Two new pyrrolizidines named lankongensisine A (1), B (2) were isolated from the roots of Ligularia lankongensis collected in Lijiang, Yunnan, and their structures were established by spectroscopic analysis.
OBJECTIVE ″-omics″study represents an unbiased perspective to examine the bio-system to discover the novel biomarker(s)which might be overlooked when targeted analysis is performed instead.Urine,due to its ease of c...OBJECTIVE ″-omics″study represents an unbiased perspective to examine the bio-system to discover the novel biomarker(s)which might be overlooked when targeted analysis is performed instead.Urine,due to its ease of collection,minimal invasion involved and rich information of the downstream metabolites,has been extensively studied.Fermentum rubrum(Hongqu,HQ capsules)is a well-known traditional medicine with the claimed slimming effect which could be related to the reduction in the deposition of total cholesterol and glycerides.Lack in sufficient clinical evidence is always one of the leading reasons that hamper traditional medicines from gaining world-wide recognition.In our pursuit of scientific support for HQ capsules in managing obesity,we aim to examine the alteration of urinary metabolites in this small-scale human clinical research.METHODS 6 Chinese subjects were included and exposed to short-term administration of HQ capsules for 3d,twice daily,two capsules each dosing.The urine samples were collected for three days prior to the dosing and on the day following the last dosing.In total,96 urine samples were collected and then separated on hydrophilic interaction chromatography(HILIC)and analyzed by Agilent 6550 ESI-Quadrupoletime-of-flight(QTOF)mass spectrometer.RESULTS Under positive mode,two compounds were found to be present only in post-dosing urine,and one compound was significantly lowered in post-dosing samples.Those two compounds might be associated with the administered HQ capsules,which is formulated with multiherbal constituents.CONCLUSION Further elucidation on the structures of these compounds is needed to enable better understanding of the mechanism of HQ capsules in managing obesity.展开更多
The structure and properties of nanocrystalline PVC were investigated. The crystalline region of nanocrystalline PVC was observed by TEM to be 80 nm. The melting point of nanocrystalline PVC was found to be 128℃which...The structure and properties of nanocrystalline PVC were investigated. The crystalline region of nanocrystalline PVC was observed by TEM to be 80 nm. The melting point of nanocrystalline PVC was found to be 128℃which is obviously lower than typical PVC (210℃). The X-ray diagrar indicated that the crystal existed in nanocrystalline PVC. The evident effect of self-plasticizing and reinforcement appeared when nanocrystalline PVC was added. The optimum amount for self-plasticizing is about 10%. The maximal impact strength of 95.1 kJ/m2 was achieved by adding 20% nanocrystalline PVC and tensile strength with 56.2 MPa which was 122% of pure PVC was obtained after adding 5% nanocrystalline PVC.展开更多
OBJECTIVE Identification of pesticide residues in TCM herbs is important for drug safety and public health.However,it is very challenging for the development of an instrument-based multi-residue pesticide analysis met...OBJECTIVE Identification of pesticide residues in TCM herbs is important for drug safety and public health.However,it is very challenging for the development of an instrument-based multi-residue pesticide analysis method for theherbalproducts due to their complex matrix.This study aims to develop a rapid method for the high-throughput detection of pesticide residues in TCM herbal products using liquid chromatography coupled to quadrupoletime of flight(LC-QTOF)mass spectrometry.METHODS In this study,we attempt to investigate possible pesticide residues in TCM herbal products which are commonly available in Singapore and to consolidate a comprehensive pesticide database for more than 250 regulated pesticides in FDA Regulations.We also attempt to perform non-targeted and targeted screenings of pesticide residues in herbal products by searching our database.RESULTS The developed LC-QTOF method demonstrates have high mass accuracy,resolution and selectivity,which makes it a very suitable tool for monitoring both target and non-target pesticides with a limit of detection at the low ppb level.Moreover,the LC-QTOF technology permits to retain all spectral data in a single run.It may avoid many difficulties related to matrix effects and will save much manpower.CONCLUSIONThis means that a variety of TCM herbs can be easily detected by this method for the presence or absence of pesticide residues that must conform to government regulations.展开更多
文摘Two new pyrrolizidines named lankongensisine A (1), B (2) were isolated from the roots of Ligularia lankongensis collected in Lijiang, Yunnan, and their structures were established by spectroscopic analysis.
基金The project supported by Temasek Polytechnic DRP project grant
文摘OBJECTIVE ″-omics″study represents an unbiased perspective to examine the bio-system to discover the novel biomarker(s)which might be overlooked when targeted analysis is performed instead.Urine,due to its ease of collection,minimal invasion involved and rich information of the downstream metabolites,has been extensively studied.Fermentum rubrum(Hongqu,HQ capsules)is a well-known traditional medicine with the claimed slimming effect which could be related to the reduction in the deposition of total cholesterol and glycerides.Lack in sufficient clinical evidence is always one of the leading reasons that hamper traditional medicines from gaining world-wide recognition.In our pursuit of scientific support for HQ capsules in managing obesity,we aim to examine the alteration of urinary metabolites in this small-scale human clinical research.METHODS 6 Chinese subjects were included and exposed to short-term administration of HQ capsules for 3d,twice daily,two capsules each dosing.The urine samples were collected for three days prior to the dosing and on the day following the last dosing.In total,96 urine samples were collected and then separated on hydrophilic interaction chromatography(HILIC)and analyzed by Agilent 6550 ESI-Quadrupoletime-of-flight(QTOF)mass spectrometer.RESULTS Under positive mode,two compounds were found to be present only in post-dosing urine,and one compound was significantly lowered in post-dosing samples.Those two compounds might be associated with the administered HQ capsules,which is formulated with multiherbal constituents.CONCLUSION Further elucidation on the structures of these compounds is needed to enable better understanding of the mechanism of HQ capsules in managing obesity.
基金This work was supported by the Natioal High Technology Research and Developmnent Program of China(863 Program No.2002AA333110)
文摘The structure and properties of nanocrystalline PVC were investigated. The crystalline region of nanocrystalline PVC was observed by TEM to be 80 nm. The melting point of nanocrystalline PVC was found to be 128℃which is obviously lower than typical PVC (210℃). The X-ray diagrar indicated that the crystal existed in nanocrystalline PVC. The evident effect of self-plasticizing and reinforcement appeared when nanocrystalline PVC was added. The optimum amount for self-plasticizing is about 10%. The maximal impact strength of 95.1 kJ/m2 was achieved by adding 20% nanocrystalline PVC and tensile strength with 56.2 MPa which was 122% of pure PVC was obtained after adding 5% nanocrystalline PVC.
文摘OBJECTIVE Identification of pesticide residues in TCM herbs is important for drug safety and public health.However,it is very challenging for the development of an instrument-based multi-residue pesticide analysis method for theherbalproducts due to their complex matrix.This study aims to develop a rapid method for the high-throughput detection of pesticide residues in TCM herbal products using liquid chromatography coupled to quadrupoletime of flight(LC-QTOF)mass spectrometry.METHODS In this study,we attempt to investigate possible pesticide residues in TCM herbal products which are commonly available in Singapore and to consolidate a comprehensive pesticide database for more than 250 regulated pesticides in FDA Regulations.We also attempt to perform non-targeted and targeted screenings of pesticide residues in herbal products by searching our database.RESULTS The developed LC-QTOF method demonstrates have high mass accuracy,resolution and selectivity,which makes it a very suitable tool for monitoring both target and non-target pesticides with a limit of detection at the low ppb level.Moreover,the LC-QTOF technology permits to retain all spectral data in a single run.It may avoid many difficulties related to matrix effects and will save much manpower.CONCLUSIONThis means that a variety of TCM herbs can be easily detected by this method for the presence or absence of pesticide residues that must conform to government regulations.
