Triterpenoid saponins from the roots of Clematis argentilucida and their cytotoxic activity.

The reinvestigation of the n-BuOH extract of the roots of Clematis argentilucida led to the isolation of four new oleanane-type triterpenoid saponins, 1-4, four known saponins, 5-8, first isolated from the species, together with ten saponins, 9-18, reported in the preceding papers. The structures of saponins 1-8 were elucidated by extensive spectroscopic analysis and chemical evidences. The cytotoxicity of all the saponins were evaluated against human tumor HL-60, HepG-2, and SGC-7901 cell lines. The monodesmosidic saponins 4, 7, 8, and 14-18 exhibited cytotoxic activity against the three cell lines with IC50 values in the range of 0.87-19.48 µM.

High performance liquid chromatographic method for the determination of cinepazide maleate and its application to a pharmacokinetic study in rats.

A simple and reliable high performance liquid chromatographic (HPLC) method has been developed and validated to quantify cinepazide maleate, a calcium blocker, in rat plasma. Cinepazide maleate and Tinidazole (internal standard) have been extracted by a simple liquid-liquid extraction before injection into chromatographic system. Chromatographic separation was achieved on a reversed phase C18 column with a mobile phase consisted of a water mixture of 10mM potassium dihydrogen phosphate (pH=4.5):methanol (40:60, v/v), pumped at flow rate of 1.0mL/min, and detected at 303nm. The method exhibited a linear range of 0.12-120µg/mL in blank rat plasma, with the lower detection limit of 0.06µg/mL. The method was statistically validated for linearity, accuracy, precision, selectivity and stability following FDA guidelines. The intra- and inter-assay coefficients of variation did not exceed ±15% from the nominal concentration. The accuracy of cinepazide maleate was within ±15% of the theoretical value. The assay has been applied successfully in a pharmacokinetic study of cinepazide maleate after a single intravenous at three doses in rat. And cinepazide maleate injection can improve the bioavailability of cinepazide maleate greatly, and has a dose-dependence profile in rats.

New cytotoxic triterpenoid saponins from the whole plant of Clematis lasiandra Maxim.

Four new oleanane type triterpenoid saponins (1-4) and three known saponins (5-7) were isolated from the whole plant of Clematis lasiandra Maxim. The structures of the four new compounds were elucidated as 3-O-ß-D-ribopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-[ß-D-glucopyranosyl-(1 → 4)]-ß-D-xylopyranosyl hederagenin (1), 3-O-ß-D-ribopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1→2)-ß-D-xylopyranosyl oleanolic acid 28-O-ß-D-glucopyranosyl ester (2), 3-O-ß-D-ribopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-ß-D-xylopyranosyl hederagenin (3) and 3-O-ß-D-ribopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-[ß-D-glucopyranosyl-(1→4)]-α-L-arabinopyranosyl hederagenin (4) on the basis of extensive spectroscopic analysis and chemical evidence. Compounds 1-7 were evaluated for their cytotoxicity against human tumor cell lines HL-60, Hep-G2 and SGC-7901, and all of the evaluated saponins showed significant cytotoxicity to those three tumor cell lines with IC50 in the range from 1.40 to 19.50 µmol/L except for compounds 2 and 6.

Application of a liquid chromatography-tandem mass spectrometry method to the pharmacokinetics, tissue distribution and excretion studies of brazilin in rats.

Brazilin is an important constituent of Caesalpinia sappan L., and has several bioactivities. In this study, a rapid and sensitive analytical method based on high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) has been developed for the determination of brazilin in rat plasma, urine, feces and tissues (brain, heart, liver, lung and kidney and spleen). Biological samples were processed with ethyl acetate containing 5% formic acid extraction, and salicylic acid (SA) was chosen as the internal standard (IS). The separation of brazilin was achieved on an Inspire C18 column (4.6mm×150mm, 5µm) with a mobile phase consisting of methanol/5mM ammonium acetate (80:20, v/v). The MS/MS detection was carried out by monitoring the fragmentation of m/z 285.1→163.0 for brazilin and m/z 137.1→93.1 for SA on a triple quadrupole mass spectrometer. The total run time was only 5.0min. The analyte showed good linearity over a wide concentration range (R(2)>0.995) and its lower limit of quantification was 2ng/mL. The accuracy and precision ranged from 97.1 to 103.3% and 1.7 to 9.1%, respectively. Recoveries (78.9-93.8%) and matrix effects (81.0-97.8%) were satisfactory in all the biological matrices examined. Stability studies (86.4-99.8%) showed that brazilin was stable during the assay procedure and long-term storage. The assay was successfully applied to plasma pharmacokinetics, tissue distribution and excretion study of rats. The pharmacokinetic parameters, such as half-life, mean residence time, maximum concentration were determined. These preclinical data of brazilin would be useful for the clinical reference.

Triterpenoid saponins from the root of Anemone tomentosa.

Three new triterpenoid saponins, tomentoside A (1), B (2) and C (3), along with four known saponins (4-7) were isolated from the root of Anemone tomentosa. The structures of the new compounds were elucidated as 3-O-ß-D-ribopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-[ß-D-glucopyranosyl-(1→4)]-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl-(1→4)-ß-D-glucopyranosyl-(1→6)-ß-D-glucopyranoside (1), 3-O-ß-D-ribopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-[ß-D-glucopyranosyl-(1→4)]-ß-D-xylopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl-(1→4)-ß-D-glucopyranosyl-(1→6)-ß-D-glucopyranoside (2) and 3-O-ß-D-galactopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-ß-D-xylopyranosyl oleanolic acid 28-O-α-L-rhamnopyranosyl-(1→4)-ß-D-glucopyranosyl-(1→6)-ß-D-glucopyranoside (3) on the basis of chemical and spectral evidence. In the oligosaccharide chains of compound 3, the characteristic D-galactose residue is a rare structural feature and secondly encountered among triterpenoid saponins from Anemone.

Two new cytotoxic triterpenoid saponins from the roots of Clematis argentilucida.

Bioassay-guided fractionation of the n-BuOH extract of the roots of Clematis argentilucida led to the isolation of two new triterpenoid saponins along with a known one, cussonside B (3). By extensive spectral analysis and chemical evidences, the structures of the two new saponins were determined to be 3ß-O-[ß-D-ribopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl] hederagenin-11,13-dien-28-oic acid (1) and 3ß-O-{ß-D-ribopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-[ß-D-glucopyranosyl-(1→4)]-ß-D-xylopyranosyl} oleanolic acid (2), respectively. Saponin 1 is the first example of triterpenoid saponins with two double bonds located at C-11 and C-13 in the aglycone from the genus Clematis. The two new saponins exhibited significant cytotoxicity against human leukemia HL-60 cell lines, human hepatocellular carcinoma Hep-G2 cell lines and human glioblastoma U251MG cell lines with a range of IC(50) values from 2.74 to 25.40µM, while 3 showed inactivity against all of the three cancer cell lines.