A practical application of front-face synchronous fluorescence spectroscopy to rapid, simultaneous and non-destructive determination of piperine and multiple adulterants in ground black and white pepper (Piper nigrum L.).

Based on the distinct fluorescence of piperine and tryptophan, and their different profiles in pepper and several possible adulterants, front-face synchronous fluorescence spectroscopy (FFSFS) was applied for the fast and non-invasive authentication of ground black pepper adulterated with papaya seed powder and buckwheat flour, and ground white pepper adulterated with whole wheat and maize flours. For either single adulterant or dual adulterants in the range of 10-40% w/w, prediction models were constructed based on the combination of unfolded total synchronous fluorescence spectra and partial least square (PLS) regression, and were validated by both five-fold cross-validation and external validation. The built PLS2 models produced suitable results, with most of the determination coefficients of prediction (Rp2) greater than 0.8, the root mean square error of prediction (RMSEP) < 5% and residual predictive deviation (RPD) greater than 2. The limits of detection (LODs) were 11.1, 5.5, 10.6 and 12.0% for papaya seed powder, buckwheat, whole wheat and maize flours, respectively. Most relative prediction errors for simulated blind samples were within ± 30%. Besides, piperine in ground black and white pepper was also determined with acceptable PLS results.

Rapid, simultaneous and non-destructive determination of multiple adulterants in Panax notoginseng powder by front-face total synchronous fluorescence spectroscopy.

The authentication of traditional herbal medicines in powder form is of great significance, as they are always of high values but vulnerable to adulteration. Based on the distinct fluorescence of protein tryptophan, phenolic acids and flavonoids, front-face synchronous fluorescence spectroscopy (FFSFS) was applied for the fast and non-invasive authentication of Panax notoginseng powder (PP) adulterated with the powder of rhizoma curcumae (CP), maize flour (MF) and whole wheat flour (WF). For either single or multiple adulterants in the range of 5-40% w/w, prediction models were built based on the combination of unfolded total synchronous fluorescence spectra and partial least square (PLS) regression, and were validated by both five-fold cross-validation and external validation. The constructed PLS2 models simultaneously predicted the contents of multiple adulterants in PP and gave suitable results, with most of the determination coefficients of prediction (Rp2) >0.9, the root mean square error of prediction (RMSEP) no >4% and residual predictive deviation (RPD) >2. The limits of detections (LODs) were 12.0, 9.1 and 7.6% for CP, MF and WF, respectively. All the relative prediction errors for simulated blind samples were between -22% and + 23%. FFSFS offers a novel alternative to the authentication of powdered herbal plants.

Pimarane, abietane, and labdane diterpenoids from Euphorbia pekinensis Rupr. and their anti-tumor activities.

Chemical investigation of the roots of Euphorbia pekinensis Rupr. led to the isolation of five undescribed labdane diterpenoids "(4S, 5S, 9R, 10S, 13R)-18-O-galloyl-labda-8(17), 14(15)-dien-13-ol; (4S, 5S, 9R, 10S, 13R)-13-hydroxy-labda-8(17), 14(15)-dien-18-one; (4S, 5S, 9R, 10S, 13R)-18-O-acetyl-labda-8(17), 14(15)-dien-13-ol; (4S, 5S, 9R, 10S)-labda-8(17), 13(16), 14(15)-trien-18-ol; (5R, 6R, 9R, 10S, 13R)-labda-8(17), 14(15)-dien-6,13-diol", two undescribed pimarane diterpenoids "(2R, 5S, 9R, 10S, 12R, 13R)-2,12-dihydroxy-isopimara-7,15-dien-3-one; (5S, 9R, 10S, 12R, 13R)-2, 12-dihydroxy-isopimara-1, 7, 15-trien-3-one)", together with nine known diterpenoids, including three pimarane-type "(3ß,11α,13α)-3,11-dihydroxypimara-7,15-diene-2,12-dione; (11R, 12S)-2,11,12-trihydroxy-ent-isopimara-1,7,15-trien-3-one; isopimara-7,15-dien-3ß-ol)", five abietane-type "helioscopinolide A-C; helioscopinolide E; helioscopinolide I″, and one lathyrane-type "jolkinol B". The structures of these compounds were elucidated by analysis of HRESIMS, 1D NMR, 2D NMR, and X-ray diffraction. These sixteen compounds were evaluated for cytotoxic activity in vitro against three human cancer cell lines, U-937, LOVO, and K-562. Jolkinol B exhibited IC50 of 3.60 µM and 8.44 µM against U-937 and LOVO cell lines, (4S, 5S, 9R, 10S, 13R)-18-O-galloyl-labda-8(17), 14(15)-dien-13-ol displayed IC50 of 5.92 µM against U-937 cell lines, isopimara-7,15-dien-3ß-ol showed IC50 of 0.87 µM against K-562 cell lines.

Systematic characterization of the metabolites of paeonol in rats using ultra performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry with an integrative strategy.

Paeonol, an active constituent in the root bark of Paeonia suffruticosa Andrews, is used to treat inflammation, headache and other diseases in clinic. Though the data on pharmacological researches of paeonol abounds, its metabolic profile is not so clear. It is essential to systematically characterize the in vivo metabolites in order to better understand its mechanism of action. In this study, ultra performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q/TOF-MS) with an integrative strategy was developed for analysis of paeonol metabolites. As a result, based on seven reference substances isolated or synthesized, twenty-five metabolites were detected and identified in urine, feces, bile and plasma of rats after oral administration of paeonol. To the best of our knowledge, 14 of these metabolites have not been reported previously. In addition, the dominating metabolic fates were oxidation, demethylation, hydrogenation, glucuronic acid and sulfate conjugations, and hydrogenation of paeonol was reported for the first time. This research provides scientific and reliable support for full understanding of the metabolic profiling of paeonol.

[Study on anti-tumor chemical constituents from pericarps of Juglans mandshurica].

OBJECTIVE: To study the anti-tumor chemical components of the pericarps of Juglans mandshurica. METHODS: The chemical constituents were isolated and purified by AB-8 macroporous adsorption resin, silica gel, Sephadex LH-20 columns and recrystallization. The structures were elucidated on the basis of physicochemical properties and NMR spectral data analysis. RESULTS: From the pericarps of Juglans mandshurica, twelve compounds were separated and identified as 3-methoxy juglone(1), 3-ethoxy juglone(2), 1,8-di-hydroxy anthraquinone (3), juglone (4), 2α, 3α, 19α-trihydroxy ursolic acid (5), 1α, 3ß-dihydroxy-olean-18-ene (6), methyl gallate (7), pterocarine(8), quercetin(9), kaempferol(10), daucosterol(11), and ß-sitosterol(12). CONCLUSION: Compounds 1 - 3 and 6 are isolated from the pericarps of Juglans mandshurica for the first time. Compounds 5 and 7 are isolated from Juglans genus for the first time.

An improved rolled strip pulse forming line.

The rolled strip pulse forming line (RSPFL) has advantages of compactness, portability, and long pulse achievability which could well meet the requirements of industrial application of the pulse power technology. In this paper, an improved RSPFL with an additional insulator between the grounded conductors is investigated numerically and experimentally. Results demonstrate that the jitter on the flat-top of the output voltage waveform is reduced to 3.8% due to the improved structure. Theoretical analysis shows that the electromagnetic coupling between the conductors of the RSPFL strongly influences the output voltage waveform. Therefore, the new structure was designed to minimize the detrimental effect of the electromagnetic coupling. Simulation results show that the electromagnetic coupling can be efficiently reduced in the improved RSPFL. Experimental results illustrate that the improved RSPFL, with dimensions and weight of Φ 290 × 250 mm and 16 kg, when used as a simple pulse forming line, could generate a well shaped quasi-square pulse with output power of hundreds of MW and pulse duration of 250 ns. Importantly, the improved RSPFL was successfully used as a Blumlein pulse forming line, and a 10.8 kV, 260 ns quasi-square pulse was obtained on a 2 Ω dummy load. Experiments show reasonable agreement with numerical analysis.

Anti-inflammatory secondary metabolites from the leaves of Rosa laevigata.

Bioassay-guided fractionation of a n-BuOH-soluble extract of the leaves of Rosa laevigata led to the isolation of three new 19-oxo-18,19-seco-ur-sane-type triterpenoids, laevigins A-C (1-3), a new oleanane-type triterpenoid saponin, laevigin D (4), a new geranylmethylbenzoate, 5-[(2″E,6″S)-6″,7″-dihydroxy-3″,7″-dimethyl-2″-octen-1″-yl]-2-(ß-D-glucopyranosyloxy)-methyl benzoate (5), together with 9 known compounds (6-14). Their structures were elucidated by spectroscopic and chemical methods. Compounds 4, 9, 11, and 12 significantly suppressed the LPS-stimulated NF-κB transcriptional activity and the release of TNFα, IL-1ß, IL-6, and IL-10 in mouse RAW 264.7 macrophages. The compound 12 exhibited moderate inhibition on NF-κB transcriptional activity with an IC50 value of 23.21 µM. The IC50 values of compound 12 were measured as 14.32, 8.53, 8.04, and 10.38 µM for the inhibitory activity on TNFα-release, IL-1ß-release, IL-6-release, and IL-10-release, respectively.