Dimethyl (E)-2-(N-phenyl-acetamido)-but-2-enedioate.

The title compound, C(14)H(15)NO(5), was obtained from the reaction of acetanilide with dimethyl acetyl-enedicarboxyl-ate in the presence of potassium carbonate. The C=C double bond adopts an E configuration and the geometry around the amide N atom is almost planar rather than pyramidal (mean deviation of 0.0032 Šfrom the C(3)N plane). The packing of the mol-ecules in the crystal structure is stabilized by inter-molecular C-H⋯O hydrogen bonds.

[FTIR spectra-principal component analysis of roots of Polygonum cuspidatum from different areas].

Polygonum cuspidatum Sieb. et Zucc. is an important Chinese traditional medicine, and has wide distribution in China. Based on their infrared fingerprint spectra, Polygonum cuspidatum root samples from 7 geographical origins could be divided into 6 classes with principal component analysis. The classification was well correlated to their geographical origins and weather. In the same class, the chemical components of P. cuspidatum are similar to each other, which can be considered as the criterion for evaluating the quality of P. cuspidatum. The results showed that their characteristic infrared spectra were similar in the range of 4000-1700 cm(-1), but varied significantly for different groups and kinds of P. cuspidatum samples in the range of 1700-900 cm(-1). The method is rapid and simple, and could be applied to evaluate the quality of this traditional Chinese medicine. It is one of the methods in the quality control of traditional Chinese medicines.

[Photosynthetic characteristics and coenological survey of Lactuca serriola in its invaded area].

Lactuca serriola, a national class quarantine object, is a new invasive species in the coastal area of Southeast China. The coenological survey showed that because of its big individual, L. serriola could easily form dominant population in its invaded area, and its main accompany species were Conyza canadensis, C. bonarinisis, Bidentis bipinnata, Oenothera laciniata, Ipomoea hederacea, Setaria viridis, Daucus carota, Xanthium sibiricum, Erigeron annuus, L. indica, Humulus scandens, Solanum nigrum and Aster sublatus. The measurements with LCA-4 portable photosynthesis and transpiration system (ADC, England) revealed that the net photosynthetic rate of L. serriola was as high as 21.22 +/- 0.45 micromol CO2 x m(-2) x s(-1), being slightly lower than that of E. annuus and C. bonarinisis, similar to that of C. canadensis, and higher than that of Chenopodium album, Plantago virginica and L. indica. Based on the photosynthesis-light response equation, the theoretic light compensation point of L. serriola was 37.58 micromol m(-2) x s(-1), its theoretic light saturation point was 1 480 micromol x m(-2) x s(-1), and theoretic maximal net photosynthetic rate was 20.81 micromol CO2 x m(-2) x s(-1). A distinct "noon break" phenomenon was observed in L. serriola photosynthesis, which might result from the high stomatal resistance against high light intensity and temperature. The main factors affecting the net photosynthetic rate of L. serriola were leaf photosynthetic active radiation, stomatal conductance, and leaf transpiration rate.

[FTIR spectra-principal component analysis of phenetic relationships of Huperzia serrata and its closely related species].

Huperzia serrata is an important medicinal plant. This species is rich in inner-specific variation with various closely related species, and their individuals are also small with few identification characters. In the present paper, the method of Fourier transform infrared spectrometer with an OMNI collector was applied to obtaining the infrared spectra of 16 leaf samples including Huperzia serrata and its five closely related species (Huperzia sutchueniana, Phlegmariurus mingchegensis, Lycopodium japonicum, Selaginella doederleinii, Selaginella heterostachys). Based on the indices of wave number-absorbance, the differences of the 16 infrared spectra were compared by the method of Principal Component Analysis (PCA). The results showed that there is good correspondence between the position relationship of PCA three-dimensional plot of the samples based on the indices of wave number-absorbance of FTIR spectra and their phenetic relationship. Therefore, the infrared spectra could be applied to identifying the samples of Huperzia serrata and its closely related species.

[Detrended correspondence analysis of phenetic relationships of bryophytes based on FTIR spectra].

Bryophytes are important high plants. However, the plants of bryophyte are small in size with few identification characters. The identification of plant samples using Fourier transform infrared spectrometer with OMNI collector is simple, convenient, fast and accurate. In the present paper, Fourier transform infrared spectrometer with OMNI collector was applied to gain the infrared spectra of 30 samples belonging to 26 bryophyte species. Based on the indices of wave number-absorbance, the differences of the 30 infrared spectra were compared by the method of Detrended Correspondence Analysis (DCA). The results showed that there is good correspondence between the position relationship of DCA two-dimensional plot of the samples based on the indices of wave number-absorbance of FTIR spectra and their classification relationship. Therefore, it is practical to apply the infrared spectra to identifying the false sample from the true one in medicine bryophytes.

[IR-fingerprinting ordination comparison on different organs of three species of isodon].

The plants of the genus Isodon are of important medicinal values, being widely used in the production of the Chinese traditional and herbal drugs. Compared with the other identification methods, the identification of the Chinese traditional and herbal drugs using the fourier-transform infrared spectrometer with OMNI collector is simple and convenient, fast and accurate. Moreover, the extraction or break of the samples are not necessary in the identification using OMNI collector. In the present paper, fourier-transform infrared spectrometer with OMNI collector is applied to gain the IR-fingerprintings of eleven samples of Isodon inflexus, I. Lophanthoides and I. Macrocalyx. Based on the indices of wavenumber-absorbance, the differences of eleven IR-fingerprintings are compared by PCA (Principal Component Analysis). The results show that it is practical to apply PCA on the basis of IR-fingerprinting to compare the chemical differences of plant samples.