Comparative study of technologies for extraction of biologically active substances from the raw material of animal origin

Technologies of isolation and concentration of biologically active substances, developed in the middle of the 20th century, need adjustment and adaptation to modern conditions both to increase the activity of substances and for greater economic efficiency. The aim of the research is the comparison of dynamics of biologically active compounds extraction from porcines pancreas in two methods: the saline method based on 0.9% sodium chloride solution, and the acidic method based on 2.4% trichloroacetic acid solution. Also the purpose of research is to assess the possibilities for further optimization of technologies. The total protein concentration based on the biuret reaction in the samples taken during the extraction, as well as the calculation and analysis of the point degrees and rates of extraction are chosen as the controlled parameters. Local maxima of the protein yields into the extractant media at the 60th, 135th and 255th minute were recorded during saline extraction; and at the 75th and 135th minute during acid extraction. Also the proteomic profile of the extracts was studied. Wide range of compounds with molecular weight of less than 52 kDa was found in extracts based on physiological saline solution, and protein substances of whole presented range of molecular weights in trichloroacetic acid based extracts were considered. The predominance of low molecular weight protein fraction of interest was noted also in this method of extraction in comparison with the other methods of extraction. According to the UniProt database, we assume availability of probable compounds with a molecular weight of less than 30 kDa in the purified acidic extract. The presence of some proteins absent in the final saline extract was noted. The acidic erythrograms showed a weak degrading effect of both types of extracts on the membranes of rat erythrocytes, as well as the cytoprotective effect of acidic ultrafiltrates (less than 3 kDa). The obtained results prove a better efficiency of trichloroacetic acid extraction method used for obtaining a mixture of a wide range of compounds, including biologically active substances of low molecular weight.

Laboratory toxicological diagnosis of trazodone intoxications

When determining the cause of poisoning by antidepressant drugs, the data of laboratory toxicological studies of biofluids for the presence of this group of drugs are of key importance. Aim. To develop the methods for determining the antidepressant drug trazodone in the blood and urine samples using high-performance liquid chromatography with a UV spectrophotometric detection, which is suitable for analytical diagnosis of the thymoleptics intoxications. Materials and methods. The model samples of human biofluids spiked with trazodone were studied. The antidepressant was isolated from the blood and urine by the liquid-liquid extraction with methylene chloride from the alkaline medium at pH 9. Concomitant endogenous impurities were removed by extraction with diethyl ether from the acidic medium at pH 1. In the study of the blood the erythrocyte mass was pre-precipitated with the help of 10 % of trichloroacetic acid solution. Chromatographic analysis was performed on a microcolumn chromatograph using a column with a reversed-phase of C18. Results. The absolute retention time of trazodone in extracts from the model samples of biofluids was 17.91±0.09 min. The quantitative content of trazodone was determined at 250 nm by the calibration dependence of the chromatographic peak area on the concentration (μg/ml) y=(1.74∙10-3±1∙10-5)x. Under the indicated extraction conditions, 35±4 % and 78±4 % of trazodone were isolated from the blood and urine, respectively. Conclusions. The methods of trazodone isolation from the biofliuds by liquid extraction followed by the determination of the drug by high performance liquid chromatography with a multiwave UV spectrophotometric detection have been developed. The methods are recommended for using in the practice of forensic and clinical toxicology.

Randomised controlled trial of 1% and 5% 5-fluorouracil creams compared with 90% trichloroacetic acid solution for anogenital wart treatment

To evaluate the efficacy and safety of 1% and 5% 5-fluorouracil (5-FU) creams compared with 90% trichloroacetic acid (TCA) for the treatment of anogenital warts. we conducted a randomised controlled study in 72 subjects allocated to three groups: 1% 5-FU, 90% TCA and 5% 5-FU; 90% TCA was administered once a week, whereas 5-FU cream was applied three times a week. Response to therapy and side-effects were evaluated weekly for seven weeks. Evaluation at week 7 demonstrated that there was no significant difference in the efficacy between 1% 5-FU cream and 90% TCA ( p = 0.763) or between 5% 5-FU cream and 90% TCA ( p = 0.274). Subjective side-effects with 1% 5-FU were significantly milder than 90% TCA; however, significantly milder objective side-effects were observed only at weeks 2, 6 and 7. The subjective side-effects with 5% 5-FU were also significantly milder than 90% TCA; however, significantly milder objective side-effects were observed only at week 2. 5-FU may become an alternative topical therapy as it offers the benefit of self-application; furthermore, a concentration of 1% 5-FU cream is recommended due to milder side-effects.

Comparative Efficacy of 50% Trichloroacetic Acid Solution with 10% Potassium Hydroxide Solution in the Treatment of Plane Warts

Background: Warts are very common disorders. Plane warts are caused by Human Papilloma Virus (HPV) occurring mostly in children and young adults. Among the treatment modalities, topical application of trichloroacetic acid (TCA) is age old. Potassium hydroxide (KOH) has a keratolytic effect on virus-infected cells. Aims: To compare the safety and efficacy of topical 10% KOH solution with 50% TCA solution in the treatment of plane warts. Materials and Methods: Sixty-four consecutive patients with plane warts were randomly assigned into two groups of thirty-two patients. Group A received 10% KOH solution and group B received 50% TCA solution once weekly until the complete clearance of warts in a maximum period of 12 weeks. Results: In group under treatment with 10% KOH, 24 patients (75.0%) complete response, 5 patients (15.6%) moderate response, 2 patients (6.3%) mild response, and 1 patient (3.1%) had no response. In group under treatment with 50% TCA, 28 patients (87.5%) showed complete response, 2 patients (6.3%) moderate response, 2 patients (6.3%) mild response. Statistically no significant difference was found between the therapeutic response to 10% KOH and 50% TCA (P=0.41). Conclusion: 10% KOH was found to be equally effective in the treatment of plane warts compared to 50% TCA with the advantage of fewer side effects.

Surface Enhanced Raman Spectroscopy Detection of Sodium Thiocyanate in Milk Based on the Aggregation of Ag Nanoparticles

A method is developed for detecting the concentration of sodium thiocyanate (NaSCN) in milk based on surface-enhanced Raman scattering (SERS) technology. A trichloroacetic acid solution can be used to enhance the SERS signal because of its function in promoting the aggregation of Ag nanoparticles (Ag NPs). Meanwhile, the protein in milk would be precipitated as trichloroacetic acid added and the interference from protein could be reduced during the detection. In this work, the enhancement factor (EF) is 7. 56 × 105 for sodium thiocyanate in water and the limit of detection (LOD) is 0.002 mg/L. Meanwhile, this method can be used to detect the concentration of sodium thiocyanate in milk. Results show that SERS intensity increased as the concentration of sodium thiocyanate increase from 10 to 100 mg/L. The linear correlation coefficient is R2 = 0.998 and the detection limit is 0.04 mg/L. It is observed that the concentration of sodium thiocyanate does not exceed the standard in the three kinds of milk. The confirmed credibility of SERS detection is compared with conventional methods.

Elimination of Methylene Blue from Solution Using Modified Scrap Tire

The disposal of the waste tires has become a serious problem faced by many countries today, recycling offers a powerful solution to this problem, for example using it as an adsorbent. In this research, we studied the modification of scrap tire by radiation with gamma ray in trichloroacetic acid solution and elucidated the possibility of using it as an adsorbent to remove Methylene Blue dye (MB) from aqueous solution. The effect of various variables, such as time passing, primary concentration of MB, the quantity of adsorbent and PH of the medium was studied in order to obtain the maximum dye removal. Equilibrium time was at 45 min, maximum adsorption was at PH=9. The results showed the scrap tires ability to be modified and the possibility of using it as an available and inexpensive adsorbent, as well as providing a safe disposal of solid waste.

Rapid Determination and Confirmation of Biogenic Amines in Tuna Loin by Gas Chromatography/Mass Spectrometry Using Ethylchloroformate Derivative

A gas chromatography-mass spectrometry (GC/MS) method is described for the easy rapid determination and simultaneous confirmation of the biogenic amines putrescine (PUT), cadaverine (CAD), histamine (HTA), and spermidine (SPD) in fresh frozen tuna loin. The method can also be used to monitor tyramine (TYR). The method involves homogenization of fish tissue, extraction of biogenic amines into trichloroacetic acid solution, centrifugation, alkalization, and derivatization of supernatant with ethylchloroformate. All seafood species were fortified to contain 2.5, 5.0, 10.0, 12.5, and 25.0 μg/g (ppm) PUT, CAD, and SPD; and 10.0, 20.0, 40.0, 50.0, and 100.0 μg/g (ppm) HTA. Determination was based on standard curves for each analyte using peak areas with matrix standards equivalent to a concentration range bracketing the spike level. A set of 5 matrix controls (unfortified tuna tissue) was also analyzed; only endogenous SPD was found in all samples. The interassay average recoveries ranged from 57 to 79% across analytes and spike levels.

Application of in situ digital holography to the study of the effect of a magnetic field on the anodic dissolution of iron in thichloroacetic acid

The effect of a magnetic field on the anodic dissolution of iron in 1.0 mol dm-3 trichloroacetic acid solution was studied by the potentiodynamic polarization method and in situ digital holography. It was found that the magnetohydrodynamic force increased the mass transport, which resulted in a faster anodic dissolution of iron. The effect of the magnetic field was analyzed by holograms and is discussed in terms of the magnetohydrodynamic force.