Design, synthesis and anticancer evaluation of novel half-sandwich Ru(II) complexes bearing pyrazalone moiety: Apoptosis inducers based on mitochondrial dysfunction and G0/G1 arrest.

Six half-sandwich Ru(II) complexes (Ru1-Ru6), integrated with 5-phenyl-2-(pyridin-2-yl)-2,4-dihydro-3H-pyrazol-3-one (PDPO1-PDPO6) ligands, were synthesized and spectroscopically characterized. The structure of Ru3 that crystallized as a monoclinic crystal with P21/c space group was further confirmed by X-ray single crystal diffraction. Prototropic tautomerism within the complexes transformed OH-form ligands to NH-form, forming a hydrogen bond (Cl1---H-N3). The complexes and ligands' cytotoxicity was assessed against several cancerous (HepG2, A549, MCF-7) and normal Vero cell lines. Relative to the ligands and Cisplatin, complexes (Ru2, Ru3, Ru5, Ru6) exhibited potent cytotoxicity against cancer cells, with IC50 values from 2.05 to 15.69 µM/L, excluding Ru1 and Ru4. Specifically, Ru2, Ru3, and Ru5 demonstrated superior anti-HepG2 properties. Compared to Cisplatin, Ru2 and Ru5 were less toxic to Vero cells, highlighting their enhanced selectivity in toxicity. Structure-activity relationship (SAR) studies indicated that t-butyl substitution (in Ru2) or -Cl (in Ru5) on the benzene ring significantly improved the selective toxicity. These complexes manifested substantial lipophilicity, cellular uptake, and were quickly hydrolyzed to Ru-H2O species. Roughly positive correlations were observed between hydrolysis rate, lipophilicity, cellular uptake, and anticancer activities. Ru2, investigated specifically, induced apoptosis in HepG2 cells at concentrations of 10 and 20 µM/L through ROS-mediated mitochondrial dysfunction and G0/G1phase arrest, associated with altered P21, cyclin D, and CDK4 expression levels.

Synthesis of benzonaphthofuroquinones and benzoylnaphthindolizinediones by reactions of flavonoids with dichlone under basylous, oxygenous and aqueous conditions: their cytotoxic and apoptotic activities.

Using flavonoids and dichlone as substrates, benzonaphthofuroquinones (1, 2, 3, 5, 6, novel; 4 new) and benzoylnaphthindolizinediones (7, 8, known; 9, new) were synthesized through common base-catalyzed method and a new method of combining base-catalyzed with O2/H2O exposing. The possible reaction mechanisms may involve the process like isomerization, hydration, oxidation, decomposition and intermolecular condensation. Benzonaphthofuroquinones (2, 3, 4, 5) were found to exhibit potent cytotoxicity against carcinoma cell lines and low toxicity to normal cell lines. The compounds 4 and 5 not only expressed a significant late-stage-apoptosis against human leukemia and melanoma, but also promoted the cleavage of caspase-3 and PARP in human leukemia, which suggested that the late-stage-apoptosis and caspase-3 pathway may be responsible for the cytotoxicities of these benzonaphthofuroquinones. The replacement of the furan ring with pyrrole system in benzoylnaphthindolizinediones (7, 8, 9) resulted in the loss of anticancer activity.

A new anthraquinone and eight constituents from Hedyotis caudatifolia Merr. et Metcalf: isolation, purification and structural identification.

Hedyotis caudatifolia Merr. et Metcalf. (HC), a folk medicine in Yao nationalities areas in China, was used to investigate the chemical constituents. Through silica gel and Sephadex LH-20 column chromatography, nine compounds were isolated and purified. By physical and chemical properties, IR, MS (EI-MS, high resolution EI-MS), 1D NMR ((1)H NMR, (13)C NMR) and 2D NMR (HSQC, (1)H-(1)H COSY, HMBC), their structures were identified as ß-sitosterol (1), stigmasterol (2), scopolin (3), 2-hydroxy-1,7,8-trimethoxyanthracene-9,10-dione (4), oleanolic acid (5), ursolic acid (6), methyl barbinervate (7), ß-daucosterol (8) and p-Hydroxybenzoic acid (9). These compounds were isolated from HC for the first time, and 4 a new anthraquinone whose biological activities are worth to be investigated in future. These compounds may contribute to the HC's pharmacological effects on treating diseases, and may be used as candidates for control index in establishing the quality control standard of HC.

Molecular docking and reaction kinetic studies of chrysin binding to serum albumin.

The binding properties of chrysin with serum albumin (SA) were investigated under physiological conditions by calorimetry, circular dichroism (CD) spectroscopy, and molecular modeling. Based on the thermodynamic data, molar reaction enthalpy, reaction order (n) and the rate constant (k) were calculated. The results of CD spectroscopy showed that chrysin could bind to SA and the conformation of SA did not have any high-ordered structural change. Computational mapping revealed chrysin binding to the subdomain IB in SA. The chrysin-serum albumin complex was stabilized by hydrophobic force and hydrogen bonding and the reaction was a spontaneous process.

4-Hy-droxy-3,5-dimeth-oxy-N-{4-[(5-methyl-1,2-oxazol-3-yl)sulfamo-yl]phen-yl}benzamide methanol monosolvate.

The title compound, C(19)H(19)N(3)O(7)S·CH(3)OH, was synthesized from syringic acid and sulfamethoxazole. The benzene rings make a dihedral angle of 41.8 (1)° and the isoxazole ring is twisted by 74.3 (1)° from the central benzene ring. The crystal packing features O-H⋯O and O-H⋯N hydrogen bonds in which the hy-droxy groups from the main mol-ecule and methanol solvent mol-ecules serve as donor groups.

Extracts from the roots of Incarvillea younghusbandii on antioxidant effects and life span prolonging in Drosophila melanogaster.

AIM: To investigate antioxidant activities and life span prolonging effects of the extracts from the roots of Incarvillea younghusbandii Sprague, and to study the correlations between these activities and the polar intensity of the extracts. METHOD: Five extracts (IYS1, IYS2, IYS3, IYS4 and YS5) with different polar intensity were prepared. Antioxidant activities in vitro were determined by LPO inhibitory and free radicals scavenging experiments. Life span prolonging effects in vivo were evaluated by feeding Drosophila melanogaster. RESULT: Total phenolic content in extracts were solvent-dependent and decreased in the order of IYS4 > IYS1 >> IYS3 > IYS5 > IYS2. Organic extracts (IYS1 and IYS4) showed excellent LPO inhibitory activity, O(2)(· -) and ·OH scavenging activity compared to ascorbic acid (or benzoic acid, or BHT), while aqueous extracts (IYS2, IYS3 and IYS5) did not. The antioxidant activities (in vitro) were solvent dependent and decreased in the order of IYS4 > IYS1 > IYS3 > IYS5 ≥ IYS2. Drosophila melanogaster was fed with organic extracts (IYS1 or IYS4) at 5.0 mg mL(-1). The mean life span were increased by 24.4% (IYS1) or 23.0% (IYS4) in female and 15.3% (IYS1) or 16.9% (IYS4) in male; the maximum life span were increased by 8.4% (IYS1) or 11.2% (IYS4) in female and 9.7% (IYS1) or 15.8% (IYS4) in male, and the survival curves were significantly shifted to the right after fifteen days in both sexes survival period. Feeding aqueous extracts (IYS2, IYS3 or IYS5) at 5.0 mg·mL(-1), the significant life span prolonging effects were not achieved. The life span prolonging effects of the extracts were solvent-dependent and decreased in the order of IYS4 ≥ IYS1 >> IYS3 > IYS2 > IYS5. CONCLUSION: Extracts from the roots of Incarvillea younghusbandii Sprague showed excellent antioxidant activities and significant life span prolonging effects in Drosophila melanogaster. Positive correlations existed between the antioxidant activities and total phenolic content. Life span prolonging effect was positively correlated with the total phenolic content or antioxidant activities. The extracts possess better life span prolonging effect in females than in males.

Isolation, purification and structure identification of two phenolic glycosides from the roots of Incarvillea younghusbandii Sprague and their antioxidant activities.

Using a bioassay-guided fractionation technique, two compounds were isolated from the roots of Incarvillea younghusbandii Sprague through silica gel, reverse-phase C18 column chromatography and reverse-phase HPLC. Their structures were identified as acteoside (1) and isoacteoside (2) by ESI-MS, GC-MS, 1D- and 2D-NMR. 1 and 2 showed *OH scavenging capacity similar with benzoic acid, higher O2*- (or *OH) scavenging capacity than ascorbic acid, far higher hepatic LPO inhibitory activities than 2, 6-di-tert-butyl-4-methylphenol (BHT) or ascorbic acid, and more powerful effect on protecting erythrocytes from oxidative damage than ascorbic acid. The *OH scavenging capacity was positively proportional to the concentrations of 1 and 2 ranging from 0.015 6 to 0.500 0 mg x mL(-1). The hepatic LPO inhibitory activities increased with the increasing concentrations of 1 and 2 from 0.001 9 to 0.250 0 mg x mL(-1), but decreased slightly with the increasing concentration from 0.250 0 to 1.0000 mg x L(-1).

Isolation, purification and structure identification of antioxidant compound from the roots of Incarvillea younghusbandii Sprague and its life span prolonging effect in Drosophila melanogaster.

For the purpose of preventative treatment for oxidative stress-mediated diseases and anti-aging, a high-antioxidant compound was isolated from the roots of Incarvillea younghusbandii Sprague for the first time through silica gel column chromatography, reverse-phase C18 column chromatography and reverse-phase semi-preparative HPLC using a bioassay-guided fractionation technique, and was identified as acteoside by ESI-MS, GC-MS, 1D- and 2D-NMR. Feeding Drosophila melanogaster with acteoside, significant life span prolonging effect were achieved at the dosage range from 0.64 to 2.56 mg mL(-1). Positive relationships existed between the dosage and the life span prolonging effect. Otherwise, acteoside possess better life span prolonging effect in females than in males.

Acaricidal activity against Panonychus citri of a ginkgolic acid from the external seed coat of Ginkgo biloba.

An acaricidal substance extracted from the external seed coat of Ginkgo biloba L. was identified by UV (ultraviolet), IR (infrared), EI-MS (electron impact ion source mass spectrometry), (1)H NMR (nuclear magnetic resonance) and (13)C NMR as 6-[(Z)-10-heptadecenyl]-2-hydroxybenzoic acid (compound 1). Laboratory bioassay on citrus red mite, Panonychus citri (Mcg), showed that compound 1 possessed the following properties. (i) Powerful contact toxicity with an LC(50) of 5.2 mg litre(-1) after 24 h that was similar to that of pyridaben (LC(50) = 3.4 mg litre(-1)) and significantly superior to that of omethoate (LC(50) = 122 mg litre(-1)). Furthermore, its LC(90) was 13.4 mg litre(-1) after 24 h, which is significantly superior to both pyridaben (LC(90) = 69.6 mg litre(-1)) and omethoate (LC(90) = 453 mg litre(-1)). (ii) Quick-acting acaricidal activity. At identical concentrations, compound 1 was much faster-acting than pyridaben or omethoate. (iii) Compound 1 had strong corrosive action on the cuticle of P. citri but no phytotoxicity to plants.