Biomedical subjects

Yu-Ying Zhao

Publications and source records attributed to Yu-Ying Zhao.

At least 19 recordsLinked to original sources

PubMed2006

Quantification and stability studies on the flavonoids of Radix hedysari.

Radix hedysari is not only a restorative food but also a famous Traditional Chinese Medicine. In this study, a simple, reliable, and reproducible high-performance liquid chromatography-ultraviolet method was developed for the first time to determine the true contents of five major flavoniods, naringenin-7-O-alpha-L-rhamanopyranosyl-(1-->2)-beta-d-glucopyranoside, ononin, formononetin, medicarpin, and an unstable flavonoid malonate (formononetin-7-O-beta-D-glucoside-6' '-O-malonate, FGM), and the stability of FGM was also investigated. Flavoniods were selected as chemical markers because they have appeared as one of the major bioactive compound groups in Radix hedysari. The stability results of FGM at different pH showed that it remained relatively stable in acidic aqueous methanol of pH 3. The HPLC assay with an improved sample preparation scheme can be readily utilized as a suitable "chemical" quality control method for Radix hedysari.

Chromatography, High Pressure Liquid↗

PubMed2006

Coumestans from Hedysarum multijugum.

Ten coumestans were isolated from the roots of Hedysarum multijugum. Their structures were elucidated as the new hedysarimcoumestans A-H (1-8), 1,3,9-trimethoxycoumestan (9), and aureol (10), on the basis of spectroscopic analyses.

Coumarins↗

PubMed2006

Calcium channel blocking activity of calycosin, a major active component of Astragali Radix, on rat aorta.

AIM: To investigate the vasoactivity of calycosin, a major active component of Astragali Radix. METHODS: Experiments were performed on isolated rat thoracic aortic rings pre-contracted with phenylephrine (PHE) or KCl. RESULTS: Calycosin produced a concentration-dependent relaxation on the tissue pre-contracted using PHE with 4.46+/-0.13 of pD(2) and 95.85%+/-2.67% of E(max); or using KCl with 4.27+/-0.05 of pD2 and 99.06%+/-2.15% of Emax, and displaced downwards the concentration-response curves of aortic rings to PHE or KCl. The relaxant effect of calycosin on denuded endothelium aortic rings was the same as on intact endothelium aortic rings, and its vasorelaxant effect was not influenced by L-NAME or indomethacin. In Ca(2+)-free solution, calycosin (30 micromol/L) did not have an effect on PHE (1 micromol/L)-induced aortic ring contraction. The effects of calycosin and nifedipine where somewhat different; calycosin decreased aortic ring contractions induced by the two agonists, but nifedipine displayed a more potent inhibitory effect on KCl-induced contractions than on PHE-induced contractions, and the vascular relaxing effects of calycosin and nifidipine were additive on PHE-induced contraction but not KCl-induced. CONCLUSION: Calycosin is a vasorelaxant. Its action is endothelium-independent and is unrelated to intracellular Ca(2+) release. It is a noncompetitive Ca(2+) channel blocker. The effect of calycosin on Ca(2+) channel blockade may be different from that of dihydropyridines. This study demonstrated a novel pharmacological activity of calycosin, and supplied a theoretic foundation for Astragali Radix application.

Animals↗

PubMed2006

A cytotoxic saponin from Albizia julibrissin.

A new triterpenoidal saponin (1: Julibroside J(21)) with a xylopyranosyl moiety located at its C-21 side chain was isolated from Albizia julibrissin DURAZZ. (Leguminosae), and its structure was determined on the basis of comprehensive spectroscopic analyses. Compound 1 showed marked inhibitory action against Bel-7402 cancer cell line at 10 microg/ml.

Albizzia↗

PubMed2006

[Studies on chemical constituents in flower of Abelmoschus manihot].

OBJECTIVE: To study the chemical constituents of Abelmoschus manihot. METHOD: Chromatographic methods were used to isolate compounds from A. manihot, and spectroscopic methods were used to identify the structures. RESULT: Thirteen compounds, myricetin (1), cannabiscitrin (2), myricetin-3-O-beta-D-glucopyranoside (3), glycerolmonopalmitate (4), 2, 4-dihydroxy benzoic acid (5), guanosine (6), adenosine (7), maleic acid (8), heptatriacontanoic acid (9), 1-triacontanol (10) , tetracosane (11), beta-sitosterol (12), beta-sitosterol-3-O-beta-D-glucoside (13) were obtained. CONCLUSION: 2-11 were obtained from the genus for the first time.

Abelmoschus↗

PubMed2005

Haplotype assembly from aligned weighted SNP fragments.

Given an assembled genome of a diploid organism the haplotype assembly problem can be formulated as retrieval of a pair of haplotypes from a set of aligned weighted SNP fragments. Known computational formulations (models) of this problem are minimum letter flips (MLF) and the weighted minimum letter flips (WMLF; Greenberg et al. (INFORMS J. Comput. 2004, 14, 211-213)). In this paper we show that the general WMLF model is NP-hard even for the gapless case. However the algorithmic solutions for selected variants of WMFL can exist and we propose a heuristic algorithm based on a dynamic clustering technique. We also introduce a new formulation of the haplotype assembly problem that we call COMPLETE WMLF (CWMLF). This model and algorithms for its implementation take into account a simultaneous presence of multiple kinds of data errors. Extensive computational experiments indicate that the algorithmic implementations of the CWMLF model achieve higher accuracy of haplotype reconstruction than the WMLF-based algorithms, which in turn appear to be more accurate than those based on MLF.

Algorithms↗

PubMed2005

Two new isoprenyl chalcones from Hedysarum gmelinii.

Two new isoprenyl chalcones, 1-[2,4-dihydroxy-3-(2-hydroxy-3-methyl-3-butenyl)phenyl]-3-(2,2-dimethyl-2H-benzopyran-6-yl)-2-propen-1-one and 1-[4-hydroxy-2-(1-hydroxy-1-methyl-ethyl)-2,3-dihydro-benzofuran-5-yl]-3-[3-(3-methyl-2-butenyl)-4-hydroxy-phenyl]-2-propen-1-one, named hedysarumine A and hedysarumine B, along with a known isoprenyl chalcone paratocarpin E were isolated from the roots of Hedysarum gmelinii for the first time. Their structures were elucidated based on NMR and MS spectral analyses.

Benzofurans↗

PubMed2005

Flavonoids from Millettia nitida var. hirsutissima.

From the stems of Millettia nitida var. hirsutissima, three new isoflavone glycosides, formononetin 7-O-beta-D-(6''-ethylmalonyl)-glucopyranoside (1, hirsutissimiside A), 5-O-methyl genistein 7-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (3, hirsutissimiside B), retusin 7,8-di-O-beta-D-glucopyranoside (4, hirsutissimiside C) and two known isoflavone glycosides (2) and (5) have been isolated. The structures of the compounds were determined by spectroscopic and chemical means.

Carbohydrate Conformation↗

PubMed2004

A new alkaloid from Dysoxylum binectariferum.

Two compounds (1 and 2) have been isolated from the stem bark of Dysoxylum binectariferum (Roxb.) Hook. f. ex Bedd. Compound 1 is rohitukine [5,7-dihydroxy-2-methyl-8-[4-(3-hydroxy-1- methyl)-piperidinyl]-4H-1-benzopyran-4-one], a known compound that has anti-inflammatory and immunomodulatory activities. Compound 2 is a new alkaloid, named rohitukine N-oxide, the structure of which was elucidated on the basis of spectral evidences and comparison with the 1H NMR data of rohitukine.

Alkaloids↗

PubMed2004

New flavonoids from Oxytropis myriophylla.

Eight compounds were isolated from Oxytropis myriophylla. On the basis of spectral analyses, their structures were elucidated to be (6R,9R)-roseoside (1), (6R,9S)-roseoside (2), adenosine (3), myriophylloside B (4), myriophylloside C (5), myriophylloside D (6), myriophylloside E (7), and myriophylloside F (8). Five flavonoids (4-8) were new compounds, and the three known compounds were isolated from this plant for the first time.

Drugs, Chinese Herbal↗

PubMed2004

[A new triterpenoid saponin julibroside J24 from the stem bark of Albiza julibrissin].

OBJECTIVE: To separate chemical and active constituents from the stem bark of Albiza julibrissin. METHODS: Chromatography and spectral methods were used. RESULTS: 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranosyl-21-O-[(6S)-2-trans-2-hydroxymethyl-6-methyl-6-O-[3-O-(6S)-2-trans-2-hydroxymethyl-6-methyl-6-hydroxy-2,7-octadienoyl)-beta-D-xylopyranosyl]-2,7-octadienoyl]-acacic acid-28-O-beta-D-glucopyranosyl-(1-->3)-[alpha-L-arabinofuranosyl-(1-->4)]-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl ester (1) was separated and identified. CONCLUSION: Compound 1 is a new saponin named as Julibroside J(24).

Albizzia↗

PubMed2004

[Studies on the chemical constituents from Potentilla multifida L].

OBJECTIVE: To study the chemical constituents of Potentilla multifida L. METHODS: Chemical constituents were isolated by the repeated silica gel chromatography and Sephadex LH-20, and their structures were identified by the spectral analysis. RESULTS: Five compounds were obtained as follows: 3beta,24-dihydroxyl-urs-12-ene (1), ursolic acid (2), euscaphic acid (3), tormentic acid (4), and epihedaragenin (5). CONCLUSION: Five compounds were isolated from this plant for the first time. Compounds 1 and 5 were isolated from this genus for the first time. Compound 1 was a new natural product.

Magnetic Resonance Spectroscopy↗

PubMed2004

[Isolation and structure identification of C-25 epimers of inokosterone from Achyranthes bidentata Blume].

AIM: To isolate C-25 epimers of inokosterone from Achyranthes bidentata Blume. and identify their structures. METHODS: To separate C-25 epimers of inokosterone by using various kinds of chromatography methods and identify their structures on basis of spectral analysis and chemical method. RESULTS: Three compounds were isolated and their structures were established as 25S-inokosterone (1), 25R-inokosterone (2) and ecdysterone (3). CONCLUSION: Compounds 1 and 2 are new C-25 configuration isomers from Achyranthes bidentata Blume., their absolute configurations are elucidated at the first time, and their 13CNMR data are reported for the first time.

Achyranthes↗

PubMed2003

Glycosyl flavonoids from the roots and rhizomes of Asarum longerhizomatosum.

Two new glycosyl flavonoids including a glycosyl aurone, together with six known flavonoids were isolated from the roots and rhizomes of Asarum longerhizomatosum. The structures of the two new compounds were elucidated as 4,6,4'-trihydroxy-aurone-4,6-di-O-beta-D-glucopyranoside (7, caulesauroneside) and naringenin-7,4'-di-O-beta-D-glucopyranoside (8, caulesnarinside). The six known flavonoids were identified as naringenin (1), naringenin-5-O-beta-D-glucopyranoside (2), naringenin-7-O-beta-D-glucopyranoside (3), chalcononaringenin-2'-O-beta-D-glucopyranoside (4), naringenin-5,7-di-O-beta-D-glucopyranoside (5), chalcononaringenin-2',4'-di-O-beta-D-glucopyranoside (6), respectively. This is the first report of the isolation of aurones in the family Aristolochiaceae.

Asarum↗

PubMed2003

Two new pterocarpenes from Hedysarum multijugum.

Two new pterocarpenes were isolated from the roots of Hedysarum multijugum, and their structures were elucidated as hedysarimpterocarpene B (1) and hedysarimpterocarpene C (2) on the basis of spectroscopic data.

Fabaceae↗

PubMed2003

[Studies on the constituents from the stems of Spatholobus suberectus].

OBJECTIVE: To investigate the constituents from the Stems of Spatholobus suberectus. METHOD: The chemical constituents were isolated by column chromatography and their strutures were identified on base of physical and spectral data. RESULT: Five compounds were isolated and identified as 2-methoxy-4-(2'-hydroxyethyl)-phenyl-1-O-beta-D-glucopyranoside (1), n-butyl-O-beta-D-fructo pyranoside (2), glycerol-alpha-pentacosanoate (3), betulinic acid (4) and hexacosanoic acid (5). CONCLUSION: The five compounds were obtained for the frist time from the stems of Spatholobus suberectus.

Fabaceae↗

PubMed2002

New thiophenes from Echinops grijisii.

A new thiophene-echinoynethiophene A (11), four new natural products, namely 5,5"-dichloro-alpha-terthiophene (1), 5-chloro-alpha-terthiophene (2), 5-acetyl alpha-terthiophene (3) and 5-carboxyl bithiophene (12), together with seven known thiophenes were isolated and purified from ethanol extract of roots of Echinops grijisii Hance. Their structures were identified on the basis of spectral data.

Alkynes↗

PubMed2002

Phenolic glucosides from Oxytropis myriophylla.

Three phenolic glucosides were isolated from Oxytropis myriophylla. On the basis of spectral analyses, their structures were elucidated as 2-methoxy-4-(3'-hydroxy-n-butyl)-phenol-1-O-beta-D-glucopyranoside (1), syringin (2), 2-methoxy-4-(3'-hydroxy-propenyl)-phenol-1-O-beta-D-glucopyranoside (3). Compound (1) is a new phenolic glucoside named myriophylloside A, the other two compounds are isolated from this plant for the first time.

Fabaceae↗