Biomedical subjects

Yingjie Chen

Publications and source records attributed to Yingjie Chen.

30 records · Page 2Linked to original sources

PubMed2004

Two new galloylglucosides from the leaves of Mallotus furetianus.

Two new galloylglucosides, mallophenols A (1) and B (2), were isolated from the leaves of Mallotus furetianus (Euphorbiaceae), together with seven known compounds, (6S,9R)-roseoside (3), aviculin (4), (+)-lyoniresinol-3alpha-O-alpha-L-rhamnopyranoside (5), (Z)-3-hexenyl-beta-D-glucopyranoside (6), 3,3,8,9,10-pentahydroxydibenzo[b,d]pyran-6-one (7), 3-hydroxy-4,5(R)-dimethyl-2(5H)-furanone (8) and gallic acid (9). The stereostructures of 1 and 2 were elucidated on the basis of spectroscopic analysis and chemical evidence.

Glucosides↗

PubMed2003

White spot syndrome virus (WSSV) infectivity for Artemia at different developmental stages.

White spot syndrome virus (WSSV) is a major pathogen of cultivated shrimp, but its host range includes a large number of crustaceans. In this investigation, Artemia franciscana was tested for susceptibility to WSSV by the oral route. Both instars and adults were challenged, and the presence of WSSV was followed through to reproductive cysts and offspring using PCR. WSSV caused a much lower cumulative mortality in Artemia than in cultivated shrimp by 10 d post-challenge. Instars, adults and reproductive cysts were PCR positive. However, the virus was undetectable by PCR in nauplii that had hatched from PCR-positive reproductive cysts. The data indicate that WSSV or WSSV genomic DNA can be vertically transmitted from WSSV-PCR-positive instars to reproductive cysts, but this DNA is removed during hatching.

Animals↗

PubMed2003

Preparative isolation and purification of two isoflavones from Astragalus membranaceus Bge. var. mongholicus (Bge.) Hsiao by high-speed counter-current chromatography.

Two isoflavones, calycosin-7-O-beta-D-glycoside and formononetin-7-O-beta-D-glycoside, were separated from n-butanol extract of the root of Astragalus membranaceus Bge. var. mongholicus (Bge.) Hsiao by high-speed counter-current chromatography in two steps using two different solvent systems composed of ethyl acetate-ethanol-n-butanol-water (30:10:6:50, v/v) and ethyl acetate-ethanol-water (5:1:5, v/v). From 200 mg of crude extract, calycosin-7-O-beta-D-glycoside (12 mg) and formononetin-7-O-beta-D-glycoside (10 mg) were isolated at over 95% purity by HPLC analyses, and their structures were identified by MS, 1H NMR and 13C NMR.

Astragalus propinquus↗

PubMed2003

Steroidal glycosides from the rhizomes of Dioscorea spongiosa.

A water extract of the rhizomes of Dioscorea spongiosa, which showed antiosteoporotic activity, was examined, and four new pregnane glycosides, named spongipregnolosides A-D (1-4), and two new cholestane glycosides, named spongiosides A (5) and B (6), were isolated together with 15 known glycosides. Their structures were determined on the basis of spectroscopic analysis and chemical methods. Among the isolated compounds, spongioside A (5), hypoglaucin G (7), methylprotodioscin (8), and (R)-oct-1-en-3-yl O-alpha-l-arabinopyranosyl-(1-->6)-alpha-d-glucopyranoside (9) showed potent inhibition against bone resorption induced by parathyroid hormone in a bone organ culture system.

Animals↗

PubMed2003

Proteomic analysis of proteins that binds specifically to the homologous repeat regions of white spot syndrome virus.

White spot syndrome virus (WSSV) is a major pathogen in the cultivated shrimp. Nine homologous repeat regions (hrrs) have been reported interspersed throughout the WSSV genome. In this investigation, the protein fraction that specifically bound to the hrrs was isolated by using DNA-affinity chromatography. A total of 9 (S1 to S9) and 5 (C1 to C5) proteins separated from the WSSV infected shrimp and the healthy shrimp, respectively, were detected by using two-dimensional polyacrylamide gel electrophoresis, and 6 proteins changed with WSSV infection were analyzed by mass spectrometry (MS). One (S4) of the 6 proteins examined was identified as WSSV ORF59 protein, and another (S3) was a shrimp arginine kinase. No homologous proteins were found with the remaining 4 proteins by searching in the WSSV ORF database and NCBI database. The specific binding site of the 6 proteins was then determined by gel mobility shift assay (GMSA). Temporal analysis revealed that ORF59 gene was transcribed at the early stage of the infection. The results we obtained provide important information to understand WSSV replication. The combination of DNA-affinity chromatography, 2D-PAGE and MS approaches should have general application to the identification of gene regulating proteins of WSSV. The results represent the first isolation of a set of proteins that bind to the hrrs, and, furthermore, lead us a new research direction for the prevention and the therapy of WSSV.

Animals↗

PubMed2003

A novel biflavonoid from roots of Glycyrrhiza uralensis cultivated in China.

A novel biflavonoid named licobichalcone was isolated from the roots of Glycyrrhiza uralensis cultivated in China, along with twelve known compounds, including five chalcones, two isoflavones, two flavanones, two flavones and one pterocarpan. Their structures were respectively elucidated on the basis of chemical and spectroscopic evidence.

Acetylation↗

PubMed2002

Preparative isolation and purification of calycosin from Astragalus membranaceus Bge. var. mongholicus (Bge.) Hsiao by high-speed counter-current chromatography.

Calycosin was purified from an ethyl acetate extract of the root of Astragalus membranaceus Bge. var. mongholicus (Bge.) Hsiao by high-speed counter-current chromatography. The separation was performed in two steps with a two-phase solvent system composed of n-hexane-chloroform-methanol-water (1:3:3:2, v/v). From 200 mg of the crude extract, 14.8 mg of calycosin was obtained at over 99% purity as determined by HPLC analysis, and its chemical structure was confirmed by MS, 1H and 13C nuclear magnetic resonance.

Astragalus Plant↗

PubMed2002

Supercritical fluid extraction for the separation of organochlorine pesticides residue in Angelica sinensis.

A method involving the simultaneous extraction and separation of 12 organochlorine pesticides (OCPs) from Angelicae sinensis was developed using supercritical fluid extraction (SFE). The pesticides in the study were alpha-, beta-, gamma- and delta-benzene hexachloride, PCNB (pentachloro- nitrobenzene), PCA (pentachloroaniline), HEPT (heptachlor), MPCPS (methyl-pentachlorophenyl sulfide), pp'-DDE [1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene], op'-DDT [1,1,1,-trichloro-2-(o-chlorophenyl)-2-(p-chlorophenyl) ethane], pp'-DDD [1,1-dichloro-2,2-bis(p-chlorophenyl) ethane], and pp'-DDT [1,1,1,-trichloro-2,2-bis (p-chlorophenyl)ethane]. The extraction conditions were optimized as follows: pure CO(2), extraction pressure 15 MPa, extraction temperature 60 degrees C, extraction time 20 min, and flow-rate 1.5 mL/min. A GC method with electron capture detection was employed to determine the OCPs in Angelicae sinensis. An HPLC method was developed for the quantitative determination of active constituents. The SFE provided high decontamination rate of OCPs and low loss of active constituents in Angelicae sinensis.

Angelica sinensis↗

PubMed2002

Structure-activity relationships of flavonoids, isolated from Scutellaria baicalensis, binding to benzodiazepine site of GABA(A) receptor complex.

Twenty-six flavonoids were isolated from Scutellaria baicalensis. Their affinities for the benzodiazepine (BDZ) binding site of GABA A receptor have been studied using [ 3H]flunitrazepam binding to rat cortical membranes in vitro. The structure-activity relationships suggested that 2'-OH flavones exhibited the most potent binding affinity, which could lead to the design and discovery of new BDZ receptor ligands.

Animals↗

PubMed2002

Inhibition of NO production increases myocardial blood flow and oxygen consumption in congestive heart failure.

Coronary blood flow (CBF) and myocardial oxygen consumption (MVO(2)) are reduced in dogs with pacing-induced congestive heart failure (CHF), which suggests that energy metabolism is downregulated. Because nitric oxide (NO) can inhibit mitochondrial respiration, we examined the effects of NO inhibition on CBF and MVO(2) in dogs with CHF. CBF and MVO(2) were measured at rest and during treadmill exercise in 10 dogs with CHF produced by rapid ventricular pacing before and after inhibition of NO production with N(G)-nitro-L-arginine (L-NNA, 10 mg/kg iv). The development of CHF was accompanied by decreases in aortic and left ventricular (LV) systolic pressure and an increase in LV end-diastolic pressure (25 +/- 2 mmHg). L-NNA increased MVO(2) at rest (from 3.07 +/- 0.61 to 4.15 +/- 0.80 ml/min) and during exercise; this was accompanied by an increase in CBF at rest (from 31 +/- 2 to 40 +/- 4 ml/min) and during exercise (both P < 0.05). Although L-NNA significantly increased LV systolic pressure, similar increases in pressure produced by phenylephrine did not increase MVO(2). The findings suggest that NO exerts tonic inhibition on respiration in the failing heart.

Animals↗

PubMed2002

Constituents with radical scavenging effect from Opuntia dillenii: structures of new alpha-pyrones and flavonol glycoside.

The aqueous ethanolic extract from the fresh stems of Opuntia dillenii HAW. showed potent radical scanvenging activity. Three new compounds, opuntioside I, 4-ethoxyl-6-hydroxymethyl-alpha-pyrone, and kaempferol 7-O-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranoside, were isolated from the extract. The structures of the new compounds were determined on the basis of chemical and physicochemical evidence and the radical scavenging effects of principal constituents were examined.

Flavonoids↗

PubMed2002

Two flavones from Scutellaria baicalensis Georgi and their binding affinities to the benzodiazepine site of the GABAA receptor complex.

A new flavone 6,2'-dihydroxy-5,7,8,6'-tetramethoxyflavone (1) together with one known flavone 5,7,2'-trihydroxy-6,8-dimethoxyflavone (2) were isolated from the roots of Scutellaria baicalensis Georgi. Their structures were elucidated on the basis of spectral evidence and their affinities for the benzodiazepine (BDZ) site of the GABAA receptor complex were evaluated with a radioligand receptor binding assay.

Animals↗