study aims to provide new data on the developmental PCD of the capitate glandular hairs in Dictamnus dasycarpus. Light, scanning, immunofluorescence labeling, and transmission electron microscopy were used to determine the different developmental processes of the capitate glandular hairs from a cytological perspective. Morphologically, the capitate glandular hair originates from one initial epidermal cell and differentiates into a multicellular trichome characterized by two basal cells, two lines of stalk cells, and a multicellular head. It is also histochemically detected by essential oils. TUNEL-positive reactions identified nuclei with diffused fluorescence or an irregular figure by DAPI, and Evans blue staining showed that the head and stalk cells lost their viability. Ultrastructural evidence revealed the developmental process by two possible modes of PCD. Non-autolytic PCD was characterized by buckling cell walls and degenerated nuclei, mitochondria, plastids, multivesicular body (MVB), and end-expanded endoplasmic reticulum in the condensed cytoplasm, which were mainly observed in the head cells. The MVB was detected in the degraded vacuole, a degraded nucleus with condensed chromatin and diffused membrane, and eventual loss of the vacuole membrane integrity exhibited typical evidence of vacuole-mediated autolytic PCD in the stalk cells. Furthermore, protoplasm degeneration coupled with dark oil droplets and numerous micro-dark osmiophilic substances was observed during late stages. The secretion mode of essential oils is also described in this paper.

Undescribed protolimonoids from the root bark of Dictamnus dasycarpus Turcz.

Nine undescribed protolimonoids, including two apotirucallane and seven tirucallane triterpenoids, as well as five known compounds, were isolated from the root bark of Dictamnus dasycarpus Turcz. Their structures were elucidated by extensive spectroscopic analysis. Compounds 4-8, with an undescribed 22,25-epoxytirucallene part, were established their absolute configuration by single-crystal X-ray diffraction of 4. Such compounds might provide evidence for the degradation of protolimonoids to limonoids, bridging an oxidative cleavage biogenetic pathway between these structurally diverse triterpenoids. None of them showed anti-inflammatory, hepatoprotective, or monoamine oxidase B inhibitory activity.

The complete chloroplast genome of Dictamnus dasycarpus Turcz. (Rutaceae).

Dictamnus dasycarpus Turcz. 1842 is a medicinal plant of China. Its dry root bark is called BAIXIANPI, which is a common traditional Chinese medicine. Here, we report the complete chloroplast genome of D. dasycarpus. The length of the genome, large single-copy (LSC), small single-copy (SSC), inverted repeat (IR), and GC content was 157,056 bp, 84,497 bp, 18,487 bp, 27,036 bp, and 38.5%, respectively. A total of 132 genes were annotated, including 87 protein coding, eight rRNA, and 37 tRNA genes. Interestingly, 15 genes contained single intron while two others contained two introns. The phylogenetic tree showed the two D. dasycarpus (D. albus) clustered in a clade, which was sister to clade formed by the species of Melicope, Tetradium, Phellodendron, and Zanthoxylum.

Antimicrobial alkaloids from the root bark of Dictamnus dasycarpus.

Two new furoquinoline alkaloids, named 1'-oxo-isoplatydesmine (1) and demethoxyacrophylline (2), as well as 11 known alkaloids (3-13) were isolated from the root bark of Dictamnus dasycarpus Turcz. The structures of 1 and 2 were established by detailed spectroscopic elucidation, such as 1 D & 2 D NMR and HRMS, etc. The unexpected autoracemization of 1 was discussed based on the stereochemistry of reported dihydrofuroquinolines. Compounds 3-5 exhibited moderate inhibitory activities against Bacillus subtilis, Candida albicans, and Pseudomonas aeruginosa with MICs 32-64 µg/ml, revealing the active principles of D. dasycarpus for treating skin diseases in its traditional usage.

The traditional uses, phytochemistry, pharmacology and toxicology of Dictamnus dasycarpus: a review.

OBJECTIVES: Dictamnus dasycarpus is a plant of the Rutaceae family, and its root bark is the main part used as a medicine, named 'Bai-Xian-Pi'. It is used to clear away heat, remove dampness, and dispel wind and also used for detoxification. The purpose of this review is to provide a systematic review about the botany, traditional uses, phytochemistry, pharmacology and toxicology of this plant. KEY FINDINGS: More than 200 compounds have been isolated and identified from the plant, including alkaloids and their glycosides, terpenoids and their derivatives and phenylpropanoids. Extensive pharmacological activities of the extracts or compounds of D. dasycarpus in vivo and in vitro were mainly confirmed, including anti-inflammatory activity, protecting cardiovascular activity, improving liver injury and anti-cancer activity. SUMMARY: In this paper, the botany, traditional uses, phytochemistry and pharmacology of D. dasycarpus were reviewed. In the future, D. dasycarpus needs further study, such as paying more attention to quality control and the utilization on agriculture. In addition, discussing the medicinal components of decoction as well as the toxicity will also contribute to the progress of clinical trial studies.

Identification and characterization of quinoline alkaloids from the root bark of Dictamnus dasycarpus and their metabolites in rat plasma, urine and feces by UPLC/Qtrap-MS and UPLC/Q-TOF-MS.

Quinoline alkaloids are the main bioactive and potentially toxic constituents in the root bark of Dictamnus dasycarpus Turcz. (BXP), a widely used traditional Chinese medicine for the treatment of skin inflammation, eczema and rubella. However, the comprehensive analysis of the chemical components and metabolites of quinoline alkaloids remain unclear. In this study, an integrated strategy by combining UPLC/Q-TOF-MS and UPLC/Qtrap-MS was established to comprehensively profile the quinoline alkaloids from BXP and their metabolites in rat plasma, urine and feces. Q-TOF-MS (MSE mode), Qtrap-MS (EMS, MIM, pMRM and NL mode) were performed for acquiring more precursor ions and clearer precursor product ions. A step-by-step manner based on the diagnostic fragment ions (DFIs), in-house database, ClogP value and dipole moment (µ) was proposed to overcome the complexities due to the similar fragmentation behaviors of the quinoline alkaloids. As a result, a total of 73 quinoline alkaloids were unambiguously or tentatively identified. Among them, 4 furoquinolines, 10 dihydrofuroquinolines, 2 pyranoquinolinones, 4 dihydropyranoquinolinones and 9 quinol-2-ones were characterized in BXP for the first time. Moreover, a total of 98 BXP-related constituents (including 57 prototypes and 41 metabolites) were detected in rat plasma, urine and feces. The metabolic pathways included phase I reactions (O-demethylation, hydroxylation and 2,3-olefinic epoxidation) and phase II reactions (conjugation with glucuronide, sulfate and N-acetylcysteine). In conclusion, the integrated strategy with the proposed stepwise manner is suitable for rapid identifying and characterizing more extensive quinoline alkaloids of BXP in vitro and in vivo. Moreover, the results will be helpful for revealing the pharmacological effective substances or toxic substances of BXP and provide a solid basis for further research.

Rapid identification, isolation, and evaluation on anti-neuroinflammatory activity of limonoids derivatives from the root bark of Dictamnus dasycarpus.

A total of 49 limonoids derivatives were rapidly identified by UNIFI software and three new limonoids derivatives, named dasycarinone (1, DAS), isodictamdiol C (2) and dasycarinone A (3), along with nineteen known compounds, were isolated from the root bark of Dictamnus dasycarpus, named as "Baixianpi" in Chinese. Their structures were elucidated on the basis of spectroscopic data (UV, IR, HR-ESI-MS, NMR, CD spectra and OR). All the compounds were tested for anti-inflammatory activities by suppressing the nitric oxide (NO) production in lipopolysaccharide (LPS) induced BV-2 cells. DAS exhibited a strong anti-inflammatory activity with IC50 value of 1.8 µM. Nuclear Factor kappa B (NF-κB) luciferase assay and enzyme-linked immune sorbent assay indicated that DAS can suppress the release of inflammatory cytokines such as Tumor Necrosis Factor α (TNF-α), interleukin 6 (IL-6) via inactivating NF-κB signaling pathways. Moreover, we found that anti-inflammatory activities of obacunone-class are better than those of limonin-class by analyzing structure-activity relationship. Our results suggested that obacunone derivatives play an important role on anti-inflammation of Baixianpi. As a representative among them, DAS showed a strong anti-inflammatory activity via suppressing NF-κB signaling pathways.

[Clinical cases and experimental evaluation of liver injury related to anti-psoriasis Keyin Pills].

Keyin Pills is a kind of traditional Chinese medicine for the treatment of psoriasis, but it has been reported that it can cause serious liver injury. In this paper, we used the integrated evidence chain method to retrieve and reevaluate the adverse drug reaction database, CNKI literature and cases of liver injury relating to Keyin Pills in specialist hepatology hospitals. We screened out 23 cases with the causal relationship of the possible grade and above. Among them, 11 cases showed the positive causal relationship only with Keyin Pills, accounting for 47.83%, suggesting that there was objective liver injury caused by Keyin Pills. The incubation period of liver injury caused by Keyin Pills is 1-90 days, and the cumulative dosage span is 20-1 800 g. There were obvious individual diffe-rences. There was no relationship between liver injury as well as dose and course of treatment, suggesting that Keyin Pills could induce immune idiosyncratic liver injury. Furthermore, based on the liver injury model induced by immunological stress, it was confirmed that Keyin Pills could induce acute liver injury in a dose-dependent manner in rats with immunological stress. The toxic dose(14 g·kg~(-1)) of a single dose was 6.7 times of the clinical equivalent dose, and had no significant effect on the biochemical index of liver function and histopathology in normal rats. Decomposition experiments showed that Dictamnus dasycarpus in Keyin Pills is the main medicinal flavor that causes special liver injury, and the other three medicines had neither liver injury nor compatibility attenuation effect. The results suggest that clinical medication shall pay attention to the risk of liver injury caused by Keyin Pills in patients with immunological stress.

Anti-inflammatory quinoline alkaloids from the root bark of Dictamnus dasycarpus.

Six undescribed quinoline alkaloids, named dasycarines A-E, and 18 known ones were isolated from the root bark of Dictamnus dasycarpus. All the structures were elucidated on the basis of comprehensive analysis of UV, IR, NMR, and HRMS spectroscopic data, and the absolute configurations were assigned via comparison of the calculated and experimental ECD data. (+)-Dasycarine A (1a) and (-)-Dasycarine A (1b) are a pair of enantiomers of dimeric furoquinoline alkaloid, which are the first dimeric via [2 + 2] cycloaddition of furan. The structure and absolute configuration of (-)-dasycarine A was determined via X-ray crystallography. Additionally, all the isolated compounds were tested for their inhibitory effects on NO production stimulated by LPS in BV-2 microglial cells. Three compounds showed strong inhibition with IC50 values below 5.0 µM; nine compounds exhibited inhibition with IC50 values in the range of 7.8-28.4 µM. Furthermore, we demonstrated that preskimmianine suppressed the levels of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and nuclear factor kappa B (NF-κB) in LPS-induced BV-2 microglial cells.

Three new compounds from Dictamnus dasycarpus and their anti-inflammatory activities.

Three new compounds (1-3), named dasycarine G (1), dasycarether (2), and dasycarester (3), along with seven known compounds (4-10) obtained from the genus Dictamnus for the first time, were isolated from the root bark of Dictamnus dasycarpus. Their structures were elucidated on the basis of spectroscopic data (UV, IR, HR-ESI-MS, 1D and 2D NMR, and CD). In the in vitro assay, compounds 1, 5, 6, 9, and 10 exhibited NO inhibitory effects of LPS-induced BV-2 cells with IC50 values in the range of 10.4 µM to 27.2 µM.

Purification, Characterization and Anti-psoriasis Effects of Polysaccharides from Dictamnus dasycarpus / 中国实验方剂学杂志

Objective::To extract crude polysaccharides from Dictamnus dasycarpus (DDP) for separation and purification, and study its anti-psoriasis effect. Method::After interception of DDP with a molecular weight of less than 10 kDa (DDP-UF) using membrane separation technology, four components (DDP-UF-1, DDP-UF-2, DDP-UF-3, DDP-UF-4) were isolated and purified by DEAE-52 cellulose column. Then, the physical and chemical properties and structural characteristics of DDP-UF-1-4 samples were determined by infrared spectroscopy, high performance gel permeability chromatography (HPGPC), high performance liquid chromatography (HPLC) and scanning electron microscope (SEM). Imiquimod cream was selected to induce mouse models of psoriasis, diethylstilbestrol was used to induce vaginal epithelial cell proliferation in female mice, interleulein-17(IL-17) and IL-23 contents of serum in each mouse group were detected by enzyme-linked immunosorbent assay (ELISA), and skin tissues of the mouse back and vaginal epithelial cells had mitotic index changes by hematoxylin-eosin staining (HE). Result::DDP-UF-1-4 all exhibited the characteristic absorption peaks of polysaccharide, and the molecular weights of DDP-UF-1-4 were 10 948, 40 148, 32 222 and 19 943 Da, respectively. The monosaccharide compositions and mole ratios of DDP-UF-1-4 were mannose-glucose-galactose(32.45∶11.35∶8.69), mannose-rhamnose-glucuronic acid-glucose-xylose(25.68∶23.44∶21.62∶18.86∶3.68), mannose-rhamnose-glucuronic acid-galacturonic acid-xylose-galactose(18.68∶4.61∶3.89∶1.65∶5.36∶6.21), glucuronic acid-galacturonic acid-glucose-xylose-galactose(11.63∶15.26∶5.32∶2.08∶3.46), respectively. SEM showed that the morphological structures of DDP-UF-1-4 were flaky or spongy. The drug groups of DDP-UF-1 and DDP-UF-3 improved the skin condition of the psoriasis mice back, inhibited mitosis of female vaginal epithelial cells and significantly reduced the contents of IL-17 and IL-23 in serum (P<0.05, P<0.01). Conclusion::Both DDP-UF-1 and DDP-UF-3 have good anti-psoriasis effects, which may be related to the inhibition of IL-23/IL-17 signaling pathway.

Anti-inflammatory effects of a methanol extract of Dictamnus dasycarpus Turcz. root bark on imiquimod-induced psoriasis.

BACKGROUND: The root bark of Dictamnus dasycarpus Turcz. has been successfully used for the treatment of inflammatory skin conditions such as eczema and pruritus. However, the anti-psoriatic effect of this plant has not until now been investigated. METHODS: The aim of this project was to investigate whether a methanol extract of Dictamnus dasycarpus Turcz. root bark (MEDD) can be used as a therapeutic agent for psoriasis in C57BL/6 mice model of imiquimod (IMQ)-induced psoriasis. IMQ and MEDD was applied to mouse skin continuously for 7 days. The skin phenotype and the levels of inflammatory cytokines, such as interferon (IFN)-γ and interleukin (IL)-17, were analyzed. The immune cell population was determined by flow cytometry, and STAT1 and 3 protein levels were measured. RESULTS: An alleviation of scaly skin phenotype, immune cell infiltration in the dermis, and epidermal hyperplasia was observed after daily MEDD treatment in the lesion-affected area. It was also found that MEDD reduced IL-17 cytokine levels decreased by 44.37% (p < 0.05), the number of IL-17-producing Th17 cells and γδT cells, and the size of the Th1 population secreting IFN-γ decreased by 45.98, 62.21, and 44.42%, respectively (p < 0.05), compared with the vehicle control group. STAT3 signals, associated with IL-17 are also reduced by MEDD. CONCLUSIONS: An anti-psoriatic effect of MEDD was observed, as determined by decreased skin inflammation, reduced number of inflammatory cytokines, and a smaller population of inflammatory cells. These results contribute to the validation of the use of MEDD in the treatment of psoriasis.

Study on Sulfated Modification and Anti-psoriasis Activity of Polysaccharide from Dictamnus dasycarpus / 中国药房

OBJECTIVE： To conduct sulfated modification of polysaccharide from Dictamnus dasycarpus （DDP-Ⅲ）， and to compare structure characteristics and anti-psoriasis activity of DDP-Ⅲ before and after sulfated modification. METHODS： DDP-Ⅲ was separated and purified with DEAE-52 anion exchange cellulose column and Sephadex G-100 column. After derived with 1-phenyl-3-methyl-5-pyrazolone， HPLC was used to determine the composition of its monosaccharide. SDDP-Ⅲ was synthesized using esterification reagent （anhydrous pyridine+chlorosulfonic acid） to modify DDP-Ⅲ. The degree of sulfate substitution was determined by barium chloride-gelatin turbidimetric method. The structures were compared by IR， Raman spectrum and SEM before and after modification. The male ICR mice were randomly divided into normal group， model group， positive group （tripterygium glycosides， 20 mg/kg） and DDP-Ⅲ/SDDP-Ⅲ low-dose， medium-dose and high-dose groups （56， 112， 224 mg/kg）. Except that normal group was given vaseline for external use， and other groups were given Imiquimod cream for external use to induce psoriasis model. At the same time， administration groups were given relevant medicine intragastrically 0.4 mL， and both normal group and model group were given constant volume of water intragastrically， once a day， for consecutive 14 d. Two hours after last medication， the serum contents of IL-17 and IL-23 were determined by ELISA. The skin scales near the tail were observed by HE staining， and the number of scales with granular layer was recorded. RESULTS： DDP-Ⅲ was composed of mannose， rhamnose， glucuronic acid， galacturonic acid and glucose. The degree of sulfate substitution was 0.65 for SDDP-Ⅲ. IR and Raman spectrum showed that the characteristic absorption peaks of sulfate radical group appeared near 1 255 cm－1 and 823 cm－1， 1 240 cm－1 and 815 cm－1 for SDDP-Ⅲ， except for same characteristic absorption peak as DDP-Ⅲ. SEM analysis showed that DDP-Ⅲ was flaky， smooth and tightly arranged； SDDP-Ⅲ was massive or granular with porous structure and loose arrangement. Animal experiment showed that compared with normal group， the epidermis of skin lesion was significantly thickened and the granular layer was significantly reduced； serum contents of IL-17 and IL-23 were increased significantly， while the number of scales with granular layer was decreased significantly （P＜0.05 or P＜0.01）. Compared with model group， above symptoms of administration groups were improved to different extent， and serum contents of IL-17 and IL-23 in positive group， DDP-Ⅲ high-dose groups， SDDP-Ⅲ medium-dose and high-dose groups were decreased significantly； the number of scales with granular layer was increased significantly， and above indexes of SDDP-Ⅲ medium-dose and high-dose groups were significantly better than corresponding DDP-Ⅲ group （P＜0.05 or P＜0.01）. CONCLUSIONS： DDP-Ⅲ contains five monosaccharide components such as mannose， etc. Both DDP-Ⅲ and SDDP-Ⅲ possess anti- psoriasis effects， and SDDP-Ⅲ exhibits stronger anti-psoriasis effect than DDP-Ⅲ. Its mechanism may be associated with inhibiting IL-23/IL-17 signaling pathway.

Chemical constituents extracted from Dictamnus dasycarpus and their α-glucosidase inhibitory activity / 中国药科大学学报

@#Five compounds were isolated from the petroleum ether extract of Dictamnus dasycarpus using various chromatographic techniques, such as column chromatography over silica gel and Sephadex LH-20. Their structures were elucidated by spectroscopic data(IR, MS, NMR), which were identified as docosanol(1), ethyl 2, 2-dibenzhydryl-3, 3-di-phenylpropionate(2), limonin(3), obacunone(4)and dictamnine(5). Compound 2 was a new compound and compound 1 was isolated from this plant for the first time. PNPG method was used to determine α-glucosidase inhibitory activity of these compounds. The results indicated that compounds 3- 5 possessed stronger inhibitory activities than the positive control of acarbose, which provided a theoretical basis for further development and utilization of Dictamnus dasycarpus.

[Mass spectrometry guided strategy based on feature fragment ions for guided-separation on quinoline alkaloids from root barks of Dictamnus dasycarpus].

The root bark of Dictamnus dasycarpus is one of common traditional Chinese medicines (TCMs). Quinoline alkaloids are one of the main active substances in this TCM and possess many biological activities including anti-titumor, anti-inflammation, anti-bacteria, anti-oxidation, and anti-platelet aggregation activities. In this study, eight quinoline alkaloids 1-8 were firstly separated from the root barks of D. dasycarpus. It was difficult to isolate more quinoline alkaloids from the remaining fraction 8 in D. dasycarpus by this conventional chemical separation, so the target analysis method combined LC-MS guided-separation of quinoline alkaloids from fraction 8 was established. MS/MS fragmentation patterns of eight quinoline alkaloids reference standard compounds 1-8 were studied by ultra-performance liquid chromatography-electrospary ionization-mass spectrometry (UPLC-ESI-MS/MS). Based on the feature fragment ion m/z 200, the parent ion scan mode was established for the target analysis of quinoline alkaloids in fraction 8. Finally, 8-methoxyflindersine (9) and N-metilatanina (10) were discovered and isolated quickly from fraction 8 guided by LC-MS, and their structures were identified by NMR and MS. Among them, compound 10 was isolated from the genus Dictamnus for the first time. These results indicated that this method is not only quick and sensitive for analyzing the quinoline alkaloids, but also to effectively guided-separate this kind of alkaloids in the root barks of D. dasycarpus.

Eudesmane-Type Sesquiterpene Glycosides from Dictamnus dasycarpus Turcz.

Eudesmane-type sesquiterpenes have been reported to exhibit varieties of biological activities. During the process of investigating this kind of natural product from the root bark of Dictamnus dasycarpus Turcz., 13 eudesmane-type sesquiterpene glycosides including six new isolates, named as dictameudesmnosides A1 (1), A2 (2), B (3), C (4), D (5), and E (6), together with seven known ones (7-13), were obtained. Herein, their structures were determined by the analysis of physical data, spectroscopic analysis, and chemical methods. The existence of α-configuration glucose units in their structures (1-5, 8) is not very common in natural glycosidic components. Meanwhile, compounds 3-5, 7, and 9-13 displayed TG accumulation inhibitory effects on HepG2 cells.