The chemical synthesis of Guanine arabinoside （ara-G） is extremely complex, time-consuming, and seriously polluted. A two-step enzymatic synthesis process was developed to acquire ara-G easily. 2,6-Diaminopurine ara...The chemical synthesis of Guanine arabinoside （ara-G） is extremely complex, time-consuming, and seriously polluted. A two-step enzymatic synthesis process was developed to acquire ara-G easily. 2,6-Diaminopurine arabinoside （ara-DA） was first synthesized with purine nucleoside phosphorylase and pyrimidine nucleoside phosphorylase produced by Enterobacter aerogenes DGW-07. The conversion yield of ara-DA could reach above 90% when the reaction liquid contained 30 mmol·L^-1 uracil arabinoside as arabinose donor, 10 mmol·L^- 1 2,6-diaminopurine as arabinose acceptor in pH 7.0 20 mmol·L^-1 phosphate buffer, and reacted at 60℃ for 48h. Then, ara-DA was effectively transformed into ara-G with adenylate deaminase produced by Aspergillus oryzae DAW-01. The total process had no complex separation and purification.展开更多
A new octadecanoyl diterpenoid glycoside,（E）-8α,15-dihydroxy-15-（3S-hydroxy-octadecanoyl）-13-labdene-8-O-α-L-arabinopyranoside（1）,was isolated from the aerial parts of Conyza blinii,and the structure was ident...A new octadecanoyl diterpenoid glycoside,（E）-8α,15-dihydroxy-15-（3S-hydroxy-octadecanoyl）-13-labdene-8-O-α-L-arabinopyranoside（1）,was isolated from the aerial parts of Conyza blinii,and the structure was identified on the basis of a detailed spectroscopic analysis,including 2D NMR spectrometry and HRESI-MS.展开更多
Nucleoside phosphorylases (NPases) were found to be induced in Enterobacter aerogenes DGO-04, and cytidine and cytidine 5′-monophosphate (CMP) were the best inducers. Five mmol/L to fifteen mmol/L cytidine or CMP cou...Nucleoside phosphorylases (NPases) were found to be induced in Enterobacter aerogenes DGO-04, and cytidine and cytidine 5′-monophosphate (CMP) were the best inducers. Five mmol/L to fifteen mmol/L cytidine or CMP could distinctly increase the activities of purine nucleoside phosphorylase (PNPase), uridine phosphorylase (UPase) and thymidine phosphorylase (TPase) when they were added into medium from 0 to 8 h. In the process of enzymatic synthesis of adenine arabinoside from adenine and uracil arabinoside with wet cells of Enterobacter aerogenes DGO-04 induced by cytidine or CMP, the reaction time could be shortened from 36 to 6 h. After enzymatic reaction the activity of NPase in the cells induced remained higher than that in the cells uninduced.展开更多
Objective: To explore the effects of dexamethasone (DXM) and vincristine (VCR) on cytosine arabinoside (Ara-C) induced apoptosis and activation of nuclear factor-k-gene binding (NF-kB) in leukemic cell line HL60-n. M...Objective: To explore the effects of dexamethasone (DXM) and vincristine (VCR) on cytosine arabinoside (Ara-C) induced apoptosis and activation of nuclear factor-k-gene binding (NF-kB) in leukemic cell line HL60-n. Methods: Apoptosis of HL60-n cells was analysed by TdT-mediated X-dUTP nick and end labeling (TUNEL) and DNA electrophoresis. NF-kB activity of HL60-n cells was detected by electrophoretic mobility shift assay (EMSA). Results: There was slight activation of NF-kB in HL60-n cells without drug induction. Ara-C at 1 mmol/L significantly enhanced the activation of NF-kB in HL60-n cells. The level of NF-kB activation induced by DXM at 1 mmol/L or VCR at 0.1 mmol/L had no significant difference compared with that of the control group. However, in HL60-n cells pre-treated with 1 mmol/L of DXM or 0.1 mmol/L of VCR, the activation of NF-kB induced by 1 mmol/L of Ara-C was significantly suppressed with inhibition rates of 31.0% and 47.0%, respectively. The apoptosis rates of HL60-n cells induced by 1.0 mmol/L, 10 mmol/L and 100 mmot/L Ara-C were 45.003.16%, 61.883.40% and 77.624.75%, respectively. The apoptotic rates of HL60-n cells induced by DXM at 1 mmol/L or VCR at 0.1 mmol/L were similar to that of the control group. However, either DXM at 1 mmol/L or VCR at 0.l mmol/L could enhance the apoptosis of HL60-n cells induced by Ara-C at 1 mmol/L with rates of 39.1% and 59.2%, respectively. Conclusion: Ara-C can induce apoptosis and activation of NF-kB in HL60-n cells. The mechanism of increased apoptosis of HL60-n cells by DXM or VCR may be related to suppression of NF-kB activation.展开更多
基金Supported by the Innovation Fund for Technology Based Firms from Ministry of Science and Technology of China(07C26213101283)
文摘The chemical synthesis of Guanine arabinoside （ara-G） is extremely complex, time-consuming, and seriously polluted. A two-step enzymatic synthesis process was developed to acquire ara-G easily. 2,6-Diaminopurine arabinoside （ara-DA） was first synthesized with purine nucleoside phosphorylase and pyrimidine nucleoside phosphorylase produced by Enterobacter aerogenes DGW-07. The conversion yield of ara-DA could reach above 90% when the reaction liquid contained 30 mmol·L^-1 uracil arabinoside as arabinose donor, 10 mmol·L^- 1 2,6-diaminopurine as arabinose acceptor in pH 7.0 20 mmol·L^-1 phosphate buffer, and reacted at 60℃ for 48h. Then, ara-DA was effectively transformed into ara-G with adenylate deaminase produced by Aspergillus oryzae DAW-01. The total process had no complex separation and purification.
基金Supported by the National Natural Science Foundation of China(No.30200024)the Natural Science Foundation of Tianjin City,China(No.033607711)
文摘A new octadecanoyl diterpenoid glycoside,（E）-8α,15-dihydroxy-15-（3S-hydroxy-octadecanoyl）-13-labdene-8-O-α-L-arabinopyranoside（1）,was isolated from the aerial parts of Conyza blinii,and the structure was identified on the basis of a detailed spectroscopic analysis,including 2D NMR spectrometry and HRESI-MS.
基金Project (No. 07C26213101283) supported by the Innovation Fundfor Technology Based Firms from the Ministry of Science andTechnology of China
文摘Nucleoside phosphorylases (NPases) were found to be induced in Enterobacter aerogenes DGO-04, and cytidine and cytidine 5′-monophosphate (CMP) were the best inducers. Five mmol/L to fifteen mmol/L cytidine or CMP could distinctly increase the activities of purine nucleoside phosphorylase (PNPase), uridine phosphorylase (UPase) and thymidine phosphorylase (TPase) when they were added into medium from 0 to 8 h. In the process of enzymatic synthesis of adenine arabinoside from adenine and uracil arabinoside with wet cells of Enterobacter aerogenes DGO-04 induced by cytidine or CMP, the reaction time could be shortened from 36 to 6 h. After enzymatic reaction the activity of NPase in the cells induced remained higher than that in the cells uninduced.
基金This work was supported by the National Natural Science Foundation of China (No. 39770330).
文摘Objective: To explore the effects of dexamethasone (DXM) and vincristine (VCR) on cytosine arabinoside (Ara-C) induced apoptosis and activation of nuclear factor-k-gene binding (NF-kB) in leukemic cell line HL60-n. Methods: Apoptosis of HL60-n cells was analysed by TdT-mediated X-dUTP nick and end labeling (TUNEL) and DNA electrophoresis. NF-kB activity of HL60-n cells was detected by electrophoretic mobility shift assay (EMSA). Results: There was slight activation of NF-kB in HL60-n cells without drug induction. Ara-C at 1 mmol/L significantly enhanced the activation of NF-kB in HL60-n cells. The level of NF-kB activation induced by DXM at 1 mmol/L or VCR at 0.1 mmol/L had no significant difference compared with that of the control group. However, in HL60-n cells pre-treated with 1 mmol/L of DXM or 0.1 mmol/L of VCR, the activation of NF-kB induced by 1 mmol/L of Ara-C was significantly suppressed with inhibition rates of 31.0% and 47.0%, respectively. The apoptosis rates of HL60-n cells induced by 1.0 mmol/L, 10 mmol/L and 100 mmot/L Ara-C were 45.003.16%, 61.883.40% and 77.624.75%, respectively. The apoptotic rates of HL60-n cells induced by DXM at 1 mmol/L or VCR at 0.1 mmol/L were similar to that of the control group. However, either DXM at 1 mmol/L or VCR at 0.l mmol/L could enhance the apoptosis of HL60-n cells induced by Ara-C at 1 mmol/L with rates of 39.1% and 59.2%, respectively. Conclusion: Ara-C can induce apoptosis and activation of NF-kB in HL60-n cells. The mechanism of increased apoptosis of HL60-n cells by DXM or VCR may be related to suppression of NF-kB activation.
文摘本研究通过观察抗CXCR4单克隆抗体12G5对Ara C杀伤HL-60细胞效应的影响,评价其在白血病骨髓 残留病变中的治疗价值。培养并共培养HL-60细胞,在共培养体系中采用12G5(10μg／ml)阻抑基质细胞SDF-1的 生物作用后,通过MTT法及细胞形态学观察检测不同浓度Ara c对HL-60细胞杀伤作用的变化。药物杀伤效应曲 线显示,在20μg／ml Ara C组,对照组中前2天A540值明显下降,但从3-4天开始出现上升,而加12G5实验组中 A540值虽然下降平缓,但持续下降,并于观察第5天后低于对照组,整个观察期中未出现反弹。在40μg／ml Ara C 组,对照组A540在0-3天明显下降,从第4天开始回升,于第5-6天与实验组曲线交叉,从7-12天时照组A540值 总体呈上升趋势,并明显高于实验组,而加12G5实验组曲线在整个观察期间虽然在7-9天有小幅度攀升,但总的 趋势是下降。细胞形态学观察显示,在两个浓度组,对照组HL-60细胞数量最初明显减少,随着培养时间延长,细 胞数量逐渐增多,实验组结果正相反。结论:12G5减弱Ara C对HL-60细胞的早期杀伤作用,但12G5增强Ara C 总体杀伤作用,同时,延缓HL-60细胞对Ara c的耐药性,因此12G5有助于白血病骨髓残留病变的治疗。
