Shuenn‐Jyi Sheu

Two new anthraquinones, 1,6-dihydroxy-5-methoxy-2-methoxymethylanthraquinone (1) and 1,5,7-trihydroxy-6-methoxy-2-methoxymethylanthraquinone (2), and one new lignan isoamericanoic acid A (3) were isolated from the fruits of Morinda citrifolia along with 11 known compounds scopoletin, luteolin, americanin A, americanin D, 3,3′-bisdemethylpinoresinol, p-cresol, p-hydroxybenzoic acid, p-hydroxybenzaldehyde, 4-hydroxy-3-methoxybenzaldehyde, 4-hydroxy-3-methoxycinnamaldehyde, and 2,5-dihydroxy-4-methoxybenzaldehyde. The structures of all compounds were elucidated by spectroscopic analysis.

A total of 50 commercial samples of Aurantii Fructus, originating from Poncitrus trifoliata for Aurantii Fructus Immaturus, Citrus aurantium, and C. wilsonii for Aurantii Fructus Maturus, respectively, were collected from Taiwan and China herbal markets. Contents of the constituents in the samples were determined within 60 min using a developed HPLC method, which had been validated in terms of precision, repeatability, and accuracy. The results of the analyses showed that the constituents were closely related to the species and also the degree of maturity of the fruits, especially in the case of hesperidin (HE), naringin (NG), neohesperidin (NE), naringenin‐7‐glucoside (NGC), narirutin (NR), and quercetin (QU). The mature fruits (C. aurantium and C. wilsonii) contained chiefly NG, HE, and NE and the immature ones (P. trifoliata) had NG, NR, and QU majorly. Within the mature samples, the ratios of HE/NE and NGC/NE values were higher than 2.94 and 0.21 in C. aurantium and lower than 1.31 and 0.02 in C. wilsonii, respectively. A flowchart that is useful for identifying Aurantii Fractus was devised, based on the various chemical identification methods.

Twenty‐eight commercial samples of Fructus Chebulae were collected from local herbal markets in Taiwan and were determined to have been derived from Terminalia chebula Retz. and Terminalia chebula Retz. var. parviflora Thwaites, which differ markedly in external appearance. Ten tannin‐related constituents [gallic acid (1), chebulic acid (2), punicalagin (4), chebulanin (7), corilagin (8), neochebulinic acid (9), ellagic acid (11), chebulagic acid (12), chebulinic acid (13) and 1,2,3,4,6‐penta‐O‐galloyl‐β‐D‐glucose (14)] were identified and quantified by HPLC. Samples derived from T. chebula. var. parviflora, which are typically round‐shaped, generally contained higher concentrations of 13 and 14 but lower levels of 12 compared with those from T. chebula, which are largely oval‐shaped. The ratio of the concentration of 14 to that of 4 may serve as a potential parameter for differentiating samples from the two origins (T. chebula, ratio 0.6 ± 0.3; T. chebula. var. parviflora, ratio 3.4 ± 2.2). Levels of the three major bioactive constituents 12–14 were found to provide good references for the quality assessment of Fructus Chebulae. The ratio of the concentration of 12 to that of 14 may offer a guideline for determining quality as well as origin of the drug (lower‐grade T. chebula, ratio 12.4 ± 6.0; medium‐grade T. chebula, ratio 8.8 ± 7.9; higher‐grade T. chebula, ratio 3.2 ± 0.8; T. chebula var. parviflora, ratio 1.6 ± 0.7). Copyright © 2005 John Wiley & Sons, Ltd.

A RP‐HPLC method for determining fourteen components (gallic acid, chebulic acid, 1,6‐di‐O‐galloyl‐D‐glucose, punicalagin, 3,4,6‐tri‐O‐galloyl‐D‐glucose, casuarinin, chebulanin, corilagin, neochebulinic acid, terchebulin, ellagic acid, chebulagic acid, chebulinic acid, and 1,2,3,4,6‐penta‐O‐galloyl‐D‐glucose) in the fruit of Terminalia chebula Retz. is described. The separation was achieved within 80 min using a binary gradient with mobile phases consisting of a pH 2.7 phosphoric acid solution and an 80% CH₃CN solution. Capillary electrophoretic analyses were also attempted, and it was found that CZE (25 mM Na₂B₄O₇, 5 mM NaH₂PO₄, pH 7.0) was an efficient method for the separation of gallotannins, while an MEKC method (25 mM Na₂B₄O₇, 5 mM NaH₂PO₄, 20 mM SDS, pH 7.0, and 10% acetonitrile) provided a better separation for most of the tannins examined. The HPLC and CE methods developed were both successfully applied to the assay of tannins in commercial samples of Chebulae Fructus.

Two stacking methods of capillary electrophoresis (CE) were developed for the separation of very dilute solutions of ephedra‐alkaloids, namely ephedrine, pseudoephedrine, methylephedrine, methylpseudoephedrine, norephedrine, and norpseudoephedrine. A sweeping method which uses a carrier comprised of phosphoric acid, sodium dodecyl sulfate (SDS), diethylamine and acetonitrile permits the detection of the alkaloids down to the 10⁻¹ μg/mL level, and the cation‐selective exhaustive injection and sweeping micellar electrokinetic chromatography (CSEI‐Sweep‐MEKC) method using phosphoric acid, SDS, and acetronitrile as electrolytes can detect down to the 10⁻³ μg/mL level. The former requires the conductance of the sample solution to be adjusted beforehand, and only five peaks were observed, two of which were overlapped. The latter is capable of separating the six alkaloids but has a somewhat poorer reproducibility. Using an optimized injection time, it was found that the more diluted a solution is, the greater the sweeping effect will be. The CSEI‐Sweep‐MEKC method with a 600 s injection time and a 10⁻¹ μg/mL solution concentration provides an amplification effect of ∼ 10⁴. The method is suitable for analyses of dilute herb drug extracts and mouse sera. The effect of buffers on the separation and validation of the methods in this study are also discussed.

Cortex Moutan (Radicis Cortex Moutan), the dried root bark of Paeonia moutan and P. spp., contains a series of water‐soluble tannins. With the eight components, 1 4,6‐di‐O‐GG (4,6‐di‐O‐galloyl‐D‐glucose), 2 1,2,3,6‐tetra‐O‐GG, 3 1,2,3,4,6‐penta‐O‐GG, 4 1,3,4,6‐tetra‐O‐GG, 5 3,4,6‐tri‐O‐GG, 6 1,3,6‐tri‐O‐GG, 7 3,6‐di‐O‐GG, and 8 1,2,6‐tri‐O‐GG, as marker substances, a rapid and efficient method of analysis based on HPLC and CE was developed. Using a phosphate eluent, a 5C18‐MS separating column, and a detection wavelength of 280 nm, HPLC was successfully used to analyze the eight constituents within 60 min. The analysis can be completed within 50 min, using the MEKC mode with a buffer composed of borate, SDS, and isopropanol, and a detection wavelength of 210 nm. The detection limit for the marker substances varied from 0.04 to 0.93 μg/mL for the HPLC method and 0.02 to 0.36 μg/mL for the CE method.

Two high‐performance liquid chromatographic methods, one combined with a photodiode array detector (LC/UV) and another with mass spectrometry (LC/MS), were developed for the analysis of aristolochic acid I and II in herbal medicines. The LC/UV method was carried out using a Cosmosil 5C18‐MS column with a gradient solvent system composed of phosphate buffer‐acetonitrile and a UV detector (390 nm). The LC/MS method was performed using an acetate buffer‐acetonitrile solvent system and positive‐ion electrospray ionization MS. The characteristic fragment ions for aristolochic acid I were selected at m/z 359, m/z 324, m/z 298, and m/z 296, and for aristolochic acid II at m/z 329, m/z 294, and m/z 268. In order to attain better resolution, solid phase extraction was used to prepare the test solution in this study.