Ginseng (Panax ginseng Meyer) has been used as traditional herbal drug in Asian countries. Ginsenosides are major components having pharmacological and biological efficacy like anti-inflammatory, anti-diabetic and anti-tumor effects. To con- trol the quality of the components in diverse ginseng products, we developed a new quantitative method using LC-MS/MS for 13 ginsenosides; Rb1, Rb2, Rc, Rd, Re, Rf, 20(S)-Rh1, 20(S)-Rh2, Rg1, 20(S)-Rg3, F1, F2, and compound K. This method was successfully validated for linearity, precision, and accuracy. This quantification method applied in four representative ginseng products; fresh ginseng powder, white ginseng powder, red ginseng extract powder, and red ginseng extract. Here the amounts of the 13 ginsenosides in the various type of ginseng samples could be analyzed simultaneously and expected to be suitable for quality control of ginseng products.
The effects of temperature and acetonitrile (ACN) concentration on microwave-assisted weak-acid hydrolysis of pro- teins were investigated. Myoglobin was hydrolyzed for 1 h using 2% formic acid and a microwave with different concentrations of ACN (0, 5, and 10%) at various temperatures (50, 60, 70, 80, 90, and 100 o C). The numbers of peptides identified with each concentration of ACN were the same for each temperature. The greatest number of peptides (18 total) was obtained with hydro- lysis at 100 o C, and 6 of these were a result of additional removal of aspartic acid at the C-terminus. Hydrolysis at 80 o C resulted in 13 peptides, of which only 1 was generated by the additional removal of aspartic acid, and 12 were observed with hydrolysis at 100 o C. Our results demonstrate that microwave-assisted weak-acid hydrolysis of proteins can be performed successfully at 80 o C, which could be beneficial for limiting side reactions and generating larger peptide sequences.
Capture of non-glycoproteins during lectin affinity chromatography is frequently observed, although it would seem to be anomalous. In actuality, lectin affinity chromatography works at post-translational modification (PTM) sites on a glycopro- tein which is not involved in protein-protein interactions (PPIs). In this study, serial affinity column set (SACS) using lectins fol- lowed by proteomics methods was used to identify PPI mechanisms of captured proteins in human plasma. MetaCore, STRING, Ingenuity Pathway Analysis (IPA), and IntAct were individually used to elucidate the interactions of the identified abundant pro- teins and to obtain the corresponding interaction maps. The abundant non-glycoproteins were captured with the binding to the selected glycoproteins. Therefore, depletion process in sample pretreatment for abundant protein removal should be considered with more caution because it may lose precious disease-related low abundant proteins through PPIs of the removed abundant proteins in human plasma during the depletion process in biomarker discovery. Glycoproteins bearing specific glycans are fre- quently associated with cancer and can be specifically isolated by lectin affinity chromatography. Therefore, SACS using Lycop- ersicon esculentum lectin (LEL) can also be used to study disease interactomes.
In this study, matrix-assisted laser desorption/ionization (MALDI) was applied to the TEMPO-assisted FRIPS for the first time. We found that 3-HPA is the optimal matrix for the analysis of p-TEMPO-Bz-Sc-peptides, which gives minimal precursor fragmentations. MALDI-TOF/TOF experiments on p-TEMPO-Bz-Sc-peptides yielded mainly [a n +H] + , [z n +H] + , and [y n ] + -type products, indicating that radical-driven peptide fragmentation occurs in MALDI-TOF/TOF-MS.
KPLA-012, a benzopyranyl 1,2,3-triazole compound, is considered a potent HIF-1α inhibitor based on the chemical library screening, and is known to exhibit anti-angiogenetic and anti-tumor progressive effects. The aim of this study was to investigate the pharmacokinetic properties of KPLA-012 in ICR mice and to investigate in vitro characteristics including the intestinal absorption, distribution, metabolism, and excretion of KPLA-012. The oral bioavailability of KPLA-012 was 33.3% in mice. The pharmacokinetics of KPLA-012 changed in a metabolism-dependent manner, which was evident by the low recovery of parent KPLA-012 from urine and feces and metabolic instability in the liver microsomes. However, KPLA-012 exhibited moderate permeability in Caco-2 cells (3.1 × 10 -6 cm/s) and the metabolic stability increased in humans compared to that in mice (% remaining after 1 h; 47.4% in humans vs 14.8% in mice). Overall, the results suggest that KPLA-012 might have more effec- tive pharmacokinetic properties in humans than in mice although further studies on its metabolism are necessary.