W C Chuang

National Taiwan Normal University, T’ai-pei, Taipei, Taiwan

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Publications (6)10.63 Total impact

  • W C Chuang · C M Cheng · H C Chang · YP Chen · S J Sheu ·
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    ABSTRACT: A total of 33 commercial samples of Evodiae fructus originated from the rutaceous plants Evodia rutaecarpa (Juss.) Benth. and E. rutaecarpa (Juss.) Benth. var. officinalis (Dode) Huang (= E. officinalis Dode), respectively, were collected from Taiwan's herbal market. The contents of eighteen constituents (including 15 alkaloids, 2 flavonoids and 1 diterpenoid) in these samples were determined by high-performance liquid chromatography within 60 minutes. Analysis results showed that the constituent contents were almost unrelated to the species, but rather closely related to the degrees of maturity of the fruit. Those fruits with open mouths and unsplit ovaries had the highest total contents, fruits with open mouths and split ovaries had lower contents, and fruits with closed mouths had the lowest contents. In terms of the individual constituents, the open-mouth fruits contained higher contents of dehydroevodiamine, evodiamine, evocarpine and rutaecarpine, whereas the closed-mouth fruits had higher contents of dehydroevodiamine, epimedoside C, evocarpine and evodiamine.
    Planta Medica 09/1999; 65(6):567-71. DOI:10.1055/s-1999-14028 · 2.15 Impact Factor
  • Chungnam Lee · C.C. Hsu · S.B. Yai · W.C. Chuang · W.C. Lin ·
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    ABSTRACT: We describe a distributed robust image mosaics system that is robust to outlier and is better in computation efficiency. The system integrates a Web-based user interface, a robust image mosaic, and a distributed computing model. In robust image mosaics, we combine both feature-based and correlation-based approaches for image registration, and then incorporate a skipped mean estimator with Levenberg-Marquardt method for robust nonlinear parameter estimation. The distributed comparing model is used to speed up the computation of the global processing of image mosaics on a network of workstations. Load balancing strategies are proposed to improve the efficiency of parallel computation under uneven load situation. Experimental results show that our system is indeed robust and has significantly speedup in computation
    Pattern Recognition, 1998. Proceedings. Fourteenth International Conference on; 09/1998
  • WC Chuang · DS Young · LK Liu · SJ Sheu ·
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    ABSTRACT: Seven protoberberine alkaloids from Coptidis Rhizoma were separated on a Cosmosil 5C18-MS column (5 mu m, 250x4.6 mm I.D.) using ammonium acetate buffer (isocratic) or ammonium acetate-sodium dodecyl sulfate buffer (gradient) with UV and electrospray ionization mass spectrometric (ESI-MS) detection. Selected-ion monitoring was used to resolve the compounds in an overlapped peak and collision-induced dissociation reaction was used to obtain structural infomation of individual components. By use of this LC-UV-ESI-MS method, these protoberberine alkaloids (berberine, palmatine, coptisine, epiberberine, jatrorrhizine, columbamine and berberastine) in a crude extract of Coptidis Rhizoma can be easily separated and identified within 50 min.
    Journal of Chromatography A 11/1996; 755(1):19-26. · 4.17 Impact Factor
  • Weng‐Chung Lin · Wu‐Chang Chuang · Shuenn-Jyi Sheu ·

    Journal of High Resolution Chromatography 09/1996; 19(9):530 - 533. DOI:10.1002/jhrc.1240190912
  • W C Chuang · W C Lin · S J Sheu · S H Chiou · H C Chang · YP Chen ·
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    ABSTRACT: A total of 37 commercial samples of paeoniae radix (Paeonia lactiflora Pall. = P. albiflora Pall, and P. vitchii Lynch), were collected from Taiwan's herbal market. The contents of eight constituents (gallic acid, oxypaeoniflorin, albiflorin, paeoniflorin, benzoic acid, pentagalloylglucose, paeonol, and benzyoylalbiflorin) in these samples were determined by high-performance liquid chromatography. It was found that constituent contents in P. lactiflora samples were generally higher than in P. vitchii samples except for the albiflorin/oxypaeoniflorin ratio and paeonol content. The major compounds of P. lactiflora were paeoniflorin, albiflorin, and pentagalloylglucose, while those in P. vitchii were paeoniflorin, pentagalloylglucose, and oxypaeoniflorin. The peak-area ratio of albiflorin/oxypaeoniflorin was higher than unity in P. lactiflora samples but lower than unity in P. vitchii, and the ratio can be used to differentiate the origin of Paeonia species clearly. In addition, the former had higher contents in the core wood but the latter in the cortex.
    Planta Medica 09/1996; 62(4):347-51. DOI:10.1055/s-2006-957899 · 2.15 Impact Factor
  • W C Chuang · H K Wu · S J Sheu · S H Chiou · H C Chang · Y P Chen ·
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    ABSTRACT: A total of 37 commercial samples of Ginseng Radix, the origins of which belonged to Panax ginseng C. A. Meyer, P. quinquefolia Linn. (American ginseng), and P. notoginseng Burkill (sanchi-ginseng), respectively, were collected from the Taiwan herbal markets. The contents of nine ginsenosides, Rb(1), Rb(2), Rc, Rd, Re, Rf, Rg(1), Rg(2), R(0), and three malonylginsenosides, mRb(1), mRb(2), mRc, in these samples were determined by high-performance liquid chromatography. It was found that the saponin contents in P. notoginseng and P. quinquefolia were generally higher than in P. ginseng. The ginsenosides that were of the highest contents in the white-ginseng, red-ginseng, and shihchu-ginseng samples of P. ginseng were Rb(1) and Rg(1); those in the root-hair of P. ginseng were Rb(1) and Re, those in P. notoginseng were Rb(1), Rg(1) and Rd, and those in P. quinquefolia were Rb(1), Re, and mRb(1). Among the samples, those of P. quinquefolia did not contain Rf and Rg(2), whilst those of shihehu-ginseng and red-ginseng of P. ginseng contained none or only traces of the malonylginsenosides. From the data of chemical analysis of a herb's constituents and its external appearance, we can postulate not only the quality but also the origin of the herb.
    Planta Medica 11/1995; 61(5):459-65. DOI:10.1055/s-2006-958137 · 2.15 Impact Factor