PHOTOPHYSICAL AND PHYSICOCHEMICAL PROPERTIES OF Cu(II)CHLORIN e4 AND Cu(II)CHLORIN e6 AS A LEAD COMPOUND OF PHOTOSENSITIZER FOR PDT

Porphyrin derivatives are potential compounds for diagnostic agent and photosensitizer in photodynamic therapy. However, they have a weakness in molar absorptivity, especially in visible region of Q band which used to excite them. Due to incapabilities of porphyrin, other tetrapyrole derivatives, such as chlorophyllin can be alternative for a lead compound of photosensitizer. In the present research, two chlorin derivatives were isolated from commercial chlorophyllin product. Their photophysical and physicochemical properties, i.e. molar absorptivity, quantum yield of fluorescence and quantum yield of singlet oxygen were determined. Chlorophyllin carboxylic acid form, Cu(II)-chlorin e4 and Cu(II)-chlorin e6,were successfully isolated with recovery of 11.33% and 16.46%, respectively.         The absorption spectrum of Cu(II)-chlorin e4 showed an intense Soret band at 406 nm and two weaker Q bands at 628nm, 658nm. Fluorescence efficiency was 0.09 while efficiency for singlet oxygen at  pH 6.3 and 7.4 were 0.0052±0.0017 and 0.0066±0.0012. Cu(II)-chlorin e6 displayed soret band at 407nm and Q bands at 627nm, 663nm. Singlet oxygen at pH 6.3 was 0.0029±0.0007, while at pH 7.4 was 0.0034±0.0001. However,  Cu(II)-chlorin e6 did not show fluorescence.Key words: Chlorophyllin, Cu(II)-chlorin e4, Cu(II)-chlorin e6, singlet oxygen fluorescenc

Formulasi Mikroemulsi Glukosamin Hidroklorida

Glukosamin hidroklorida (glukosamin HCl) merupakan senyawa yang sudah populer sebagai suplemen untuk mengurangi rasa nyeri dan kerusakan sendi pada penderita osteoarthritis. Namun terdapat beberapa faktor yang menjadi tantangan dalam pengembangan sediaan glukosamin, yaitu dosis yang besar untuk diabsorpsi secara perkutan serta masalah stabilitas glukosamin di dalam air yang mudah sekali membentuk maillard product. Penelitian ini bertujuan untuk mengembangkan mikroemulsi glukosamin HCl untuk penggunaan transdermal sehingga permeabilitas terhadap stratum korneum meningkat dan stabilitas sediaan lebih baik. Dalam penelitian ini glukosamin HCl dikembangkan dalam bentuk mikroemulsi M/A dan diperoleh formula optimum dengan komposisi glukosamin HCl 15%, isopropil miristat 4,2%, Tween 80 22,70%, isopropil alkohol 5,70%, natrium metabisulfit 0,10%, aquadeion 52,30%. Uji karakterisasi menunjukkan mikroemulsi memenuhi persyaratan secara organoleptis, viskositas, serta ukuran globul. Mikroemulsi stabil pada uji sentrifugasi. Sementara uji kadar dengan menggunakan metode KCKT diperoleh hasil 14,9%

Simultaneous Determination Of Paracetamol And Ibuprofene Mixtures By High Performance Liquid Chromatography = Penetapan secara Simultan Campuran Parasetamol dan Ibuprofen dengan Kromatografi Cair Kinerja Tinggi

ABSTRACT Analytical method for the determination of paracetamol and ibuprofene mixtures has been developed by High Performance Liquid Chromatography using C-18 column and acetinitrile â phosphate buffer pH = 4.5 (75:25) containing 0.075 % sodium hexanesulfunate as a mobile phase. The detector was set at 215 nm. Using such conditions, retention time for paracetamol and ibuprofen was 4.89 and 7.11 min, respectively. The recovery for paracetamol and ibuprofen was found to be 101.07± 0.73 % and 102.02 ± 1.58 %, respectively. The detector limits of the method was 1.30 and 1.60 pg/ml with the relative standard deviation (RSD) 0.74 and 1.52 % for paracetamol and ibuprofen, respectively. Keywords: paracetamol, ibuprofen, multi-component, validation, HPL

SIMULTANEOUS DETERMINATION OF PARACETAMOL AND IBUPROFENE MIXTURES BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

Analytical method for the determination of paracetamol and ibuprofene mixtures has been developed by High Performance Liquid Chromatography using C-18 column and acetinitrile - phosphate buffer pH = 4.5 (75:25) containing 0.075% sodium hexanesulfunate as a mobile phase. The detector was set at 215 nm. Using such conditions, retention time for paracetamol and ibuprofen was 4.89 and 7.11 min, respectively. The recovery for paracetamol and ibuprofen was found to be 101.07± 0.73% and 102.02 ± 1.58%, respectively. The detector limits of the method was 1.30 and 1.60 μg/mL with the relative standard deviation (RSD) 0.74 and 1.52% for paracetamol and ibuprofen, respectively.   Keywords: paracetamol, ibuprofen, multi-component, validation, HPLC

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Prediksi dan Identifikasi Struktur Protein EGFR Kanker Paru dengan Mutasi Titik L718Q/T790M Secara Pemodelan Homologi In Silico

EGFR receptors play an important role in the growth of cancer cells, and these receptors have undergone various types of mutations. At this time, the effect of the L718Q / T790M point mutation on the EGFR receptor is not known, therefore the aim of this study is to predict the EGFR structure with the L718Q / T790M point mutation using in silico homology modeling. The mutant protein was successfully modeled using SWISS-Model expasy webserver and showed good evaluation results after the protein was minimized as indicated by the results of the Ramachandran outlier score of 0%, clashscore 0.98, and MolProbity 1.15. Identification of the active site of the mutant protein shows a conformational change of the active site that causes a steric collision between the inhibitor group and the amino acid side chain of the mutant protein. Keywords: EGFR, mutation, homology modeling, in silico

The binding modes of cationic porphyrin-anthraquinone hybrids to DNA duplexes: <i>in silico</i> study

<div><p>Cationic porphyrin-anthraquinone hybrids bearing peripheral substituents, either pyridine, imidazole, or pyrazole rings have been investigated for their binding mode to DNA duplexes. The four kinds of DNA duplexes were used, which represent intercalation and groove binding modes. AutoDock 4.2 was used to dock nine hybrid compounds to four DNA duplexes, while monitoring of conformational changes of four best hybrid–DNA complexes during 2 ns was performed by Amber9 molecular dynamics package. The binding energy calculation of best four complexes was then carried out using MMPBSA method. The hybrid compounds interacted to DNA duplexes through intercalation and groove binding modes. The minor groove binding of DNA was energetically preferred by cationic porphyrin hybrids due to favorable electrostatic and van der Waals interactions. Both electrostatic and van der Waals contributions were able to distinguish the binding mode of porphyrin hybrid to DNA duplexes.</p></div