STUDIES ON ZEOLITE-CATALYZED ALKOXY LATION OF TERPENES(Ⅲ)——METHOXYLATION OF α-PINENE AND β-PINENE

We have reported H-Mordenite-catalyzed alkoxylation of camphene and tricyclene with C1--C4 alcohols, and discussed the relationship of the structure to the odor of a series of major products. Alkoxylation of α-pinene （3） and β-pinene （5）, which are catalyzed by strongly acidic cation exchange resin, boron-trifluoride ether-

Methoxylation and Direct Hydrogenative Coupling of Chloronitrobenzenes in Continuous Flow

A novel continuous flow method for the methoxylation of chloronitrobenzenes was developed. The reaction went smoothly and high yields were achieved under the optimized conditions. Furthermore, up to 76% yield of azoxybenzenes were obtained from the corresponding nitrobenzenes in the presence of NaOH in continuous flow. Compared to batch conditions, the reaction time was significantly shortened, and the chemical waste was reduced obviously.

Extrasurrenal Pheochromocytoma: A Case Report and Review of the Literature

Introduction: Pheochromocytoma is a rare cause of endocrine hypertension. We report the case of an extra-adrenal pheochromocytoma discovered in the setting of an abdominal mass. Observation: The patient was 25-year-old and presented with headaches, excessive sweating and palpitations, followed by a sensation of abdominal weightlessness and diastolic arterial hypertension. Abdominal computed tomography revealed a retroperitoneal, right para-renal extra-adrenal mass. In biology, an increase in urinary methoxylated derivatives at the expense of normetanephrine. Conclusion: Pheochromocytoma is a rare disease, diagnosed by measuring urinary or plasma methoxylated derivatives. Conventional or nuclear imaging allows topographic diagnosis. Genetic studies helps to identify other tumors.

Co-delivery of resveratrol and docetaxel via polymeric micelles to improve the treatment of drug-resistant tumors

Co-delivery of anti-cancer drugs is promising to improve the efficacy of cancer treatment.This study was aiming to investigate the potential of concurrent delivery of resveratrol(RES)and docetaxel(DTX)via polymeric nanocarriers to treat breast cancer.To this end,methoxyl poly(ethylene glycol)-poly(D,L-lactide)copolymer(mPEG-PDLA)was prepared and characterized using FTIR and 1H NMR,and their molecular weights were determined by GPC.Isobologram analysis and combination index calculation were performed to find the optimal ratio between RES and DTX to against human breast adenocarcinoma cell line(MCF-7 cells).Subsequently,RES and DTX were loaded in the mPEG-PDLA micelles simultaneously,and the morphology,particle size distribution,in vitro release,pharmacokinetic profiles,as well as cytotoxicity to the MCF-7 cells were characterized.IC50 of RES and DTX in MCF-7 cells were determined to be 23.0μg/ml and 10.4μg/ml,respectively,while a lower IC50 of 4.8μg/ml of the combination of RES and DTX was obtained.The combination of RES and DTX at a ratio of 1:1(w/w)generated stronger synergistic effect than other ratios in the MCF-7 cells.RES and DTX loaded mPEG-PDLA micelles exhibited prolonged release profiles,and enhanced cytotoxicity in vitro against MCF-7 cells.The AUC(0→t)of DTX and RES in mPEG-PDLA micelles after i.v.administration to rats were 3.0-fold and 1.6-fold higher than that of i.v.injections of the individual drugs.These findings indicated that the co-delivery of RES and DTX using mPEG-PDLA micelles could have better treatment of tumors.

Influence of Mobile Phase Composition on the Enantioseparation of Methoxyl Flavanones with Self-prepared CDMPC Column and Chiral Recognition Mechanism

The influence of different alcohol modifiers in mobile phase on the chiral separation of 4-methoxyl flavanone, 5-methoxyl flavanone and 6-methoxyl flavanone on cellulose tris (3, 5-dimethylphenylcarbamate) (CDMPC) column was studied and the chiral recognition mechanism was discussed. Using hexane-tert-butanol (1.31 mol L-1) as the mobile phase, those three methoxyl flavanones were excellently separated on CDMPC chiral column.

Antioxidant Activity of Methoxylated Flavonoids in Oils in Deep Frying Processes

Methoxylated flavonoids isolated from cold acetone leaf wash of Polygonum senegalense;5-hydroxy-7-methoxyflavanone 1 and 5-hydroxy-6,7-dimethoxy-flavanone 3, were tested for their ability to enhance thermal stability of vegetable oils. Determination of the peroxide value (P.V.) and the p-Anisidine value (p-A.V.) was done according to the standard methods of analysis. The compounds were tested for in vitro cytotoxicity against a mammalian cell-line, Chinese Hamster Ovarian (CHO) using the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazoliumbromide (MTT)-assay. Studies on changes in peroxide and p-Anisidine values for the oils heated to temperatures between 180°C and 200°C recorded better stability enhancement at 100 ppm concentration with these flavonoids than the commercial antioxidant, butylated hydroxytoluene (BHT). The plant-based flavonoids had no significant cytotoxic effect against the CHO cell-line and may serve as alternative antioxidants to synthetic ones which have previously raised great concern over the health of consumers.

Efficient synthesis of 1,6-hexamethylene diurethane through coupling transesterification and methoxycarbonylation with methyl phenyl carbonate as intermediate

A reaction coupling system of transesterification and methoxycarbonylation with methyl phenyl carbonate （MPC） as intermediate was established to efficiently prepare 1,6-hexamethylene diurethane （HDU） from 1,6- bexametbylene diamine （HDA）. The feasibility of the system was explored using the thermodynamics analysis, the reaction mechanism and the experiment results. The optimal reaction was carried out to get higher HDU yield. The thermodynamic analysis showed that the metboxycarbonylation of HDA with MPC, the Gibbs free energy of which was negative, was a spontaneous process. Furthermore, the equilibrium constant of the methoxycarbonylation of HDA with MPC was much greater than that of the transesterification of dimethyl carbonate （DMC） with phenol, so the reaction coupling could be realized under mild conditions. The reaction mechanism analysis indicated that phenoxy anion was the key spedes for reaction coupling. Higher MPC concentration was detected when sodium phenoxide was used as transesterification reactant with DMC, since the phenoxy anion of sodium phenoxide could be dissociated more easily. Sodium pbenoxide was more suitable to prepare HHDU through reaction coupling. A yield of HDU as high as 98.3% could be reached under the optimal conditions of mPhONa/mDMC = 0.027 and nDMC/nHDa = 8/1 at 90 ℃ in 2 h.

Methoxyl methyl ether isoamylene quercetin, a quercetin derivative, protects rat aorta endothelial cells against oxidation and apoptosis

Methoxyl methyl ether isoamylene quercetin （MIAQ） is one of the newly synthesized quercetin derivatives. The present study investigated the effect of MIAQ on rat aorta endothelial cells （RAECs） injured by hydrogen peroxide （H2O2）, as well as the potential mechanisms. We observed that MIAQ at 2.5-10μmol/L significantly enhanced the viability of injured RAECs, and the effect was more potent than quercetin and ct-tocopherol. However, M1AQ at the same concentration failed to show anti-oxidant activity in a cell-free system. In H2O2-injured endothelial cells treated with MIAQ （5-10μmol/L）, the level of nitric oxide （NO） and malondialdehyde was decreased, and the activities of superoxide dismutase and glutathione peroxidase was enhanced. In addition, RAECs treated with MIAQ （2.5-10 μmol/L） exhibited significant inhibiting apoptosis. In conclusion, MIAQ had protective effect on RAECs, possibly through increasing NO production and antioxidases activities, as well as inhibiting apoptosis. These findings suggest that MIAQ is possibly beneficial in the prevention of atherosclerosis and other diseases related to endothelial injury.

Debrominated and methoxylated polybrominated diphenyl ether metabolites in rainbow trout(Oncorhynchus mykiss) after exposure to decabromodiphenyl ether

Decabromodiphenyl ether （BDE209） is the primary component in a commonly used flame retardant. Previous studies had proved that BDE209 itself was not toxic, while its metabolites including debrominated diphenyl ethers （De-BDEs） and methoxylated brominated diphenyl ethers （MeO-BDEs） posed a potential threat to organisms. Many studies had indicated that BDE209 could metabolize quickly in mammals, but lacking in the basic data about the metabolism of BDE209 in fish. In the present study, two replicate treatment groups of rainbow trout （Oncorhynchus rnykiss） were exposed to BDE209 via a single intraperitoneal injection approximately 100 and 500 ng/g, respectively. Muscle, liver and blood samples were collected to analyze the specific metabolites on day 1 and day 28 post injection. The highest concentration of BDE209 was detected in muscle tissues, from 796.1 ng/g wet weight （day 1） to 687.1 ng/g wet weight （day 28） in high dose group, suggesting that BDE209 could accumulate slightly in muscle tissues. However, BDE209 was not detected in the blood for all treatments. Most congeners of De-BDEs were found in muscle and liver tissues, with the highest concentration in the liver. The main De-BDEs were nona-, octa-, hepta- and penta-De-BDEs. A total of seven MeO-BDE metabolites were observed among different fish tissues. Blood had the highest contribution of the MeO-BDE metabolites. Each MeO-BDE congener increased over the 28 days. These results in contrast to other studies suggested possible species-specific differences in metabolic abilities.

Advances in Enantioselective Construction of Trifluoromethoxylated Stereogenic Carbon Centers

In recent years,the trifluoromethoxy(OCF3)functional group has received extensive attention in phar-maceuticals,agrochemicals and material sciences.However,the methods for the enantioselective syn-thesis of trifluoromethoxylated stereogenic carbon centers are rare owing to the nature of easy decom-position of OCF3 anion and limited OCF3 reagent.And the asymmetric trifluoromethoxylation will be a hot research topic in near future due to the unique biological properties of a single isomer.This article mainly focuses on the recent advances in the enantioselectiveconstruction of trifluoromethoxylated stereogenic carbon centers.

Two new xanthones from Lomatogonium carinthiacum

AIM: To study the chemical constituents of Lomatogonium carinthiacum(Wulfen) Rchb. METHOD: The CHCl3-soluble fraction was separated by chromatography and the structures of the new compounds were elucidated by spectral experiments. RESULTS: Two new xanthones, 1, 8-dihydroxy-4, 5-dimethoxy-6, 7-methylenedioxyxanthone(1), 1, 4, 8-trimethoxyxanthone-6-O-β-D-glucoronyl-(1→6)O-β-D-glucoside(2) were isolated from the whole plant of Lomatogonium carinthiacum. CONCLUSION: Compounds 1 and 2 are new natural products.

Toxicokinetics and the related metabolites in rainbow trout(Oncorhynchus mykiss) after exposure to decabromodiphenyl ether

Decabromodiphenyl ether(BDE209) is poorly absorbed by mammals,and little information is available on the toxicokinetics of BDE209 and its metabolites in fish.In the present study,rainbow trout(Oncorhynchus mykiss) were administered to 100 ng/g and 500 ng/g body wet weight of BDE209 via a single intraperitoneal injection and parent BDE209 and its metabolites were sequentially monitored for 28 days.The results showed that toxicokinetic profiles of BDE209 could be described by the one-compartment model.In the higher dose group(500 ng/g wet weight),the calculated half-life(t1/2) and elimination rate(ke) were 17.7 d and 0.039/d in the liver,and 100.3 d and 0.007/d in the muscle,respectively.Three major methoxylated brominated diphenyl ethers(MeO-BDEs) were detected with 2,2',4,4'-tetrabromo-5-methoxydiphenyl ether(5-MeO-BDE47) being detected in all tissue samples.There was no significant temporal change of 5-MeO-BDE47 concentration in the muscle,whereas an exponential increase was observed in the liver.Therefore,the metabolism rate of BDE209 depended on the administered dose.BDE209 was hardly accumulated in the muscle of rainbow trout,while the liver was a primary metabolic organ.MeO-BDEs were formed via metabolism of BDE209,which probably played a significant role in fish toxicology as a potential indicator.