In this study, glutaraldehyde-crosslinked chitosan beads were prepared and characterized for the immobilization of Burkholderia cepacia lipase (BCL, 23,000 U/g). The crosslinking time and the concentration of glutaraldehyde were evaluated. The morphological modifications and the chemical interac...

Special proton-gradient-transfer acid complexes (PGTACs) in which the bonded protons are not equivalent and have gradients in transfer ability, acidity, and reactivity were reported. The acidity gradient of the protons gave the PGTACs excellent catalytic activity and selectivity in the esterific...

As an alternative to the chemical synthesis of geranyl acetate, the aim of the present study is to better understand its enzymatic synthesis in a 1 mL packed bed reactor (PBR) using supercritical CO2 as a green solvent and immobilized lipase B from Candida antarctica as a catalyst. Using a full ...

Geranyl acetate (1) was oxidized thermally and photochemically using (mcpba, H2O2) respectively to obtain (E)-5-(3, 3-dimethyloxiran-2-yl)-3-methylpent-2-enyl acetate (2) and 3-(2-(3, 3-dimethyloxiran-2-yl) ethyl)-3-methyloxiran-2-yl) methyl acetate (3). On the other hand, photooxygenation of 1 ...

The interest in new natural products used in cosmetic industry has increased the research in order to synthesize those compounds. The aim of this work is to assess the reaction of the transesterification between geraniol and vinyl acetate for the enzymatic synthesis of geranyl acetate, using Nov...

Background: To explore the sexual difference in the feedback regulation of hepatic bile acid synthesis, glycodeoxycholic acid (GDCA) was administered to 15 male and 14 female rabbits. Methods: After bile diversion, GDCA equivalent to the hepatic bile acid influx was infused intraduodenally. Bili...

During the last decade a special interest has been focused on studying the relationship between the composition and structure of emulsions and the extent of lipolysis, driven by the necessity of modulate lipid digestion to decrease or delay fats absorption or increase healthy fat nutrients bioav...

Non-alcoholic steatohepatitis (NASH) is a progressive inflammatory and fibrotic disease. However, the progression mechanism of NASH is not well understood. Bile acids are endogenous molecules that regulate cholesterol homeostasis, lipid solubilization in the intestinal lumen, and metabolic signa...

A novel vector pM4aB for lactic acid bacterial was developed using a bile salt hydrolase gene from Lactobacillus plantarum as a potential food-grade selection marker. The 3.0-kb pM4aB consisted of the replicon of Lactobacillus plasmid pM4, a multiple cloning site and the bsh gene, which was cons...

Inhibition of bile salt export pump (BSEP) causes hepatic accumulation of toxic bile acid (BA), leading to hepatocyte death. We reported a sandwich-cultured hepatocyte (SCH)–based model that can estimate potential cholestatic compounds by assessing their ability to induce hepatotoxicity in comb...

Bile acids are biosynthesized from cholesterol in hepatocytes and usually localize in the enterohepatic circulation system. This system is regulated by several transporters that are expressed in the liver and intestine. Organic solute transporter (OST) α/β, which is known as a bidirectional tr...

Feedback regulation of derepressed hepatic bile acid biosynthesis was studied individually with glycocholic, glycodeoxycholic, and glycoursocholic acids by infusion into bile acid-depleted rabbits. Construction of a bile fistula drained the endogenous bile acid pool (90% glycodeoxycholic acid, 1...

Six cholic acid derivatives (1–6) were isolated from broth cultures of Bacillus amyloliquefaciens UWI-W23, an isolate from the Trinidad Pitch Lake. The compounds were extracted via solvent extraction and/or XAD resin adsorption and purified using silica gel column chromatography. Their structur...

Micellar electrokinetic chromatography (MEKC) was introduced to evaluate the hydrophobicity of cephalosporins (cefpim, cefpirom, cefazolin, ceftazidim, cephradin, cefuroxim, cefotaxim, cephapirin and cephalothin) (Fig. 1). Partition coefficients of cephalosporins were calculated between a micell...

The new aporphines dehydroocopodine (V) and dicentrinone (VI) have been isolated from Ocotea macropoda, eleven known alkaloids have been isolated from Hernandia Jamaicensis. The structures of the new alkaloids are based upon spectroscopic evidence, as well as on partial synthesis from closely re...

Ethnopharmacological relevanceThe preparations of teas and syrups using Duguetia furfuracea have been used in folk medicine to treat rheumatism and back pain. Several rheumatic diseases are anti-inflammatory and are treated with several anti-inflammatories.

1.1. The effects of the oxyaporphine alkaloid thalicminine on guinea-pig isolated ileum, trachea, aorta and pulmonary artery and on blood pressure and heart rate of anesthetized guinea-pigs were studied.2.2. Thalicminine (1–300 μM) caused the relaxation of the longitudinal ileal segments. The ...

Unsaturated oxoesters and amides have been submitted to cross-coupling metathesis with trimethylallylsilane using Grubbs' catalyst. The resulting allysilanes underwent, under irradiation, intramolecular [2+2] photocycloaddition leading to trimethylsilylmethylcyclobutanes. By treatment with ...

A tributyltin hydride reduction and an atom transfer fragmentation of a iodomethyl cyclobutane have been used to complete two modified syntheses of silphinene with complete regioselectivity in the introduction of the silphinene double bond.

The construction of tricyclo[5.2.1.01,6]decene skeleton was achieved by cyclobutane ring formation via improved radical reaction using SmI2-H2O-HFIP and SmI2-LiCl conditions in good yields. Those additives were studied to increase the reactivity of SmI2. Two interesting reactions via neighboring...