Efficient Synthesis of Glycosylated Matijin‐Su Derivatives via Ultrasonic Irradiation

Matijin‐Su ( 1 ) is a phenylalanine dipeptide compound with anti‐hepatitis B virus (HBV) activity. Previous reports suggest that the synthesis of glycosylated Matijin‐Su derivatives needs at least 10 steps. To simplify the synthetic procedure, we have developed a shorter and more efficient method for the preparation via ultrasound irradiation. Two galactopyranosylated ( 2 ) and two glucopyranosylated ( 3 ) derivatives were synthesized in 6 or 7 steps. The overall yields for the total synthesis of galactopyranosylated derivatives were markedly increased to 39% ( 2a ) or 22% ( 2b ). And the yields for glucopyranosylated derivatives also reached 29% ( 3a ) or 16% ( 3b ).     

Gas-liquid chromatography of some alkyl derivatives of 5-fluorouracil

Various procedures for converting 5-fluorouracil into its methyl, butyl and hexyl derivatives are described. Structures were established as the N,N'-dialkyl derivatives using mass spectrometry or combined gas-liquid chromatography-mass spectrometry. The reaction conditions, i.e., the amount of derivatization reagents and reaction time, were optimized. Gas-liquid chromatographic characteristics of the derivatives were investigated on different stationary liquid phases, and 2% or 3% SP-2250, 5% XE-60 and 5% OV-1 were found to be superior. With 5-chlorouracil as the internal standard a linear response for the various derivatives was observed in the microgram range. The applicability of the different dialkyl derivatives in the measurement of 5-fluorouracil in biological materials is discussed.     

Aqueous-Phase Synthesis of 2-Aminothiazole and 2-Iminothiazolidine Derivatives catalyzed by Diammonium Hydrogen Phosphate and DABCO

2-Aminothiazole and 2-iminothiazolidine derivatives were synthesized from the reaction of phenacyl bromide, thiourea, and its derivatives in aqueous media catalyzed by diammonium hydrogen phosphate (10%) and DABCO (10%) at room temperature in an efficient and simple procedure.     

Reaction of aldimine anions with vinamidinium chloride: three-component access to 3-alkylpyridines and 3-alkylpyridinium salts and access to 2-alkyl glutaconaldehyde derivatives

N-tert-Butylimino derivatives of aldehydes were deprotonated with LDA and reacted with vinamidinium chloride to give 2-alkylaminopentadienimine derivatives, which were isolated as their corresponding hydrochloride in 68-81% yield. Reaction of these derivatives with ammonium acetate or salts of primary amines, in n-butanol at 80 degrees C, afforded the corresponding 3-alkylpyridines or 3-alkylpyridinium salts in high yield. Alkaline hydrolysis of 2-alkylaminopentadieneimine derivatives allowed a practical accesss to potassium salts of 2-alkylglutaconaldehyde.     

Effect of plant matrix and fluid ethanol concentration on supercritical fluid extraction efficiency of schisandrin derivatives

An investigation of the effect of plant matrix on the supercritical fluid extraction efficiency of five schisandrin derivatives is reported, exhibiting a great difference with respect to extraction efficiency depending on the matrix. Pure supercritical CO2 at 60 degrees C and 34.0 MPa cannot fully recover schisandrin derivatives from the leaves as much as from the other matrices. Only 36.9% of these compounds are extracted from leaves of Schisandra chinensis by supercritical CO2 in comparison with organic solvent extraction. However, more than 80% of schisandrin derivatives are obtained from both stem and fruit parts. Ethanol addition also shows a different effect depending on plant matrix; that is, CO2 modified with 10% ethanol could enhance the yield of schisandrin derivatives from leaves by four times when compared with that of pure CO2, but it has little effect on both stems and fruits.     

Synthesis of novel (1-alkanoyloxy-4-alkanoylaminobutylidene)-1,1-bisphosphonic acid derivatives

A novel strategy for the synthesis of (1-alkanoyloxy-4-alkanoylaminobutylidene)-1,1-bisphosphonic acid derivatives (1a-d) via (1-hydroxy-4-alkanoylaminobutylidene)-1,1-bisphosphonic acid derivatives (2a-d), starting from alendronate has been developed with reasonable 51-77% overall yields. Intermediate products, (1-hydroxy-4-alkanoylaminobutylidene)-1,1-bisphosphonic acid derivatives (2a-d), were prepared in water with reasonable to high yields (52-94%).     

Synthesis of two A-B-C type conjugated amphiphilic triblock fullerene derivatives and their application in organic solar cells

Two A-B-C type conjugated amphiphilic triblock fullerene derivatives C60-2 HMTPB and C60-2 EHTPB were obtained in multi steps synthesis with three different blocks,and the amphiphilic diblock molecular C60-4 TPB was also preferred as a reference.When as modifying layer on zinc oxide(ZnO),the three fullerene derivatives can all reduce the work function of ZnO via modulation of the interfacial dipoles and lead a better electrical coupling.As introducing treatment of toluene,the obvious self-assembly of fullerene derivatives were observed,which were supported by X-ray diffraction and contact angle of water measurement.Base on PTB7-Th:PC71 BM system,the inverted organic solar cells devices with structure of ITO/ZnO/fullerene derivatives/PTB7-Th:PC71BM/Mo03/Al got power conversion efficiencies of 8.62%,8.83%and 9.00%for C60-4 TPB,C60-2 HMTPB and C60-2 EHTPB,respectively,compared 8.13%of devices with bare ZnO.The result of conjugated amphiphilic triblock fullerene derivatives provides a straightforward approaching by simultaneously modulating the morphology and interfacial work function of ZnO,which can also lead high performance in optoelectronic devices.     

Reduction of 3‐Acyl Derivatives of Oxindoles,Benzo[b]furan‐2‐ones,and Benzo[b]thiophen‐2‐ones to the Corresponding Alkyl Derivatives by Sodium Borohydride–Acetic Acid

It was found that 3‐acyl derivatives of oxindoles, benzo[b]furan‐2‐ones, and benzo[b]thiophen‐2‐ones could be efficiently and conveniently reduced to the corresponding alkyl derivatives by pelletized sodium borohydride in acetic acid. A typical procedure involves heating the acylated substrates for approximately 90 min in a slurry of glacial acetic acid and sodium borohydride to provide the 3‐alkyl product in yields ranging from 62% to 96%. This synthetic methodology represents a convenient approach to the synthesis of the alkyl derivatives.     

2-Thiazolidinone: a novel thiol protective surrogate of complete atom efficiency, a practical synthesis of (+)-biotin

2-Thiazolidinone derivatives were shown to be novel protective surrogates of a thiol group in l-cysteine derivatives. After elaboration at the C-4 substituent, the thiol group was completely liberated by simple heating in DMF whose atom efficiency is 100%. A practical synthesis of (+)-biotin was accomplished by the use of the strategy employing 4-functionalized 2-thiazolidinone derivatives as the intermediates, allowing a synthesis of (+)-biotin in 10 steps and in 31% overall yield. Short steps, high yield, and ease of operation of the present approach would permit the hitherto most efficient access to (+)-biotin.     

Characterisation of liposomes containing aminolevulinic acid and derived esters

Liposomes of different compositions have been designed to improve delivery of aminolevulinic acid (ALA) and its esterified derivatives ALA-Hexyl ester (He-ALA) and ALA-Undecanoyl ester (Und-ALA) for its use in photodynamic therapy (PDT). Egg yolk phosphatidyl choline (PC), phosphatidic acid (PA) and phosphatidyl glycerol (PG) were employed in the preparation of the liposomes. Sonicated vesicles composed of PC, PC-PG (80:20) or PC-PA (80:20) containing ALA or derivatives were obtained and purified by a minicolumn centrifugation method. PC liposomes presented encapsulation percentages around 6% for 2 mM ALA, 13% for 2 mM He-ALA and 51% for 2 mM Und-ALA. The addition of PG or PA to the formulation, resulted in an increased entrapment: 19% for 2 mM ALA, 69% for 2 mM He-ALA and 87% for 2 mM Und-ALA in PC-PG liposomes and 21% for 2 mM ALA, 60% for 2 mM He-ALA and 87% for 2 mM Und-ALA in PC-PA liposomes. Higher concentrations of ALA or derivatives resulted in lower percentages of entrapment. The three formulations containing ALA or derivatives were stable up to 1 week upon storage at 4 degrees C. However, upon dilution with medium, ALA leaked from the liposomes, while on the contrary, He-ALA was highly retained, being therefore a good choice for its use in PDT. The stability of Und-ALA upon dilution could not be tested, but Und-ALA proved to have the highest entrapment efficacy.     

新型2－乙内酰硫脲衍生物的合成与表征

新型2－乙内酰硫脲衍生物的合成与表征;乙酰乳酸合成酶;磺酰脲;乙内酰硫脲;合成     

2-甲基-1,8-萘啶衍生物的甲基溴代反应

报道了2-甲基-1,8-萘啶衍生物的甲基溴化反应,以N-溴代琥珀酰亚胺(NBS)为溴化剂、红外光为引发剂,得到单溴代产物2-溴甲基-1,8-萘啶衍生物及其二溴代副产物2-二溴甲基-1,8-萘啶衍生物,对比了两种不同的反应条件,通过对影响甲基溴化产物产率的反应条件进行优化改进,得到单溴代产物的较优合成条件为：NBS的用量为原料的1.2倍,500 W红外灯为光源,反应时间为2 h。 该反应条件下,单溴代产物的产率可达到54.6%。     

合成(E)-2,3-二卤-2-丁烯-1,4-二醇及其衍生物的新方法

采用乙醇 /苯为反应溶剂 ,以α -炔醇为反应原料 ,氯化铜为卤化剂 ,立体专一性合成 (E) - 2 ,3-二卤 - 2 -丁烯 - 1 ,4-二醇及其衍生物。分离产率为 1 0 0 % ,粗产品纯度即可达 98% (GC)     

Production and Digestibility Studies of β-Galactosyl Xylitol Derivatives Using Heterogeneous Catalysts of LacA β-Galactosidase from Lactobacillus Plantarum WCFS1

The synthesis of β-galactosyl xylitol derivatives using immobilized LacA β-galactosidase from Lactobacillus plantarum WCFS1 is presented. These compounds have the potential to replace traditional sugars by their properties as sweetener and taking the advantages of a low digestibility. The enzyme was immobilized on different supports, obtaining immobilized preparations with different activity and stability. The immobilization on agarose-IDA-Zn-CHO in the presence of galactose allowed for the conserving of 78% of the offered activity. This preparation was 3.8 times more stable than soluble. Since the enzyme has polyhistidine tags, this support allowed the immobilization, purification and stabilization in one step. The immobilized preparation was used in synthesis obtaining two main products and a total of around 68 g/L of β-galactosyl xylitol derivatives and improving the synthesis/hydrolysis ratio by around 30% compared to that of the soluble enzyme. The catalyst was recycled 10 times, preserving an activity higher than 50%. The in vitro intestinal digestibility of the main β-galactosyl xylitol derivatives was lower than that of lactose, being around 6 and 15% for the galacto-xylitol derivatives compared to 55% of lactose after 120 min of digestion. The optimal amount immobilized constitutes a very useful tool to synthetize β-galactosyl xylitol derivatives since it can be used as a catalyst with high yield and being recycled for at least 10 more cycles.     

取代噻吩双酰胺类化合物的设计、 合成及生物活性

利用中间体衍生化方法, 将噻吩环引入到双酰胺类化合物中, 合成了一系列取代噻吩双酰胺类化合物1~3; 目标化合物的结构经核磁共振波谱、 红外光谱及元素分析确认. 生物活性测试结果表明, 化合物1在600 mg/L剂量下对小菜蛾具有良好的杀虫效果, 致死率均为100%, 其中化合物1a和1e在20 mg/L剂量下对小菜蛾的致死率仍达到60%以上; 改变双酰胺结构中的吡唑环得到化合物2和3, 其杀虫活性消失, 说明该类化合物中吡唑环结构对杀虫活性具有关键作用.     

Synthesis and anticancer activities of 5,6,7-trimethylbaicalein derivatives

The aim of this study was to develop potential anticancer agents based on a naturally occurring baicalein, a flavonoid from Scatellariae radix. Cinnamic acid derivatives were converted to corresponding chlorides and then condensed with 3,4,5-trimethoxyphenol in the presence of BF(3) x Et(2)O to give chalcones. Intramolecular cyclization of these intermediates by the actions of DMSO/I(2) afforded the desired trimethylbaicalein derivatives. Cell viability after treatment with the tested compound for 2 d was determined by a colorimetric MTT assay. The results indicated that most of the derivatives showed improved inhibition of proliferation of Hep G2 cells. Compound 9 was the most potent, in which the cell viability was reduced to <2% at the 25 microM level. In the case of Hep 3B cells, 8a, 8b and 8f showed moderate inhibition of their proliferation and 25 microM was required to reduce the viability to ca. 30%. On the other hand, prostate DU145 cells were more resistant. Most of the derivatives caused a 60% inhibition of DU145 cells only at a concentration of 100 microM or above.     

间接糖基化马蹄金素衍生物的合成及抗乙肝病毒活性研究

以二缩三乙二醇或三缩四乙二醇为连接臂, 通过间接引入具有肝靶向性的D-半乳糖配基的方法, 设计合成了6个半乳糖糖基化修饰的肝靶向马蹄金素(MTS)衍生物; 通过¹H NMR, ¹³C NMR, ¹H-¹H COSY, HMQC和ESI-MS对其结构进行了表征; 并以HepG2 2.2.15为细胞模型初步评价了目标化合物的抗乙肝病毒(HBV)活性. 结果表明, 所有目标化合物对HBV DNA的复制均有抑制作用, 且具有一定的量效关系. 化合物15b的体外抗HBV活性最好, 后期研究将选用其进行小鼠体内组织分布实验, 并与原型化合物以及Y101体内组织分布情况进行比较研究, 以验证半乳糖基的引入能否提高MTS衍生物的肝靶向性.     

Cu(I)-catalyzed asymmetric oxidative cross-coupling of 2-naphthol derivatives

The asymmetric oxidative coupling reaction between 2-naphthol or binaphthol derivatives and 3-hydroxy-2-naphthoate derivatives with the copper(I)-(S)-(−)-isopropylidenebis(4-phenyl-2-oxazoline) catalyst was carried out. The reaction proceeded in a highly cross-coupling selective manner (≤99.7%) to produce the binaphthyl or quaternaphthyl derivative in good yield (≤92%) with enantioselectivity of up to 74%.     

Water extract of onion catalyst: An economical green route for the synthesis of 2-substituted and 1,2-disubstituted benzimidazole derivatives with high selectivity

An efficient, environmental friendly and substrate controlled method of synthesis of 2-substituted benzimidazole derivatives 3 and 1,2-disubstituted benzimidazole derivatives 4 with high selectivity has been achieved from the reaction of o-phenylenediamine 1 and aldehydes 2 in the presence of water extract of onion and selecting suitable reaction medium. This method is widely applicable for variety of aldehydes such as aromatic/aliphatic/heterocyclic aldehydes and 1,2-diamines to afford 2-substituted benzimidazole derivatives 3 and 1,2-disubstituted benzimidazole derivatives 4 in good to excellent yields (up to 96%). The developed method of water extract of onion catalysis produced 2-substituted benzimidazoles 3 from aromatic aldehydes having electron-withdrawing groups, whereas aromatic aldehydes bearing electron donating groups selectively furnished 1,2-disubstituted benzimidazole 4 derivatives. The process described here has several advantages of cheap, low energy consumption, commercially available starting materials, operational simplicity and nontoxic catalyst. The use of water extract of onion makes this present methodology green and giving a useful contribution to the existing methods available for the preparation of benzimidazole derivatives. In addition, Hammett correlation of substituent constant (σ) vs percentage (%) yield has been established.     

Antihyperglycemic agents from Ammannia multiflora

The serial chromatographic separation of chloroform and n-butanol fractions of Ammannia multiflora resulted in the isolation and characterization of 4-hydroxy-alpha-tetralone (1) and 3,3'-(2R,5R)-tetrahydrofuran-2,5-diyldiphenol (ammaniol, 2). Compound 1 was chemically modified into six semi-synthetic acyl and aryl derivatives (1A - 1F). The isolated compounds 1 and 2 along with semi-synthetic derivatives 1A - 1F were evaluated for in vitro antihyperglycemic activity employing 2-deoxyglucose uptake by L-6 rat muscle cell lines. The results indicated that both the isolates, as well as derivatives (1A - 1F), have the property to stimulate glucose uptake. Ammaniol (2) increased glucose uptake significantly (64.8%), while one of the aryl derivatives of 1, 4-O-(3,4,5-trimethoxybenzoyl)-alpha-tetralone (1D), showed potent antihyperglycemic activity and increased glucose uptake by 94.6%, even more than rosiglitazone (88.8%). Further, since 1D possesses better antihyperglycemic activity than rosiglitazone (standard), this might be a new safer antidiabetic drug of herbal origin.