Publications by authors named "Changqi Hu"

Objectives: This study aims to determine the clinical effect of an external attachment implant, called JUST J1 MINI (hereafter referred to as J1 implant), with simple tonal retention on the narrow alveolar area of the anterior teeth (4.5-5.5 mm).

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Objective: To explore the changes in bone height of the maxillary sinus floor at different sinus ridge heights after transcrestal sinus floor elevation (tSFE) with the simultaneous implantation of short implants.

Methods: A total of 74 Bicon short implants were implanted into 37 patients during the same period of maxillary sinus elevation. The residual bone height (RBH)<4 mm group has 43 sites, and the RBH≥4 mm group has 31 sites.

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Objective: To study the chemical constituents in roots of Caragana sinica.

Method: The constituents were isolated by silica gel column chromatography, and their structures were identified by spectroscopic methods.

Result: Seven compounds were identified as (+) - stenophyllol B (1), 4-hydroxybenzoic acid (2), odoratin (3), resveratrol (4), cararosinol A (5), leachinol C (6), carasinaurone (7) respectively.

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The conversion from kobophenol A into carasinol B, two main chemical constituents of Caragana sinica, was confirmed by in vitro acid-catalyzed epimerization. The result provides important information about the biotransformation of kobophenol A in plants and its metabolism in rats.

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The asymmetric unit of the title compound, C(18)H(24)O(6)·H(2)O, contains a 14-membered macrolide mol-ecule and a water mol-ecule. In the crystal structure, intra-molecular C-H⋯O and O-H⋯O hydrogen bonds help to stabilize the mol-ecular conformation, while inter-molecular O-H⋯O hydrogen bonds link the mol-ecules, forming an infinite network. The absolute configuration was assigned by comparison with related zearalenone compounds, but needs verification.

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The title compound, C(16)H(14)O(7)·H(2)O, possesses a planar three-ring skeleton; its carbonyl, one of the two hydroxy and two of the three methoxy O atoms and the water mol-ecule form hydrogen bonds, giving rise to a layer structure.

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This study was intended to look for anti-HIV chemical constituents of aerial parts of Caragana rosea Turcz. Column chromatographic technique was used for the isolation and purification of constituents of Caragana rosea under the guide of anti-HIV assay. The structures were established on the basis of physical and chemical properties and spectroscopic data.

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The X-ray single-crystal structure of natural salidroside (=2-(4-hydroxyphenyl)ethyl beta-D-glucopyranoside; 1), isolated from Cistanche deserticola, is reported for the first time, as well as its absolute configuration. The radical-scavenging activity of 1 towards the superoxide radical anion (O*2-) was determined experimentally by chemiluminescence measurements of the pyrogallol-luminol system, and compared to that of the corresponding aglycone, i.e.

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The biological effects of soy isoflavones have attracted considerable interest in recent years, leading to numerous studies on dietary intake and epidemiology. (-)-(S)-equol (3) is a metabolite produced in vivo from the isoflavone daidzein, a kind of soy phytoestrogen, by the action of gut microflora. It has higher biological activity than its precursor.

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During our studies on the metabolism of kobophenol A (1) in rats, we had isolated, purified, and identified the main new oxidative metabolite of 1, koboquinone A (2) from rats' feces. To elucidate the metabolic pathway of 1 in rats, we conducted the in vitro metabolic experiments of 1 by human intestinal bacteria and found that Klebsiella pneumoniae produced appreciable amounts of 2. This was verified by means of high performance liquid chromatography mass/mass spectrometry (HPLC/MS/MS) analysis.

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The objectives of this research were to determine simultaneously the contents of two stilbene tetramers, carasinol B (1) and kobophenol A (2), and one stilbene trimer, (+)-alpha-viniferin (3), in Jin Que-gen in different regions. A HPLC method has been developed for efficiently quantifying the three analytes in the plant. Using this method, different samples of Jin Que-gen were evaluated.

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Objective: To study the chemical constituents from Caragana intermedia.

Methods: The compounds were separated by chromatography methods. Their structures were identified by spectral analysis.

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Natural products derived from plants provide a rich source for development of new anticancer drugs. Recent studies suggest that modulation of subcellular localization of retinoid X receptor-alpha (RXRalpha) represents a potential approach for inducing cancer cell apoptosis. In this study, we screened a herbal library for inducing translocation of RXRalpha from the nucleus to the cytoplasm.

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The objectives of this research were to determine simultaneously the contents of two stilbene tetramers, carasinol B (1) and kobophenol A (2), and one stilbene trimer, (+)-alpha-viniferin (3), in the roots, tubers, and leaves of Caragana sinica in various seasons. A HPLC method has been developed for efficiently quantifying the three analytes in the plant. Using this method, different samples of Caragana sinica were evaluated.

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This research aims to study the metabolism and pharmacokinetics of phytoestrogen kobophenol A (1), the main active compound of Caragana sinica (Buc'hoz) Rehd. (Fabaceae), in rats. Metabolites of 1 in rats' feces were isolated and purified by multi-chromatograph techniques; three new metabolites of 1, named koboquinone A (M1), koboquinone B (M2) and koboquinone C (M3), were isolated, purified from rats' feces after they being orally administered with 1.

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Bioassay-guided fractionation of the ethanol extract of the aerial parts of Caragana rosea Turcz. led to the isolation of two new (cararosinol C and cararosinol D) and four known [scirpusin A (1), cis-scirpusin A (2), maackin (3), scirpusin B (4)] stilbene dimers. This is the first identification of these compounds from this plant and the first time that compound 2 has been isolated as a natural compound.

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A new resveratrol dimer, carasiphenol A (1), and a new resveratrol trimer, carasiphenol B (2), have been isolated from the aerial parts of Caragana sinica. Their structures have been elucidated from spectroscopic evidence, especially HMBC and NOE experiments. The relative configuration of the known dimer pallidol (6) was confirmed by X-ray diffraction.

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Four new eudesmanes, namely, 4(15)-eudesmene-1beta,7alpha-diol (1), 4(15)-eudesmene-1beta,7beta-diol (2), 7-trinoreudesma-4(15),8-dien-1beta-ol-7-one (3), and eudesma-4(15),7-dien-1beta-ol (4), as well as three known compounds, 5-epi-eudesma-4(15)-ene-1beta,6beta-diol (5), 4(15)-eudesmene-1beta,6alpha-diol (6), and 4(15)-eudesmene-1beta,5alpha-diol (7), were isolated from the aerial part of Caragana intermedia. The structures were elucidated by spectroscopic and spectrometric analyses including 1D, 2D NMR, HRMS, and IR. The structures of compounds 1, 5, 6, and 7 were confirmed by X-ray crystallographic analysis.

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Two new phase I metabolites of phytoestrogen kobophenol A (1), called koboquinone A (2) and B (3), have been isolated from the feces of rats orally administered 1. Their structures were determined by spectroscopic methods. 2 also showed activity of stimulating the proliferation of cultured osteoblasts.

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Aim: To study the chemical constituents of Caragana intermedia.

Methods: The compounds were separated by chromatography methods, their structures were identified by spectral analysis.

Results: Ten compounds were isolated and identified as 5,7,4'-trihydroxy-3,3'-dimethoxyflavone (1), 3,5,7,8,4'-pentahydroxy-3'-methoxyflavone(2), puercetin(3), limocitrin(4), 5,7,3',4'-tetrahydroxy-3-methoxyflavone(5), 7,3',5'-trihydroxyflavanone(6), 5,7,3',4'-tetrahydroxy-3,8-dimethoxyflavone(7), butein(8), liquiritigenin(9) and 5,7,4'-trihydroxy-3,8-dimethoxyflavone(10).

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To examine the binding sites of miyabenol C (Miy C) and kobophenol A ( Kob A) with estrogen receptor (ER), computer modeling was applied to determine 3D structure of Miy C and Kob A. Molecular docking of the components to ER was carried out to find the binding sites between them. PCR mutagenesis was used to change the structure of ER cDNA.

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Aim: To improve E-screen assay and make it more accurate to screen estrogenic compounds.

Methods: Estrogen receptor antisense RNA expression plasmid (pCASER) was constructed and introduced into MCF-7 with lipofectAMINE(TM), and positive clones were screened out with G418. PCR amplification was employed to identify whether estrogen receptor (ER) cDNA fragment had been inserted into MCF-7 cell genomes.

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