3-（3，4-二甲氧基苯基）-6-甲基香豆素合成方法的改进

目的：探讨3-芳基取代香豆素衍生物的简易合成方法。方法：以5-甲基水杨醛和3,4-二甲氧基苯乙酸为原料,在醋酐和三乙胺条件下,经加热环合反应,合成3-（3,4-二甲氧基苯基）-6-甲基香豆素。结果：与文献方法相比,本法的一步反应收率从12％～33％提高到73．6％。结论：本法操作简单,收率高,更具实用性。     

α,ω-双（2苯-并咪唑）二硫化合物合成工艺的优化

目的优化α,ω-双（2苯-并咪唑）二硫化合物的合成条件。方法以邻苯二胺、二硫化碳为原料,加入四丁基溴化铵作催化剂,在氢氧化钠的碱性条件和氮气保护下经缩合反应和加热闭环生成2苯-并咪唑硫醇钠;然后经氯化制得α,ω-双（2苯-并咪唑）二硫化合物。结果经波谱确证为目标物,总收率90%以上。结论该工艺原料易得,条件温和,产率较高,适合工业化。     

6-溴-2-己酮的合成

目的化学合成6-溴-2-己酮。方法以1,3-溴丙烷与乙酰乙酸乙酯为原料经环合、开环、溴代等反应合成。结果与结论目标产物的含量用GC方法测定含量95%以上,收率81.5%。     

2-吡啶甲醇及2-吡啶甲醛的合成

以 2 -甲基吡啶为原料、过氧化氢为氧化剂制备 2 -吡啶甲醇和 2 -吡啶甲醛,工艺方法经济、安全     

6-甲基-4-苯基-3,4-二氢香豆素的合成工艺改进

目的:以浓磷酸为催化剂制备6-甲基-4-苯基-3,4-二氢香豆素.方法:以对甲酚和苯甲醛为主要原料,经脱水、环合等方法制备目标产物.结果:产品收率达74.2%.结论:该方法有效降低了酸对设备的腐蚀程度,使合成工艺条件得到了优化,利于工业化生产.     

6-氨基-3,4-二氢-2(1H)-喹啉酮的合成

苯胺用3-氯丙酰氯酰化得到N-苯基-3-氯丙酰胺,在AlCl3作用下闭环得到3,4-二氢-2(1H)-喹啉酮后,经HNO3/H2SO4硝化、Pd-C/H2还原反应得到6-氨基-3,4-二氢-2(1H)-喹啉酮,总收率79%(按实际反应的苯胺计).     

3,4-二甲基-2-碘代苯甲酸的合成

目的研究合成肿瘤血管破坏剂Vadimeza的关键中间体3,4-二甲基-2-碘代苯甲酸的合成方法。方法以乙醛酸(2)为起始原料,首先与乙酸酐反应生成2,2-二乙酰氧基乙酸(3),然后与氯化亚砜反应得到相应的酰氯后,与2,3-二甲基苯胺(5)进行酰化反应得到N-(2,2-二乙酰氧基)乙酰基-2,3-二甲基苯胺(6),再与盐酸羟胺反应得到N-(2-羟亚氨基)乙酰基-2,3-二甲基苯胺(7);最后经甲磺酸脱水环合、双氧水氧化开环和Sandmeyer反应得到目标产物3,4-二甲基-2-碘代苯甲酸(1)。结果合成了3,4-二甲基-2-碘代苯甲酸,7步反应总收率达到45.0%,目标产物结构经ESI-MS、1H-NMR确证。结论本合成方法原料易得,反应条件温和,适合大规模制备。     

2,4-二氨基-6-(取代苄基)-5-甲基吡啶[2,3-d]并嘧啶衍生物的合成及抗癌活性的研究

二氨基吡啶并嘧啶类化合物具有很强的抑制二氢叶酸还原酶的作用。这类化合物中BW301u已进行临床试验以治疗癌症。本文报道了17个2,4-二氨基-6-取代苄基-5-甲基-吡啶[2,3-d]并嘧啶类化合物的合成及对L_(1210)细胞的抑制作用。合成化合物的结构经由MS-EI,~1H-NMR及元素分析确证。以MTT法测定了它们对L_(1210)细胞的抑制作用。     

2,2-二氟-2-(2-吡啶)乙醇的合成

深静脉血栓的形成是目前现代医学中最难治疗而又可能导致生命危险的一种常见的疾病.目前,国内外对静脉血栓栓塞症越来越重视,2,2-二氟-2-(2-吡啶)乙醇就是N一苯酰氨类血栓抑制剂的重要中间体.     

Synthesis of some 3,4-disubstituted-6,7-dihydro-imidazo[2,1-b][1,3]thiazole and 3,4-disubstituted-7,8-dihydro-6H-imidazo[2,1-b][1,3]thiazine derivatives and evaluation of their cytotoxicities against F2408 and 5RP7 cells

This article describes the synthesis of 3,4-disubstituted-6,7-dihydro-imidazo[2,1-b][1,3]thiazoles and 3,4-disubstituted-7,8-dihydro-6H-imidazo[2,1-b][1,3]thiazines, having substituted or nonsubstituted phenyl rings at the 5,6 and 2,3 positions, respectively, their cytotoxic effects through noncancer (F2408) and cancer (5RP7) cells, and their detailed ¹H- and ¹³C-nuclear magnetic resonance (NMR) spectral characterization. The title compounds were obtained by the cyclization of 4,5-diaryl-imidazole-2-thione and dihaloalkane (i.e., 1,2-dihaloethane or 1,3-dihalopropane), in the presence of potassium carbonate (K₂CO₃) in N,N-dimethyl formamide (DMF). 4,5-Diaryl-imidazole-2-thione was prepared by condensation of α-hydroxyketones (acyloins), which were obtained by treating aldehydes with cyanide, with thioureas in AcOH. The structure of imidazo[2,1-b][1,3]thiazole and imidazo[2,1-b][1,3]thiazine derivatives was confirmed by infrared (IR), ¹H-NMR, and ¹³C-NMR. The cytotoxicities of the synthesized compounds on both of noncancer (F2408) and cancer (5RP7) cells were measured by 3-(4,5-dimethyl-thiazollyl-2)-2,5-diphenyltetrazolium (MTT) assay. In the presence of only lower doses of compounds 9 and 11, bearing methyl or methoxy substituents on the phenyl ring of imidazo[2,1-b][1,3]thiazole scaffold, the cytotoxic effect was higher on 5RP7 cells than control cells after 24 h.     

Novel Antiinflammatory Analgesics: 3-(2-/4-Pyridylethyl)-Benzoxazolinone and Oxazolo[4,5-β]pyridin-2-one Derivatives

Twenty-two new 3-[2-(2-and/or 4-pyridyl)ethyl]benzoxazolinone and oxazolo[4,5-b]pyridin-2-one derivatives have been synthesized by reacting 2-and/or 4-vinylpyridine and appropriate benzoxazolinones and oxazolo[4,5-b]pyridine-2-one. Their chemical structures have been proven by IR, ¹H-NMR, ¹³C-NMR, mass spectroscopy, and elemental analysis. The analgesic activities of these compounds were investigated by a modified Koster′s Test. Test results revealed that, at 100 mg/kg dose level, most of the compounds showed significant analgesic activities when compared to aspirin. Therefore the compounds were screened for their antiinflammatory activities using the carrageenan hind paw edema test. Compounds 1, 7, 10, 11, 12, 13, 15, 18, 20, 21 were found more active than indomethacine. In gastric ulceration studies gastrointestinal bleeding was not observed at 100 mg/kg dose level in compounds 1 and 2 .     

Presence of heterocyclic aromatic amines (HAs) in smoked “Provola” cheese from Calabria (Italy)

This study evaluated the residual levels of heterocyclic aromatic amines (HAs) in “Provola” cheese samples from Calabria, smoked using natural methods and using commercial buffered smoke. A comparative study of HAs concentrations was carried out on different portions of these samples: the rind, exterior part, core and on slice. Quantitative determination of HAs was carried out by HPLC using a fluorescence detector and analysis in HPLC–MS was conduced to confirm the presence of these amines. Residual levels of HAs were found in all naturally smoked “Provola” cheese samples. The results obtained showed that the smoking process performed using traditional methods contributes to HAs contamination while the use of commercial buffered smoke can be considered a safer technique for smoking of food.     

Investigations on the synthesis and pharmacological properties of N-substituted derivatives of 4-alkoxy-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones

Synthesis of N-substituted derivatives of 4-alkoxy-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones (10-14, 18-21) is described. In the "writhing syndrome" test all compounds studied exhibited potent analgesic activity which was superior than that of acetylsalicylic acid. In the "hot plate" test imides 10, 12, 13, 18-20 acted also stronger than aspirin. Furthermore all compounds tested significantly suppressed the spontaneous locomotor activity of mice and prolonged barbiturate sleep of these animals.     

Genotoxic and oxidative stress effects of 2-amino-9H-pyrido[2,3-b]indole in human hepatoma G2 (HepG2) and human lung alveolar epithelial (A549) cells

Abstract

2-Amino-9H-pyrido[2,3-b]indole (AαC), which is present in high quantities in cigarette smoke and also in fried food, has been reported to be a probable human carcinogen. However, few studies have reported on the genotoxicity and oxidative stress induced by AαC. This study investigated the genotoxic effects of AαC in human hepatoma G2 (HepG2) and human lung alveolar epithelial (A549) cells using the comet assay. Significant increases in DNA fragment migration indicated that AαC causes serious DNA damage in HepG2 and A549 cells. The role of oxidative stress in the mechanism of AαC-induced genotoxicity was clarified by measuring the level of intracellular reactive oxygen species (ROS), the GSH/GSSG ratio and the formation of 8-hydroxydeoxyguanosine (8-OHdG), a marker of oxidative DNA damage. The results showed that the levels of ROS and 8-OHdG increased, whereas the GSH/GSSG ratio decreased. The concentration of 8-OHdG was positively related to DNA damage. Taken together, these results indicate that AαC can induce genotoxicity and oxidative stress and that AαC likely exerts genotoxicity in HepG2 and A549 cells through ROS-induced oxidative DNA damage. This is the first report to describe AαC-induced genotoxic and oxidative stress in HepG2 and A549 cells.     

Antiparkinsonian effects of novel adenosine A(2A) receptor antagonists

The present work describes the synthesis of a pyrazinopurinedione derivative which was together with a series of pyrimidopurinedione derivatives tested for potential antiparkinsonian activity in two tests: the "oxotremorine" and the "reserpine" test. For the studies compounds which had shown affinity for the adenosine A(2A) receptor were chosen. One compound, a pyrazinopurinedione derivative, without affinity for A(2A) receptors, but showing adenosine A(1) receptor affinity was also investigated. The performed preliminary tests indicated that, contrary to the pyrazinopurinedione all pyrimidopurinediones demonstrated antiparkinsonian effects. As a result of present studies it may be concluded that antiparkinsonian effects of the examined compounds are correlated with the antagonistic activity toward adenosine A(2A) receptors in this class of compounds. However a direct correlation of the potency of both effects was not observed possibly due to different pharmacokinetic properties of the compounds. The most active derivatives of the present series were aryl-substituted pyrimidopurinediones.     

Synthesis and Antimicrobial Activity of 6-Thioxo-6,7-dihydro-2H-[1,2,4]triazino[2,3-c]-quinazolin-2-one Derivatives

Potassium 8-R¹-9-R²-10-R³-3-R-2-oxo-2H-[1,2,4]triazino[2,3-c]quinazoline-6-thiolates 2.1–2.26 were synthesized via cyclocondensation of 6-R-3-(3-R¹-4-R²-5-R³-aminophenyl)-1,2,4-triazin-5-ones 1.1–1.26 with carbon disulfide, potassium hydroxide, and ethanol or with potassium O-ethyl dithiocarbonate in 2-propanol. The corresponding thiones 3.1–3.26 were obtained by treatment of 2.1–2.26 with hydrochloric acid. It was found that the nature of the substituents in positions 3, 4, and 5 of the corresponding 6-R-3-(3-R¹-4-R²-5-R³-aminophenyl)-1,2,4-triazin-5-ones were affected on the terms of the reaction. The structures of compounds were proven by a complex of physicochemical methods (¹H, ¹³C NMR, LC–MS, and EI-MS). The results of the antibacterial and antifungal activity assay allowed the determination of the high sensitivity of Staphylococcus aureus ATCC 25923 (MIC 6.25–100 μg/mL, MBC 12.5–200 μg/mL) to the synthesized compounds.     

Synthesis of a delta opioid agonist in [2H6], [2H4], [11C], and [14C] labeled forms

In support of a program to develop a treatment for depression, four labeled forms of a delta opioid agonist were prepared. The [²H₄] labeled form was prepared using a relatively straightforward conversion of [²H₄]bromoethanol to [²H₄]N‐methyl‐2‐hydroxyethylamine. The key step in the synthesis of the [²H₆] labeled form involved the Pd‐catalyzed exchange in D₂O of 8‐quinolin‐8‐ol to give [²H₆] 8‐quinolin‐8‐ol. The C‐14 labeled form was synthesized in one step using [¹⁴C]carbonylation, and the C‐11 labeled form was prepared in two steps from ¹¹CH₃I. Copyright © 2011 John Wiley & Sons, Ltd.     

A validated spectrophotometric and liquid chromatography method for determination and purity evaluation of 4-methoxy-2-[2-hydroxy-3(4-phenyl-1-piperazinyl)]propyl-2,3-dihydro-6-methyl-1,3-dioxo-1H-pyrrolo[3,4-c]pyridine

A spectrophotometric analysis of the UV-spectrum of 4-methoxy-2-[2-hydroxy-3(4-phenyl-1-piperazinyl)]propyl-2,3-dihydro-6-methyl-1,3-dioxo-1H-pyrrolo[3,4-c]pyridine (I) in 0.01 M HCl was performed by determining the values of specific absorption coefficients at the following analytical wavelengths: 224, 285 and 348 nm. The separation by means of TLC of compound I and of its five decomposition products was also studied. Silica gel coated plates (60 F(254)) were used and the mobile phase was consisted of butanol-acetic acid (1.05 kg/l)-water (80:12:30, v/v/v). The HPLC method (LiChrosorb(R) 100 RP-18 column 250 x 4.0 mm I.D., dp=5 microm; mobile phase: acetonitrile-0.01 M phosphate buffer (H(3)PO(4)+KH(2)PO(4); pH 3) (50:50, v/v-phase A) or (30:70, v/v-phase B) was validated by determination of the following parameters: selectivity, precision, linearity, stability of the analite and LOD as well as LOQ. Kinetic studies of the decomposition process of I in both acidic and alkaline environments indicate instability of the imide group.     

Synthesis and cytotoxic evaluation of some new[1,3]dioxolo[4,5-g]chromen-8-one derivatives

Background

Homoisoflavonoids are naturally occurring compounds belong to flavonoid classes possessing various biological properties such as cytotoxicity. In this work, an efficient strategy for the synthesis of novel homoisoflavonoids, [1,3]dioxolo[4,5-g]chromen-8-ones, was developed and all compounds were evaluated for their cytotoxic activities on three breast cancer cell lines.

Methods

Our synthetic route started from benzo[d][1,3]dioxol-5-ol which was reacted with 3-bromopropanoic acid followed by the reaction of oxalyl chloride to afford 6,7-dihydro-8H-[1,3]dioxolo[4,5-g]chromen-8-one. The aldol condensation of the later compound with aromatic aldehydes led to the formation of the title compounds. Five novel derivatives 4a-e were tested for their cytotoxic activity against three human breast cancer cell lines including MCF-7, T47D, and MDA-MB-231 using the MTT assay.

Results

Among the synthesized compounds, 7-benzylidene-6,7-dihydro-8H-[1,3]dioxolo[4,5-g]chromen-8-one (4a) exhibited the highest activity against three cell lines. Also the analysis of acridine orange/ethidium bromide staining results revealed that 7-benzylidene-6,7-dihydro-8H-[1,3]dioxolo[4,5-g]chromen-8-one (4a) and 7-(2-methoxybenzylidene)-6,7-dihydro-8H-[1,3]dioxolo[4,5-g]chromen-8-one (4b) induced apoptosis in T47D cell line.

Conclusion

Finally, the effect of methoxy group on the cytotoxicity of compounds 4b-4d was investigated in and it was revealed that it did not improve the activity of [1,3]dioxolo[4,5-g]chromen-8-ones against MCF-7, T47D, and MDA-MB-231.