高效液相色谱法测定血管紧张素转化酶抑制剂的活性

建立了体外直接测定血管紧张素转化酶抑制剂活性的高效液相色谱分析方法。以马尿酰-组氨酰-亮氨酸为反应底物,血管紧张素转化酶为催化剂,反应所生成的马尿酸为测定指标,未加酶抑制剂的反应为空白对照。使用ZORBAX SB-C18色谱柱(4.6 mm i.d.×150 mm,填料粒径5　μm),柱温25 ℃,流动相为乙腈-超纯水(体积比为25∶75,各含0.05%（体积分数）三氟乙酸及0.1%（体积分数）三乙胺),流速0.5 mL/min,检测波长228 nm。在马尿酸浓度为0.005～1.000 mmol/L时,马尿酸浓度与其峰面积呈良好的线性关系(r＝0.9999),最小检测限为0.50 μmol/L;该方法对马尿酸的回收率为99.48%～105.64%,相对标准偏差(RSD)为2.20%(n＝6)。该方法可适用于血管紧张素转化酶抑制剂活性的体外测定,具有操作简便、精密度和准确性高的特点,为降血压药物的研制提供了方便可靠的检测手段。     

Practical and Scalable Synthesis of Ethyl (R)-Piperidine-3-acetate

A practical and scalable synthesis of ethyl (R)-piperidine-3-acetate was achieved from commercially available 3-pyridylacetic acid in 76% overall yield. The practical synthesis was demonstrated on 100-g scale. One-pot reductive N-ethylation of the pyridinium salt with acetonitrile gave an N-ethyl piperidine derivative.     

D/L扁桃酸的合成研究

对D／L扁桃酸的合成工艺进行了优化,尤其在溶剂的选择与回收,二氯化物的制备以及产品的纯化与提取等方面作了有效的改进,收率与纯度有很大改善,分别达到80％和99．4％。     

Direct enantiomeric TLC resolution of dl-penicillamine using (R)-mandelic acid and l-tartaric acid as chiral impregnating reagents and as chiral mobile phase additive

DL-Penicillamine has been resolved into its enantiomers by normal-phase TLC using L-tartaric acid as chiral impregnating reagent as well as chiral mobile phase additive, while (R)-mandelic acid has been found to be successful as a chiral impregnating reagent. The solvent system acetonitrile-methanol-water (5:1:1, v/v) was found to be successful when L-tartaric acid was used as impregnating agent while the solvent combination acetonitrile-methanol-(0.5% l-tartaric acid in water, pH 5)-glacial acetic acid (7:1:1.1:0.7, v/v) was successful as mobile phase as it contained L-tartaric acid as the chiral additive. (R)-mandelic acid was successful as chiral impregnating reagent with ethyl acetate-methanol-water (3:1:1, v/v), as the mobile phase. The effects of concentration of chiral selectors, temperature and pH were examined on enantiomeric resolution. The spots were detected with iodine vapors and the detection limits were found to be 0.12 microg for each enantiomer of penicillamine with L-tartaric acid, under both the conditions, and 0.11 microg with (R)-mandelic acid.     

绍兴黄酒中ACE活性抑制肽的分离分析

首次将绍兴黄酒中的肽类组分进行大孔吸附树脂柱层析和高效凝胶过滤色谱以及反相色谱的多步提取纯化与抑制血管紧张素转换酶（AcE）活性试验,并首次利用基体辅助激光解吸电离-飞行时间串联质谱分析和液相色谱-电喷雾电离四极杆-飞行时间串联质谱联用分析鉴定出黄酒中4种ACE活性抑制肽的氨基酸序列为：VEDGGV、PST、NT和LY。     

Asymmetric Synthesis of (S,S,S)-2-Aza-bicyclo-[3.3.0]-octane-3-carboxylic Acid Benzyl Ester: Formal Synthesis of Ramipril

An asymmetric synthesis of (S,S,S)-2-aza-bicyclo-[3.3.0]-octane-3-carboxylic acid benzyl ester 2 as an intermediate of angiotensin converting enzyme (ACE) inhibitor, ramipril 1, is described.

重要手性合成砌块R－丁三醇的合成及纯化

从天然L－酒石酸出发，经过环硫酸酯还原等四步反应，合成了重要手性合成 砌块R－丁三醇，总产率为60％。同时，找到了一种有效的纯化多羟基化合物的方 法。     

固定化酶不对称合成（S）＋—（＋）—布洛芬的研究

能够不对称水解布洛芬乙酯的酵母菌Ｔ１５８固定化在壳聚糖珠中，固定化酵母菌的活力回收达６０％，最适温度为４５℃，半衰期为７５ｄ以上。     

Synthesis of Atamestane (SH 489): An Aromatase Inhibitor

Atamestane (SH 489) was synthesized from 17β-Acetoxy-1α-methyl-5α-androstan-3-one. Thus dibromination followed by dehydrobromination of the A-ring gave dienone (5) in good yield, which was hydrolyzed and oxidized to give the title compound in 60% overall yield.     

Sulphamic Acid （H2NSO3H）-Catalyzed Multicomponent Reaction of β-Naphthol： An Expeditious Synthesis of Amidoalkyl Naphthols

Sulphamic acid （H2NSO3H） was found to be an efficient catalyst for the multicomponent condensation reaction of β-naphthol, aromatic aldehydes and urea or amides to afford the corresponding α-amidoalkyl-β-naphthols in good yields. The remarkable features of this new procedure are high conversions, short reaction time, clean reaction profiles and simple experimental and work-up procedures.     

合成SGLT2抑制剂埃格列净的新方法

以D-(+)-葡萄糖酸内酯为原料,经三甲硅基保护羟基后与5-溴-2-氯-4′-乙氧基二苯甲烷偶联制得(2S,3R,4S,5S,6R)-2-［4-氯-3-(4-乙氧苄基)苯基］-6-(羟甲基)-2-甲氧基四氢-2H-吡喃-3,4,5-三醇（2）; 2经羟基保护、氧化和羟醛缩合等5步反应制得(3S,4S,5R,6S)-3,4,5-三(苄氧基)-6-［4-氯-3-(4-乙氧苄基)苯基］-2-(羟甲基)-6-甲氧基四氢-2H-吡喃-2-甲醛（7）; 7经还原、脱苄同时关环制得埃格列净(1S,2S,3S,4R,5S)-5-［4-氯-3-(4-乙氧苄基)苯基］-1-(羟甲基)-6,8-二氧杂二环［3.2.1］辛烷-2,3,4-三醇,其结构经¹H NMR和LC-MS表征。     

Exploration of mandelic acid-based polymethacrylates: Synthesis,properties, and stereochemical effects

Mandelic acid (MA) was utilized as a chiral biomass-based precursor to synthesize methacrylic monomers suitable for radical polymerization. A series of polymers were made that incorporated varying feeds of monomer stereopurity and the properties of these materials were investigated. High molar masses (>90 kg/mol) were achieved and the chirality in each polymer closely reflected the stereopurity of the monomer feeds. It was discovered that stereochemical effects had very little influence on the thermal and viscoelastic properties of the polymers produced, however, the steric bulk of the chiral pendants resulted in glassy, amorphous, and thermally stable materials with very low degrees of entanglement. The synthesis, thermal, and viscoelastic properties are discussed.     

4-氯苯乙醇的合成

以4-氯苯乙酸为起始原料,耦合酯化和还原反应合成了4-氯苯乙醇(1),其结构经1H NMR和MS表征。较适宜的反应条件为:4-氯苯乙酸30 mmol,无水乙醇120 mmol,n(4-氯苯乙酸)∶n(SOCl2)∶n(NaBH4)=1.0∶0.5∶1.6,于室温反应3 h完成酯化反应,产物不经分离直接于75℃反应5 h完成还原反应,1收率高于95%,含量大于99%。     

Glyceric Prodrug of Ursodeoxycholic Acid (UDCA): Novozym 435-Catalyzed Synthesis of UDCA-Monoglyceride

Bile acids (BAs) are a family of steroids synthesized from cholesterol in the liver. Among bile acids, ursodeoxycholic acid (UDCA) is the drug of choice for treating primary biliary cirrhosis and dissolving cholesterol gallstones. The clinical effectiveness of UDCA includes its choleretic activity, the capability to inhibit hydrophobic bile acid absorption by the intestine under cholestatic conditions, reducing cholangiocyte injury, stimulation of impaired biliary output, and inhibition of hepatocyte apoptosis. Despite its clinical effectiveness, UDCA is poorly soluble in the gastro-duodeno-jejunal contents, and pharmacological doses of UDCA are not readily soluble in the stomach and intestine, resulting in incomplete absorption. Indeed, the solubility of 20 mg/L greatly limits the bioavailability of UDCA. Since the bioavailability of drug products plays a critical role in the design of oral administration dosages, we investigated the enzymatic esterification of UDCA as a strategy of hydrophilization. Therefore, we decided to enzymatically synthesize a glyceric ester of UDCA bile acid to produce a more water-soluble molecule. The esterification reactions between UDCA and glycerol were performed with an immobilized lipase B from Candida antarctica (Novozym 435) in solvent-free and solvent-assisted systems. The characterization of the UDCA-monoglyceride, enzymatically synthesized, has been performed by ¹H-NMR, ¹³C-NMR, COSY, HSQC, HMBC, IR, and MS spectroscopy.     

三烃基锡配合物(PhCMe_2CH_2)_3Sn[O_2C(CHRPh)] [R: OH(1), H(2)]的合成、结构、热稳定性、量子化学及毒性研究

甲醇中氧化双[三(2-甲基-2-苯基)丙基锡]分别与DL-扁桃酸、苯乙酸反应,合成了2个三烃基锡配合物(PhCMe2CH2)3Sn[O2CCH(OH)Ph](1)和(PhCMe2CH2)3Sn(O2CCH2Ph)(2)。经IR、1H和13C NMR、元素分析和X-射线单晶衍射表征结构。1和2均属三斜晶系,空间群P1。配合物1晶体学参数:a=0.971 1(2)nm,b=1.176 6(3)nm,c=1.700 8(4)nm,α=96.840(12)°,β=103.235(12)°,γ=110.725(11)°,Z=2,V=1.726 0(7)nm3,Dc=1.288 g·cm-3,μ(Mo Kα)=0.773 mm-1,F(000)=696,R1=0.032 5,wR2=0.087 3。配合物2晶体学参数:a=0.972 85(9)nm,b=1.161 40(11)nm,c=1.689 31(16)nm,α=96.830(5)°,β=101.935(5)°,γ=110.770(4)°,Z=2,V=1.707 1(3)nm3,Dc=1.271 g·cm-3,μ(Mo Kα)=0.778 mm-1,F(000)=680,R1=0.024 8,wR2=0.067 3。1和2的中心锡原子均为畸变四面体构型。通过分子间C-H…O或C-H…π作用,1和2分别形成一维带状或链状结构。热重分析结果表明,1和2具有良好的稳定性。毒性测试的初步结果表明,配合物1、2具有较好的环境相容性,对石螺急性毒性较小。     

Essential of Proline and Valine Residues in the Peptide Derived from Lactoferrin for Angiotensin Converting Enzyme Inhibition

We synthesized Leu‐Arg‐Pro‐Val‐Ala‐Ala‐Glu, the peptide contained in lactoferrin (Lf), to identify the angiotensin converting enzyme (ACE) inhibition. In an attempt to know the structure‐activity relationship of this peptide, we replaced Pro (the third amino acid residues from N‐terminal) or Val (the fourth amino acid residues from N‐terminal) with Ala (neutral amino acid), Glu (acidic amino acid) or Lys (basic amino acid) to produce six peptides. From the in vitro ACE inhibition (IC₅₀) of these synthesized peptides, the original peptide (Leu‐Arg‐Pro‐Val‐Ala‐Ala‐Glu) showed higher ACE inhibition than the replaced six peptides. Thus, replacement of Pro at the third amino acid residues or Val at the fourth position with Ala, Glu or Lys revealed the ACE inhibition to be lower than the original form of Leu‐Arg‐Pro‐Val‐Ala‐Ala‐Glu. Otherwise, we added one peptide at the C‐terminal of Leu‐Arg‐Pro‐Val‐Ala‐Ala‐Glu and found both products with an addition of Val (Leu‐Arg‐Pro‐Val‐Ala‐Ala‐Glu‐Val) or Ile (Leu‐Arg‐Pro‐Val‐Ala‐Ala‐Glu‐Ile) showing a lower ACE inhibition than the original one. The ACE inhibitions produced by both replaced peptides were without significance. Also, deletion of the last peptide at the C‐terminal (Leu‐Arg‐Pro‐Val‐Ala‐Ala) failed to produce a marked change of ACE inhibition as compared to the original one. These results suggest that Pro and Val are essential in the peptide for inhibition of ACE activity.     

Enantioselective Synthesis of ((1R,2R)-Cyclohexane-1,2-diyl)bis(methylene)dimethanesulfonate,a Lurasidone Hydrochloride Intermediate

A concise, economical, and highly enantioselective synthesis of bismesylate intermediate of lurasidone HCl, an antipsychotic, has been developed. The key steps involved in the synthesis are thionyl chloride–catalyzed esterification of tetrahydrophthalic anhydride in MeOH, epimerization of cis to trans isomer, hydrolysis of the diester, resolution of the diacid, reduction with Red-Al, and finally bismesylation of the corresponding diol, which provided the desired intermediate ((1 R,2 R)-cyclohexane-1,2-diyl)bis(methylene) dimethanesulfonate in overall good yield.     

Synthesis of (+)‐13‐Stemarene and (+)‐18‐Deoxystemarin: Expeditious Preparation of the Key 6‐exo‐Hydroxybicyclo[2.2.2]octan‐2‐one Ethylene Dithioacetal

An expeditious preparation of the 6‐exo‐hydroxybicyclo[2.2.2]octan‐2‐one ethylene dithioacetal 2b , a key intermediate in the synthesis of (+)‐13‐stemarene ( 4 ) and (+)‐18‐deoxystemarin ( 5 ) is described. Compound 2b was obtained as the major product by equilibrating the endo rich mixture of 6‐hydroxybicyclo[2.2.2]octan‐2‐one ethylene dithioacetals 2 with TsOH in benzene at reflux, easily available from the corresponding hydroxy ketones 9 . The model experiments which preceeded the above transformation, not previously described in the literature, are also presented.