8-O-烯丙基-4,4'-二甲基花椒毒酚的合成及其抗增殖活性

以焦性没食子酸和乙酰乙酸乙酯为原料,经Pechmann反应、Williamson成醚、环化、还原和脱水等反应合成了新化合物8-O-烯丙基-4,4'-二甲基花椒毒酚(5),总收率32.0%,其结构经1H NMR,13C NMR和ESI-MS表征。抗增殖活性测试结果表明:5对人类肝癌细胞Hep G2、结肠癌细胞HCT和子宫癌细胞SA具有一定的抗增殖活性,其中对Hep G2的抑制活性最高,IC50为(27.57±1.00)μmol·L-1。     

A dual-function chemosensor based on coumarin for fluorescent turn-on recognition of Hg2+ and colorimetric detection of Cu2+ in aqueous media

A novel coumarin derivative CTT was synthesized via the condensation of 7-(N,N-diethylamino) coumarin-3-aldehyde with 5-amino-1,3,4-thiadiazole-2-thiol and its structure was characterized using infrared spectroscopy (IR), ¹H NMR, mass spectrometry (MS) techniques, and elemental analysis. The recognition properties of CTT with metal ions were investigated in CH₃CN–H₂O (v/v = 1/1) solution using UV–vis absorption and fluorescence emission spectrum method. The results showed that CTT could monitor Cu²⁺ and Hg²⁺ simultaneously as a dual-function chemosensor in CH₃CN–H₂O (v/v = 1/1). CTT could be used to detect Cu²⁺ colorimetrically; when using CTT, a color change from yellowish-brown to yellowish-green could be readily observed by the naked eye. CTT showed turn-on fluorescent recognition of Hg²⁺, the fluorescence enhancement was attributed to the inhibited C=N isomerization and the obstructed excited state intramolecular proton transfer (ESIPT) of CTT. The recognition mechanism of CTT for Cu²⁺ and Hg²⁺ was studied by experiments and theoretical calculations, respectively. Therefore, CTT has the ability to be a “single chemosensor for dual targets.”     

Efficient Synthesis of (3E)‐3‐[Amino(aryl)methylidene]chromane‐2,4‐diones (=(3E)‐3‐[Amino(aryl)methylene]‐2H‐1‐benzopyran‐2,4(3H)‐diones) via a Three‐Component Reaction

The Michael‐type addition of a 4‐hydroxycoumarin (=4‐hydroxy‐2H‐1‐benzopyran‐2‐one) 1 to a β‐nitrostyrene (=(2‐nitroethenyl)benzene) 2 in the presence of AcONH₄ leads to substituted (3E)‐3‐[amino(aryl)methylidene]chroman‐2,4‐diones (=(3E)‐3‐[amino(aryl)methylene]‐2H‐1‐benzopyran‐2,4(3H)‐diones) 4 (Table 1). High yields, short reaction time, and easy workup are advantages of this novel one‐pot three‐component reaction.     

Study of polyethylene glycol as a green solvent in the microwave-assisted extraction of flavone and coumarin compounds from medicinal plants

In this paper, the application of polyethylene glycol (PEG) aqueous solution as a green solvent in microwave-assisted extraction (MAE) was firstly developed for the extraction of flavone and coumarin compounds from medicinal plants. The PEG solutions were optimized by a mono-factor test, and the other conditions of MAE including the size of sample, liquid/solid ratio, extraction temperature and extraction time were optimized by means of an orthogonal design L(9) (3(4)). Subsequently, PEG-MAE, organic solvent-MAE, and conventional heating reflux extraction (HRE) were evaluated with nevadensin extraction from Lysionotus pauciflorus, aesculin and aesculetin extraction from Cortex fraxini. Furthermore, the mechanism of PEG-MAE was investigated, including microwave-absorptive property and viscosity of PEG solutions, the kinetic mechanism of PEG-MAE and different microstructures of those samples before and after extraction. Under optimized conditions, the extraction yields of nevadensin from L. pauciflorus, aesculin and aesculetin from C. fraxini were 98.7%, 97.7% and 95.9% in a one-step extraction, respectively. The recoveries of nevadensin, aesculin and aesculetin were in the range of 92.0-103% with relative standard derivation lower than 3.6% by the proposed procedure. Compared with organic solvent-MAE and conventional extraction procedures, the proposed methods were effective and alternative for the extraction of flavone and coumarin compounds from medicinal plants. On the basis of the results, PEG solution as a green solvent in the MAE of active compounds from medicinal plants showed a great promising prospect.     

Synthesis and properties of crown ether functionalized coumarin substituted zinc phthalocyanine

The novel 6,7-[15-crown-5]-3-[p-(2,3-dicyanophenoxy)phenyl]coumarin (1) and its non-peripherally substituted zinc phthalocyanine complex (2) have been prepared and characterized by elemental analysis, ¹H NMR (for compound 1), MALDI-TOF, FT-IR and UV-Vis spectral data. Fluorescence intensity changes of compound 1 have been determined by addition of Na⁺ or K⁺ ions at 25 °C in THF. The effects of the chromenone crown ether substituent of the phthalocyanine molecule on the photophysical (fluorescence quantum yield and lifetime) and photochemical (singlet oxygen generation and photodegradation) properties were also investigated. The fluorescence of the zinc phthalocyanine complex is effectively quenched by addition of 1,4-benzoquinone (BQ).     

Synthesis, characterization, spectroscopic and electrochemical properties of phthalocyanines substituted with four 3-ferrocenyl-7-oxycoumarin moieties

The synthesis, spectroscopic and electrochemical properties of the tetra-(3-ferrocenyl-7-oxycoumarin)-substituted zinc (II) and cobalt (II) phthalocyanines (3 and 4) are reported for the first time. The synthesis of novel 3-ferrocenyl-7-hydroxycoumarin (1) was performed according to Perkin reaction, and the ligand, 7-(3,4-dicyanophenoxy)-3-ferrocenylcoumarin (2), was synthesized by the reaction of 3-ferrocenyl-7-hydroxycoumarin with 4-nitrophthalonitrile in the presence of K₂CO₃ as the base in dry dimethylformamide. The preparation of the corresponding zinc (II) and cobalt (II) metallo phthalocyanines (3 and 4) substituted with 3-ferrocenyl-7-oxycoumarin moieties at β-positions of the phthalocyanine ring was achieved by the cyclotetramerization of the coumarin ligand (2) with relevant metal(II) acetates in dry 2-dimethylaminoethanol. The new compounds have been characterized by elemental analyses, FT-IR, ¹H NMR, Mass and electronic spectroscopy. The fluorescence property of the zinc metallo phthalocyanine (3) is strongly affected by the presence of ferrocenyl moiety. The ferrocenyl moieties were very efficient in quenching the excited state of 3, which show very poor fluorescent intensity. The electrochemical properties of the complexes were also investigated by cyclic and differential pulse voltammetry techniques in non-aqueous medium. It was found that the redox-active ferrocene substituents are reduced concurrently at one potential.     

Brønsted acid catalyzed Diels-Alder reactions of 2-vinylindoles and 3-nitrocoumarins: an expedient synthesis of coumarin-fused tetrahydrocarbazoles

A Brønsted acid catalyzed Diels-Alder reaction of 2-vinylindoles and 3-nitrocoumarins has been described. The methodology allows a rapid and expedient synthesis of a variety of coumarin-fused polycyclic indoles in good yields (up to 82%) with high diastereoselectivities (up to >19:1).     

液相色谱-串联质谱法测定白芷中3种香豆素

建立了白芷中欧前胡素,异欧前胡素和氧化前胡素的液相色谱-串联质谱分析法。白芷提取液经Waters XTerra-C18(150mm×3.9 mm,5μm)色谱柱分离,以1mmol/L乙酸铵溶液和乙腈为流动相进行洗脱,以电喷雾正离子(ESI+)模式电离,多反应监测(MRM)模式检测,外标法定量。欧前胡素,异欧前胡素和氧化前胡素分别在0.05～10μg/mL,0.05～13μg/mL和0.1～120μg/mL范围内呈线性相关,相关系数(r)分别为0.9993,0.9991和0.9994,检出限分别为30,30和50 ng/mL,平均加标回收率为100.1%,99.4%和98.4%,相对标准偏差分别为2.2%,2.6%和2.8%(ρ=0.5μg/mL,n=6),该法可以满足同时检测白芷中欧前胡素,异欧前胡素和氧化前胡素的需求。     

A ratiometric fluorescent chemodosimeter for Cu(II) in water with high selectivity and sensitivity

Coumarin derivative 1 was synthesized as an efficient ratiometric chemodosimeter for the detection of Cu(II) in 99% water/DMSO (v/v) at pH 7.0. Mechanism studies suggested that 1 formed a complex with Cu(II) at 2:1 ratio accompanied by quenching of green fluorescence at 524 nm; when the solution was heated to 50 °C for 30 min, Cu(II)-promoted hydrolysis of coumarin lactone moiety of 1 occurred with bright blue fluorescence at 451 nm emerged. With fluorescence intensity ratio detection at 451 nm and 524 nm, 1 features an excellent sensitivity with the detection limit of 15 nmol L⁻¹ toward Cu(II) and a good selectivity over other metal ions.     

A Coumarin-Derived Fluorescence Chemosensors Selective for Copper(II)

Abstract

Two different coumarin derivatives have been connected via animine linkage to obtain a new fluorescence signaling system. The coumarin derivative (L) containing a C-N group was designed as an example for illustration. The free ligand L is almost nonfluorescent due to the isomerization of C-N double bond in the excited state. However, in the presence of a Cu(II) ion, this isomerization is stopped because of bonding to the metal ion, resulting in a high-intensity (400-fold) emission. In this way, we designed a new compound for copper-selective and ratiometric chemosensors.