The new title compound, chiral 2-（3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl）- 2-oxoethyl acetate, has been synthesized via reduction, cyclization and acylation reaction. The structure of the product has been conf...The new title compound, chiral 2-（3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl）- 2-oxoethyl acetate, has been synthesized via reduction, cyclization and acylation reaction. The structure of the product has been confirmed by IR, 1H NMR, 13C NMR, LC-MS （ESI） and single-crystal X-ray diffraction. （R）-2-（3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl）-2-oxoethyl acetate crystallizes in monoclinic, space group P21/c with a = 11.867（2）, b = 8.4087（2）, c = 14.325（6） A^°, β = 117.59（2）°, Z = 4, V = 1266.9（6） A^°3, Dc = 1.307 g/cm^3, F（000） = 528, μ（MoKα） = 0.097 mm-1, R = 0.0453 and wR = 0.1237; （S）-2-（3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl）-2-oxoethyl acetate belongs to the triclinic system, space group P with a = 8.2647（17）, b = 8.7034（17）, c = 9.5479（19） A^°, α = 105.33（3）, β = 100.95（3）, γ = 105.14（3）°, Z = 2, V = 614.1（2） A^°3, Dc = 1.348 g/cm^3, F（000） = 264, μ（MoKα） = 0.10 mm-1, R = 0.0613 and wR = 0.1037. Both of the molecules prefer to form crystal packing through C–H…O hydrogen bonds.展开更多
Ethyl ester of 5,7-dimethyl coumarin-4-acetic acid has been synthesized from 3,5-Xylenol in a two step sequence of reaction involving Pechmann cyclisation and acid catalyzed esterification. The title compound 2 crysta...Ethyl ester of 5,7-dimethyl coumarin-4-acetic acid has been synthesized from 3,5-Xylenol in a two step sequence of reaction involving Pechmann cyclisation and acid catalyzed esterification. The title compound 2 crystallizes in Monoclinic form, space group P 1 21/c 1, with a = 8.6248(4) ?, b = 18.9103(8) , c = 8.4204(4)?, β = 101.241(2)?, V = 1347.00(11) ?, D cal = 1.283 Mg/cm3, Z = 4. The molecule is stabilized by intermolecular C-H … O bonds.展开更多
目的 构建 、鉴定自身互补双链DNA的腺相关病毒（scAAV）重组载体，使其分泌表达Exendin-4，检测其转导效率并观察在糖尿病大鼠模型中的治疗作用。 方法 应用基因工程方法改建穿梭质粒pSSHG-CMV，插入外源性基因Exendin-...目的 构建 、鉴定自身互补双链DNA的腺相关病毒（scAAV）重组载体，使其分泌表达Exendin-4，检测其转导效率并观察在糖尿病大鼠模型中的治疗作用。 方法 应用基因工程方法改建穿梭质粒pSSHG-CMV，插入外源性基因Exendin-4，构建重组scAAV载体，感染HEK293细胞，ELISA检测转染NIH3T3细胞上清Exendin-4滴度，链佐霉素诱导20只6周龄体质量180～220 g SD成年雄性大鼠为糖尿病鼠模型，逆向注射重组scAAV于糖尿病大鼠颌下腺，检测其血糖及胰岛素分泌水平。 结果 重组scpSSHG/exn4可有效包装和复制，病毒滴度为2.5×1011pfu/mL，转染细胞上清分泌Exendin-4浓度可达到4.53 ng/mL，scAAV治疗组血糖浓度在2、4周及8周均低于对照组[分别为（639.17±27.89）vs （396.00±34.00），（657.02±39.87） vs （315.62±42.56），（215.6±24.7） vs （458.6±19.7） mg/dL]，胰岛素浓度均高于对照组[分别为（156.8±24.5） vs （535.9±35.6），（236.5±12.3） vs （495.3±18.6），（620.43±46.90） vs （381.56±21.78） pg/mL]，二者比较有显著统计学差异（P〈0.05）。 结论 成功构建重组双链腺伴病毒scAAV-Ex-4，具有高效转导能力，对糖尿病大鼠模型具有控制血糖及增加胰岛素分泌作用。展开更多
Synthetic exendin-4 exhibits dose-dependent glucose-regulatory activity similar to that of native glucagon-like peptide-1(GLP-1). Moreover, exendin-4 is resistant to degradation by dipeptidyl peptidase-Ⅳ(DPP-Ⅳ) whil...Synthetic exendin-4 exhibits dose-dependent glucose-regulatory activity similar to that of native glucagon-like peptide-1(GLP-1). Moreover, exendin-4 is resistant to degradation by dipeptidyl peptidase-Ⅳ(DPP-Ⅳ) while GLP-1 is degraded by DPP-Ⅳ with a half-life of less than 2 min in mammals. In this study the stability of exendin-4 in human plasma was evaluated in vitro. Exendin-4 was incubated in plasma at 37 ℃, extracted and subsequently analyzed by using high performance liquid chromatography(HPLC). Exendin-4 was slowly broken down in plasma. Its half-life time is 9.57 h. The degradation products were identified by mass-spectrum(MS). According to natural sequence of exendin-4, we deduced that the cleavage were between the Thr5 and Phe6 bond, Phe6 and Thr7 bond, and Thr7 and Ser8 bond of the N-terminus region of the peptide, and the results of ESI-TOF-MS prove that our primary conclusion was correct.展开更多
基金supported by the National Natural Science Foundation of China(No.31572042)Natural Science Foundation of Heilongjiang Province(B201303)the Research Science Foundation in Technology Innovation of Harbin(No.2015RAYXJ010)
文摘The new title compound, chiral 2-（3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl）- 2-oxoethyl acetate, has been synthesized via reduction, cyclization and acylation reaction. The structure of the product has been confirmed by IR, 1H NMR, 13C NMR, LC-MS （ESI） and single-crystal X-ray diffraction. （R）-2-（3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl）-2-oxoethyl acetate crystallizes in monoclinic, space group P21/c with a = 11.867（2）, b = 8.4087（2）, c = 14.325（6） A^°, β = 117.59（2）°, Z = 4, V = 1266.9（6） A^°3, Dc = 1.307 g/cm^3, F（000） = 528, μ（MoKα） = 0.097 mm-1, R = 0.0453 and wR = 0.1237; （S）-2-（3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl）-2-oxoethyl acetate belongs to the triclinic system, space group P with a = 8.2647（17）, b = 8.7034（17）, c = 9.5479（19） A^°, α = 105.33（3）, β = 100.95（3）, γ = 105.14（3）°, Z = 2, V = 614.1（2） A^°3, Dc = 1.348 g/cm^3, F（000） = 264, μ（MoKα） = 0.10 mm-1, R = 0.0613 and wR = 0.1037. Both of the molecules prefer to form crystal packing through C–H…O hydrogen bonds.
文摘Ethyl ester of 5,7-dimethyl coumarin-4-acetic acid has been synthesized from 3,5-Xylenol in a two step sequence of reaction involving Pechmann cyclisation and acid catalyzed esterification. The title compound 2 crystallizes in Monoclinic form, space group P 1 21/c 1, with a = 8.6248(4) ?, b = 18.9103(8) , c = 8.4204(4)?, β = 101.241(2)?, V = 1347.00(11) ?, D cal = 1.283 Mg/cm3, Z = 4. The molecule is stabilized by intermolecular C-H … O bonds.
文摘目的 构建 、鉴定自身互补双链DNA的腺相关病毒（scAAV）重组载体，使其分泌表达Exendin-4，检测其转导效率并观察在糖尿病大鼠模型中的治疗作用。 方法 应用基因工程方法改建穿梭质粒pSSHG-CMV，插入外源性基因Exendin-4，构建重组scAAV载体，感染HEK293细胞，ELISA检测转染NIH3T3细胞上清Exendin-4滴度，链佐霉素诱导20只6周龄体质量180～220 g SD成年雄性大鼠为糖尿病鼠模型，逆向注射重组scAAV于糖尿病大鼠颌下腺，检测其血糖及胰岛素分泌水平。 结果 重组scpSSHG/exn4可有效包装和复制，病毒滴度为2.5×1011pfu/mL，转染细胞上清分泌Exendin-4浓度可达到4.53 ng/mL，scAAV治疗组血糖浓度在2、4周及8周均低于对照组[分别为（639.17±27.89）vs （396.00±34.00），（657.02±39.87） vs （315.62±42.56），（215.6±24.7） vs （458.6±19.7） mg/dL]，胰岛素浓度均高于对照组[分别为（156.8±24.5） vs （535.9±35.6），（236.5±12.3） vs （495.3±18.6），（620.43±46.90） vs （381.56±21.78） pg/mL]，二者比较有显著统计学差异（P〈0.05）。 结论 成功构建重组双链腺伴病毒scAAV-Ex-4，具有高效转导能力，对糖尿病大鼠模型具有控制血糖及增加胰岛素分泌作用。
文摘Synthetic exendin-4 exhibits dose-dependent glucose-regulatory activity similar to that of native glucagon-like peptide-1(GLP-1). Moreover, exendin-4 is resistant to degradation by dipeptidyl peptidase-Ⅳ(DPP-Ⅳ) while GLP-1 is degraded by DPP-Ⅳ with a half-life of less than 2 min in mammals. In this study the stability of exendin-4 in human plasma was evaluated in vitro. Exendin-4 was incubated in plasma at 37 ℃, extracted and subsequently analyzed by using high performance liquid chromatography(HPLC). Exendin-4 was slowly broken down in plasma. Its half-life time is 9.57 h. The degradation products were identified by mass-spectrum(MS). According to natural sequence of exendin-4, we deduced that the cleavage were between the Thr5 and Phe6 bond, Phe6 and Thr7 bond, and Thr7 and Ser8 bond of the N-terminus region of the peptide, and the results of ESI-TOF-MS prove that our primary conclusion was correct.
