Spectrophotometric Method Research Articles

Neuroprotective Effect of Boswellia serrata against 3-NP Induced Experimental Huntington’s Disease

Objectives:: The study aimed to assess the neuroprotective effect of Boswellia serrata against 3-NP-induced experimental Huntington’s disease. Background:: Previous studies have shown Boswellia to have sedative, analgesic, and anti-tumour effects. Boswellia serrata yields four pentacyclic triterpene acids and boswellic acid, a bioactive substance that prevents leukotriene biogenesis. Methods:: The potential neuroprotective effect of Boswellia serrata against 3-nitro propionic acid (3-NP)-induced Huntington's disease (HD) was examined at oral doses of 45 mg/kg, 90 mg/kg, and 180 mg/kg. In this study, HD was induced by 3-NP at a dose of 10 mg/kg in Wistar rats. The study used 56 Wistar rats (8 per group) for biochemical (inflammatory markers, acetylcholinesterase activity) and behavioural (elevated plus maze, Y-maze, open-field, tail suspension tests, etc.) assessments. Additionally, a histological examination of the brain was carried out. In addition, the analysis of Boswellia serrata extract was performed by different analytical techniques, like UV spectrophotometer, FTIR, and HPLC methods. Results:: In the brain, succinate dehydrogenase is a mitochondrial enzyme irreversibly inhibited by 3-NP. Administration of 3-NP resulted in HD with altered behavioural and motor changes in rats. Treatment with Boswellia serrata resulted in remarkable protection of rats against 3-NP-induced behaviour and motor deficits in a dose-dependent manner. Moreover, in rats administered with 3-NP, Boswellia serrata improved memory performance and lowered levels of inflammatory biomarkers. These results have also been supported by histopathological analysis. Acetyl-11-keto-p-boswellic acid was found to be the main active component of Boswellia serrata extract. Conclusion:: Boswellia serrata at a dose of 180 mg/kg exhibited better protection compared to the other doses against HD induced by 3-NP. More detailed studies based on molecular targets are needed for the Boswellia serrata to transition from the bench to the bedside for use as an adjuvant in HD patients.

From the chokeberry fruit products and by-products to health-promoting effects through multifaceted in vitro bioactivity evaluation and molecular docking studies

BACKGROUND: Polyphenolic-rich chokeberry extracts and juice could provide health benefits in humans. Moreover, by-products after processing stand out as a potential new source of valuable compounds. OBJECTIVE: The research aimed to evaluate in vitro bioactivity of chokeberry fruit extract, juice, and waste extract (material remaining after juice processing) based on their chemical composition and molecular docking analysis. METHODS: Spectrophotometric methods were used to determine the phenolics, anthocyanins, flavonoids, and proanthocyanins content in freeze-dried samples. Additionally, individual anthocyanins, flavonoids, and sugars were identified through HPLC analysis. The antioxidant capacity was tested using two in vitro methods and assessing antimicrobial activity. The effects of tyrosinase and acetylcholinesterase inhibition were examined using spectrophotometric methods. Molecular docking analysis identified the interaction of chokeberry components with the active sites of these enzymes. RESULTS: The waste extract exhibited the most robust antioxidant activity within the DPPH system. While bactericidal activity was absent across all chokeberry preparations, they demonstrated inhibitory effects on specific microbiological strains relevant to the gastrointestinal tract. Results revealed the chokeberry products’ ability to inhibit tyrosinase and acetylcholinesterase. Molecular docking confirmed the strong interactions between chokeberry compounds and these enzymes. CONCLUSION: The results indicate the potential of chokeberry products and by-products as valuable resources for pharmaceutical applications.

First report of betalain production from endolichenic Bacillus sp. LDAB-1 from Dirinaria aegilita: Insights from novel quantification methodology of image processing.

Pigments are widely used in food supplements envisaging attractive colors along with health benefits. The desired advancements in the nutraceutical and antioxidant properties of pigments utilized in food products necessitate the search for novel additives. The present study is the first in the field to report the pigment-producing endolichenic bacteria, Bacillus sp. LDAB-1 from Dirinaria aegilita. Morphological, biochemical, and molecular characterization of the bacterium emphasizes that ideal pigment production occurs when utilizing sucrose and sodium nitrate. The pigment was salted out and dialyzed for further qualitative characterization using ultraviolet-visible, fluorescence, and Fourier transforminfraredspectra and the results corroborated the presence of betalains. The antioxidant activity of betalain is closer to the efficiency of α-tocopherol, which confers the pigment properties for antioxidant and nutraceutical significance. An optimal methodology for pigment affirmation is an issue when using an alternative methodology. Hence, the present assessment employs a comparative analysis of findings from both a spectrophotometric method and image processing technology encompassing RGB, CMYK, YCbCr, and L*a*b*color space models. Amongst these, the L*a*b* model potentially provides an effective modality for determining the pigment concentration. Bland-Altman plot analysis indicates similar consistency levels in betalain quantification by both methods at 95% confidence intervals, affirming the integrity and consistency of color image processing technology. Consequently, the present study represents novelty and innovativeness in reporting endolichenic Bacillus sp. LDAB-1 from D. aegilita and a rational image optimization protocol for pigment elucidation characteristics.

Chromatographic and Spectrophotometric Determination of Clindamycin in Pharmaceutical Products

Accurate, precise, and reliable chromatographic and spectrophotometric methods were developed for determining clindamycin (CLD) in pharmaceutical formulations. The spectrophotometric method was adopted for flow injection analysis (FIA). The method is based on the online oxidation of CLD and measuring the absorbance of the resulting product using a flow cell at 605 nm. Experimental conditions, including FIA variables and reaction conditions, were optimized. The chromatographic separation was achieved using a C8 column and an isocratic mobile phase. The composition of the mobile phase selected for the analysis consists of a mixture of phosphate buffer (50%), MeOH (35%), and ACN (15%), adjusted to a pH of 3.47 by phosphoric acid. The eluent was monitored with a UV detector at 205 nm. The linearity range was 10–200 and 50–800 µg/mL for the FIA and HPLC, respectively. The applicability of the FIA and HPLC methods was validated by analyzing CLD in synthetic and commercial pharmaceutical products. No significant interferences were observed from the common excipients usually used in commercial formulations.

Comparative evaluation of six commercial adult toothpaste formulations reveals cytotoxicity and altered functions in a human oral melanocyte model: an in vitro study.

This study aims to compare six commercial adult toothpaste (labeled as A, B, C, D, E, and F) for cytotoxicity and melanocyte function alterations in vitro using primary human epidermal melanocytes from a Caucasian donor (HEMn-LP cells) as a model of oral melanocytes. Cells were incubated with toothpaste extracts (50% w/v) in culture media at dilutions (1:25, 1:50, 1:100, 1:200, 1:500, 1:800, and 1:1000) for 24h. MTS and LDH assays were used to assess cytotoxicity. The effects of noncytotoxic toothpaste concentrations on melanocyte functional endpoints were then examined using spectrophotometric methods. All toothpaste showed concentration-dependent cytotoxicity that was heterogeneous across toothpaste containing SLS detergent. IC50 values of cytotoxicity followed the order: A = E > C > B > D > F. To compare toothpaste, they were tested at 1:800 and 1:1000 dilutions that were noncytotoxic after 24h. None of the toothpaste affected cellular melanin production. However, toothpaste A, C, and D suppressed tyrosinase activity at both dilutions, while toothpaste B suppressed tyrosinase activity only at 1:800 dilution. Toothpaste A, C, E, and F elevated ROS production at 1:800 dilution, with no change at 1:1000 dilution. Toothpaste has a heterogeneous effect on melanocytes. Toothpaste B, E, and F at 1:1000 dilution were the safest as they did not alter melanocyte functions at this dilution, although toothpaste F is the least cytotoxic of these. Future studies are necessary to expand these results in a physiological environment of oral tissue. The findings of this study provide novel insight into the biocompatibility studies of toothpaste on oral melanocytes. They can aid dental practitioners and consumers in selecting noncytotoxic toothpaste that do not contribute to ROS generation by melanocytes in the oral cavity or lead to cytotoxicity and impaired cellular function.

Two eco-friendly spectrophotometric methods for the concurrent estimation of diacerein and meloxicam: greenness and whiteness assessment

Two eco-friendly spectrophotometric methods for the concurrent estimation of diacerein and meloxicam: greenness and whiteness assessment

Continuous wavelet transform and integration of discrete wavelet transform with principal component analysis and fuzzy inference system for the simultaneous determination of ethinyl estradiol and drospirenone in combined oral contraceptives

In this study, the spectrophotometric method integrated with continuous wavelet transform (CWT) and coupled discrete wavelet transform (DWT) with fuzzy inference system (FIS) was developed for the simultaneous determination of ethinyl estradiol (EE) and drospirenone (DP) in combined oral contraceptives (COCs). The CWT approach was performed in the linearity range of 0.6–6 µg/mL for EE and 0.9 to 18 µg/mL for DP. Biorthogonal with an order of 1.3 (bior1.3) at a wavelength of 216 nm and Daubechies with an order of 2 (db2) at a wavelength of 278 nm were selected as the best wavelet families for obtaining the best zero crossing point for EE and DP, respectively. The limit of detection (LOD) of 0.7677 and 0.3222 µg/mL and the limit of quantification (LOQ) of 2.326 and 0.9765 µg/mL were obtained for EE and DP, respectively. The mean recovery of 103.24% and 99.77%, as well as root mean square error (RMSE) of 0.1896 and 0.1969, were found for EE and DP, respectively. In the DWT, the absorption of the mixtures was decomposed using different wavelets named db4, db2, Symlet2 (sym2), and bior1.3. Each of the wavelet outputs was dimension reduced by the principal component analysis (PCA) method and considered as FIS input. The wavelet of db4 with the coefficient of determination (R2) of 0.9979, RMSE of 0.0968, and mean recovery of 100.63% was chosen as the best one for the EE, while bior1.3 with R2 of 0.9955, RMSE of 0.4055, and mean recovery of 101.93% was selected for DP. These methods were successfully used to analyze the EE and DP simultaneously in tablet pharmaceutical formulation without any separation step. The suggested methods were compared with a reference method (HPLC) using analysis of variance (ANOVA) at a 95% confidence level, and no significant difference was observed in terms of accuracy. The suggested chemometric methods are reliable, rapid, and inexpensive, and can be used as an environmentally friendly alternative to HPLC for the simultaneous estimation of the mentioned drugs in commercial pharmaceutical products.

Xác định acetamiprid bằng phương pháp quang học sử dụng dung dịch nano vàng được ổn định bằng Polydiallyldimethylammoni clorua

On this research, the development of a simple, cost-efective and highly sensitive spectrophotometric method for acetamiprid detection based on the localized surface plasmon resonance of polydiallyldimethylammonium chloridestabilized gold nanoparticles. By naked eyes, one can detect acetamiprid by the visual change of gold solution color from red to purple, corresponding to the shift of maximum absorbance wavelength in the UV-Vis spectrum. Quantification of acetamiprid is possible through a linear relationship between the maximum absorbance wavelength and the acetamiprid concentrations in the range of 8×10-8 -2×10-6 M. Under the optimum conditions including pH 5, NaCl concentration of 0.02 M and incubation time 20 min, the present method has high precision (RSD < 5%), very low limit of detection (LOD) of 2.7×10-8 M, limit of quantification (LOQ) of 8.2×10-8 M. This method has been successfully applied to determine acetamiprid in several pesticide samples and vegetable samples. The measurement results of acetamiprid in the pesticide samples of the research method with the HPLC-UV method showed a difference of < 2%, while for the vegetable sample, the difference between the research method and the LC-MS/method method/ MS < 5% shows that the method has high accuracy and reliability.

The ameliorating effects of apigenin and chrysin alone and in combination on polycystic ovary syndrome induced by dehydroepiandrosterone in rats

Objective: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age and is one of the main causes of ovulation infertility, affecting 5-10% of women. Inflammation, hormonal imbalances, and disruption of the oxidant-antioxidant balance are the main factors in the pathophysiology of PCOS. This study was designed to answer the question of whether apigenin and chrysin have therapeutic effects on the dehydroepiandrosterone (DHEA)-induced rat model of PCOS. Materials and Methods: The experimental PCOS model was created by administering 6 mg/100g DHEA subcutaneously to 21-day-old female Wistar rats for 28 days, followed by treatment with natural agents 50 mg/kg apigenin and 50 mg/kg chrysin by oral gavage twice a week for one month. The predominant cell type was determined by microscopic analysis in vaginal smears daily from day 10 to day 28 of the experiment. In tissue supernatants, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activities, and malondialdehyde (MDA) levels were obtained by spectrophotometric method with appropriate manual methods; follicle-stimulating hormone (FSH), luteinizing hormone (LH), progesterone, interleukin (IL)-18, IL-1β, and IL-13 levels were determined by enzymelinked immunosorbent assay (ELISA) method. In addition, histological sections obtained from ovarian tissue samples were stained with hematoxylin-eosin and examined under a light microscope. Results: The results showed that treatment with apigenin and chrysin alone and in combination reduced MDA, LH, FSH, progesterone, IL-1β, IL-13, and IL-18 levels compared with PCOS rats. Furthermore, enzymatic activities of antioxidants including CAT, SOD, and GPx in the ovaries increased in therapeutic groups compared to the PCOS group. Conclusion: In conclusion, this study demonstrates the potential therapeutic efficacy of apigenin and chrysin, either alone or in combination, in alleviating the hormonal imbalances, inflammation, and oxidative stress in DHEA-induced PCOS rats. Apigenin, in particular, emerges as a promising agent for PCOS treatment, showing superiority over chrysin and combination treatments in ameliorating cystic follicles and improving various parameters associated with PCOS pathophysiology. These findings suggest that apigenin holds promise as a novel therapeutic agent for PCOS and warrants further investigation in clinical settings.

Detection of ciprofloxacin in ear drop using UV spectrophotometric method based on gold nanoparticles as a sensing probe

Detection of ciprofloxacin in ear drop using UV spectrophotometric method based on gold nanoparticles as a sensing probe

Revolutionizing Phenolic Content Determination in Vegetable Oils: A Cutting-Edge Approach Using Smartphone-Based Image Analysis.

This study addressed the need for a more accessible and efficient method of analyzing phenolic content in vegetable oils. The research aimed to develop a method that could be widely adopted by both researchers and industry professionals, ultimately revolutionizing the way phenolic content in vegetable oils is analyzed. This study developed a method of determining the total phenolic content (TPC) in vegetable oils using smartphone image analysis in the RGB color model. The method employed a gallic acid calibration solution and demonstrated exceptional determination coefficients for the RGB colors. The R-red color was selected as the basis for the analyses, and the method was statistically equivalent to standard UV/Vis spectrophotometry. The highest TPC was determined in hemp and olive oils, while the lowest was found in rice bran, grapeseed, and macadamia nut oils. This study concluded that smartphone image analysis, mainly using the R component of the RGB color model, was a superior alternative to traditional spectrophotometric methods for determining the TPC in vegetable oils. This innovative approach could revolutionize phenolic content analysis by providing researchers and industry professionals with a cost-effective, safe, and efficient tool. The estimated limit of detection (LOD) of 1.254 mg L-1 and limit of quantification (LOQ) of 3.801 mg L-1 further confirmed the reliability and comparability of the method. With these findings, it was expected that the method would be widely adopted in the future.

Comparison of Different Methods for Determining 5-hydroxymethylfurfural in Assessing the Quality of Honey from Greater Poland

This paper presents the results of testing the content of 5-hydroxymethylfurfural (HMF) in honey from Greater Poland. The production of honey from this area of Poland, its processing, and its consumption are closely related to the sustainable development of this region. It is created in the process of the production, storage, and transport of honey, especially during its thermal processing. Therefore, it can be an indicator in the analysis of sustainable development throughout the life cycle of honey and its products. The aim of this research was to determine the HMF content in Greater Poland’s honey available on the Polish market using three different methods and to compare the obtained results. The methodology used was as follows: two spectrophotometric methods (White and Winkler) and an HMF determination method based on the LC-MS/MS technique developed especially for this study. The determined HMF content in all tested honey samples did not exceed the applicable standard. The determined HMF values in all honey samples ranged from 0 to 28.5 mg HMF/kg honey. All results fell within the scope of European Council Directive 2001/110/EC of 20 December 2001, i.e., they did not exceed the HMF content in honey, which is 40 mg/kg. The results will encourage modifications to the universal honey testing procedures to be developed for the agri-food sector. In the study, seven honeys of different origins and types were selected; three HMF detection methods were selected; a comparative procedure was developed; and the content of the reference ingredient in honey was determined.

A Comprehensive Examination of UV-VIS Spectrophotometric Methods in Pharmaceutical Analysis Between 2015-2023.

Quality control is a system of validated procedures in which many samples, including active pharmaceutical ingredients and final products, are analyzed using standard or validated analytical methods. Analytical methods used in analyzing active pharmaceutical ingredients or final products in the pharmaceutical industry can be methods registered in pharmacopeias and developed by the company itself. For this reason, published papers related to pharmaceutical analysis attract analysts and researchers' attention. In this study, pharmaceutical analysis and bioanalysis studies carried out between 2015 and 2023 were examined using Google Scholar, and the recent trends were determined for pharmaceutical analysis. Among the published papers performing conventional analytical techniques for pharmaceutical analysis, those applying UV-VIS spectrophotometry method were selected to predict a future perspective in this study. In addition to the data obtained, the current situation of the pharmaceutical industry was considered to correlate with the obtained data for pharmaceutical analysis. The results were presented with comparative tables and summarizing graphs. Interpreting the results allowed us to determine the trends that pharmaceutical analysis studies will lead in the future. This study can be helpful for researchers working on pharmaceutical analysis in both the industry and academia to predict future trends in pharmaceutical analysis. As a result of the literature research covering the dates 2015-2023, 56% of UV-VIS Spectrophotometric methods are used on pharmaceutical dosage forms, 27% are bulk, 16% are pure, 2% are biological materials, and 0.4% are herbal. Made from materials. Of these studies, 28% were conducted in the 200-240 nm range, 27% were conducted in the 240-300 nm range, and only 44% were conducted at >300 nm. Interpreting the results allowed us to determine the trends that pharmaceutical analysis studies will lead in the future. This study can be helpful for researchers working on pharmaceutical analysis in both the industry and academy side to predict future trends for pharmaceutical analysis.

Comparative evaluation of dissolution profiles of the generic drug lamivudine 150 mg tablet marketed in Peru vs. the innovative Epivir.

Lamivudine is one of the most prescribed drugs in the world, and is used to treat human immunodeficiency and hepatitis B. This study aimed to evaluate the quality attributes and compare the dissolution profiles of two batches (A and B) of generic lamivudine 150 mg tablets with the innovator drug Epivir 150 mg tablets. We conducted an analytical, experimental, cross-sectional study, and used a spectrophotometric method at a wavelength of maximum absorption (λ) corresponding to 270 nm, to measure the percentage of dissolved drug. The study evaluated identification, content, dissolution and mass uniformity. Apparatus 2 USP (Paddle) 75 rpm, 900 mL of dissolution medium (37 ± 0.5 °C) was used in three dissolution media: pH 1.2; 4.5 and 6.8. Samples of 5 mL were obtained at 5, 10, 15, 20 and 30 min. Both batches of generic lamivudine (A and B) were found to have the same dissolution kinetic profile as the innovator drug. Both formulations met the criteria of very fast dissolving (85% dissolved in 15 min), and fast dissolving (85% dissolved in 30 min) drugs. Therefore, it was not necessary to calculate the similarity factor. We concluded that generic drugs A and B are in vitro equivalents to the innovator drug Epivir. Motivation for the study. To evaluate the quality of antiretroviral drugs used in the treatment of HIV dispensed in the HAART Program of the Ministry of Health of Peru. Main findings. Two batches of generic lamivudine drugs were found to achieve a dissolution rate greater than 85% at 15 min, being equivalent in vitro to the reference product Epivir. Implications. There is a need to apply the current regulations regarding equivalence between drugs by the regulatory authority prior to their authorization and to include dissolution profile tests as a requirement in public drug purchases, especially in national strategies (HIV, TB, etc.), in order to ensure quality products for the population.

Therapeutic effect of the solvent fraction of hexane leaf extract of Tapinanthus bangwensis (Engl. & K. Krause) (Loranthaceae) in alloxan-induced pathology in diabetic rats

Plant-based products are gradually replacing pharmaceuticals in treating ailments, including diabetes, due to their safety, cost-effectiveness, potency, and availability. Therefore, the current study looked into the therapeutic effect of the solvent fraction of hexane leaf extract of Tapinanthus bangwensis (HEXETACF) (Loranthaceae) in alloxan-induced pathology in diabetic rats. The biochemical parameters were estimated using analytical grade kits via spectrophotometric method. The laboratory rats were distributed into group W (five rats on feed and water), group X (seven rats + 150 mg/kg alloxan solution only), group Y (seven rats + 150 mg/kg alloxan solution + 200 mg/kg BW silymarin for 21 days), and group Z (seven rats + 150 mg/kg alloxan solution + 250 mg/kg BW HEXETACF for 21 days). The results showed that HEXETACF and silymarin (SILY) reduced blood glucose concentration by 33.77% and 34.80%, respectively, after the 21st day of treatment (p < 0.05). Additionally, alkaline phosphatase (ALP) and alanine aminotransferase (ALT) activity in SILY and HEXETACF were significantly decreased compared to the diabetic group (p < 0.05), but no significant decrease in aspartate aminotransferase (AST) activity was observed between the test samples and the diabetic group. Furthermore, the test samples lowered malondialdehyde (MDA) levels, by improving glutathione, superoxide dismutase (SOD), and catalase (CAT) activity. The HEXETACF and SILY significantly decreased triglyceride levels (TG) compared to the diabetic group at p < 0.05. They also reduced low-density lipoprotein (LDL) and cholesterol levels and increased the high-density lipoprotein levels compared to the diabetic group. Additionally, no significant decrease in serum electrolytes (Na+, K+, and Cl-), urea, and creatinine (including albumin and total protein) values was observed in HEXETACF and SILY, while hematological indices increased compared to the diabetic group. Histology results revealed that the test samples had normalized glomeruli, β-islet cells, and hepatocytes. However, a trace of mild congestion was noticed in the STDG. But edemic blood congestion was observed in the diabetic group. In conclusion, the current result demonstrated that HEXETACF may be a promising antidiabetic agent that could replace mSILY.

Development and Validation of UV-VIS Spectrophotometric Method for Estimation of Methylprednisolone from Dissolution Media

A simple, accurate UV-Spectrophotometric method has been developed using a dissolution media, 0.1% Tween 20 as a solvent to determine the Methylprednisolone. At a predetermined λmax of 245 nm, method was proved linear in the range of 5- 40 μg/ml with good correlation coefficient (R2= 0.998) and excellent recovery (between 98 and 101%). This method was successfully applied to the determination of methylprednisolone from dissolution media, 0.1% Tween 20 solution. This method can be employed for the dissolution study of methylprednisolone in injectable suspension.

Development And Validation of UV Spectrophotometric Method for The Estimation pf Amlodipine Besylate in Bulk and Dosage Form

A rapid, simple, accurate, and specific UV Spectrophotometric method has been developed for the determination of Amlodipine Besylate in bulk and dosage form. The spectrophotometric detection was carried out at an absorption maximum of 239 nm using dil. HCl as a solvent. The detector response for the Amlodipine Besylate was linear over the selected concentration range 4-20 µg/ml with a correlation coefficient of 0.999 and equation for the regression curve was found to be y= 0.109x + 0.006. These methods can be adopted in the routine assay analysis of Amlodipine Besylate API and pharmaceutical dosage form.

Development And Validation of UV-VIS Spectrophotometric Method for Determination of Triamcinolone from Dissolution Media

A simple, accurate UV-VIS Spectrophotometric method has been developed using a dissolution media, Tween 20 (0.15%) as a solvent to determine the Triamcinolone. At predetermined λmax of 240 nm, method was proved linear in the range of 10-50 µg/ml with good correlation coefficient (R2= 0.998) and excellent recovery (between 98 and 101%). This method was successfully applied to the determination of Triamcinolone from dissolution media, 0.15% Tween 20 aqueous solution. This method can be employed for the dissolution study of Triamcinolone in injectable suspension.

Oak Leaves as a Raw Material for the Production of Alcoholic Fermented Beverages.

This study aimed to point out the possible use of oak leaves (Q. petraea) in the production of fermented alcoholic beverages. Parameters such as antioxidant capacity, total phenolic content, phenolics and sugars were determined using spectrophotometric and chromatographic methods. pH values were also determined, and in the final product with a fermentation length of 85 days, the alcohol content was determined and sensory analysis performed. The antioxidant capacity of the beverage was lower compared to the infusions before fermentation, and its highest values were recorded in the leaf samples, in which the highest values of phenolic compounds and the total phenolic content were also recorded. A decrease in the content of total phenolics was recorded with the increasing length of fermentation in beverage samples. However, the fermentation process had a positive effect on the contents of some phenolic substances such as catechin, gallic acid and gallocatechin. Sensory analysis showed a higher acceptability of the fermented beverage without the addition of orange, which could be caused by the higher sugar content in these samples. Oak leaves therefore represent a suitable raw material for the production of a fermented alcoholic beverage, without the need to enrich the taste with other ingredients.

Trimeric and Tetrameric Cationic Styryl Dyes as Novel Fluorescence and CD Probes for ds-DNA and ds-RNA.

The wide use of mono- or bis-styryl fluorophores in biomedical applications prompted the presented design and study of a series of trimeric and tetrameric homo-analogues, styryl moieties arranged around a central aromatic core. The interactions with the most common biorelevant targets, ds-DNA and ds-RNA, were studied by a set of spectrophotometric methods (UV-VIS, fluorescence, circular dichroism, thermal denaturation). All studied dyes showed strong light absorption in the 350-420 nm range and strongly Stokes-shifted (+100-160 nm) emission with quantum yields (Φf) up to 0.57, whereby the mentioned properties were finely tuned by the type of the terminal cationic substituent and number of styryl components (tetramers being red-shifted in respect to trimers). All studied dyes strongly interacted with ds-DNA and ds-RNA with 1-10 nM-1 affinity, with dye emission being strongly quenched. The tetrameric analogues did not show any particular selectivity between ds-DNA or ds-RNA due to large size and consequent partial, non-selective insertion into DNA/RNA grooves. However, smaller trimeric styryl series showed size-dependent selective stabilization of ds-DNA vs. ds-RNA against thermal denaturation and highly selective or even specific recognition of several particular ds-DNA or ds-RNA structures by induced circular dichroism (ICD) bands. The chiral (ICD) selectivity was controlled by the size of a terminal cationic substituent. All dyes entered efficiently live human cells with negligible cytotoxic activity. Further prospects in the transfer of ICD-based selectivity into fluorescence-chiral methods (FDCD and CPL) is proposed, along with the development of new analogues with red-shifted absorbance properties.