Biodegradable polymer based novel drug delivery systems brought a considerable attention in enhancing the therapeutic efficacy and bioavailability of various drugs. 14-deoxy 11, 12-didehydro andrographolide(poorly wat...Biodegradable polymer based novel drug delivery systems brought a considerable attention in enhancing the therapeutic efficacy and bioavailability of various drugs. 14-deoxy 11, 12-didehydro andrographolide(poorly water soluble compound) loaded polycaprolactone(nanoDDA) was synthesized using the solvent evaporation technique. Nano-DDA was characterized by scanning electron microscopy(SEM) and dynamic light scattering(DLS) studies. Fourier Transform InfraRed Spectroscopy(FTIR) was used to investigate the structural interaction between the drug and the polymer. Functional characterization of the formulation was determined using drug content, cellular uptake and in vitro drug release. 2-deoxy-D-[1-~3H] glucose uptake assay was carried out to assess the antidiabetic potential of nano-DDA in L6 myotubes.The nano-DDA displayed spherical shape with a smooth surface(252.898 nm diameter), zeta potential, encapsulation and loading efficiencies of -38.9 mV, 91.98 ± 0.13% and 15.09 ± 0.18% respectively. No structural alteration between the drug and the polymer was evidenced(FTIR analysis). Confocal microscopy studies with rhodamine 123 loaded polycaprolactone nanoparticles(Rh123-PCL NPs) revealed the internalization of Rh123-PCL NPs in a time dependent manner in L6 myoblasts. A dose dependent increase in glucose uptake was observed for nano-DDA with a maximal uptake of 108.54 ± 1.42% at 100 nM on L6 myotubes, thereby proving its anti-diabetic efficacy. A biphasic pattern of in vitro drug release demonstrated an initial burst release at 24 h followed by a sustained release for up to 11 days. To conclude,our results revealed that nano-DDA formulation can be a potent candidate for antidiabetic drug delivery.展开更多
The title compound (C19H25NO4, Mr = 331.40) was synthesized and its crystal structure was determined by single-crystal X-ray structure analysis. The compound belongs to space group P212121 with a = 7.738(2), b = 10.13...The title compound (C19H25NO4, Mr = 331.40) was synthesized and its crystal structure was determined by single-crystal X-ray structure analysis. The compound belongs to space group P212121 with a = 7.738(2), b = 10.131(2), c = 21.535(4) ? V = 1688.3(6) 3 and Z = 4. The final R and wR factors are 0.0557 and 0.1489, respectively for 2936 (I > 2s(I)) independent observable reflections. The result shows that the title compound is a tetracyclic alkaloid with four chiral centers, and the absolute configuration of the newly formed one is 6S. The piperidine ring is in chair conformation, while the other two aliphatic rings are in twist boat conformation. The title compound was the mainly isolated reduction product, which means that the hydrogen anion attacks the carbonyl group at the opposite side away from the phenyl group because of its steric effect.展开更多
In search of potential 2＇,3＇-dideoxyguanosine （ddG） and 2＇,3＇-didehydro-2＇,3＇-dideoxyguanosine （D4G） prodrugs, a series of 6-modified ddG, D4G analogs were synthesized and evaluated for their anti-HIV activi...In search of potential 2＇,3＇-dideoxyguanosine （ddG） and 2＇,3＇-didehydro-2＇,3＇-dideoxyguanosine （D4G） prodrugs, a series of 6-modified ddG, D4G analogs were synthesized and evaluated for their anti-HIV activities and cyto- toxities in cell-based assays. All analogs showed low cytotoxieities and some of them displayed benign anti-HIV activities. The active triphosphate forms in vivo, ddGTP and D4TTP, were also synthesized by a novel and facile ＂one-pot＂ method. The recognition of ddGTP and D4TTP by Taq, Therminater DNA polymerase and HIV reverse transcriptase （RT） incorporated in DNA/RNA strands were investigated by a non-radioactivity method and Km were determined.展开更多
Two new indole alkaloids, named ibogamine-18-carboxylic acid, 3, 4-didehydro-7, 8-dioxo-methyl ester 1, ibogamine-18-carboxylic acid, 16, 17-didehydro-9, 17-dihydro-9-hydroxy （2-oxopropyl）-methyl ester 2, were isola...Two new indole alkaloids, named ibogamine-18-carboxylic acid, 3, 4-didehydro-7, 8-dioxo-methyl ester 1, ibogamine-18-carboxylic acid, 16, 17-didehydro-9, 17-dihydro-9-hydroxy （2-oxopropyl）-methyl ester 2, were isolated from Ervatamia hainanensis. Their structures were elucidated on the basis of spectroscopic methods.展开更多
文摘Biodegradable polymer based novel drug delivery systems brought a considerable attention in enhancing the therapeutic efficacy and bioavailability of various drugs. 14-deoxy 11, 12-didehydro andrographolide(poorly water soluble compound) loaded polycaprolactone(nanoDDA) was synthesized using the solvent evaporation technique. Nano-DDA was characterized by scanning electron microscopy(SEM) and dynamic light scattering(DLS) studies. Fourier Transform InfraRed Spectroscopy(FTIR) was used to investigate the structural interaction between the drug and the polymer. Functional characterization of the formulation was determined using drug content, cellular uptake and in vitro drug release. 2-deoxy-D-[1-~3H] glucose uptake assay was carried out to assess the antidiabetic potential of nano-DDA in L6 myotubes.The nano-DDA displayed spherical shape with a smooth surface(252.898 nm diameter), zeta potential, encapsulation and loading efficiencies of -38.9 mV, 91.98 ± 0.13% and 15.09 ± 0.18% respectively. No structural alteration between the drug and the polymer was evidenced(FTIR analysis). Confocal microscopy studies with rhodamine 123 loaded polycaprolactone nanoparticles(Rh123-PCL NPs) revealed the internalization of Rh123-PCL NPs in a time dependent manner in L6 myoblasts. A dose dependent increase in glucose uptake was observed for nano-DDA with a maximal uptake of 108.54 ± 1.42% at 100 nM on L6 myotubes, thereby proving its anti-diabetic efficacy. A biphasic pattern of in vitro drug release demonstrated an initial burst release at 24 h followed by a sustained release for up to 11 days. To conclude,our results revealed that nano-DDA formulation can be a potent candidate for antidiabetic drug delivery.
基金This work was financially supported by theHongkongPolytechnikeUniversity
文摘The title compound (C19H25NO4, Mr = 331.40) was synthesized and its crystal structure was determined by single-crystal X-ray structure analysis. The compound belongs to space group P212121 with a = 7.738(2), b = 10.131(2), c = 21.535(4) ? V = 1688.3(6) 3 and Z = 4. The final R and wR factors are 0.0557 and 0.1489, respectively for 2936 (I > 2s(I)) independent observable reflections. The result shows that the title compound is a tetracyclic alkaloid with four chiral centers, and the absolute configuration of the newly formed one is 6S. The piperidine ring is in chair conformation, while the other two aliphatic rings are in twist boat conformation. The title compound was the mainly isolated reduction product, which means that the hydrogen anion attacks the carbonyl group at the opposite side away from the phenyl group because of its steric effect.
基金The research was supported by the fund of the National Natural Science Foundation of China，the Ministry of Science and Technology of China (No.2008ZX10303).Anti-HIV activity evaluation in pseudotyped HIV system was performed by Institute of Materia Medica,Chinese Academy of Medical Science and Peking Union Medical College.Anti-HIV activity evaluation in HIV-1/MT2 cells was performed by HD
文摘In search of potential 2＇,3＇-dideoxyguanosine （ddG） and 2＇,3＇-didehydro-2＇,3＇-dideoxyguanosine （D4G） prodrugs, a series of 6-modified ddG, D4G analogs were synthesized and evaluated for their anti-HIV activities and cyto- toxities in cell-based assays. All analogs showed low cytotoxieities and some of them displayed benign anti-HIV activities. The active triphosphate forms in vivo, ddGTP and D4TTP, were also synthesized by a novel and facile ＂one-pot＂ method. The recognition of ddGTP and D4TTP by Taq, Therminater DNA polymerase and HIV reverse transcriptase （RT） incorporated in DNA/RNA strands were investigated by a non-radioactivity method and Km were determined.
文摘Two new indole alkaloids, named ibogamine-18-carboxylic acid, 3, 4-didehydro-7, 8-dioxo-methyl ester 1, ibogamine-18-carboxylic acid, 16, 17-didehydro-9, 17-dihydro-9-hydroxy （2-oxopropyl）-methyl ester 2, were isolated from Ervatamia hainanensis. Their structures were elucidated on the basis of spectroscopic methods.
