Five novel nor-eremophilane-type sesquiterpenoids, peniroqueforins E-H and J (1-4 and 7), two new eremophilane-type sesquiterpenoids, peniroqueforins I and K (5 and 8), and a new eudesmane-type sesquiterpenoid, peniroqueforin L (9), along with four known compounds (6 and 10-12), were isolated and characterized from fungus Penicillium roqueforti (P. roqueforti). The structures and absolute configurations of these compounds were determined through comprehensive spectroscopic analyses, electronic circular dichroism (ECD) data analyses, and single-crystal X-ray diffraction methods. The anti-multi-drug resistance (MDR) cancer activity of these compounds was evaluated using SW620/Ad300 cells. Notably, the half maximal inhibitory concentration (IC₅₀) value of paclitaxel (PTX) combined with 1 in SW620/Ad300 cells was 50.36 nmol·L^-1, which was 65-fold more potent than PTX alone (IC₅₀ 3.26 μmol·L^-1). Subsequent molecular docking studies revealed an affinity between compound 1 and P-glycoprotein (P-gp), suggesting that this nor-eremophilane-type sesquiterpenoid (1) could serve as a potential lead for MDR reversal in cancer cells through P-gp inhibition.
Penicillium/chemistry* ; Humans ; Sesquiterpenes/isolation & purification* ; Cell Line, Tumor ; Molecular Structure ; Drug Resistance, Neoplasm/drug effects* ; Antineoplastic Agents/pharmacology* ; Drug Resistance, Multiple/drug effects* ; Molecular Docking Simulation

BACKGROUND: Different derivatives of chitosan with different molecular weights or degrees of deacetylation show different anti-tumor effects.OBJECTIVE: To study the inhibition effect of water-soluble chitosan and its derivatives, such as sulfonated chitosan, carboxymethyl chitosan and chitooligosaccharides for the growth of hepatocellular carcinoma cell line SMMC7721.DESIGN, TIME AND SETTING: Controlled experiments based on observation were carried out in Jiangxi Institute of Digestive Disease (Nanchang, Jiangxi, China) from January 2004 to December 2006.MATERIALS: Hepatoma cell line SMMC7721 was provided by Jiangxi Institute of Digestive Disease (China). 85.5% deacetylated chitooligosaccharides and 85% deacetylated water-soluble chitosan were produced by Jinan Haidebei Ocean Biological Engineering Co., Ltd (China); Carboxymethyl chitosan and 88.5% deacetylated chitosan were the products of Shanghai Qisheng Biological Products Co., Ltd (China).METHODS: Sulfonated chitosan was prepared using 88.5% deacetylated chitosan and chlorosulfonic acid-formamide, and then was detected with infrared spectroscopy in the Detection Analysis and Test Center, East China University of Science and Technology. SMMC7721 cells in the log phase were inoculated into 96-well culture plates, which were then added with water-soluble chitosan, sulfonated chitosan, carboxymethyl chitosan and chitooligosaccharides with the final concentrations of 25, 50, 100, 200, 400 and 800mg/L. This test was repeated for 3 times, while the control group was also set each time. After 72 hours of routine culture, MTT solution was added into each well and inoculated for another 4 hours. After the culture was terminated, dimethyl sulfoxid was added. The absorbance value of each well was measured at 490nm wavelength on a microplate reader. Three tests were measured to obtain the mean value. Also the inhibition rate was calculated.MAIN OUTCOME MEASURES: Growth inhibition effect of chitosan and its derivatives on the hepatoma cell line SMMC7721.RESULTS: Among the chitosan and its derivates at four kinds of concentrations, water-soluble chitosan and sulfonated chitosan could significantly inhibit the growth of SMMC7721 cells (P<0.001), and the effect was the most significant in the case of sulfonated chitosan. Treatment with water-soluble chitosan and sulfonated chitosan at the concentration of 50mg/L could inhibit the growth of SMMC7721 cells in a dose-dependent manner, and reached a peak at the concentration of 400mg/L and 800mg/L, respectively. Carboxymethyl chitosan and chitooligosaccharides showed no growth inhibition effect (P>0.05).CONCLUSION: Water-soluble chitosan and sulfonated chitosan have significant antigrowth effects on hepatoma carcinoma cells, while carboxymethyl chitosan and chitooligosaccharides are ineffective.