(1S)-1-[(4R)-2,2-dimethyl-1,3-dioxolan+-4-yl][-2-hydroxyethylamm onium benzoate, a versatile building block for chiral 2-aminoalkanols: concise synthesis and application to nelfinavir, a potent HIV-protease inhibitor

A concise synthesis of a versatile chiral C4 building block for 2-aminoalkanols, (1S)-1-[(4R)-2,2-dimethyl-1,3-dioxolan-4-yl]-2-hydroxyethylammo nium benzoate (1a), was described. 1 (1a and its enantiomer 1b) acted as four stereoisomers of optically active 2-amino-1,3,4-butanetriol. The versatility of 1 was demonstrated by its application to the practical synthesis of nelfinavir (2), a potent HIV-protease inhibitor, as well as by the stereospecific synthesis of three diastereomers of 2.     

Synthesis of 2-(1-Alkoxyvinyl)oxazolidines by Condensation of 2-Alkoxypropenals with 2-Aminoalkanols and Ring-Chain Tautomerism of the Products

Reactions of 2-alkoxypropenals with 2-aminoalkanols afforded tautomeric mixtures of previously unknown 2-(1-alkoxyvinyl)oxazolidines and imino alcohols. The condensation takes 2 h at room temperature (89-100%) or 1-5 min under microwave irradiation. The tautomeric equilibrium shifts toward the open-chain structure with increase in the solvent polarity (CDCl₃, CD₂OD, DMSO-d ₆, D₂O) and temperature. The presence of substituents in the oxazolidine ring raises the stability of the cyclic tautomer.     

Determination of Cadmium(ii), Copper(ii), Mercury(ii), and Lead(ii) in Water Using Stochastic Sensors Based on Graphite and Diamond Paste Modified with 1H-Pyrrole-1-Hexanoic Acid

Graphite/diamond pastes modified with 1H-pyrrole-1-hexanoic acid were used for the design of stochastic sensors. The proposed stochastic sensors were used to determine four heavy metals, copper(II), cadmium(II), mercury(II), and lead(II), in water samples. The sensitivities of the stochastic sensors were high for all four metal ions, and their limits of determination were sufficiently low to enable detection at very minute concentrations; in some cases, unreachable using standard methods of analysis. The recoveries of copper(II), cadmium(II), mercury(II), and lead(II) in water samples were higher than 93.00%, with relative standard deviation values lower than 1.00%. The sensors were used to simultaneously determine copper(II), cadmium(II), mercury(II), and lead(II) in water samples. The obtained results were in agreement with those obtained using standard analytical methods.     

新型NO供体的合成及其体外释放NO性能

新型NO供体的合成及其体外释放NO性能;金属卟啉;NO载体;合成;体外释NO作用     

Micro-CT参数对骨质疏松性椎体压缩性骨折术后复发的预测价值

本研究探讨Micro-CT参数对骨质疏松性椎体压缩性骨折(OVCF)患者术后复发的预测价值。选取OVCF患者127例,根据术后6个月骨折复发情况分为复发组(n=41)与未复发组(n=86)。患者均接受Micro-CT检查,对比两组Micro-CT参数,即骨体积分数(BV/TV)、骨小梁厚度(Tb.Th)、骨小梁间隙(Tb.Sp)、结构模型指数(SMI),以及骨密度(BMD)、骨矿含量(BMC),分析各参数与BMD、BMC及术后复发相关性,并评价各参数对术后复发的预测价值。结果显示,复发组骨体积分数(BV/TV)、骨小梁厚度(Tb.Th)低于未复发组,骨小梁间隙(Tb.Sp)、结构模型指数(SMI)高于未复发组(P<0.05);BV/TV、Tb.Th与骨密度(BMD)、骨矿含量(BMC)呈正相关,Tb.Sp、SMI与BMD、BMC呈负相关(P<0.05);将年龄、BMD、BMC等其他因素控制后,BV/TV、Tb.Sp、Tb.Th、SMI与OVCF术后骨折复发显著相关(P<0.05);BV/TV、Tb.Sp、Tb.Th、SMI联合预测OVCF术后骨折复发的曲线下面积(AUC)最大,为0.888(P<0.05)。提示Micro-CT参数在OVCF患者中呈异常表达,采用Micro-CT检查可为临床预测OVCF术后骨折复发提供科学指导。     

Supercritical fluid extraction for identification and determination of volatile metabolites from Angelica dahurica by GC-MS

The volatile components of Angelica dahurica were obtained by supercritical fluid extraction (SFE) method. These oils obtained were analyzed by GC-MS (identification and determination of metabolites). The compounds were identified according to their retention indices and mass spectra (electron impact (EI), 70 eV). The effects of different parameters, such as pressure, temperature, flow rate of CO(2), and the amount of modifier, on the SFE of A. dahurica oil were investigated. A total of 50 compounds of SFE extracts were identified. Phellopterin (PO), isoimperatorin (IO), imperatorin (IM), alloimperatorin (AM), byakangelicin, isooxypeucedanin, and pimpinellin were the major coumarin compounds identified in A. dahurica SFE extracts. The quantitations of PO, IO, IM, and AM were then accomplished. The calibration curves showed good linearity (R(2) >0.99) in the concentration ranges tested. The recoveries were higher than 85%, with RSDs less than 10%. The GC-MS method was successfully validated and applied to the quantitation of A. dahurica.     

用色谱-质谱方法鉴定薄荷油中的异构体

用毛细管气相色谱－质谱联用、程序升温方法分析了一种薄荷油的化学成分、共分离出20个组分,其中含4组异构体,它们分别是：m/z=136的5个成分α－蒎烯、β－蒎烯、β－月桂烯、α－菲兰烯和柠檬烯;m/z＝154的2个成分（cis)－薄荷酮和（2R－cis)－薄荷酮;m/z＝156的2个成分（1α.2α.5β）－薄荷醇和（1α.2β.5β）－薄荷醇;以及m/z＝204的8个成分（1α,3aα,3bβ,6aβ,6bα）－十氢－3a－甲基－6－亚甲基－1－异丙基－环丁烷并[1,2:3,4]二环戊烯、[1R-(1R,4E,9S)－4,11,11－三甲基－8亚甲基－双环（7．2．0）十一碳4－烯、[1R-(1aα,7α,7aα,7bα]-1a,2,3,5,6,7,7a,7b-八氢－1,1,7,7a-四甲基－1氢－环丙烷[α]并萘、[1aR-(1aα,4aα,7α,7aβ,7bα）－十氢,1,1,7－三甲基4－亚甲基－1－氢－环丙烷[e]并奥、（1S-exo）－2－甲基－3－亚甲基－2－（4－甲基－3－戊烯基）－二环（2．2．1）庚烷、（3aα,3bα,4α,7β,7aR）－八氢－7甲基－3亚甲基－4－异丙基－1氢－不戊烷[ 1,3]并环丙烷[1,2]并苯、1－乙烯基－1－甲基－2－异丙烯基－4（1－甲基亚乙基）环己烷和绿叶烯。     

自组装制备聚(丙烯酸叔丁酯-b-甲基丙烯酸二甲胺基乙酯)壳交联胶束

以1-氯代乙苯为引发剂、氯化亚铜/N,N,N′,N″,N″-五甲基二乙撑三胺(PMDETA)为催化体系、丁酮-异丙醇为混合溶剂,通过原子转移自由基聚合法制备不同分子量的大分子引发剂聚丙烯酸叔丁酯(1-PECl)及不同嵌段比的两亲性嵌段共聚物聚(丙烯酸叔丁酯-b-甲基丙烯酸二甲胺基乙酯)(P(tBA-b-DMAEMA))。通过1H-NMR表征了P(tBA-b-DMAEMA)的结构,GPC测试了其分子量及分子量分布。P(tBA-b-DMAEMA)在选择性溶剂中自组装形成核-壳结构的胶束,引用了乙烯基乙二醇二碘醚(BIEE)为交联剂与链段PDMAEMA发生化学交联反应从而得到稳定的壳交联胶束结构,并通过马尔文粒径仪研究了自组装所得胶束的温度及pH敏感性。     

Hydrazone-based ligands for micro-solid phase extraction-high performance liquid chromatographic determination of biogenic amines in orange juice

Eight hydrazone-based ligands were synthesized, trapped in a silica sol-gel matrix, and were subsequently used in the micro-solid phase extraction (μ-SPE) of biogenic amines (BAs). The BAs investigated were tryptamine, phenylethylamine, putrescine, histamine, tyramine and spermidine. Prior to the extraction, dansyl chloride was added to the samples which were heated to 70°C for 10 min. The samples were extracted with μ-SPE, after which analytes were desorbed using acetonitrile via ultrasonication. The extracts were analysed by high performance liquid chromatography (HPLC) with ultraviolet detection. Of the eight ligands investigated as sorbents, benzophenone 2,4-dinitrophenylhydrazone was found to be the most promising. The enhanced π-π interaction between the analytes and the ligand facilitated the adsorption process. Under the most suitable extraction conditions, the method demonstrated good linearity with correlation coefficient of more than 0.985 over a concentration range of 1-50 μg L(-1). Satisfactory repeatability with relative standard deviations of 7.43-11.30% (n=3) were obtained. Detection limits ranged from 3.8 to 31.3 ng L(-1). The μ-SPE method exhibited lower recoveries (71.5-87.4%) when compared to the solid phase extraction technique (79.7-95.0%), but enrichment factors of 94-460 were obtained. The proposed μ-SPE-HPLC method was applied to the determination of BAs in orange juice purchased from local supermarkets, with satisfactory results. The orange juices were characterized by the presence of relatively high levels of putrescine (range, 550-2210 μg L(-1)) but tryptamine and phenylethylamine were not detected in any of the tested samples.     

固相微萃取-气相色谱-质谱法分析香樟籽挥发性成分

采用固相微萃取-气相色谱-质谱法分离和鉴定香樟籽的挥发性成分,用归一化法测定其相对含量。共分离出76种组分,鉴定出47种化合物,其含量占总挥发性成分的97.4%。主要挥发成分为樟脑(57.89%)、柠檬烯(12.68%)、α-蒎烯(4.42%)、莰烯(2.69%)、香橙烯(2.34%)、伞花烃(2.26%)及β-蒎烯(2.12%)。     

Air sampling of aromatic hydrocarbons in the presence of ozone by solid-phase microextraction

Effects of ozone on air sampling of standard gas mixtures of aromatic hydrocarbons were tested using solid-phase microextraction (SPME). Standard concentrations of ozone ranging from 10 ppb (v/v) to 6400 ppm (v/v) were generated using an in-house built ozone generator based on corona discharge. Effects of temperature, discharge voltage, and oxygen flow on the ozone generation were tested. The working dc voltage had the greatest effect on generated ozone concentration and was proportional to the ozone concentration. Generation temperature and oxygen flow rate were inversely proportional to ozone concentrations. Produced ozone was mixed with standard benzene, toluene, ethylbenzene, and xylenes (BTEX) gas at less than 100 ppb (v/v). Air samples were collected with poly(dimethylsiloxane) (PDMS) 100 microm SPME fibers and analyzed by gas chromatography (GC)-flame ionization detection (FID) and GC-MS. Significant reductions of BTEX concentrations were observed. In addition, some products of BTEX-ozone-oxygen reactions were identified. SPME worked well as a rapid sampler for BTEX and BTEX-ozone-oxygen reaction products. No significant deterioration of the PDMS coating and no significant reduction of absorption capacity were observed after repeated exposure to ozone.     

Isolation and identification of metabolites from dihydromyricetin

Dihydromyricetin (DHM) is the major bioactive constituent of Rattan Tea, which is the tender stems and leaves of Ampelopsis grossendentata. Seven metabolites (2-8) of DHM (1) were obtained by the chromatographic method. The metabolites 2-5 were obtained from the urine of rats administered orally with DHM; and metabolites 6-8 were detected in the fecal specimens of rats, which were also produced by human intestinal bacteria (HIB) in vitro, and were separated from the cultured media of HIB containing DHM. Their structures were elucidated as 5,7,3',5'-tetrahydroxyflavanonol (2); 5,7,3',5'-tetrahydroxy-4'-methoxyflavanonol (3); 5,7,4',5'-tetrahydroxy-3'-methoxyflavanonol (4); and dihydromyricetin-O-5-beta-D-glucuronide (5); (2R,3S)-5,7,3',4',5'-pentahydroxyflavanonol (6); 3,4,5,7,3',4',5'-hepthydroxyflavan (7) and 5,7,3',4',5'-pentahydroxyflavanone (8) on the basis of UV, NMR and LC-MS/MS data. These seven metabolites were formed through familiar metabolic reactions. Dihydromyricetin-O-5-beta-D-glucuronide (5) is a new compound. The (13)C-NMR data of (2) and (4) are reported for the first time.     

聚芳醚腈共聚物的合成与性能

以二卤代苯甲腈，对苯二酚，间苯二酚为原料，制备了几种不同间苯二酚／对苯二酚比的聚芳醚腈树脂。采用流涎成膜法制备了它们的薄膜。对薄膜样品进行了红外光谱分析和热分析，测定了力学性能，在扫描电子显微镜上观察了薄膜拉伸断面。     

固相微萃取-气相色谱-质谱技术分析槐花的挥发性成分

用顶空固相微萃取操作,结合气相色谱-质谱联用技术对槐花挥发性成分进行了鉴定,并用面积归一化法测定其相对含量.共鉴定出化合物31种,包括酮、醇、酸、甾醇、酚、醛、酯、烷烃、烯烃及杂环等10类化合物,其中酮类化合物占总色谱馏出峰面积的21.15%;醇类化合物占13.78%;酸类占9.15%.其主要化合物有:1,9,12三氧-4,6-二氨基环十四烷-5-硫酮(20.58%),棕榈酸(9.05%),9,12,15-十八三烯醇(7.05%),(Z,Z)-9,12-十八碳二烯酸(6.85%),β-谷甾醇(6.11%).该技术可以简便快捷准确地进行槐花挥发性成分的分析鉴定.     

3.0T MRI检查结合X线钼靶诊断乳腺恶性肿瘤的研究

本研究探讨3.0T磁共振成像(MRI)结合X线钼靶诊断乳腺恶性肿瘤的价值。采用回顾性研究方法,选取乳腺肿块患者110例162个病灶,给予3.0T MRI及X线钼靶检查。经病理确诊为恶性病变101个;恶性病灶形态不规则、边缘毛刺、时间-信号强度曲线(TIC)类型Ⅲ型和早期增强率≥60%比例明显高于良性病灶(P<0.05),而分叶状比例和表观扩散系数(ADC)值明显低于良性病变(P<0.05);恶性病变X线钼靶表现:形态不规则、钙化、结构不对称和大导管征比例明显高于良性病变(P<0.05);MRI联合X线钼靶诊断乳腺恶性病变的灵敏性、准确性和阴性预测值明显高于MRI诊断(P<0.05)。3.0T MRI检查结合X线钼靶诊断乳腺恶性肿瘤有较好的价值。     

增塑剂对可吸收缝合线后处理工艺条件和降解性能的影响

分别在对二氧环己酮均聚物和对二氧环己酮-乙交酯共聚物中加入增塑剂进行纺丝,制得聚对二氧环己酮单丝缝合线(PDS)和对二氧环己酮-乙交酯共聚物单丝缝合线(PDG).用DSC方法研究了增塑剂含量对PDS缝合线热性能的影响和不同热定型条件的PDG缝合线的热性能,测试了热定型温度对PDG缝合线初始强度、模量及柔量的影响,考察了增塑剂含量对两种缝合线的生物降解性能和力学降解性能影响.研究结果表明,PDS缝合线的玻璃化转变温度Tg、结晶温度Tc以及熔融温度Tm均随着增塑剂含量的增加而降低,但其结晶能力增加.随着热定型温度的增加,PDG缝合线的初始打结强度、熔融热均提高,熔融温度Tm基本保持不变.两种缝合线的强度保留率随着增塑剂含量的增加均先增加后减小,而重量保留率随着增塑剂含量增加始终减小.     

阀切换-离子色谱法测定1,2-环氧丁烷产品中有机酸

建立了阀切换-离子色谱法测定1,2-环氧丁烷（1,2-BO）产品中有机酸（甲酸、乙酸和丙酸）的方法。样品经乙醇稀释后,通过阀切换技术,有机酸被IonPac TAC-ULP1捕集柱捕集,然后进入IonPac AS11分析柱分离,并由电导检测器检测。结果表明：甲酸、乙酸和丙酸均能实现较好地分离,在各自的范围内其色谱峰面积呈现良好的线性关系。实际样品的加标回收率为92.5%~111.8%,相对标准偏差小于5.6%（n=3）,检出限为0.60~4.80 μg/L。该方法具有前处理简单、快速、准确等特点,适用于不溶于水的有机体系中有机酸的分析。     

十一种2,3-二取代喹喔啉-1,4-二氧化物抗菌剂的合成与谱学研究

采用直接氧化法和Beirut反应合成了十一种抗菌剂2,3-二取代喹喔啉-1。4-二氧化物.给出了完整的UV,IR,NMR数据和有关谱学特性.EPR研究表明这些N-氧化物在溶液光解过程中生成稳定的顺磁物.从含有2,3-环丁亚基喹喔啉-1,4-氧化物(2g)的氯仿溶液光解体系记录的EPR谱得到9.69G(1N)、3.59G(2H),1.25G(2H)和0.76G(1H)等超精细分裂值,指认为1-羟基-2,3-环丁亚甲基喹喔啉-4-氧基(4).指出喹喔啉-1,4-氧化物与对萘醌化合物有结构、物性的类似性.     

芹菜籽香气成分研究

采用固相微萃取法萃取黑龙江产芹菜籽香气成分,然后用GC—MS进行成分分析,并与水蒸气蒸馏法获得的精油成分进行比较．用CAR on PDMS萃取柱进行顶空固相微萃取时,共检测出26种成分,鉴定出占总成份89．650％的20种成分,主要成分为柠檬烯（35．980％）,β-月桂烯（20．500％）,β-蛇床烯（16．160％）,正戊基苯（5．295％）,β-蒎烯（3．412％）,α-蛇床烯（3．293％）．水蒸汽蒸馏法提取芹菜籽,以1．18％产率获得精油,共检测出23个成分,鉴定出占总精油91．375％的18种成分,主要成分为柠檬烯（31．149％）,β-蛇床烯（22．281％）,对甲苯基异戊酸酯（14．944％）,α-2-丙烯基苯甲醇（9．872％）,β-月桂烯（4．324％）和α-蛇床烯（4．322％）．