Guofu Qiu

Aesculetin-induced apoptosis through a ROS-mediated mitochondrial dysfunction pathway in human cervical cancer cells

Aesculetin (1) is an important coumarin found in various plant materials. It has been shown to have antiproliferative effects on several types of human cancer cells, but its effect on cervical cancer cells in vitro is unknown. In this study, we investigated that the cytotoxic effect of 1 on a non-cancer cell line (293) was smaller than on a tumor cell line (HeLa). This is the first report showing the possible mechanism of antiproliferative effect of 1 for the prevention of cervical cancer in cell culture models. It was found that 1 inhibited cell viability by inducing apoptosis, as evidenced by the formation of apoptotic bodies, generation of reactive oxygen species (ROS), and the accumulation of cells in the sub-G1 phase. Treatment with compound 1 decreased the cell growth in a dose-dependent manner with an IC50 value of 37.8 μM. Aesculetin-induced apoptosis was correlated with mitochondrial dysfunction (ΔΨm), leading to the release of cytochrome c from the mitochondria to the cytosol, as well as the proteolytic activation of caspases in HeLa cells. These results indicate that 1 induces apoptosis in HeLa cells through a ROS-mediated mitochondrial dysfunction pathway.

Synthesis and potential anticonvulsant activity of new N-3-substituted 5,5-cyclopropanespirohydantoins

Thirteen new 5-cyclopropanespirohydantoins with various N-3 substituents were synthesized and their pharmacological activity was determined with the objective to better understand their structure-activity relationship (SAR) for anticonvulsant activity. The anticonvulsant effects of these compounds were evaluated by maximal electroshock seizure (MES) test and subcutaneous pentylenetetrazole (scPTZ) test models in mice. All compounds substituted with cyclopropyl group at fifth position of hydantoin ring showed better protection against MES test. Compounds 5b, 5d, 5e, 5g and 5j were found to be the most potent compounds of this series and compared with the reference drug phenytoin sodium in MES test. Compound 5j also showed equipotent activity with the standard drug sodium valproate at the doses of 20 and 40 mg kg(-1) in scPTZ test.

Synthesis and anticonvulsant activity of new 6-methyl-1-substituted-4,6-diazaspiro[2.4]heptane-5,7-diones.

In the present study on the development of new anticonvulsants, twenty new 6-methyl-1-substituted-4,6-diazaspiro[2.4]heptane-5,7-diones were synthesized and tested for anticonvulsant activity using the maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) screens. Their neurotoxicity was determined by the rotorod test. In this series, all of the alkyl- and aryl-substituted 5,5-cyclopropanespirohydantoins showed more or less protection against MES and/or scPTZ models. The most active of the series was 6-methyl-1-(4-(methylsulfonyl)phenyl)-4,6-diazaspiro[2.4]heptane-5,7-dione (6 t), which showed a MES ED(50) value of 12.5 mg/kg in mice. The median toxic dose (TD(50)) was 310 mg/kg, providing compound 6 t with a protection index (PI = TD(50)/ED(50)) of 24.8 in the MES test which is better than phenytoin.

Synthesis, characterization and biological evaluation of some 16E-arylidene androstane derivatives as potential anticancer agents.

A series of new 16E-arylidene androstane derivatives were synthesized and characterized. The new compounds were screened for their anticancer activities against the human cancer cell lines SW480, A549, HepG2 and HeLa in vitro using the MTT assay. The results of the in vitro study showed that a number of compounds have shown IC(50) values lower than 20 μM against the four cancer cell lines.

Synthesis, characterization and biological evaluation of some 16β-azolyl-3β-amino-5α-androstane derivatives as potential anticancer agents

A series of new 16β-azolyl-3β-amino-5α-androstane derivatives were synthesized and characterized. The new compounds were screened for their anticancer activity against the human cancer cell lines SW480, A549, HepG2, HeLa and SiHa in vitro using the MTT assay. The results of the in vitro study showed that a number of compounds have shown IC(50) values lower than 20 μM against the five cancer cell lines.

Synthesis and anticonvulsant activity of N-3-arylamide substituted 5,5-cyclopropanespirohydantoin derivatives.

In the present study on the development of new anticonvulsants, twenty new N-3-arylamide substituted 5,5-cyclopropanespirohydantoin derivatives were synthesized and tested for anticonvulsant activity using the maximal electroshock (MES), subcutaneous pentylenetetrazole (scPTZ) screens, which are the most widely employed seizure models for early identification of candidate anticonvulsants. Their neurotoxicity was determined applying the rotorod test. Three compounds 5d, 5j and 5t showed promising anticonvulsant activities in both models employed for anticonvulsant evaluation. The most active compound 5j showed the MES-induced seizures with ED50 value of 9.2 mg/kg and TD50 value of 421.6 mg/kg after intraperitoneally injection to mice, which provided compound 5j with a protective index (TD50/ED50) of 45.8 in the MES test.

Iron-catalyzed efficient intermolecular amination of C(sp3)–H bonds with bromamine-T as nitrene source

[Fe(N4Py)(CH3CN)](ClO4)2 can efficiently catalyze intermolecular nitrene insertion of sp3 C–H bonds with bromamine-T as the nitrene source, forming the desired tosylprotected amines with NaBr as the by-product.

Chemical composition and antioxidant activity of the essential oil of endemic Viola tianshanica

The composition and in vitro antioxidant activities of the essential oil and methanol extract of the aerial parts of Viola tianshanica were evaluated in this research. GC–MS analysis of the essential oil resulted in the identification of 15 constituents, representing 89.67% of the oil. The major compounds detected in the essential oil were dibutyl phthalate (15.19%), hexadecanoate methyl (8.65%), n-hexadecanoic acid (3.07%) and 2,3-pentanedione (2.62%). Essential oil and methanol extract were tested for their antioxidant activities using 1,1-diphenyl-2-picryl-hydrazyl free radical scavenging and β-carotene linoleic acid assay. In addition, the total phenol of essential oil, polar subfraction and non-polar subfraction were determined.

Synthesis and antibacterial activity of 3-O-carbamoyl derivatives of 6,11-di-O-methylerythromycin A: a novel class of acylides.

A novel series of acylides, 3-O-carbamoyl derivatives of 6,11-di-O-methylerythromycin A, were synthesized and evaluated for their antibacterial activity. These compounds have significant antibacterial activity against gram-positive pathogens, including erythromycin-resistant but methicillin-susceptible Staphylococcus aureus, erythromycin-resistant and methicillin-resistant S. aureus, erythromycin-resistant Streptococcus pneumoniae, and gram-negative pathogens, such as Haemophilus influenzae. Among the derivatives tested, compounds 4p, 4r, 4w, 4x and 4z were found to have potent activity against most susceptible and resistant bacteria. Compound 4p exhibited excellent antibacterial activity in comparison to the others.

Steroidal Ammonium Compounds as New Neuromuscular Blocking Agents

Neuromuscular blocking agents are widely used as an anesthesia auxiliary in surgery, which induce relaxation of skeletal muscles by blocking signal transmission at the neuromuscular junction. Many neuromuscular blocking agents s were developed over the past decades, but none of them fully meets the needs of the clinic by various reasons. In this study, a series of quaternary ammonium steroidal neuromuscular blocking agents were synthesized and evaluated on isolated mouse phrenic nerve–hemidiaphragms for their bioactivities. The initial separation of mono‐ and bis‐quaternary ammonium compounds turned out to be very challenging on regular silica gel chromatography. Therefore, a facile purification method, in which the silica gel was pretreated with methanolic sodium bromide solution, was finally achieved. Compounds 3g (0.36 μm) and 4g (0.37 μm) exhibited excellent neuromuscular blocking activities, which were about sixfold to sevenfold higher in potency than that of rocuronium (2.50 μm). In addition, other bis‐quaternized compounds also showed good potencies close to that of rocuronium. Furthermore, the preliminary structure–activity relationship of this series was also elucidated. Benzyl group was found to be a promising quaternary group in this series.