UV-Vis Spectrophotometric Method Research Articles

Tea (Camellia sinensis) cultivated in three agro-ecological regions of Bangladesh: Unveiling the variability of methylxanthine, bioactive phenolic compound, and antioxidant activity

Tea (Camellia sinensis) is a widely consumed beverage known for its numerous health benefits, largely attributed to its rich content of quality determining secondary metabolites such as methylxanthine compounds and bioactive phenolic compounds. The goal of this study was to find out variations of the levels of methylxanthines, bioactive phenolic compounds, and antioxidant activity in methanolic and hot water extracts of 129 tea samples grown in three different ecological regions of Bangladesh named Panchagar, Sylhet, and Chattogram. Methylxanthine and bioactive phenolic compounds were determined by using HPLC-DAD, and the antioxidant profile was analysed by UV–vis spectrophotometric methods for methanol and hot water extracts of tea leaves. The IC50 values showed the trend as Panchagar > Sylhet > Chattogram and Sylhet > Chattogram > Panchagar for water and methanol extract, respectively. The results revealed significant (p < 0.05) variations in the levels of methylxanthines content: Panchagar > Chattogram > Sylhet. Caffeine was significantly higher (103.02 ± 5.55 mg/g of dry extract) in the methanolic extract of tea leaves of Panchagar district and lower (53.33 ± 4.30 mg/g of dry extract) in the hot water extract of Sylhet district. Panchagar and Chattogram possessed significantly (p < 0.05) higher catechin content for methanol (57.01 ± 5.50 mg/g dry extract) and hot water (55.23 ± 4.11 mg/g dry extract) extracts, respectively. The utilization of canonical discriminant functions yielded highly favorable outcomes in the classification of tea from three distinct cultivation origins in Bangladesh, relying on their inherent features. This study demonstrated the potential effects of geographical variations on the bioactive compounds and antioxidant properties of tea, emphasizing the importance of regional differences in tea cultivation for optimizing its health benefits as well as dispersing tea cultivation across the country.

PENGARUH KONSENTRASI PELARUT TERHADAP AKTIVITAS ANTIOKSIDAN SEDIAAN SERUM EKSTRAK KULIT BUAH NAGA MERAH (Hylocereus Polyrhizus)

The skin of red dragon fruit (Hylocereus Polyrhizus) contains active substances that are useful for extracting in making natural serums. Antioxidants, one of the important compounds in serum that can protect the skin and capture free radicals. This study aims to prove the presence of antioxidants in serum made from red dragon fruit peel extract, and to compare the effect of using 70% and 96% ethanol solvents on the physical properties and antioxidant activity of the serum. The extraction method used was maceration extraction, by testing the flavonoid content and free ethanol content in the extract. The physical properties of the serum were tested including organoleptics, pH, homogeneity, viscosity, spreadability and stickiness. Meanwhile, antioxidant activity was tested using the UV-VIS spectrophotometric method. The research results show that red dragon fruit peel extract contains flavonoids with orange and red colors, and does not have an ester odor. Serum preparations from 70% and 96% ethanol extracts have semisolid form, characteristic odor, color differences, pH 5, homogeneous, with viscosities of 464 cPs and 341 cPs respectively. The spreadability of the serum is 7.1 cm and 9.7 cm, while the adhesive power is 0.88 and 0.93. The serum antioxidant activity of 70% and 96% ethanol extracts was 39.59 µg/mL and 45.87 µg/mL. The 70% ethanol extract serum meets the standard physical properties of serum and has stronger antioxidant activity compared to the 96% ethanol extract serum, indicated by the lower IC50 value. Flavonoids, as antioxidant compounds, have various types and different polarities depending on the position and number of hydroxyl groups.

Determination of Catechin Content in Green and Black Tea (Camellia sinensis L.) by UV-Vis Spectrophotometric Method

Tea is one of the most commonly consumed beverages around the world. The chemical compounds contained in tea have a good effect on health because they contain polyphenolic compounds, catechins. This study examined the catechin compound content of black tea and green tea from Karanganyar (A) and Malang (B). This research aims to determine the differences in catechin levels in black and green tea types in Malang, East Java, and Karanganyar, Central Java plantations. The research method used was experimental. Identification of catechin content was done using UV-Vis Spectrophotometry method. Tea is extracted by brewing, 4 grams of green tea is brewed using distilled water for 6 minutes, while 5.6 grams of black tea is brewed using distilled water for 10 minutes with the comparison used is pure catechin solution. The results obtained for green tea Karanganyar (A) had a catechin content of 3.61±0.083%, green tea Malang (B) had a level of 2.97±0.037%, black tea Karanganyar (A) had a level of 3.14±0.065%, and black tea Malang (B) had a level of 1.60±0.009%. It is concluded that the catechin content of green tea is higher than black tea, and of the two samples, the high catechin content comes from Karanganyar (A). Keywords: catechins, green tea, black tea, malang, karanganyar

Smartphone-Based Spectrophotometer for Facile and Fast Determination of Lipid Peroxidation in Local Fried Food

During lipid peroxidation in foods, deterioration rancidity occurred, and a toxic by-product also accumulated. The well-known marker of lipid peroxidation in food is malondialdehyde (MDA), suspected to be carcinogenic and mutagenic in humans. MDA level is determined using thiobarbituric acid (TBA) assay. The pink color of the MDA-TBA2 complex after the reaction can be measured spectrophotometrically at 530-540 nm. Several analytical methods, including smartphone-based methods, have been used to determine the MDA-TBA2 complex, such as UV-Vis spectrophotometry and HPLC-DAD. Therefore, this research aimed to determine lipid peroxidation in fried food using a simple smartphone-based spectrophotometer. The device was established using a paper box, LED lamps, and a test tube. Various concentrations of MDA were reacted with TBA reagent and then submitted to the device. RGB intensity data were converted to absorbance values and used to construct linear regression. Results showed that the G value from the smartphone-based spectrophotometer provided consistent results with R2 of 0.9869, including 0.93 and 95.17% precision and accuracy, respectively. Then, the developed device was finally used to determine the MDA in local fried food samples. The concentration of MDA in fried foods was successfully determined with high precision (0.96) and accuracy (88.33 %) compared to the traditional UV-Vis spectrophotometric method. Thus, this study provides a practical guideline for developing quick and easy accessibility, portability, and low-cost spectrophotometer for lipid peroxidation assessment in fried food and other future food matrices.

DETERMINATION OF FLAVONOID CAPACITY BY USING ETHANOL EXTRACT OF CIPLUKAN LEAVES (Physalis angulata L.) USING UV-VIS SPECTROFOTOMETRY METHODS

Ciplukan leaves (Physalis angulata L.) have a composition of main phytochemical compounds including alkoloids, phenolics, tannins, flavonoids that can function as antioxidants, antibacterial, antiviral, anti-inflammatory, antiallergic, and anticancer. The purpose of this study was to identify and determine the levels of flavonoid compounds contained in the Ethanol Extract of Ciplukan Leaf (Physalis angulata L.) Ethanol extraction of Ciplukan Leaves (Physalis angulata L.) was carried out using the maceration method using 96% ethanol solvent, a flavonoid identification test was carried out on the Ethanol Extract of Ciplukan Leaves with the addition of Mg metal powder, concentrated HCI, and 10% NaOH, then determining Flavonoid levels using the UV-Vis spectrophotometric method using Quercetin as a comparative raw material. A qualitative test of Ethanol Extraction of Ciplukan Leaves (Physalis angulata L.) containing flavonoids has been carried out. Determination of flavonoid levels using UV-vis spectrophotometry obtained 0.0235%.

Usability of simplified UV–Vis spectrophotometric methods for the determination of nitrate in the presence of organic matter and chloride as interfering factors

Abstract The presence of nitrate in groundwater and surface water in concentrations above levels suitable for human consumption is an increasingly common problem. This is mainly due to human activity, such as the excessive use of fertilizers and the inadequate deactivation of pits. Water analysis laboratories very often carry out analyses to determine nitrate to control the presence of this anion in water intended for human consumption. One of the most commonly used methods is spectrophotometry, both with commercially available kits and by direct measurement of specific wavelengths. However, in these methods, the presence of organic matter and chloride can influence the results obtained. Thus, in this study, the applicability of the simplification (without acidification) of two methods for the determination of nitrate in water by ultraviolet–visible absorbance was verified in the presence of the above-mentioned interfering factors, and it was found that the absorbance method at 220 nm corrected for the absorbance at 275 nm, in its simplified form without acidification, can be used with concentrations of organic matter of 20 mg L−1 for high nitrate concentrations (10 mg L−1 NO3-N).

Heterometallic bridged Pt(II)‐Zn(II) complexes: Influence of the substituent in 4′‐position in inert terpy ligand on antigenotoxicity, potential antitumor activity and mechanism of interactions of the complexes with biomolecules

The synthesis and characterization of novel hetrometallic complexes [{cis‐PtCl(NH3)2(μ‐4,4′‐bipyridyl)ZnCl(terpy‐Cl)}](ClO4)2 (C1a), [{trans‐PtCl(NH3)2(μ‐4,4′‐bipyridyl)ZnCl(terpy)}](ClO4)2 (C2a), [{cis‐PtCl(NH3)2(μ‐pyrazine)ZnCl(terpy‐Cl)}](ClO4)2 (C3a) and [{trans‐PtCl(NH3)2(μ‐pyrazine)ZnCl(terpy‐Cl)}](ClO4)2 (C4a) (where terpy‐Cl = 4′‐chloro‐2,2′:6′,2′′‐terpyridine) was done. Acid–base titrations were performed by UV–Vis spectrophotometric method to evaluate the pKa values of corresponding aqua complexes. Interactions between complexes and important biomolecules, guanosine‐5′‐monophosphate (5′‐GMP) and glutathione (GSH) were examined by 1H NMR spectroscopy. The chloride substituent at the 4′ position on the middle pyridine ring of terpyridine ligand significantly affects the coordination of biomolecules, as well as overall stability of complexes. The complexes were evaluated in vitro for the antioxidant prevention of DNA damages. All tested novel complexes demonstrated a significant reduction in DNA damage against oxidative modifications of DNA caused by the hydroxyl and peroxyl radicals. Also, cytotoxicity evaluation showed that significant cytotoxicity occurs only after long‐term effect of C1a, C2a and C3a, complexes in HCT‐116 cells. Molecular docking studies predict results in agreement with experimental research.

Determination of Total Phenolic Content and Total Flavonoid Content of Nutmeg Flesh (Myristica Fragrans Houtt) Ethanol Extract from South Aceh Province

The nutmeg plant (Myristica fragrans Houtt) is often used as a medicinal ingredient and has medicinal efficacy. Nutmeg samples were obtained from South Aceh district, which is the main commodity obtained in the area. This study aims to measure the total phenolic content (TPC) and total flavonoid content (TFC) of the ethanol extract of nutmeg flesh. The dried nutmeg flesh was extracted (maceration) using an ethanol solvent, and the extract weight was 18.35%. The TPC and TFC analysis use the UV-visible spectrophotometer method and are measured at wavelengths of 759 nm and 495 nm, respectively. Gallic acid standards were used to measure total phenolic levels and quercetin standards to measure total flavonoid levels. Data of linearity, R square (R2), LoD, and LoQ were also calculated for each standard. The TPC and TFC contents in the ethanol extract of nutmeg flesh were found to be 76.972 ± 0.97 mg GAE/g and 15.625 ± 0.26 mg QE/g respectively. The presence of phenolic compounds and flavonoids shows that the ethanol extract of nutmeg flesh has high value metabolites that show good biological activity.

Identification of Chlorogenic Acid, Caffeine, Melanoidin, Sucrose, and Protein Content of Local Indonesia Arabica Coffee Base on Its Cupping and Variety Variation

The increased demand for high-quality coffee led to the need to evaluate coffee quality for market acceptance. Indonesia has Arabica, which has the potential for high selling value. Arabica coffee varieties, including Ateng, Lini S, and Sigararutang, affect the content of compounds in coffee beans, such as chlorogenic acid, caffeine, melanoidin, sucrose, and protein. The objective of this study was to analyze the impact of Arabica coffee varieties on the compound composition and flavor characteristics of coffee. The UV-Vis spectrophotometric methods were used to determine the quantity of chlorogenic acid, caffeine, melanoidin, sucrose, and protein in different Arabica coffee varietals. The study revealed that the content of these compounds differed among the varieties. The Lini S variety had the highest chlorogenic acid and caffeine content, while the Ateng variety had the highest melanoidin, sucrose, and protein content. The varying levels of chlorogenic acid and caffeine in coffee significantly impact its flavor, resulting in a unique sour and bitter taste in coffee brew. Melanoidin, a high-molecular-weight brown compound, contributes to the malty flavor of coffee, along with sweet, nutty, caramel, and spice notes. Sucrose adds a sweet hint to coffee brew, while protein has a relatively minimal influence on coffee flavor.

ACTIVITY TEST OF BRACTEA BOUGAINVILLEA SPECTABILIS WILLD SOLAR SCREEN CREAM EXTRACT IN WAY IN VITRO AND IN VIVO

Excessive radiation exposure to the skin can cause erythema and pigmentation on the skin. Bougainvillea spectabilis Willd\'s ethanol extract contains bioactive compounds that have medicinal properties, such as phenolic compounds and flavonoids which have conjugated double bonds which are able to specifically absorb UV radiation so they can be applied chemical absorber. This study aims to test the sunscreen activity of the ethanol extract of Bougainvillea spectabilis Willd bractea in vitro using the UV-Visible spectrophotometric method which is determined by calculating the % Transmission value of erythema (% Te), the value of % Transmission pigmentation (% Tp), and the value Sun Protection Factor (SPF). As well as regular testing alive by observing the effect of erythema on the skin of white mice (Rattus norvegicus) which is irradiated with UV light. Analysis results in vitro showed that Willd\'s Bougainvillea spectabilis ethanol extract cream was able to provide sunscreen activity with concentrations of 1.5%, 1.0%, 0.5% with SPF values respectively 21.22 (ultra protection); 16.69 (ultra protection) and 12.48 (maximum protection) compared to the Para amino benzoic acid (PABA) control 6.95 (extra protection), with a percent erythema (% Te) concentration value of 1.5%, 1.0% , 0.5% with consecutive values of 6.85 (standard suntan); 7.26 (standard suntan) and 10.42 (fast tanning) compared to control cream Para amino benzoic acid (PABA) 28.15 (fast tanning), with a percent pigmentation value (% Tp) concentration of 1.5%, 1.0 %, 0.5% with consecutive values of 7.29 (sunblock); 7.56 (sunblock) and 11.62 (sunblock) compared to the Para amino benzoic acid (PABA) control, namely 60.10 (extra protection). Then on to testing alive using one-way ANOVA analysis, it was found that Bougainvillea spectabilis Willd bractea ethanol extract was able to inhibit the emergence of erythema in test animals significantly (p&lt;0.05) in all treatment groups, with the diameter of erythema formed at concentrations of 1.5%, 1.0% , 0.5% produces an erythema score of 1, which means very little erythema is produced.

UV-Vis spectrophotometric determination of rare earth elements (REE) speciation at near-neutral to alkaline pH. Part I: m-cresol purple properties from 25-75 °C and Er hydrolysis.

The speciation and mobility of rare earth elements (REE) strongly depends on pH, which controls the formation of charged aqueous hydroxyl species. The latter potentially play an important role in controlling heavy REE adsorption on clay minerals in near-neutral to alkaline waters such as in regolith-hosted REE mineral deposits. However, accurate REE hydrolysis constants are needed for developing geochemical models that can predict the role of these charged species in natural systems. Here, we develop a robust experimental UV-Vis spectrophotometric method using m-cresol purple to determine in situ pH from 25 to 75 °C. This method is used to derive the average ligand number and hydrolysis constants of erbium (Er) at 25 °C in aqueous solutions with low ionic strength (≤0.001 mol L-1) at pH from ∼7 to 9.5 and in the presence of Er concentrations from 0 to 0.057 mM. The average ligand number ranges between 1 and 3 indicating that Er(OH)2+, Er(OH)2+ and Er(OH)03 control speciation in the experiments. The logarithm of the Er hydrolysis constants (, n = 1 to 3) derived at infinite dilution for the reaction Er3+ + nH2O = Er(OH)n3-n + nH+ are: , , . Implementation of these experimental data into a geochemical model indicates that the Er(OH)2+ and Er(OH)03 species are both stable in a much wider pH range than previously predicted. Consequently, the positively charged REE hydroxyl complexes can potentially control the fractionation of light vs. heavy REE via adsorption as observed in the formation of certain regolith-hosted REE deposits.

Validasi Metode Analisis Iodin Secara Spektrofotometri UV-Vis pada Dua Variasi Pelarut

In this study, the method of analysis of iodine by UV-Vis spectrophotometry was validated. Two other solvents, ethanol, and cyclohexane were used to validate this approach. The UV-Vis Spectrophotometer method's linearity, detection, and quantization limitations, precision, and accuracy were investigated as variables. The results of the linearity tests indicated that the method was proportionally verified because the r values for the two iodine solutions in ethanol and cyclohexane varied between 0.990 and 0.999, respectively. This suggests that the values were higher than 0.99. The LOD values for the ethanol solvent were 4.441 mg/kg and the LOQ was 14.802 mg/kg, whereas the cyclohexane solvent had an LOD value of 2.660 mg/kg and the LOQ was 8.866 mg/kg. According to the required precision acceptance, the %RSD value of 2%, precision values for both standard iodine solutions with two modifications of solvents demonstrated good results. Recovery percentages of ethanol solvents are 96% and cyclohexane solvents are 86%, respectively, according to accuracy measurements. The combined uncertainty value for this test is 0.109 for the ethanol solvent and 0.019 for the cyclohexane solvent, respectively. This research provides a comprehensive understanding of the validity of the iodine analysis method, establishing a robust foundation for the sustainability and reliability of using UV-Vis spectrophotometer in the analysis

PENENTUAN KADAR NITROGEN DIOKSIDA (NO2) DALAM UDARA AMBIEN DENGAN METODE GRIESS SALTZMAN MENGGUNAKAN SPEKTROFOTOMETER

Nitrogen dioxide (NO2) contributes greatly as a precursor to a number of harmful secondary air pollutants including nitric acid, the nitrate portion of secondary inorganic aerosols and oxidants including ozone. Nitrogen dioxide gas (NO2) is an ambient air pollutant along with the element nitrogen monoxide (NO) which is usually produced from human activities such as burning vehicle engine fuel, burning rubbish, burning coal and industry. This research aims to monitor the quality of air pollution in industrial areas in East Jakarta. The NO2 content in the air can be determined using the UV-Vis spectrophotometer method based on SNI 7119-2: 2017. The principle of NO2 testing uses a UV-Vis spectrophotometer based on SNI 7119-2: 2017. From the results of the tests carried out, it can be concluded that the NO2 level obtained in sample 1 was found to be 25,153 µg/Nm3, in sample 2 the NO2 level was 28,371 µg/Nm3, in sample 3 the NO2 level was 107,022 µg/Nm3, in sample 4 the NO2 level was 29,720 µg/Nm3. Nm3, and in sample 5 the NO2 level was 83.446 µg/Nm3. Based on PP RI No. 22 attachment VII of 2021 concerning air pollution control, the quality standard for NO2 is 200 µg/Nm3 for 1 hour. So it can be concluded from the results of the tests that have been carried out that the NO2 levels in the environment are still below the quality standard, which means that it is not a source of NO2 pollution, is safe and meets the requirements for human health and the environment.

The Effect of Extraction Method on Total Flavonoid Content of Ageratum conyzoides Ethanol Extract

This research is a type of comparative research using a quantitative approach. The study population was the population of Bandotan plants in the Kudus and Jepara regions. The organ parts taken from the plant were leaves, while the stems, roots and flowers were not extracted in this study. The extraction method used maceration and soxhletation with 96% ethanol solvent. Furthermore, to determine the total flavonoid content of &lt;em&gt;Ageratum conyzoides &lt;/em&gt;leaf extraction results using the UV Vis Spectrophotometric method, it is known that &lt;em&gt;Ageratum conyzoides &lt;/em&gt;leaf extract using the Soxhletation method has a higher total flavonoid content (0.32% b/v) compared to the Maceration method (0.22% b/v). The results of the total flavonoid test were then analyzed using the &lt;em&gt;Mann Whitney U Test. &lt;/em&gt;Based on the &lt;em&gt;Mann Whitney U Test &lt;/em&gt;shows that the value of Asymp. Sig. (2- tailed) of 0.102 &amp;gt; 0.05. Therefore, it can be concluded that there is no significant difference between maceration and soxhletation extraction methods on total flavonoids of &lt;em&gt;Ageratum conyzoides &lt;/em&gt;extract.

Complex-Forming Properties of the Anti-Inflammatory Sialorphin Derivative Palmitic Acid-Lysine-Lysine-Glutamine-Histidine-Asparagine-Proline-Arginine with Cu(II) Ions in an Aqueous Solution.

The present work describes the complexation of the anti-inflammatory sialorphin derivative Pal-Lys-Lys-Gln-His-Asn-Pro-Arg (palmitic acid-lysine-lysine-glutamine-histidine-asparagine-proline-arginine) with Cu(II) ions in an aqueous solution, at a temperature of 25.0 ± 0.1 °C, over the whole pH range. The complexing properties were characterized by potentiometric and UV-Vis spectrophotometric methods. The potentiometric method was used to calculate the logarithms of the overall stability constants (log β) and the values of the stepwise dissociation constants (pKa) of the studied complexes. The percentage of each species formed in an aqueous solution was estimated from the species distribution curve as a function of pH. The absorbance (A) and molar absorption coefficient (ε) values for the Cu(II)-sialorphin derivative system were determined with UV-Vis spectroscopy. Our studies indicate that the sialorphin derivative forms stable complexes with Cu(II) ions, which may lead to future biological and therapeutic applications.

The Effect of Different Extraction Methods on Total Tannin Content of Methanol Extract of Simpur Air Leaves (Dillenia suffruticosa)

The use of metal mordants in fabric dyeing can harm the environment and health, so it is necessary to look for natural mordants that are more environmentally friendly. The utilization of Simpur Air leaves (Dillenia suffruticosa) as a biomordant is one of the efforts to produce a more environmentally friendly tannin mordant. D. suffruticosa has been reported to contain tannin compounds in all parts of the plant. However, scientific evidence of differences in the total tannin content of methanol extracts of D. suffruticosa leaves with various extraction methods have not been found so far. This study aims to determine the effect of different extraction methods on the yield value and total tannin content of methanol extracts of D.suffruticosa leaves using UV-Vis spectrophotometric method at a wavelength of 755.8 nm with Folin Ciocalteau reagent. D. suffruticosa leaves are extracted by using three methods, namely maceration, soxhletation and reflux. Tannic acid is used as a comparator. The results show that the yield value of D. suffruticosa leaves extracted by maceration, soxhletation and reflux methods were 8.35%; 12.26%; and 25.24%, respectively. The total tannin content of methanol extract of D. suffruticosa leaves with maceration method is 0.15% ± 0.007; soxhletation is 0.18% ± 0.007 and reflux is 0.21% ± 0.016. Based on the results of the data analysis, the significance value &lt;0.05 was obtained. It can be concluded that the extraction method affects the yield value and total tannin content of methanol extract of D. suffruticosa leaves.

Application of validated UV spectrophotometric and colorimetric method to quantify minoxidil in the development of trilayer dissolving microneedle: Proof of concept in ex vivo and in vivo studies in rats

Alopecia areata (AA) is an autoimmune-induced hair loss condition, by utilizing MNX, a hair growth-promoting compound. However, minoxidil (MNX) administration's efficacy is hindered by low bioavailability and adverse effects. To enhance its delivery, Trilayer Dissolving Microneedles (TDMN) are introduced, enabling controlled drug release. The study's primary was to establish a validated UV-Vis Spectrophotometer method for Minoxidil analysis in rat skin affected by alopecia areata. This method adheres to International Conference Harmonization (ICH) and FDA guidelines, encompassing accuracy, precision, linearity, quantification limit (QL), and detection limit (DL). The validation method was conducted through two approaches, namely UV region validation using PBS and the colorimetric method in the visible region (Vis). The validated approach is then employed for assessing in vitro release, ex vivo permeation, and in vivo pharmacokinetics. Results indicate superior MNX extraction recovery using methanol compared to acetonitrile. Method C (5mL methanol) is optimal, offering high recovery with minimal solvent usage. Precision assessments demonstrate %RSD values within MNX guidelines (≤15%), affirming accuracy and reproducibility. UV-Vis spectroscopy quantifies MNX integration into TDMN, using PVA-PVP, with concentrations aligning with ICH standards (95% to 105%). In conclusion, TDMN holds promise for enhancing MNX delivery, mitigating bioavailability and side effect challenges. The validated UV-Vis Spectrophotometer method effectively analyzes MNX in skin tissues, providing insights into AA treatment and establishing a robust analytical foundation for future studies.

Perbandingan Flavonoid Total Ekstrak Sirih Cina (Peperomia pellucida L. Kunth) dengan Variasi Konsentrasi Etanol Menggunakan Spektrofotometri UV-Vis

Chinese betel can be used to lower cholesterol, heal broken bones, rheumatoid arthritis, anti-fungal medication, gout, protect the digestive system, treat urinary tract disorders and so on. Chinese betel plants contain active compounds such as terpenoids, flavonoids, alkaloids, saponins and phenols. Flavonoids are natural chemicals found in plants. Flavonoids also have antioxidant properties to reduce the effects of free radicals. The research aims to determine the total flavonoid content of Chinese betel extract with variations of 70%, 80% and 96% ethanol using the UV-Vis spectrophotometric method. This method was carried out by quantitative analysis of the total flavonoid content of Chinese betel ethanol extract using UV-Vis spectrophotometry and qualitative analysis using concentrated Mg and HCL powder. The material used is Chinese betel extract (Peperomia pellucida) obtained from Jembrana district, Bali province. Other materials used are 70% ethanol, 80% ethanol, 96% ethanol and ethanol p.a., sodium acetate, distilled water, AlCl3, quercetin, Mg powder and concentrated HCL. The results of testing the total flavonoid content in Chinese betel ethanol extract varied in concentration of 70%, namely containing flavonoids of 2.78576 g/100g EQ, 80% ethanol Chinese betel extract containing flavonoids of 5.132503 g/100g EQ, and Chinese betel ethanol extract 96 % contains flavonoids of 6.77682 g/100g EQ. The highest flavonoid content results were obtained by the 96% ethanol concentration extract because 96% ethanol has polar properties so it can attract flavonoid compounds well. Qualitative analysis of flavonoids showed positive results with the formation of a brownish red color.

In vitro biodistribution studies on clinically approved FGFR inhibitors ponatinib, nintedanib, erlotinib and the investigational inhibitor KP2692

Binding towards human serum albumin (HSA) and α1-acid glycoprotein (AGP) of three approved fibroblast growth factor receptor (FGFR) inhibitors ponatinib (PON), nintedanib (NIN) and erdafitinib (ERD), as well as the experimental drug KP2692 was studied by means of spectrofluorometric and UV–visible spectrophotometric methods. Additionally, proton dissociation processes, lipophilicity, and fluorescence properties of these four molecules were investigated in detail. The FGFR inhibitors were predominantly presented in their single protonated form (HL+) at pH 7.4 (at blood pH). At gastric pH (pH 1–2) the protonated forms (+1 – +3) are present, which provide relatively good aqueous solubility of the drugs. All of the four inhibitors are highly or extremely lipophilic at pH 7.4 (logD7.4 ≥ 2.7). At acidic pH 2.0 PON and ERD are rather lipophilic, NIN is amphiphilic, while KP2692 is highly hydrophilic. All four compounds bind to HSA and AGP. Moderate binding of PON, KP2692 and NIN was found towards albumin (logK’ = 4.5–4.7), while their affinity for AGP was about one order of magnitude higher (logK’ = 5.2–5.7). ERD shows a larger affinity for both proteins (logK’HSA ≈ 5.2, logK’AGP ≈ 7.0). The computed constants were used to model the distribution of the FGFR inhibitors in blood plasma under physiological and pathological (acute phase) conditions. The changing levels of the two proteins under pathological conditions compensate each other for PON and NIN, so that the free drug fractions do not change considerably. In the case of ERD the higher AGP levels distinctly reduce the free available fraction of the drug. Comparison with clinical pharmacokinetic data indicates that the here presented solution distribution studies can very well predict the conditions in cancer patients.

Studies on the Sonochemical assisted Oxidation Reaction of Potassium Iodide for Iodine Release using Ultrasound

Ultrasound (US) application and sonochemical reactions in various environmental processes are gaining importance. In this regard, liberation of iodine obtained through oxidation of potassium iodide (KI) using US has been studied in the present work. This method finds wide application of oxidation process in various applications such as unit process reactions, synthetic chemistry as well as waste remediation. Process parameters such as time and ultrasound power have been investigated. Liberation of iodine from the reaction system has been analyzed using UV-Visible spectrophotometric method through iodometry. Maximum liberation of iodine was obtained using ultrasound (25 W, 20 kHz) for 30 minutes treatment with 10 ml of 16.6% KI solution. The study finds potential use in sonochemical based oxidation reactions and environmental processes.