A simple method to discriminate Guangchenpi and Chenpi by high-performance thin-layer chromatography and high-performance liquid chromatography based on analysis of dimethyl anthranilate.

Citri Reticulatae Pericarpium (CRP), the dried pericarp of Citrus reticulata Blanco, can be divided into "Guangchenpi" (GCP, the dried pericarps derived from Citrus reticulata 'Chachi') and "Chenpi" (CP, the dried pericarps derived from other cultivars of Citrus reticulata Blanco). To discriminate between GCP and CP, a simple and reliable high-performance thin-layer chromatography (HPTLC) method was firstly developed to analyze the volatile compound dimethyl anthranilate, and a high-performance liquid chromatography (HPLC) method was established to simultaneously quantify dimethyl anthranilate and three predominant flavonoids (hesperidin, nobiletin and tangeretin) in CRP samples. Both the HPTLC analysis and HPLC-orthogonal partial least squares discrimination analysis (OPLS-DA) indicated that GCP can be effectively distinguished from CP based on analysis of dimethyl anthranilate. Our results indicated that dimethyl anthranilate can be used as a marker compound for discrimination of GCP and CP. This work provided a convenient approach which might be applied for quality evaluation of CRP.

Cultivar differentiation of Citri Reticulatae Pericarpium by a combination of hierarchical three-step filtering metabolomics analysis, DNA barcoding and electronic nose.

The traditional Chinese medicine Citri Reticulatae Pericarpium (CRP) was mainly originated from the dried pericarp of Citrus reticulata 'Chachi' (Crc), Citrus reticulata 'Dahongpao' (Crd), Citrus reticulata 'Unshiu' (Cru) and Citrus reticulata 'Tangerina' (Crt) in China. Since these four cultivars have great similarities in morphology, reliable methods to differentiate CRP cultivars have rarely been reported. To discriminate the differences of these CRP cultivars, herein an efficient and reliable method by combining metabolomics, DNA barcoding and electronic nose was first established. The hierarchical three-step filtering metabolomics analysis based on liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) indicated that 9 species-specific chemical markers including 6 flavanone glycosides and 3 polymethoxyflavones could be considered as marker metabolites for discrimination of the geoherb Crc from other cultivars. A total of 19 single nucleotide polymorphism (SNP) sites were found in nuclear internal transcribed spacer 2 (ITS2) of CRP, and three stable SNP sites (33, 128 and 174) in the ITS2 region can distinguish the four CRP cultivars. The electronic nose coupled with chemometrics could also be used to effectively distinguish Crc from other CRP cultivars. Therefore, our results indicated that the integrated method will be an effective strategy for discrimination of similar herbal medicines.

Evaluation of anti-lipase activity and bioactive flavonoids in the Citri Reticulatae Pericarpium from different harvest time.

BACKGROUND: Inhibition of pancreatic lipase is an attractive approach to the treatment of obesity and other metabolic disorders. Naturally occurring phytochemicals are promising sources of lipase inhibitors. PURPOSE: In the present study, the anti-lipase activity of Citri Reticulatae Pericarpium (CRP) extracts was firstly evaluated in vitro. Moreover, the dynamic alteration of bioactive flavonoids in CRP collected at different time and its correlation with anti-lipase activities was investigated. STUDY DESIGN/METHODS: Quantitative analysis of multi-components by a single-marker (QAMS) method was developed and validated for simultaneous determination of six flavonoids including narirutin, hesperidin, didymin, nobiletin, 3,5,6,7,8,3',4'-heptamethoxyflavone and tangeretin. Anti-lipase activity evaluation and docking studies of the flavonoids was also carried out to screen out the candidate lipase inhibitors. RESULTS: The QAMS method validation results exhibited that the developed method had desirable specificity, linearity, precision and accuracy. CRP collected in early months contained higher concentrations of bioactive flavonoids, and exhibited more potent anti-lipase activity. CONCLUSION: Harvest timing had a significant impact on the amounts of bioactive flavonoids and the anti-lipase activities of CRP extracts. The contents of total flavonoids were positively correlated with the anti-lipase activities of CRP, and polymethoxyflavones played a significant role in the hypolipidemic effect of CRP. Nobiletin might be the most potential lipase inhibitor in CRP.

Qualitative and quantitative analysis of chemical constituents in Ardisiae Japonicae Herba.

Ardisiae Japonicae Herba is a well-known traditional Chinese medicine for the treatment of bronchitis conjunctivitis, pneumonia, and trauma. In this work, a high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry method was first established for the separation and structural identification of the chemical constituents in Ardisiae Japonicae Herba. A total of 15 compounds including coumarins, flavonoid glycosides, and catechins were identified or tentatively characterized based on their chromatographic behaviors and mass spectral fragmentation and by comparisons with the reference standards. Furthermore, a simple high-performance liquid chromatography with diode array detection method was developed for the simultaneous determination of five major constituents. Results obtained from method validation, including linearity, precision, repeatability, stability, and recovery, showed that the established method was reliable and accurate. Bergenin and quercitrin were found to be the most abundant constituents and could be served as chemical markers for quality control of Ardisiae Japonicae Herba.

A new compound, methylbergenin along with eight known compounds with cytotoxicity and anti-inflammatory activity from Ardisia japonica.

A new compound, methylbergenin (1), was isolated from the whole plants of Ardisia japonica (Thunb.) Bl. (Myrsinaceae), along with eight known compounds: demethoxybergenin (2), bergenin (3), afzelin (4), quercitrin (5), bauerenol (6), bauerenone (7), α-spinasterol (8) and chondrillasterone (9). Compounds 1, 7 and 9 were isolated from A. japonica for the first time. The structure of compound 1 was determined on the basis of NMR (1D and 2D) and mass spectroscopic analysis. The absolute configuration of 1 was assessed by single-crystal X-ray diffraction. Compounds 1, 4, 5, 7 and 9 showed potential inhibitory effects against nitric oxide production in LPS stimulated RAW 264.7 murine macrophages. In addition, Compounds 7 and 9 exhibited cytotoxicity against A549 and HepG-2 cells.

Novel naphtho[2,1-d]oxazole-4,5-diones as NQO1 substrates with improved aqueous solubility: Design, synthesis, and in vivo antitumor evaluation.

A new series of ortho-naphthoquinone analogs of ß-lapachone were designed, synthesized and evaluated. The biological results indicated that most of our compounds were efficient substrates for NQO1. The new scaffold with water-soluble side chain resulted in greater solubility under acidic condition compared to ß-lapachone. Thus avoiding the use of hydroxylpropyl ß-cyclodextrin which would finally cause the rapid drug clearance from the blood and dose-limiting toxicity in the form of hemolytic anemia. The most soluble and promising compound in this series was 2-((4-benzylpiperazin-1-yl)methyl)naphtho[2,1-d]oxazole-4,5-dione (3k), which inhibited cancer cell (NQO1-rich A549 cell line) growth at IC50 values of 4.6±1.0µmol·L(-1). Furthermore, compound 3k had in vivo antitumor activity in an A549 tumor xenografts mouse model comparable to the activity obtained with ß-lapachone. The results indicated that these ortho-naphthoquinones could serve as promising leads for further optimization as novel substrates for NQO1.

Two new triterpenoid glycosides from the leaves of Anthocephalus chinensis.

Nine compounds were isolated from the leaves of Anthocephalus chinensis by column chromatography on silica gel and Sephadex LH-20, and their structures were elucidated by spectroscopic techniques as clethric acid-28-O-ß-d-glucopyranosyl ester (1), mussaendoside T (2), ß-stigmasterol (3), hederagenin (4), ursolic acid (5), clethric acid (6), 3ß,6ß,19α,24-tetrahydroxyurs-12-en-28-oic acid (7), mussaendoside I (8), and cadambine (9). Compounds 1 and 2, and 7 and 8 were isolated from the plants of this genus for the first time, and compounds 1 and 2 were new triterpenoid glycosides.