Characteristics of partial acid hydrolysis in five plant polysaccharides / 中草药

Objective: To study the characteristics of partial acid hydrolysis in five different plant polysaccharides and the composition of their hydrolysic products. Methods: Polysaccharides were partially hydrolyzed with trifluoroacetic acid (TFA) at different concentration (0.05, 0.2, and 0.5 mol/L), respectively, and the hydrolytic characteristics were studied by ultra-performance liquid chromatography (UPLC) coupled with multivariate statistricts. Results: The characteristic structural segments of ephedra polysaccharide were the contents of glucuronic acid in trapped fluid hydrolyzed with 0.05 mol/L TFA (X1GlcUA), arabinose in permeation fluid hydrolyzed with 0.05 mol/L TFA (X2Ara), arabinose in trapped fluid hydrolyzed with 0.2 and 0.5 mol/L TFA (Y1Ara and Z1Ara), and galacturonic acid in the permeation fluid hydrolyzed with 0.2 mol/L TFA (Y2GalUA), which could distinguish other plant polysaccharide samples. Conclusion: The proposed method is precise and practical for the analysis on monosaccharide compositon in Chinese materia medica by UPLC coupled with multivariate statistics and partial acid hydrolytic reaction, which further provides the basis for the quality control of the plant polysaccharides.

A Case of Chemical Burn Caused by Trifluoroacetic Anhydride that Mimicked a Hydrofluoric Acid Burn

A 22-year-old woman was referred to our emergency department for the treatment of a chemical injury on her arm. She had accidentally spilled 99% trifluoroacetic anhydride (TFAA) over her left forearm during an organic chemistry experiment. She visited a primary care unit, and then she was referred to our hospital for inactivation of the released fluoride ions. Her skin lesions were different from those caused by hydrofluoric acid (HF) injury. The injured area showed painful whitish maculae and patchy areas with accentuated rim. No vesiculation and bulla formation was detected. We intradermally injected a 5% solution of calcium through a 24-gauge needle into the burned skin. After the injection, she complained of more severe pain. Although TFAA contains fluorine, it does not release free fluoride ions on contact with the skin, unlike HF. In fact, application of calcium gluconate for TFAA burns is not recommended. Rather, it should be avoided since it increases pain and local abscess formation.

Determination of trifluoroacetic acid in bivalirudin by HPLC / 中国生化药物杂志

Purpose To establish a HPLC method for determination of the content of trifluoroacetic acid in bivalirudin.Methods Kromasil 100-5 C_(18) column(4.6 mm×200 mm,5 μm)and 0.07% phosphoric acid solution(pH 3.0)-methanol(98:2)as the mobile phase at a flow rate of 1.0 mL/min were used with a column temperature of 30 ℃,a detection wavelength of 210 nm and a injection volume of 20 μL.Results The standard curve of trifluomacetic acid was linear in the range of 198.4-992.0 μg/mL,r=0.999 9.The detection limit Was 40 ng.The average recovery rate of method was 99.9%,and RSD was 0.41%.Conclusion The method of content determination was practicable and accurate.It can be used for content determination of trifluoroacetic acid in bivalirudin.

Liver Function and Inhaled Anesthetics

The liver is the major site of endogenous and exogenous drug metabolism. The primary result of drug metabolism is the production of more water-soluble and therefore more easily excreted drug metabolites. Drugs are sometimes biotransformed into more reactive metabolites, which may lead to toxicity. Volatile anesthetics, like most drugs, undergo metabolism in the body and are sometimes associated with toxic reactions. Here, author will discuss the metabolism and hepatic toxicity of inhaled anesthetics. Toxicity and liver injury have been reported after repeated exposure on subsequent occasions to different fluorinated anesthetics. This phenomenon of cross-sensitization has also been reported with the chlorofluorocarbon(CFC) replacement agents, the hydrochlorofluorocarbons(HCFCs). Halothane, enflurane, sevoflurane, isoflurane, desflurane are all metabolized to trifluoroacetic acid, which have been reported to induce liver injury in susceptible patients. The propensity to produce liver injury appears to parrel metabolism of the parent drug: halothane(20%) >>>> enflurane(2.5%) >> sevoflurane(1%) > isoflurane(0.2%) > desflurane(0.02%). The use of any anesthetic must be based on its benefits and risks, how it may produce toxicity, and in which patients it may be most safely administered. Nonhalogenated inhaled anesthetics (nitrous oxide, xenon) chemically inert and not metabolized in human tissue. The perfect anesthetic agents dose not exist. But ongoing research attempts to uncover emerging toxicities. Xenon is not currently approved for clinical use. Other than the expense associated with its use, it may be the most ideal anesthetic agent. In general, surgical manipulation or disturbance of the surgical site appears to be more important in decreasing hepatic blood flow than current anesthetic agents such as isoflurane, sevoflurane, and desflurane or technique. However, the clinician is challenged to balance new information with current clinical practices and choice the safest, most effective agents for each patient.

The Effect of Trifluoroacetic Acid, a Metabolite of Isoflurane on the ATP-sensitive Potassium Channel in Rabbit Ventricular Myocytes / 대한마취과학회지

BACKGROUND: Activation of ATP-sensitive K+ channels (KATP channels) in the cardiac muscle produces cardioprotective effects during myocardial ischemia. Previous experimental evidence indicates that volatile anesthetics exert beneficial actions in ischemic myocardium and enhance functional recovery of stunned myocardium. More recently, volatile anesthetics have been demonstrated to produce cardioprotective effects in stunned myocardium in vivo, and these effects are blocked by a KATP channel antagonist. This finding suggests that KATP channel activation by isoflurane may mediate antiischemic effects. However, it was demonstrated that isoflurane inhibited KATP channel activity in rabbit ventricular myocytes. To explain the discrepancy, the present investigation tested the hypothesis that isoflurane and its metabolite, trifluoroacetic acid, contributes to the activation of KATP channels in rabbit ventricular myocytes. METHODS: Single ventricular myocytes were isolated from rabbit hearts by an enzymatic dissociation procedure. Single-channel currents were measured in inside-out patch configurations of the patch-clamp technique. The perfusing liquid was equilibrated with isoflurane by passing 100% O2 through a vaporizer. RESULTS: Isoflurane inhibited KATP channel activity without a change in the single-channel conductivity. Isoflurane decreased the burst duration and increased the interburst duration. In addition, isoflurane diminished the ATP sensitivity of KATP channels. Trifluoroacetic acid, a metabolite of isoflurane, enhanced the channel activity in a dose-dependent fashion. Trifluoroacetic acid increased the burst duration and decreased the interburst duration without a change in the single-channel conductivity. Isoflurane and trifluoroacetic acid diminished the ATP sensitivity of KATP channels. CONCLUSIONS: These results imply that isoflurane and its metabolite could mediate cardioprotective effects via KATP channel activation during myocardial ischemia.