Study on the Reaction Mechanism of Naphthalene with Oxalyl Chloride

The reaction of naphthalene with oxalyl chloride in the presence of anhydrous AlCl3 was investigated. The homolog of dinaphthyl methanone can be obtained mainly from this reaction. Naphthalene conversion does not have evident correlation with the amount of AlCl3. The results show that the reaction proceeds via carbon cation electrophilic substitution reaction-free radical substitution reaction pathway.

Molecular Spectra and Dissociation Dynamics of Oxalyl Chloride: Effect of External Electrical Fields

Oxalyl chloride is a highly toxic and caustic substance, which widely exists in human production and life as a kind of volatile organic compound. Based on the density functional theory B3 LYP at 6-311++G(d, p) level, the influences of external electric field on the bond length, bond energy, dipole moment and dissociation mechanism are optimized. The results indicate that the C_1–Cl_3 bond length increases while the C_4–Cl_6 bond decreases. At the same time, the carbon-carbon bond length gradually increases with the increase of electric field. The total energy decreases while the dipole moment gradually increases with the increase of electric field. In the infrared spectra, the vibration frequency of the carbon-chlorine(C_4–Cl_6) bond decreases while the vibration frequency of the carbon-oxygen bond increases. In the ultraviolet-visible spectra, the wavelength of the strongest absorption peak increases as the external electric field increases and shows an observable red shift phenomenon. Additionally, single point energies of oxalyl chloride along the carbon-carbon bond are scanned with the equation-of-motion coupled cluster method restricted to single and double excitations(EOM-CCSD) method and the potential energy curves under different external electric fields are obtained. The dissociation barrier in potential energy curve decreases because of the breakage of carbon-carbon bond with the increase of external electric field. These results provide reference for further researches on the properties of oxalyl chloride and offer a theoretical basis for the study of oxalyl chloride degradation.

HPLC Determination of Neurotoxin β-N-oxalyl-L-α, β-diaminopropionic acid and Its α -Isomer in Lathyrus sativus by Precolumn Derivatisation with 1-Fluoro-2,4-dinitrobenzcne

A rapid and simple method is presented for determining β-N-oxalyl-α. β- diaminopropionic acid (β -ODAP) and its much less toxic α -isomer (α -ODAP) in Lathyrus sativus. Seed and foliage extracts of Lathyrus sativus were treated with 1-fluoro-2,4-dinitrobenzene (FDNB) and a reversed-phase high-performance liquid chromatographic method for the separation of the derivatives in the pmol range is reported.

Quantum Chemistry Study on Dissociation of Oxalyl Bromide

The multi-bond dissociation dynamics of oxalyl bromide （（BrCO）2） has been investigated by DFT and CIS calculations. Upon the results, conclusion could be drawn that dissociation of C-Br bond of oxalyl bromide at the ground state （So） is of barfierless. After the absorption of a photon, （BrCO）2 is excited to the first excited state and one of its C-Br bonds is broken to yield Br ·＊ and BrCOCO· ＊ free radicals. In addition, BrCOCO · ＊ with high energy is apt to release energy, and ultimately, turns into BrCOCO ·of the ground state. The energy is adequate for BrCOCO· to break down into Br · and 2CO; at the same time the C-C and C-Br bonds of BrCOCO · free radicals dissociate.

山黧豆AAE超家族基因鉴定及LsAAE3的酶活检测

【目的】三七素(β-N-草酰-L-α,β-二氨基丙酸,β-ODAP)是山黧豆、三七等物种中的神经活性物质,其生物合成与草酰辅酶A密切相关。研究基于全基因组鉴定山黧豆草酰辅酶A合成酶的编码基因,为β-ODAP生物合成的调控研究奠定基础。【方法】用AMP结合结构域隐马尔科夫模型在山黧豆基因组中鉴定酰基激活酶超家族(acyl-activating enzyme superfamily,AAE)基因,在此基础上,克隆山黧豆草酰辅酶A合成酶基因LsAAE3,用多序列比对、原核表达及酶活检测等方法分析LsAAE3基因功能。【结果】山黧豆中至少存在22条AAE家族基因;系统发育分析表明:LsAAE3与拟南芥AtAAE3等聚为一支,隶属于酰基辅酶A合成酶家族。基因克隆及序列分析表明:LsAAE3基因cDNA全长为1566 bp;LsAAE3和AtAAE3的保守结构域类似,均含有AMP结合位点、CoA结合位点及AAE保守结构域。SDS-PAGE检测表明所获融合蛋白条带单一,大小在56 kD左右;用His标签抗体进行Western blot分析发现,诱导后和纯化的融合蛋白均能检测到特征条带,说明所获融合蛋白为LsAAE3。体外酶活检测表明:LsAAE3具有草酰辅酶A合成酶活性,其活性发挥依赖于ATP、Mg^(2+)。【结论】研究在全基因组水平鉴定山黧豆AAE超家族基因,并验证了LsAAE3具有草酰辅酶A合成酶活性,为进一步分析山黧豆LsAAE3在β-ODAP生物合成过程中的功能奠定基础。

Surfen and oxalyl surfen decrease tau hyperphosphorylation and mitigate neuron deficits in vivo in a zebrafish model of tauopathy

Background:Tauopathies comprise a family of neurodegenerative disorders including Alzheimer’s disease for which there is an urgent and unmet need for disease-modifying treatments.Tauopathies are characterized by pathological tau hyperphosphorylation,which has been shown to correlate tightly with disease progression and memory loss in patients suffering from Alzheimer’s disease.We recently demonstrated an essential requirement for 3-O-sulfated heparan sulfate in pathological tau hyperphosphorylation in zebrafish,a prominent model organism for human drug discovery.Here,we investigated whether in vivo treatment with surfen or its derivatives oxalyl surfen and hemisurfen,small molecules with heparan sulfate antagonist properties,could mitigate tau hyperphosphorylation and neuronal deficits in a zebrafish model of tauopathies.Results:In vivo treatment of Tg[HuC::hTau^(P301L);DsRed]embryos for 2 days with surfen or oxalyl surfen significantly reduced the accumulation of the pThr181 tau phospho-epitope measured by ELISA by 30%and 51%,respectively.Western blot analysis also showed a significant decrease of pThr181 and pSer396/pSer404 in embryos treated with surfen or oxalyl surfen.Immunohistochemical analysis further confirmed that treatment with surfen or oxalyl surfen significantly decreased the AT8 tau epitope in spinal motoneurons.In addition,in vivo treatment of Tg[HuC::hTau^(P301L);DsRed]embryos with surfen or oxalyl surfen significantly rescued spinal motoneuron axon-branching defects and,as a likely consequence,the impaired stereotypical touch-evoked escape response.Importantly,treatment with hemisurfen,a surfen derivative devoid of heparan sulfate antagonist activity,does not affect tau hyperphosphorylation,nor neuronal or behavioural deficits in Tg[HuC::hTau^(P301L);DsRed]embryos.Conclusion:Our findings demonstrate for the first time that surfen,a well-tolerated molecule in clinical settings,and its derivative,oxalyl surfen,could mitigate or delay neuronal defects in tauopathies,including Alzheimer’s disease.

Solvent-free synthesis of substituted five membered heterocycles: One-pot reaction of primary amine and alkyl propiolate or isothiocyanate in the presence of oxalyl chloride

A novel, convenient and efficient approach to the synthesis of pyrrole and imidazole derivatives via the reaction between primary amines, alkyl propiolates or isothiocyanate and oxalyl chloride is described. The method offers several advantages including high yields of products and performing reaction under solvent-free conditions.

Quantum chemical study of chlorine-dissociation of oxalyl chloride (ClCO)_2→2Cl+2CO

The multi-bond dissociation dynamics of oxalyl chloride ((ClCO)2) is investigated by ab initio calculation. Dissociation of C-Cl bond of oxalyl chloride in the ground state is of barrierless. After the absorption of a photon, (ClCO)2 is excited to the first excited state and one of its C-Cl bonds is broken to yield Cl and ClCOCO* free radicals. In addition, ClCOCO* with high energy is prone to release energy (Q), and to turn into ClCOCO in the ground state. The energy (Q) is ade-quate for ClCOCO to break down into ClCO and CO, and even for ClCO into Cl and CO. The result is consistent with the experimental data that Kong reported.

寄主诱导的基因沉默干扰核盘菌致病基因OAH在甘蓝型油菜抗菌核病中的应用

油菜是我国第一大油料作物,菌核病是我国油菜面临的主要病害之一。本试验利用HIGS技术将核盘菌中关键致病基因SS1G_08218(OAH)的干扰片段转化到甘蓝型油菜中,获得含有siRNA的转基因油菜植株,研究HIGS介导的SsOAH基因沉默对油菜抗菌核病的影响。接种核盘菌后的抗病鉴定结果表明,SS.OAH.RNAi转基因油菜植株对核盘菌抗性增强;R18、R25和R36株系叶片接菌后病斑部位核盘菌菌丝内的OAH基因表达量均低于野生型,证明siRNA在转基因油菜中成功表达;在添加了转基因油菜叶片提取物的培养基上培养的核盘菌扩展面积显著小于野生型,分别降低35.29%、21.98%、31.53%,且菌丝生长显著迟缓,扩展长度较短,分支少,生长过程中发生断裂,生长异常,将其接种于正常的野生型油菜后,其致病力明显下降;对转基因油菜叶片接种核盘菌后观察发现,叶片上的菌丝扩展较为稀疏,生长受阻,侵染垫形成受到抑制,暗示在油菜中表达OAH基因的干扰片段影响了菌丝生长和扩展;进一步检测其病斑组织中的草酸含量发现,接菌36 h、48 h后转基因油菜病斑组织中的草酸含量为391μg g^(-1)、446μg g^(-1),与野生型相比分别减少54μg g^(-1)、32μg g^(-1)。这一研究表明在油菜中表达核盘菌OAH的干扰片段能够降低核盘菌侵染时草酸的积累,从而增强转基因油菜对核盘菌的抗性水平。本试验利用HIGS技术研究了干扰核盘菌关键致病基因OAH增强油菜对核盘菌的抗性,为选育油菜抗菌核病品种提供理论基础和种质资源。

基于分光光度法原理萃铜余液中铜离子在线监测仪的研制

针对湿法炼铜工艺中对萃铜余液中铜离子浓度分析的要求,以双环己酮草酰二腙分光光度法为基础,对溶液中杂质的干扰进行掩蔽,实现了铜离子浓度的自动分析测量。介绍了在线监测仪的测定方法、原理、化学流路以及测量过程,对仪器的各项性能进行了测试。结果表明,铜离子在线监测仪运行稳定、重复性好、精密度高,分析结果与现场手工分析基本一致。可以满足现场对铜离子浓度在线监测的需求。

含三苯胺结构单元的荧光探针用于选择性检测草酰氯和光气

草酰氯和光气被广泛用于各种有机中间体的生产,由于其具有较高的毒性,为确保工作环境和公共场所安全,需要开发便捷可靠的检测方法。该项研究将邻苯二胺作为反应活性位点与三苯胺荧光团耦合,设计、合成了一种基于分子内电荷转移(Intramolecular Charge Transfer,ICT)的荧光探针(标记为DATPA)用于同时检测草酰氯和光气,其在溶液中对草酰氯和光气的检测限分别为70 nM和5.5μM。该探针分子在神经性毒剂模拟物氯磷酸二乙酯和各种酰氯类化合物的抗干扰性研究中对草酰氯和光气表现出优异的选择性。在此基础上,通过简单的方式制备了一种基于DATPA的便携试纸条并成功用于检测气相中的草酰氯和光气。

萘与草酰氯反应机理的探讨

研究在N2气氛和无水AlCl3存在的条件下,萘与草酰氯反应。反应混合物GC/MS,GC/FTIR检测结果表明,该反应经历了碳正离子亲电取代-自由基取代反应历程,并讨论了催化剂AlCl3量对产物组成的影响。

[Emim]Cl-AlCl_3离子液体催化蒽与草酰氯的Friedel-Crafts酰基化反应

合成了重要的功能高分子中间体1,2-蒽乙二酮,最佳反应条件为:AlCl3在[Emim]Cl-AlCl3离子液体中的摩尔分数为0.67,离子液体与蒽的物质的量比为2,草酰氯与蒽物质的量比为2,反应温度为40℃,反应时间6h,1,2-蒽乙二酮产率可达91.5%,选择性达98.3%。且[Emim]Cl-AlCl3离子液体对环境污染小,并可循环使用。在相同实验条件下,对等物质的量的AlCl3、FeCl3、[Emim]Cl-AlCl3及[Emim]Cl-FeCl3的催化作用进行了对比,结果表明[Emim]Cl-AlCl3的效果最好。通过萃取、重结晶等方法得到了1,2-蒽乙二酮纯品,通过熔点测定、GC、GC/MS、FT-IR和1HNMR对反应产物进行定性和定量分析。

不对称草酰胺桥联Cu(Ⅱ)-Co(Ⅱ)异双核配合物的合成和表征

合成了一种新型草酰胺配体和铜单核配合物 ,并以铜单核配合物为母体合成了Cu(Ⅱ ) -Co(Ⅱ )异双核配合物 .以元素分析、红外光谱、摩尔电导、热重分析和室温磁矩对新合成配合物进行了表征 .经研究推定 ,新合成异双核配合物具有草酰胺桥联结构 ,Cu(Ⅱ )和Co(Ⅱ )

AlCl3催化蒽与草酰氯的C-酰基化反应

为制备多环芳烃中间体,用AlCl3作催化剂,研究了常温常压下,蒽与草酰氯的C-酰基化反应.GC-MS分析了产物组成,GC考察了各因素对蒽转化率和产物选择性的影响.结果表明:反应生成了氯蒽、9-蒽甲酸、9-氯甲酰基-10-蒽甲酸、9-酮酸-9,10-二氢-10-蒽甲醇、9-氯乙基-10-氯乙烯基蒽和9,10-二氢-9,9′-二蒽甲酮等Friedel-Crafts碳正离子无法解释的产物;用碳正离子亲电取代-芳环上自由基亲电取代双反应历程可合理解释"反常产物"的生成;双反应历程可合理解释各因素对蒽转化率和产物选择性的影响.蒽与草酰氯的C-酰基化反应可以制备新型多环芳烃中间体9-氯甲酰基-10-蒽甲酸、1,2-蒽乙二酮和9,10-二氢-9,9′-二蒽甲酮.

微生物发酵法降解山黧豆毒素的研究

为了寻找具有降解山黧豆神经毒素(ODAP)的菌株,本实验选择30种菌株,以含有已知量的ODAP的山黧豆粉提取液为培养基,采用邻苯二甲醛法检测培养前后培养基中ODAP的消耗量,筛选具有能够明显利用和消耗ODAP的菌株.实验结果表明,有2种菌株对ODAP有明显的降解和消耗作用.还探讨了这两种菌株在山黧豆培养基中的生长情况与ODAP降解情况的相关性以及酶促反应的基本动力学,从所获得的试验结果可断定被筛选出的2株菌种经发酵可产生ODAP降解酶.

2,4-二硝基氟苯柱前衍生测定山黧豆毒素β-ODAP

利用2,4-二硝基氟苯为柱前衍生试剂,建立了测定山黧豆中毒素β-Ν-草酰基-L-α,β-二氨基丙酸(简称-βODAP)及其无毒性的异构体α-N-草酰基-L-α,β-二氨基丙酸(简称α-ODAP)的恒组分洗脱高效液相色谱方法。利用固相萃取进行样品预处理并优化了流动相的pH值,利用Hyperchem和Gaussian 98优化得到二者的空间结构并计算了它们的极性,从理论上解释了两个异构体的色谱行为。最佳色谱条件是固定相C18,5μm,15 mm×4.6 mm,流动相为25 mmol/L KH2PO4/乙腈,(90∶10,V/V),流速为0.8 mL/m in,室温,测定了特定条件下山黧豆成长过程中两个异构体的含量。

草酰基二茂铁衍生物合成与结构表征

以草酰氯为酰化剂,无水三氯化铝为催化剂,二氯乙烷为溶剂,对二茂铁和乙基二茂铁分别进行了草酰化反应,得到了草酰基二茂铁和草酰基-(乙基二茂铁)两种草酰基二茂铁衍生物。通过1HNMR、FT-IR、质谱和元素分析对目标产物进行了结构表征;利用差热分析(DTA)和热重(TG)研究了在高氯酸铵(AP)中分别添加5%题称目标化合物后的热分解性能,发现添加草酰基二茂铁衍生物后,AP的DTG峰温提前了约100℃。

苯与草酰氯反应机理的探讨

研究了在N2气氛和升华处理的无水A lC l3催化作用下,苯与草酰氯反应。反应产物的GC/MS检测结果表明,苯甲酸(28.4%)和二苯甲酮(33.4%)是主要产物,而二苯乙二酮的量却很少,推测该反应经历了碳正离子亲电取代-自由基取代反应历程。并讨论了未处理的和升华处理的A lC l3活性对产物组成的影响。