Biomedical subjects

Zhi-Hong Jiang

Publications and source records attributed to Zhi-Hong Jiang.

At least 19 recordsLinked to original sources

PubMed2006

Amplification of DNA-binding affinities of protoberberine alkaloids by appended polyamines.

This communication describes a synthetic approach toward the amplification of the moderate DNA-binding affinities of protoberberine alkaloids. Specifically, three protoberberine derivatives bearing two to six primary amino groups at the 3- and 9-positions of protoberberine were synthesized and characterized by NMR ((1)H and (13)C) and HRMS. Studies on their affinities toward calf thymus (CT) DNA by ethidium bromide (EB) displacement and spectrophotometric titration experiments indicate that these polyamino protoberberines show more than 10(3)-fold enhanced DNA-binding affinities relative to palmatine and thus are exploitable as strong DNA-binders.

Acylation↗

PubMed2006

Determination of glucosinolates in traditional Chinese herbs by high-performance liquid chromatography and electrospray ionization mass spectrometry.

A reversed-phase HPLC method has been developed for determination of twelve intact glucosinolates--glucoiberin, glucocheirolin, progoitrin, sinigrin, epiprogoitrin, glucoraphenin, sinalbin, gluconapin, glucosibarin, glucotropaeolin, glucoerucin, and gluconasturtiin--in ten traditional Chinese plants. The samples were extracted with methanol and the extracts were cleaned on an activated Florisil column. A mobile phase gradient prepared from methanol and 30 mmol L(-1) ammonium acetate at pH 5.0 enabled baseline separation of the glucosinolates. Glucosinolate detection was confirmed by quadrupole time-of-flight tandem mass spectrometric analysis in negative-ionization mode. Detection limits ranged from 0.06 to 0.36 microg g(-1) when 5 g of dried plant was analyzed. Recoveries of the glucosinolates were better than 85% and precision (relative standard derivation, n = 3) ranged from 5.3 to 14.6%. Analysis of the glucosinolates provided scientific evidence enabling differentiation of three pairs of easily confused plants.

Chromatography, High Pressure Liquid↗

PubMed2006

Combinative method using HPLC quantitative and qualitative analyses for quality consistency assessment of a herbal medicinal preparation.

A selective and efficient quality consistency assessment system was developed for monitoring the manufacturing processes of a Chinese herbal preparation, qingfu guanjieshu (QFGJS) capsule, and for assessing its stability over time. This system is based on quantitative determination of four marker compounds, i.e., sinomenine, paeoniflorin, paeonol, and curcumin, and on qualitative fingerprinting analysis of QFGJS using high-performance liquid chromatography-photodiode array detection (HPLC-DAD) method. The separation was performed on a Phenomenex ODS column by gradient elution with acetonitrile and aqueous phase (containing 0.1% phosphoric acid, adjusted with triethylamine to pH 3.5+/-0.2) at a flow-rate of 1.0 ml/min. In fingerprinting analysis, the chemical characteristics of four herbs present in QFGJS (excluding radix Aconiti Lateralis Preparata) were present in the HPLC chromatographic file. In addition, quantitative determination of hypaconitine was carried out with our published HPLC method as a supplement for quality control of the radix Aconiti Lateralis Preparata in QFGJS. The results showed that the contents of these five marker compounds and HPLC fingerprint profiles of three batches of QFGJS products collected at 3 months after production in the stability testing were relatively consistent. This well-developed method could be used for quality assessment of the complex preparations of herbal medicine.

Aconitine↗

PubMed2006

DNA-binding affinities and sequence selectivity of quaternary benzophenanthridine alkaloids sanguinarine, chelerythrine, and nitidine.

A comparative study on the intercalating binding of sanguinarine, chelerythrine, and nitidine with CT DNA, poly(dG-dC).poly(dG-dC), poly(dA-dT).poly(dA-dT), and seven sequence-designed double-stranded oligodeoxynucleotides has been performed using fluorometric and spectrophotometric techniques, aiming at providing insights into their sequence selectivity for DNA-binding. The results show that both sanguinarine and nitidine bind preferentially to DNA containing alternating GC base pairs [d(TGCGCA)(2)], while chelerythrine exhibits quite distinct sequence selectivity from sanguinarine, which shows a high specificity for DNA containing contiguous GC base pairs [5'-TGGGGA-3'/3'-ACCCCT-5'].

Alkaloids↗

PubMed2006

The angiosuppressive effects of 20(R)- ginsenoside Rg3.

Aberrant angiogenesis is an essential step for the progression of solid tumors. Thus anti-angiogenic therapy is one of the most promising approaches to control tumor growth. In this study, we examined the ability of 20(R)-ginsenoside Rg3 (Rg3), one of the active compounds present in ginseng root, to interfere with the various steps of angiogenesis. Rg3 was found to inhibit the proliferation of human umbilical vein endothelial cells (HUVEC) with an IC50 of 10 nM in Trypan blue exclusion assay. Rg3 (1-10(3) nM) also dose dependently suppressed the capillary tube formation of HUVEC on the Matrigel in the presence or absence of 20 ng/ml vascular endothelial growth factor (VEGF). The VEGF-induced chemoinvasion of HUVEC and ex vivo microvascular sprouting in rat aortic ring assay were both significantly attenuated by Rg3. In addition, Rg3 (150 and 600 nM) remarkably abolished the basic fibroblast growth factor (bFGF)-induced angiogenesis in an in vivo Matrigel plug assay. The Matrix metalloproteinases (MMPs), such as MMP-2 and MMP-9, which play an important role in the degradation of basement membrane in angiogenesis and tumor metastasis present in the culture supernatant of Rg3-treated aortic ring culture were found to decrease in their gelatinolytic activities. Taken together, these data underpin the anti-tumor property of Rg3 through its angiosuppressive activity.

Angiogenesis Inhibitors↗

PubMed2006

Spacer length and attaching position-dependent binding of synthesized protoberberine dimers to double-stranded DNA.

Six jatrorrhizine homodimers and berberine-jatrorrhizine heterodimers have been synthesized in moderate to good yields from the reaction of jatrorrhizine with alpha,omega-dibromoalkanes and 9-O-(omega-bromoalkyl)berberines, respectively. Their binding activities toward calf thymus (CT) DNA and three double-stranded oligodeoxynucleotides, d(AAGAATTCTT)(2), d(TAAGAATTCTTA)(2), and d(TTAAGAATTCTTAA)(2), were investigated by means of spectrofluorimetric and spectrophotometric titrations. The results indicate that these dimers exhibit enhanced DNA-binding affinities due to the cooperative interaction of the two protoberberine subunits. A comparative study of the DNA-binding behaviors of berberine homodimers, jatrorrhizine homodimers, and berberine-jatrorrhizine heterodimers suggests that spacer length and attaching position are of great importance in modulating their DNA-binding affinities.

Berberine↗

PubMed2006

High-performance liquid chromatography coupled with tandem mass spectrometry applied for metabolic study of ginsenoside Rb1 on rat.

Liquid chromatography coupled with mass spectrometry and tandem mass spectrometry has been applied to investigate the in vivo metabolism of ginsenoside Rb(1) in rat. Both positive electrospray ionization mass spectrometry and negative electrospray ionization mass spectrometry were used to identify the Rb(1) and its metabolites in rat plasma, urine, and feces samples. Oxygenation and deglycosylation were found to be the major metabolic pathways of Rb(1) in rat. A total of nine metabolites were detected in urine and feces samples collected after intravenous and oral administration. Deglycosylated metabolism of Rb(1) generated other ginsenosides as the major metabolites, such as Rd, Rg(3) or F(2), Rh(2), or C-K. This result indicates that the ginsenoside Rb(1) has many pharmacological activities and could be used as a prodrug.

Administration, Oral↗

PubMed2006

Interaction study between double-stranded DNA and berberine using capillary zone electrophoresis.

Two non-self-complementary 17-mer double-stranded DNA (dsDNA) with four different central base pairs were designed to systematically investigate the binding affinity and sequence specificity of berberine with dsDNA by capillary zone electrophoresis (CZE). The data analysis with the Kenndler model proved only low affinity between dsDNA and berberine and suggested some weak binding preference of berberine for AATT-containing to GGCC-containing dsDNA. The binding constant, Ka, between berberine and dsDNA(AB) was about (1.0 +/- 0.7) x 10(3) M(-1). In addition, the separation of single-stranded DNA (ssDNA) from dsDNA under simple electrophoretic conditions enabled CZE to be a potentially alternative tool to check the extent of DNA annealing, which is usually done by the time-consuming and labor-intensive slab electrophoresis.

Base Sequence↗

PubMed2006

Distinguishing the medicinal herb Oldenlandia diffusa from similar species of the same genus using fluorescence microscopy.

The light microscope is routinely used for microscopic identification of Chinese Materia Medica (CMM). However, the fluorescence microscope has not been used for this purpose until now. The CMM, Baihuasheshecao, mostly used as a component of herb tea, is a well known folk-medicine in China. According to the Chinese Pharmacopoeia, its source is the species Oldenlandia diffusa (Willd.) Roxb. Two other species of the same genus, namely O. corymbosa (L.) Lam and O. tenelliflora Bl., had been found in use as Baihuasheshecao. To find a quick and easy method to distinguish O. diffusa from these similar species of the same genus, the fluorescence microscope was used to investigate the fluorescence emission characteristics of the three tissues, which were compared with light microscopy images of the same material. The results showed that some tissues of the three herbs emit autofluorescence. Specially, the wall of endoderm cells of O. diffusa and O. tenelliflora emit autofluorescence, while similar tissue of O. corymbosa does not. Hence, fluorescence microscopy can be helpful in the identification of CMM.

Microscopy, Fluorescence↗

PubMed2006

Site-specific binding of chelerythrine to single cytosine and thymine bulges in DNA hairpins.

Chelerythrine exhibits pronounced antitumor and apoptosis activities. In order to provide insights into the molecular mechanism of its pharmacological effects, binding selectivity of chelerythrine to a series of single-base bulged DNA hairpins has been assayed by using spectrofluorometric technique. The results indicated that chelerythrine binds specifically to C- and T-bulge sites in DNA hairpins, while sanguinarine exhibits extremely weak binding selectivity to any single-base bulged DNA hairpins, although it has very similar structure with chelerythrine.

Alkaloids↗

PubMed2006

Determination of iridoid glucosides for quality assessment of Herba Oldenlandiae by high-performance liquid chromatography.

Herba Oldenlandiae, the dried herb of Oldenlandia diffusa (WILLD.) ROXB. (Family Rubiaceae), is officially listed in the Chinese Pharmacopoeia. In the herbal market, two substitutes originated from O. corymbosa (L.) LAM and O. tenelliflora BL. are commonly used. In light of this, the target in setting up a method for quality assessment of Herba Oldenlandiae is urgently needed. In this article, a simple and reliable high-performance liquid chromatographic (HPLC) method was developed for quantifying asperuloside (1), E-6-O-p-coumaroyl scandoside methyl ester (2) and E-6-O-p-coumaroyl scandoside methyl ester-10-methyl ether (3) in Herba Oldenlandiae derived from O. diffusa. Among them, compound 3 is a new compound isolated from O. diffusa. All these unique compounds were used as markers for the first time in the quality assessment of Herba Oldenlandiae. The results showed that the contents of compounds 1-3 were significantly varied among different samples whilst those of compounds 2 and 3 were found to be lower in contents in the two substitutes of O. diffusa. The analytical method is suitable for quality control of Herba Oldenlandiae and useful in differentiation from its confusable species. The method has been fully validated with satisfactory linearity, accuracy, precision and stability.

Chromatography, High Pressure Liquid↗

PubMed2006

Control release effects of binders used in pills of traditional Chinese medicine herbs.

This research investigated the effects of control release of binders that are used in the pills of Chinese herbal medicine, namely, as processed honey, starch paste, beeswax, or mixtures thereof. Aspirin and baicalin were used as the active pharmaceutical ingredients (API). The processed honey was heated to 110 degrees C, 120 degrees C, or 130 degrees C. In these pills, the binders were the only excipients. The pills were prepared by the stir method using a mixer at 80 degrees C without pressure. The differential thermal analysis (DTA) showed that the melting points of aspirin and baicalin were changed by the binders. The Fourier Transform infrared spectra (FT-IR) of aspirin and baicalin suggest that there are different non-covalent molecular interactions between the API and the binders, such as C-H-pi and hydrogen bond interaction. The dissolution profiles indicate that changing the ratio of the binders altered the patterns of dissolution of the API; thus, this ration may be used to control the release of API from the pills.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2006

[Study on chemical constituents of flavonoids in fresh herb of Houttuynia cordata].

OBJECTIVE: To study the flavonoid constituents in fresh herb of Houttuynia cordata. METHOD: Various column packing materials including Diaion HP - 20, Sephadex LH - 20, ODS and silica gel were employed for the isolation and purification of compounds from H. cordata. The structures of the compounds were identified by physiochemical properties and spectral analysis. RESULT: Five compounds were isolated, and their structures were identified as quercetin-3-O-beta-D-galactoside-7-O-beta-D-glucoside (1), kaempferol-3-O-alpha-L-rhamnopyranosyl-(1 --> 6)-beta-D-glucopyranoside (2), quercitrin (3), hyperin (4), quercetin 3-O-alpha-L-rhamnopyranosyl-7-O-beta-D-glucopyranoside (5). CONCLUSION: Compounds 1, 2 and 5 were separated from H. cordata for the first time.

Flavonoids↗

PubMed2005

Synthesis and DNA-binding affinities of monomodified berberines.

Four new monomodified berberines have been synthesized in moderate to good yields starting from berberine and fully characterized by HRMS and 1H NMR. Spectrometric titration and ethidium bromide displacement experiments indicate that these berberine derivatives, especially the one having primary amino group, strongly bind with calf-thymus DNA, presumably via an intercalation mechanism.

Berberine↗

PubMed2005

Synthesis, DNA-binding affinities, and binding mode of berberine dimers.

Six novel berberine dimers (3a-f) were synthesized in 37-84% yield from the reaction of berberrubine (2) with dihaloalkanes of varying lengths from two to seven carbons. Their interactions with calf thymus (CT) DNA and three double helical oligodeoxynucleotides, d(AAGAATTCTT)2, d(AAGCATGCTT)2, and d(TAAGAATTCTTA)2, were investigated by means of fluorometric titration and ethidium bromide (EB) displacement experiments. Compared with the monomeric parent berberine (1), these dimers' DNA-binding affinities increased up to approximately 100-fold, suggesting a cooperative interaction of the two berberine subunits in the molecules. Furthermore, these dimers linked by different spacers show a prominent structure-activity relationship when bound with oligodeoxynucleotides. The relative binding affinities are in the order of 3b>3a>3c>3d>3e>3f with d(AAGAATTCTT)2 and d(TAAGAATTCTTA)2, and 3b>3c>3a>3d>3e>3f with d(AAGCATGCTT)2. Dimer 3b, linked with a propyl chain, exhibits the highest binding affinity. This suggests that a propyl chain may be the most suitable spacer to bridge the two berberine units for DNA binding. Spectrophotometric titration and competitive EB displacement of berberine (1) and dimer 3b indicate that both berberine and its dimers form intercalating complexes with duplex DNA. A larger redshift, a stronger hypochromic effect, and a much higher EB displacement ratio, observed in 3b, indicate that the dimer is in more intimate contact with DNA than berberine. In addition, no obvious binding of canadine (4), a hydrogenated product of berberine, with CT DNA was observed, suggesting critical roles of the quaternary ammonium cation and planar structure in the DNA-binding of berberine.

Base Sequence↗

PubMed2005

Application of microscopy in authentication of Chinese patent medicine--Bo Ying compound.

To establish a quality control method for the Chinese Patent Medicine (CPM)-Bo Ying Compound (BYC), a comparison study was carried out on it with microscopy. The micro-morphological characteristics of its 22 components in the CPM and in the crude constituents have been documented and compared with each other. Their corresponding features were described and documented with color digital micrographs, so as to authenticate the presence of genuine crude constituents in BYC. The results showed that almost all constituents of BYC are found within their representative fragments in the CPM except one (Borax) that could dissolve or merge with the other components. Also the study indicated that light microscopy, an easy and economical method, could be used for the identification of this kind of CPM that contains plant and animal materials without the specific characteristic chemical marker compounds.

Drugs, Chinese Herbal↗

PubMed2005

The pharmacokinetics and tissue distribution of sinomenine in rats and its protein binding ability in vitro.

Sinomenine, an alkaloid derived from the Chinese medical plant Sinomenium acutum, was studied with regard to its pharmacokinetics and tissue distribution in rats, and to its protein binding ability in the plasma of rats and rabbits and in the solutions of albumin and alpha-1-acid-glycoprotein. An HPLC analytical method was developed for determining sinomenine. The results demonstrated that oral administration with a single dosage at a rate of 90 mg sinomenine/kg in rats achieved about 80% bioavailability, while most of the other pharmacokinetic parameters were similar to the data from the animals treated intravenously. This indicates that oral administration of sinomenine would be appropriate in clinics. In rats, at 45 min after oral dosage, the drug was found to distribute widely in the internal organs, with tissue concentrations (from highest to lowest) in the order of kidneys, liver, lungs, spleen and heart, brain and testicles. At 90 min after dosing, the tissue concentrations in the organs were markedly decreased. The liver and kidneys manifested as the dominant organs with high tissue concentrations that might be responsible for metabolism and elimination of sinomenine. Examination of the protein binding ability showed that sinomenine with 4 microg/ml concentration in the plasma of rats and rabbits or in the albumin solution achieved a protein binding rate of more than 60%, while in the solution of alpha-1-acid-glycoprotein the rate was only about 33%. This result suggests that sinomenine might have much more potent binding ability with albumin than with alpha-1-acid-glycoprotein, resulting from its acidic property.

Administration, Oral↗

PubMed2005

Synthesis of linked berberine dimers and their remarkably enhanced DNA-binding affinities.

This communication describes the facile synthesis of five novel berberine dimers and their strong affinities toward double-stranded DNA. These berberine dimers were synthesized in 37-84% yields from the reaction of berberrubine with dihaloalkanes of varying lengths, and fully characterized by HRMS and 1H NMR. Compared with the monomeric parent berberine, these dimers showed greatly enhanced binding affinities up to approximately 100-fold, with two double helical oligodeoxynucleotides, d(AAGAATTCTT)2 and d(TAAGAATTCTTA)2, which was investigated by means of fluorescence spectrometry.

Base Sequence↗