Comparative pharmacokinetics study of five alkaloids in rat plasma and related compound-herb interactions mechanism after oral administration of Shuanghua Baihe tablets.

Shuanghua Baihe tablet is a traditional Chinese patent medicine which showed special advantages in the treatment of recurrent aphthous stomatitis. Scientists have improved and implemented the LC-MS/MS method, which is specific and sensitive, for comparative pharmacokinetics study of five alkaloids, including palmatine, berberine, epiberberine, jatrorrhizine and coptisine in rat plasma after oral administration of Rhizoma Coptidis extract and Shuanghua Baihe tablets. The results showed that Shuanghua Baihe tablets could promote the absorption of these five alkaloids and improved their bioavailability compared with R.

Comparative pharmacokinetic study of baicalin and its metabolites after oral administration of baicalin and Chaiqin Qingning capsule in normal and febrile rats.

An accurate, precise, selective, and sensitive high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) method was developed for the simultaneous determination of baicalin and its metabolite, baicalein 6-O-glucopyranuronoside, in normal and febrile rats plasma. Two analytes, along with hesperidin as an internal standard, were determined by multiple reactions monitoring (MRM) operated in the positive electrospray ionization (ESI) mode. Chromatographic separation was performed on an Agilent ZORBAX Extend-C18 column (100mm×2.

Catechol-O-Methyltransferase and UDP-Glucuronosyltransferases in the Metabolism of Baicalein in Different Species.

Background: Baicalein is the major bioactive flavonoid in some herb medicines and dietary plants; however, the detailed metabolism pathway of its major metabolite oroxylin A-7-O-β-D-glucuronide in human was not clear. It was important to illustrate the major metabolic enzymes that participate in its elimination for the clinic use of baicalein.

Objectives: We first revealed a two-step metabolism profile for baicalein and illustrated the combination of catechol-O-methyltransferase (COMT) and uridine diphosphate-glucuronosyltransferases (UGTs) in drug metabolism, further evaluated its bioactivity variation during drug metabolism.

HPLC-Q-TOF-MS/MS Analysis of the Constituents in the Rat Biological Fluids After Oral Administration of Qing Ru Xiao granules.

A high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry method was established to detect as many constituents in rat biological fluids as possible after oral administration of Qing Ru Xiao granules (QRX). An Agilent Poroshell 120 EC-C18 column was adopted to separate the sample constituents, and mass spectra were acquired in positive and negative ion modes. First, the fingerprints of QRX were established, resulting in 28 components being detected within 30 min.

Identification of chemical constituents and rat metabolites of Kangxianling granule by HPLC-Q-TOF-MS/MS.

A high-performance liquid chromatography coupled with quadrupole time-of-flight mass tandem mass spectrometry method was established to characterize the chemical constituents of Kangxianling granule (KXL), a traditional Chinese medicine formula, and the metabolic profile in rat urine and plasma after oral administration of KXL. A total of 27 compounds in KXL extract and 13 prototype compounds with 12 metabolites in rat urine and plasma were identified. Among the 27 detected compounds, 15 were identified by comparing the retention time and MS data with that of reference compounds and the other 12 compounds were tentatively assigned based on the MS data and reference literature.

Characterization of chemical constituents and rats metabolites of Shuanghua Baihe tablets by HPLC-Q-TOF-MS/MS.

A high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry method was established to detect as many constituents in rat biological fluids as possible after oral administration of Shuanghua Baihe tablets (SBT). An Agilent Poroshell 120 EC-C18 column was adopted to separate the samples, and mass spectra were acquired in positive and negative modes. First, the fingerprints of SBT were established, resulting in 32 components being detected within 40 min.

Terpenoid indole alkaloids from Mappianthus iodoides Hand.-Mazz.

Ten terpenoid indole alkaloids, mappiodines A-C and mappiodosides A-G, together with eight known compounds, were isolated from stems of Mappianthus iodoides Hand.-Mazz. Their structures were elucidated by spectroscopic analyses including 1D, 2D NMR, MS and CD methods.

Caesalminaxins A-L, cassane diterpenoids from the seeds of Caesalpinia minax.

Fourteen new cassane diterpenoids, caesalminaxins A-L (1-14), and three known compounds were isolated from the seeds of Caesalpinia minax. Among the new diterpenoids, compounds 3 and 4 possess a rare spiro C/D ring system. The C-16 epimeric mixture 1/2 has an unprecedented carbon skeleton, presumably derived from 3 by cleavage of the C-13-C-14 bond.

Guanidine alkaloids from Plumbago zeylanica.

Eleven new guanidine alkaloids, plumbagines A-G (2-8) and plumbagosides A-D (9-12), as well as two known analogues (1, 13), were isolated from the aerial parts of Plumbago zeylanica. Their structures were elucidated by spectroscopic analyses including 1D and 2D NMR, MS, IR, and CD methods. The absolute configuration of 1 was determined by single-crystal X-ray diffraction of its derivative (1a).