352 research outputs found
Analisis Adduct DNA Setelah Pemberian Natrium Nitrit Dan Dimetilamin Secara Berulang Pada Tikus
Nitrosodimethylamine is a carcinogenic compound which can be formed from the reaction of nitrite and dimethylamine that is found in food. Nitrosodimethylamineis activated in liver and alkylates the DNA base and producing a DNA adductssuch as O6-methylguanine and N7-methylguanine that have a role incarcinogenesis. In this research, DNA was isolated from rat’s blood which waspreviously given nitrosodimethylamine’s precursor, sodium nitrite anddimethylamine. DNA adducts can be obtained from hydrolysis in hydrochloricacid 0.1 N for 30 minutes at 7000C. Then the adducts were analyzed using High Performance Liquid Chromatography (HPLC), with a strong cation exchangecolumn (Supelcosil LC-SCX, 5 μm, 250 x 4.6 mm), mobile phase consisting ofammonium phosphate with a final concentration of 40 mM, pH 3.00, flow rate 1.5mL/minute, column temperature 30oC and detected at exitation wavelength 286 nm and emission wavelength 366 nm. This method gave an acceptable validation result according to accuracy and precicion test results that fulfill the requirementand linear calibration curve with a quantitation limit of 22,5403 ng/mL. Rats were divided into six groups that two groups were given nitrosodimethylamine aspositive control, three groups were given prekursor, and the other was normalcontrol.Blood samples were collected in 1,2 and 4 hour after last induced. Aftergiving sodium nitrite 110 mg/kg bw and dimethylamine (1:5) orally for a week,N7-methylguanine and O6-methylguanine had not been detected in rat’s blood
DETERMINATION OF SIBUTRAMINE ADULTERATED IN HERBAL SLIMMING PRODUCTS USING TLC DENSITOMETRIC METHOD
Determination of sibutramine adulterated in herbal slimming product using thin layer chromatography (TLC) densitometric method with TLC silica gel 60 F254 aluminium plate as stationary phase and mixture of toluen-diethylamine (10:0.3) as mobile phase has been developed. The calibration curve in the concentration range of 0.50 to 5.00 µg/spot showed good linier relationship (r2 = 0.9986). The limit of detection and quantitation (LOD and LOQ) were 217.5 ng and 724.9 ng/spot, respectively. The method gave satisfactory specificity, linierity, precision and accuracy validation criteria and was applied for determination of sibutramine in herbal slimming products obtained from several drugstrores in Depok City, West Java, Indonesia. Results of the determination showed that six of seven samples analyzed were detected containing sibutramine HCl with the concentration of 2.45 - 26.24 mg in a single dosage of slimming herbal product
PREPARATION AND CHARACTERIZATION OF POROUS HYDROXYAPATITE AND ALGINATE COMPOSITE SCAFFOLDS FOR BONE TISSUE ENGINEERING
Objective: To prepare and characterize composite scaffolds of a hydroxyapatite (HA) and an alginate having high viscosity.Materials and Methods: HA powder was synthesized using wet chemical precipitation, the alginate powder was extracted from the Sargassum duplicatum seaweed, and the HA/alginate composite scaffolds were prepared by freeze-drying. X-ray diffraction and Fourier transform infrared techniques were utilized to characterize the HA and alginate, and electron microscopy was used to evaluate the HA and the HA/alginate composite scaffolds. The HA/alginate composite scaffold obtained from the commercially available HA and alginate powders were employed as a comparison.Results: Synthesized HAs were identified as the HA phase, which contained absorbed water, phosphate, and carbonate groups. The extracted alginate contained the carboxyl, cyclic ether and hydroxyl groups. The scaffolds prepared from the HA and alginate mixture were three-dimensional and containing interconnected pores with a diameter ranging from 150 to 300 µm and pore walls of a composite construction.Conclusion: A three-dimensional scaffold was produced using a freeze-drying method from a composite of HA and the high viscosity alginate solution. The scaffold was highly porous and showed interconnected pores, with a diameter ranging from 150 to 300 µm
Development and Validation of TLC-Densitometric Method for Analysis of Paracetamol, Mefenamic Acid and Ibuprofen Simultaneously in “Pegel Linu” Traditional Medicines
Jamu is a traditional or herbal medicine that is widely used by Indonesian people for prevention, maintenance and treatment of diseases. Traditional medicines contain plants or extracted plant material, or combinations thereof. The adulteration practice violates the laws. However, the presence of undeclare synthetic chemical drugs in the herbal products are still often found, among others, analgesic and anti-inflammatory drugs. The purpose of this study is to obtain a validated, simpler and lower operational cost of TLC-densitometric method to analyze paracetamol, mefenamic acid and ibuprofen in herbal medicines in “pegel linu” herbal medicines. The samples were extracted with ethanol, then separated over silica gel GF254 TLC plate with mixture of chloroform-ethanol (8:1) as mobile phase and analyzed using TLC-densitometry. The method has a satisfactorily specificity and linearity, and met the precision and accuracy criteria at the concentration of 1500 ng/spot for paracetamol, 1250 ng/spot for mefenamic acid, and 2000 ng/spot for ibuprofen. The results of the determination of eight samples showed that four of them were positive containing paracetamol with the concentration of 337.12 - 505.55 mg/single dosage
QUANTIFICATION OF HYALURONIC ACID AND METHYLSULFONYLMETHANE IN DIETARY SUPPLEMENTS
Objective: Osteoarthritis can be treated by taking oral supplements containing compounds that can nourish bones and joints such as hyaluronic acid,methylsulfonylmethane (MSM), chondroitin, glucosamine, and collagen. This study aimed to develop and validate tests for analyzing two compounds,namely, hyaluronic acid and MSM, simultaneously and to determine both their levels in a mixed sample.Methods: Hyaluronic acid derivatization was carried out using fluorenylmethyloxycarbonyl chloride and then analyzed by liquid chromatographywith fluorescence detection, while MSM was analyzed using gas chromatography. After the development of optimal conditions for each separation,system suitability tests were developed and calibration curves used for tests of accuracy and precision as well as for level determination. Hyaluronicwas detected at an excitation wavelength of 255 nm and emission wavelength of 330 nm. The mobile phase used was acetonitrile-acetate pH 4.2 (1: 4)with a flow rate of 1.0 mL/min.Results: The developed method was linear (r=0.9983) in the range of 5–50 ppm and the limits of detection (LOD) and quantitation (LOQ) were 3.55and 11.84 ppm, respectively. The initial column temperature for MSM analysis was 110°C and the mobile phase used was nitrogen gas at a flow rate of0.8 mL/min. The method was linear (r=0.9998) in the range of 4000–15,000 ppm and the LOD and LOQ were 332.90 and 1109.67 ppm, respectively.Conclusion: A simulated sample containing both compounds was assessed to contained 98.63% hyaluronic acid and 99.35% MSM
SYNTHESIS OF ACETYL AND BENZOYL ESTERS OF XANTHORRHIZOL AND ITS OXIDATION PRODUCTS AND EVALUATION OF THEIR INHIBITORY ACTIVITY AGAINST NITRIC OXIDE PRODUCTION
Objective: Xanthorrhizol is known to have anti-inflammatory activity. However, new xanthorrhizol derivatives with improved anti-inflammatoryactivity and reduced toxicity are needed.Methods: In this study, the derivatives of xanthorrhizol were synthesized and spectroscopically characterized, and their inhibitory activities againstnitric oxide (NO) production were evaluated in RAW 264.7 macrophage cells.Results: The first stage of synthesis produced compounds 2a and 2b in 58.49% and 63.26% yields, respectively. Compounds 2a and 2b were oxidizedusing potassium permanganate, giving compounds 3a and 3b in yields of 51.92% and 43.78%, respectively. Compounds 1, 2a, 3a, and 3b alongwith diclofenac sodium (the positive control) exhibited IC50 values for NO production of 31.82, 73.85, 354.05, 97.19, and 78.43 ÎĽM, respectively. Incontrast, compound 2b did not show any inhibitory activity. Based on cytotoxicity assay, compounds 1, 2a, 2b, 3a, 3b, and diclofenac sodium had LD50values of 30.97, 65.15, 31.15, 117.86, 53.40, and 51.67 ÎĽM, respectively. The NO inhibitory activities of compounds 2a, 3a, and 3b were lower than thatof xanthorrhizol (compound 1). However, cytotoxicity tests showed that compounds 2a, 3a, and 3b had reduced toxicities compared to xanthorrhizol.Conclusion: The modification of xanthorrhizol through esterification and oxidation produced derivative compounds with weaker anti-inflammatoryactivity but reduced cytotoxicity
Characterization of CRISPR RNA guided immunity in Bacillus halodurans type I-C system
Prokaryotes utilize the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) – Cas (CRISPR-associated) adaptive immune system to defend against infection. A CRISPR locus consists of an AT-rich leader region followed by a series of DNA repeats interspersed by foreign DNA-derived spacers. Upon viral infection, Cas proteins acquire short fragments from the invader and insert them as new spacers into the CRISPR locus. CRISPR transcripts are generated from the CRISPR locus and assemble with Cas proteins to form the surveillance complex. The CRISPR RNA guides the complex to target foreign genetic elements bearing sequence complementarity to the crRNA and recruits a Cas nuclease for degradation. The research presented in this dissertation focuses on understanding the mechanisms of CRISPR RNA guided immunity in Bacillus halodurans type I-C system during adaptation and interference.
Cas4 is widespread across types I, II and V and is thought to be involved in spacer acquisition along with the universally conserved Cas1 and Cas2 proteins, but the role of Cas4 has remained unclear. Using a combination of biochemical and structural experiments, we reveal that type I-C Cas4 in B. halodurans interacts directly with Cas1 and Cas2, forming a Cas4-Cas1-Cas2 complex, that mediates spacer selection, processing, and integration during CRISPR immunity. Cas4 associates tightly with Cas1 and the presence of CRISPR DNA substrates helps to stabilize the higher order complex. Cas4 selectively captures spacers that contain protospacer adjacent motifs (PAMs), short sequences required for proper target recognition by the surveillance complex, and processes the substrate directly upstream of the PAM site. When in complex with Cas1-Cas2, Cas4 cleaves spacers endonucleolytically and the complex preferentially integrates the processed spacers at the leader-repeat junction in the CRISPR locus. Together, our findings demonstrate that Cas4 is indispensable in CRISPR immunity by providing functional spacers for target recognition.
For target recognition, type I-C system is unique in that only three proteins are required to form its surveillance complex. It is unknown how type I-C Cascade searches for targets using this minimal machinery. We investigated binding interactions of B. halodurans type I-C Cascade with dsDNA and found that, unlike E. coli type I-E Cascade, type I-C Cascade has much strong non-specific affinity for DNA. These observations suggest a search mechanism involving longer-lived interactions with DNA, potentially through one-dimensional sliding. To test this, we initiated development of a single-molecule fluorescence resonance energy transfer (FRET) assay to directly visualize how Cascade searches target DNA in real time. We constructed a system suitable for labeling type I-C Cascade with a fluorophore for the smFRET assay. Using this system, we detected bulk FRET between Cy3-labelled dsDNA target and Cy5-labelled Cascade upon DNA binding. These experiments established a FRET system that will be used for future smFRET experiments to understand the kinetics and mechanisms for searching DNA targets by type I-C Cascade
Penetapan Kadar Triprolidina Hidroklorida Dan Pseudoefedrina Hidroklorida Dalam Tablet Anti Influenza Secara Spektrofotometri Derivatif
The determination of triprolidine hydrochloride and pseudoephedrine hydrochloride in anti influenza tablet has been performed using derivative spectrophotometry method. Triprolidine hydrochloride and pseudoephedrine hydrochloride were determined by measuring the first derivative ratio amplitudes, at 227,6 nm (zero crossing for pseudoephedrine hydrochloride) and at 230,0 nm (zero crossing for triprolidine hydrochloride) respectively. The linear calibration graphs were obtained for 5-50 ppm of triprolidine hydrochloride and for 100-800 ppm of pseudoephedrine hydrochloride. The results showed that the method is rapid, simple and can be applied successfully to assay simultaneously of two components in tablet preparation
Synthesis and Preliminary In Vitro Anti-inflammatory Evaluation of Mannich Bases Derivatives of 4’-Methoxy-substituted of Asymmetrical Cyclovalone Analogs
Two of Mannich bases derivatives of 4’-methoxy-substituted of asymmetrical cyclovalone analog (ACA) (2a and 2b) were synthesized. The synthesized compounds and the other two Mannich bases derivatives of 4'-methoxy-substituted ACA (2c and 2d) were evaluated for their in-vitro anti-inflammatory activity preliminary by protein denaturation inhibition method using a final concentration of 1.57 μM. The study found that all the Mannich bases exhibited anti-inflammatory potential with inhibition ranging from 33.17- 42.47%. The activity of 2b (42,47%) and 2d (41.90%) was higher than that of diclofenac sodium (35.27%) and the parent compound 1 (38.16%). As a conclusion, 2b and 2d have a prospect as a potential candidate for an anti-inflammatory agent. Further study should be done using more specific methods
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