Six novel E-32-aryl substituted chlorins (5a–5f) were synthesized via improved regioselective bromination and Suzuki–Miyaura cross-coupling reactions with chlorin e6 (1) as a starting material. All the π-extension photosensitizers 5a–5f exhibited significant bathochromic-shifts (ca. 10 nm) in the far red part of the spectrum called the phototherapeutic window and decreased photobleaching under irradiation of 660 nm light. Moreover, 5a–5f possessed higher phototoxicity in vitro against HepG2 cells (IC50 = 0.73 ± 0.04, 2.33 ± 0.22, 0.78 ± 0.05, 0.50 ± 0.04, 2.25 ± 0.16 and 0.65 ± 0.11 μM, respectively) compared with chlorin e6 (IC50 = 28.9 ± 1.2 μM). The enhanced cellular uptake and reactive oxygen species (ROS) production of modified chlorins were found to be responsible for their increased in vitro phototoxicity.

•A series of flavone-7-phosphoramidate derivatives was synthesized.•Some derivatives had shown selective inhibition against hepatoma HepG2 cells.•Compounds 8d, 16d and 17d could almost thoroughly induce HepG2 cells in G2/M phase.•Phosphoramidate group significantly improved the apoptosis induction of compound 16d.•Compound 16d (IC50 = 5.5 ± 1.3 μM) induced early apoptosis in HepG2 cells.A series of flavone-7-phosphoramidate derivatives were synthesized and tested for their antiproliferative activity in vitro against human hepatoma cell line HepG2 and human normal hepatic cell line L-O2. Compound 8d, 16d and 17d, incorporating the amino acid alanine, exhibited high inhibitory activity on HepG2 cell line with IC50 values of 9.0 μmol/L, 5.5 μmol/L and 6.6 μmol/L. The introduction of acyl groups played a pivotal role in the selective inhibition toward human hepatoma HepG2 cells, except for compound 8a, 9a and 16b. Compound 8d, 16d and 17d could significantly induce G2/M arrest in HepG2 cells. Specially, Compound 16d could lead early apoptosis in HepG2 cells.

Nine new chlorin derivatives containing maleimide functional group and amino acid residue with chlorin e6 scaffold (compounds 1–6) or pheophorbide a scaffold (compounds 7–9) were synthesised from chlorophyll a. The all nine derivatives demonstrated increased photo cytotoxic activity in HepG2 cell (IC50 3.2–20.5 μM) comparing with chlorin e6 and its trimethyl ester. Their photo cytotoxicities were approximately dependent on their abilities to produce singlet oxygen (1O2) in the cells.

Cinobufacini (Huachansu) injections have been widely used for the treatment of various cancers in clinical applications in China. As an aqueous extract of the skin of Bufo bufo gargarizans Cantor (toad skin), cinobufacini contains many polar compounds; however the chemical profile of these polar compounds is still unclear, which increases the risk of pharmacological safety. There are very few studies on the separation and purification of polar components from toad skin, especially in the preparative scale. In this study, a unique method based on a homemade polar-modified C18 stationary phase was developed and successfully applied to separate polar compounds from toad skin. Compared with previous purification systems based on the C18 stationary phase, the poor retention problem of polar compounds was well resolved through the use of the polar-modified C18 column and good resolutions were also achieved. Seven compounds were purified and five of them (uracil, hypoxanthine, 3-hydroxy-4H-pyrazolo[4,5-d]pyridazin-7(1H)-one, thymine and bufothionine) were identified by MS, 1H NMR and 13C NMR. In addition, 3-hydroxy-4H-pyrazolo[4,5-d]pyridazin-7(1H)-one was identified as a new compound and hypoxanthine was found from the skin of Bufo bufo gargarizans Cantor for the first time. These results indicate that this method shows promise for the separation of polar compounds in toad skin.

The objective of this study is to establish a centrifugal partition chromatography (CPC) method for determination of the urea ingredient in urea cream. The mechanism of this method is that urea is determined by UV detector at 430 nm after being extracted from the cream and derivatized on line via Ehrlich reaction in rotor of CPC, where the reaction products dissolve in the mobile phase and the cream matrix retains in the stationary phase. The mixed solvent consisting of n-hexane, methanol, hydrochloric acid and p-dimethylaminobenzaldehyde with a ratio of 1000 mL:1000 mL:18 mL:2.0 g is used for solvent system of CPC. The CPC method proposed offers good precision and convenience without complex sample pretreatment processes.Download high-res image (171KB)Download full-size image

Cinobufacini (Huachansu) injections have been widely used for the treatment of various cancers in clinical applications in China. As an aqueous extract of the skin of Bufo bufo gargarizans Cantor (toad skin), cinobufacini contains many polar compounds; however the chemical profile of these polar compounds is still unclear, which increases the risk of pharmacological safety. There are very few studies on the separation and purification of polar components from toad skin, especially in the preparative scale. In this study, a unique method based on a homemade polar-modified C18 stationary phase was developed and successfully applied to separate polar compounds from toad skin. Compared with previous purification systems based on the C18 stationary phase, the poor retention problem of polar compounds was well resolved through the use of the polar-modified C18 column and good resolutions were also achieved. Seven compounds were purified and five of them (uracil, hypoxanthine, 3-hydroxy-4H-pyrazolo[4,5-d]pyridazin-7(1H)-one, thymine and bufothionine) were identified by MS, 1H NMR and 13C NMR. In addition, 3-hydroxy-4H-pyrazolo[4,5-d]pyridazin-7(1H)-one was identified as a new compound and hypoxanthine was found from the skin of Bufo bufo gargarizans Cantor for the first time. These results indicate that this method shows promise for the separation of polar compounds in toad skin.