Biomedical subjects
Publications and source records attributed to Yan-Ping Shi.
This review covers the structures and biological activities of eudesmane-type sesquiterpenoids from the plants of the Asteraceae family. Biosynthetic studies or chemical syntheses leading to the revision of structures or stereochemistries have also been included, and 593 references are cited.
HPLC methods have been developed for chiral resolution of the enantiomers of dl-tetrahydropalmatine (THP) and dl-tetrahydroberberine (THB), two active constituents of Corydalis yanhusuo W.T. Wang. On the analytical scale, good baseline separation of the enantiomers was achieved using cellulose tris(3,5-dimethylphenylcarbamate) chiral stationary phases in both normal-phase and polar organic modes. Validation of the analytical methods, including linearity, limits of detection, recovery, and precision, and semipreparative resolution of dl-THP and dl-THB, were achieved with methanol as mobile phase, without any basic additives, in polar organic mode using cellulose tris(3,5-dimethylphenylcarbamate) chiral stationary phases. On the semipreparative scale, small quantities of the individual enantiomers of THP and THB were isolated for study of the chiroptical properties of the individual enantiomers.
A validated reversed-phase high-performance liquid chromatographic (RP-HPLC) method was developed for the determination of bergenin in rat plasma. Bergenin in rat plasma was extracted with methanol, which also acted as a deproteinization agent. Chromatographic separation of bergenin was performed on a C(18) column, with a mobile phase of methanol-water (22:78, v/v) at a flow-rate of 0.8 mL/min and an operating temperature of 40 degrees C, and UV detection was set at 220 nm. The calibration curve was linear over the range 0.25-50 microg/mL (r = 0.9990) in rat plasma. The limit of quantification was 0.25 microg/mL using a plasma sample of 100 microL. The extraction recoveries were 83.40 +/- 6.02, 81.49 +/- 2.40 and 72.51 +/- 2.64% at concentrations of 0.5, 5 and 50 microg/mL, respectively. The intra-day and inter-day precision and accuracy were validated by relative standard deviation (RSD%) and relative error (RE%), which were in the ranges 3.74-9.91 and -1.6-8.0%. After intravenous administration to rats at the dose of 11.25 mg/kg, the plasma concentration-time curve of bergenin was best conformed to a two-compartment open model. The main pharmacokinetic parameters indicated that bergenin exhibited a wide distribution and moderate elimination velocity in rat.
Room-temperature ionic liquids (ILs) are liquids that are constituted entirely of ions and can provide a solvent environment quite unlike any other available at room temperature. They continue to attract considerable interest in the chemistry research community as they are good solvents for a wide range of both inorganic and organic materials. In this study, a CZE method has been established for resolving natural flavonoids, quercetin, kaempferol and isorhamnetin in the Chinese herbal extract from Hippophae rhamnoides and its medicinal preparation (Sindacon Tablet). In this method, 1-alkyl-3-methyl-imidazolium-based ILs are used as the additive, and the effects of the alkyl group, imidazolium counterion (anionic part), along with the concentration of IL are investigated and discussed. Baseline separation, high efficiencies and symmetrical peaks of the three flavonoids were obtained. The separation mechanism seems to be the hydrogen-bonding interaction between the imidazolium cations of IL and the flavonoids.
Five new eremophilenolides, 1beta-angeloyloxy-6beta,10beta-dihydroxy-8beta-methoxyeremophil-7(11)-en-8alpha,12-olide ( 1), 1beta-angeloyloxy-6beta,10alpha-dihydroxy-8alpha-methoxyeremophil-7(11)-en-8beta,12-olide ( 2), 1beta,6beta-diangeloyloxy-8beta,10beta-dihydroxyeremophil-(11)-en-8alpha,12-olide ( 3), 1beta,6beta-diangeloyloxy-8alpha,10 alpha-dihydroxyeremophil-7(11)-en-8beta,12-olide ( 4), 1beta-angeloyloxy-8-oxoeremophil-6,9-dien-12-oic acid methyl ester ( 5) and one known compound, 8beta,10beta-dihydroxyeremophilenolide ( 6) were isolated from the extract of the whole plant of Ligularia myriocephala Ling. Their structures and stereochemistry were elucidated by various spectroscopic methods including intensive 2D-NMR techniques (COSY, gHMQC, gHMBC and (1)H- (1)H NOESY) and HR-ESI-MS. A single-crystal X-ray experiment was performed for compound 1.
Two novel and eight known triterpenoids were isolated from alcoholic extract of the whole plant of Pyrethrum tatsienense. The structures of new compounds were elucidated as olean-12-en-3beta,11alpha,16beta-triol-3-O-palmitate (1), ursa-12-en-3beta,11beta,16beta-triol-3-O-palmitate (2) by spectroscopic methods including intensive 2D NMR techniques (H1-H1 COSY, gHMQC, gHMBC) and FAB-MS, and the known compounds were identified on the basis of comparing their NMR data with those of corresponding compounds in the literature.
Two new 8,9-seco-cacalol-type sesquiterpene lactones, ligulolide C (1 and 2) and six known sesquiterpenes, adenostylide (3 and 4), cacalol (5), 1 -hydroxy-2-(3'-pentenyl)-3,7-dimethylbenzofuran (6), 1beta, 6alpha-dihydroxy-4(14)-eudesmene (7) and (+)-oplopanone (8), have been isolated from an extract of the whole plant of Ligularia virgaurea spp. oligocephala. The structures of 1 and 2 were confirmed by spectroscopic methods including 1D and 2D NMR spectra. A discussion of biogenesis of 1 and 2 was described. Cytotoxicity against selected cancer cells human promyelocytic leukemia (HL-60), human ovarian (HO-8910) and human lung epithehial (A-549) of compounds 1-8 were measured in vitro.
Capillary zone electrophoresis (CZE), using a 20 mmol/L borate buffer at pH 10.5, was developed for the identification and determination of three coumarins--7-hydroxy-coumarin (HC), 7-hydroxy-8-methoxy-coumarin (HMC) and 7-O-beta-D-glucosyl-coumarin (GC)--in the extracts of the flower of Cacalia tangutica. Regression equations revealed linear relationships (correlation coefficient 0.9986-0.9990) between the corrected peak area (the ratio of peak area to migration time) of each constituent and its concentration. The relative standard deviations (RSD) of the migration time and peak area were 1.45-1.52 and 2.60-3.84% (intra-day), and 1.75-2.22 and 2.90-4.04% (inter-day), respectively. The recoveries of three constituents ranged between 94.5 and 105.6%. The effects of pH value, buffer concentration and applied voltage on the migration behavior of HC, HMC and GC were investigated. The contents of the three active constituents in the flower of Cacalia tangutica were successfully determined within 6 min under the optimum conditions chosen. Moreover, the dissociation constants for three coumarins were also determined by CE.
A simple and rapid capillary electrophoretic method was developed for the simultaneous determination of noradrenaline (NA) and dopamine (DA) in Portulaca oleracea L. The buffer solution used in this method was 40 mM tris (hydroxymethyl) aminomethane (Tris)-H3PO4 at pH 2.00 containing 15% methanol. The effects of pH value, organic modifier, and applied voltage were investigated. The linear ranges of NA and DA were 0.5-100 microg/mL (r=0.9952) and 6.25-200 microg/mL (r=0.9992), respectively. The relative standard deviations of the corrected peak area were 6.73% and 4.26%, respectively. NA and DA in Portulaca oleracea L. were simultaneous determined successfully within 5.6 min. In this way, the contents of NA and DA in different parts (stem, leaves, and seeds) of P. oleracea L. and in different extracts of leaves with different solvents (distilled water, 50% methanol, and methanol) were studied.
One novel and seven known steroids were isolated from the alcohol extract of the whole plant of Saussurea ussuriensis. The structure of the new compound was elucidated as stigmast-5-en-3beta,7alpha,22-triol (1) by spectroscopic methods including intensive 2D NMR techniques (H1-H1 COSY, gHSQC, gHMBC) and HR-SI-MS and the known compounds were identified on the basis of comparing their NMR data with those of corresponding compounds in the literature.
[structure: see text] [structure: see text] Sesquiterpene lactones, ligulolide A (1) and 6beta,8alpha-dihydroxy-1-oxoeremophila-7(11),9(10)-diene-12,8-olide (2), were isolated from Ligularia virgaurea spp. oligocephala. Their structures were established by analysis of one- and two-dimensional NMR data. The relative stereostructures were determined on the basis of NOESY and single-crystal X-ray experiments. 1 represents a novel sesquiterpene carbon framework, and a possible biosynthetic process is proposed. 2 is a novel eremophilane-type sesquiterpene.
As part of an ongoing program to explore the chemical constituents of Caribbean marine invertebrates, a family of 13 new diterpene glycosides, pseudopterosins P-Z (1-11) and seco-pseudopterosins H (12) and I (13), have been isolated from the organic extracts of two collections of the sea whip Pseudopterogorgia elisabethae procured near the Colombian Southwestern Caribbean Sea. The structures of compounds 1-13, including absolute stereochemistry, have been proposed on the basis of comprehensive spectral analyses, chemical transformations, specific rotation, and TLC chromatographic analyses. Pseudopterosin Q (2) inhibited thromboxane B2 (TXB2) (IC50 = 4.7 microM) and superoxide anion (O2-) (IC50 = 11.2 microM) generation from E. coli lipopolysaccharide (LPS) activated rat neonatal microglia in vitro. In contrast, pseudopterosins P (1), U (6), V (7), W (8), and X (9) as well as seco-pseudopterosins H (12) and I (13) demonstrated minimal effects on both TXB2 and O2- release. In addition, some of the new compounds displayed strong antituberculosis, antiviral, antimalarial, and anticancer activity.
A new capillary electrophoresis (CE) method was established for simultaneous assay of six flavonoid O-glycosides, asebotin (AS), kaempferol 3- O-beta- D-glucopyranoside (KG), kaempferol 3- O-alpha- L-rhamnopyranoside (KR), 7-methoxykaempferol 3- O-alpha- L-rhamnopyranoside (KMR), quercetin 3- O-beta- D-glucopyranoside (QG) and quercetin 3- O-alpha- L-rhamnopyranoside (QR) obtained from Chinese herbal plant extract of Saussurea mongolica. The optimum buffer system was 30 mmol/L borate buffer (Na2B4O7/HCl, pH 9.00) with 40 % (v/v) methanol. Voltage was 15 kV and detection at 270 nm. The application of this method for the separation and determination of the six flavonoid O-glycosides in S. mongolica is reported. The relative standard deviations of migration times and peak areas were < 2.61 and 4.41%, respectively. The contents of six natural products ranged from 0.043 to 0.60 mg/g and recoveries ranged from 92.4 to 104.4%. The effects of pH value, buffer concentration, surfactant, beta -cyclodextrin and organic modifier on the separation were investigated.
From an extract of the whole plant of Ligularia virgaurea ssp. oligocephala, three new eremophilane sesquiterpene lactones, 10alpha-hydroxy-1-oxoeremophila-7(11),8(9)-dien-12,8-olide (1), 6alpha,10alpha-dihydroxy-1-oxoeremophila-7(11),8(9)-dien-12,8-olide (2), 6beta,10beta-dihydroxyeremophila-7(11),8(9)-dien-12,8-olide (3), as well as four known sesquiterpene lactones with the same carbon skeleton, named toluccanolides A-C (4, 5, 7) and 6beta-hydroxy-8alpha-methoxyeremophila-1(10),7(11)-dien-12,8beta-olide (6) were isolated. Their structures were elucidated by spectroscopic methods including intensive 2D NMR techniques (gCOSY, gHMQC, gHMBC and 1H-1H NOESY for 2) and HR-ESI-MS.
A novel nor-terpenoid, named lappulanocarpine A and a known terpenoid derivative, nine known steroids and three known long chine esters were isolated from the alcoholic extract of the whole plant of Lappula anocarpa. The novel structure was characterized by means of spectral methods including 1D-, 2D-NMR and HR-ESIMS and the known compounds were identified on the basis of comparing their NMR data with those of the corresponding compounds in the literature.
A simple, rapid and accurate high-performance liquid chromatographic (HPLC) technique coupled with photodiode array (PDA) detection was developed for the simultaneous determination of noradrenaline (NA) and dopamine (DA) in Chinese herbal plant extracts from the different parts of Portulaca oleracea L. The effects of various parameters, such as sodium dodecyl sulfate (SDS) concentration, pH value and proportion of methanol on chromatographic behavior of the analytes (NA and DA) were investigated. Separation of NA and DA was achieved within 10 min by a mobile phase consisting of 70% (v/v) methanol and 0.02 M potassium dihydrogen phosphate solution, which contained 30 mM SDS and was adjusted to pH 3.0 with H3PO4. NA and DA showed good linear relationships in the range of 0.004-6.00 microg and 0.011-8.25 microg respectively. The correlation coefficients of the calibration curve for the analytes exceeded 0.999. The detection limits for NA and DA were 0.40 ng and 0.55 ng, at a signal-to-noise ratio of 3, respectively. Moreover, the optimized HPLC method was employed to analyze three different parts of Portulaca oleracea L.
Capillary zone electrophoresis, using 30 mM borate buffer (pH 9.00) with 10% (v/v) methanol, was established for the identification and determination of four phenylpropanoid glycosides (PPGs)--echinocoside (ECH), verbascoside (VER), pedicularioside M (PED-M) and pedicularioside A (PED-A)--in extracts of Pedicularis longiflora var tubiformis, Pedicularis longiflora and Pedicularis Kansuensis. Regression equations revealed linear relationships (correlation coefficients: 0.9993-0.9999) between the peak area of each compound (ECH, VER, PED-M and PED-A) and its concentration. The relative standard deviations of the migration times and peak areas were <1.93 and 4.54%, respectively. The recoveries of four PPGs ranged between 95.6 and 108.4%. The effects of several CE parameters on the resolutions were studied systematically.
From the whole plant of Salvia roborowskii, four new germacrane sesquiterpene esters, 3beta,6beta,8alpha-triacetoxy-4beta,5alpha-epoxy-1-oxogermacr-10(14)-ene, 3beta,6beta,8alpha-triacetoxy-4beta,5alpha-epoxygermacr-1 (10) E-ene, 3beta,6beta,8alpha-triacetoxy-4beta,5alpha:1alpha,10beta-diepoxygermacrane and 6beta-acetoxyglechomafuran were isolated, and their structures were elucidated by spectroscopic methods including 2D NMR techniques (1H-1H COSY and 1H-1H NOESY for 1).