Germacranolide sesquiterpenes from Carpesium cernuum and their anti-leukemia activity.

In this study, three new germacranolide sesquiterpenes (1-3), together with six related known analogues (4-9) were isolated from the whole plant of Carpesium cernuum. Their structures were established by a combination of extensive NMR spectroscopic analysis, HR-ESIMS data, and ECD calculations. The anti-leukemia activities of all compounds towards three cell lines (HEL, KG-1a, and K562) were evaluated in vitro. Compounds 1-3 exhibited moderate cytotoxicity with IC50 values ranging from 1.59 to 5.47 µmol·L-1. Mechanistic studies indicated that 2 induced apoptosis by decreasing anti-apoptotic protein Bcl-2 and activating the caspase family in K562 cells. These results suggest that compound 2 is a potential anti-leukemia agent.

UPLC-MS-MS Determination of Dihydrocodeine in Human Plasma and Its Application to a Pharmacokinetic Study.

A sensitive and rapid ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS-MS) method was developed to determine dihydrocodeine (DHC) in human plasma using diazepam as the internal standard (IS). Sample preparation was accomplished through a liquid-liquid extraction procedure with ethyl acetate. The analyte and IS were separated on an Acquity UPLC BEH C18 column (2.1 × 50 mm, 1.7 µm) with the mobile phase of acetonitrile and 1% formic acid in water with gradient elution at a flow rate of 0.4 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer equipped with positive-ion electrospray ionization by multiple reaction monitoring (MRM) of the transitions at m/z 302.3 → 199.2 for DHC and m/z 285.1 → 193.1 for IS. The linearity of this method was found to be within the concentration range of 0.5-100 ng/mL with a lower limit of quantification of 0.5 ng/mL. The overall run time was 4.0 min. The method herein described was superior to previous methods and was successfully applied to the pharmacokinetic study of DHC in healthy Chinese volunteers after oral administration.

Determination of kurarinone in rat plasma by UPLC-MS/MS.

A sensitive and rapid ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed to determine kurarinone in rat plasma using chlorzoxazone as the internal standard (IS). Sample preparation was accomplished through a liquid-liquid extraction procedure with ethyl acetate to 0.2 mL plasma sample. The analyte and IS were separated on an Acquity UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 µm) with the mobile phase of acetonitrile and 1% formic acid in water with gradient elution at a flow rate of 0.40 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer equipped with electrospray ionization (ESI) by multiple reactions monitoring (MRM) of the transitions at m/z 437.0→301.2 for kurarinone and m/z 168.1→132.1 for IS. The linearity of this method was found to be within the concentration range of 20-2000 ng/mL with a lower limit of quantification of 20 ng/mL. Only 3.0 min was needed for an analytical run. The matrix effect was 94.7-107.2% for kurarinone. The intra- and inter-day precision (RSD%) were less than 8.2% and accuracy (RE%) was within ±9.0%. The recovery ranged from 77.3% to 85.6%. Kurarinone was sufficiently stable under all relevant analytical conditions. The method was also successfully applied to the pharmacokinetic study of kurarinone in rats.

UPLC-MS/MS method for determination of avicularin in rat plasma and its application to a pharmacokinetic study.

A rapid, sensitive and selective ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed and validated for the determination and pharmacokinetic investigation of avicularin in rat plasma. Sample preparation was accomplished through a simple one-step deproteinization procedure with 0.2 mL of acetonitrile-methanol (9:1, v/v) to a 0.1 mL plasma sample. Plasma samples were separated by UPLC on an Acquity UPLC BEH C18 column using a mobile phase consisting of acetonitrile-0.1% formic acid in water with gradient elution. The total run time was 1.60 min and the elution of avicularin was at 1.20 min. The detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction-monitoring (MRM) mode using the respective transitions m/z 434.1→301.3 for avicularin and m/z 237.2→194.3 for carbamazepine (IS), respectively. The calibration curve was linear over the range of 10-3000 ng/mL with a lower limit of quantitation (LLOQ) of 10 ng/mL. Mean recovery of avicularin in plasma was in the range of 84.2-89.5%. Intra-day and inter-day precision were both <12%. This method was successfully applied in pharmacokinetic study after intravenous administration of 5.0mg/kg avicularin in rats.

[Chlorophyll content and net photosynthetic rate of Machilus pauhoi and M. leptophylla].

By using SPAD-502 chlorophyll meter, LI-6400 portable photosynthesis system, and spectrophotometer, the leaf SPAD value, net photosynthetic rate (Pn), and chlorophyll (a + b) content (Ct) of 3-year-old Machilus pauhoi and M. leptophylla seedlings were measured, and the relationships of SPAD value with Pn and Ct were analyzed. The M. pauhoi seedlings were grown from the seeds originated from Suichuan County of Jiangxi Province and Jian'ou County of Fujian Province, named as MPS and MPJ, respectively; while the M. leptophylla seedlings were grown from the seeds originated from Shangyou County of Jiangxi Province, named as MLG. There were significant differences in the mean chlorophyll content of MPS, MPJ, and MLG. The SPAD value and the contents of chlorophyll (a + b) (Ct), chlorophyll a (Ca) and chlorophyll b (Cb) were in the order of MPS < MLG < MPJ, with the mean SPAD value being 43.80, 45.12, and 50.67 and the Ct value being 1.944, 2.831, and 3.447 mg c g(-1), respectively. The chlorophyll content was influenced by the maturing degree of mesophyll tissues of M. pauhoi and M. leptophylla, being lower in current-year leaves than in 2-year-old leaves. The Ct of same age leaves at different crown layers of MPS and MPJ and of MLG was in the order of upper layer < middle layer < lower layer and of upper layer < lower layer < middle layer, respectively, and the SPAD value of the same lamina at different positions was in the order of apex < middle < base. SPAD value had a significant positive linear correlation with Ct, and a statistically not significant positive correlation with Pn.