DFT Investigation on the Electronic Properties and Intramolecular Hydrogen Bond of Trans-Cis and Cis-Trans Methyl Substituted N-Benzoyl-N’-(2-pyridyl)thiourea

Five single molecule methyl substituted Benzoyl pyridinylthiourea compounds namely N-benzoyl-N’-(2-pyridyl)thiourea, N-benzoyl-N’-(6-methyl-2-pyridyl)thiourea, N-benzoyl-N’-(5-methyl-2-pyridyl)thiourea, N-benzoyl-N’-(4-methyl-2-pyridyl) thiourea and N-benzoyl-N’-(3-methyl-2-pyridyl)thiourea are investigate theoretically for trans-cis and cis-trans conformation at B3LYP 6-31G(d,p) level of theory. Electronic properties have been analyzed by Gaussian 09W package and AIMAll code. Methyl substituent and its position give noticeable effect to reactivity, stabilization, and hydrogen bond interaction strength. AIM prove that 6-methyl substituted on pyridyl ring has significant effect to preferent conformation

N-(4-Chloro­butano­yl)-N′-[2-(trifluoro­meth­yl)phen­yl]thio­urea

In the title compound, C12H12ClF3N2OS, the dihedral angle between the benzene ring and the thio­urea fragment is 69.41 (5)°. The thio­urea N—H atoms adopt an anti conformation, such that one of them forms an intra­molecular N—H⋯O hydrogen bond, generating an S(6) ring. In the crystal, both N—H groups form inversion dimers, one via a pair of N—H⋯S hydrogen bonds and one via a pair of N—H⋯O hydrogen bonds. These lead to R 2 2(8) and R 2 2(12) loops, respectively. Weak C—H⋯Cl, C—H⋯F, C—H⋯S and π–π [centroid–centroid separation = 3.7098 (6)Å and slippage = 1.853 Å] inter­actions also occur

Cytotoxicity and genotoxicity studies of synthesized amino acid thiourea derivatives on acanthamoeba spp. and human corneal epithelial cells

Two newly-synthesized amino acids thiourea derivatives; 2-(3-benzoylthioureido)-3-mercaptopropanoic acid and 2-(3-benzoylthioureido)-4-(methylthio)butanoic acid, which were labeled as M1 and M2 respectively, were evaluated for their potential as anti-amoebic agent, aiming for a new discovery in amoebic keratitis treatment. The compounds were tested on Acanthamoeba castellanii (CCAP 1501/2A) and Acanthamoeba sp. (Hospital Kuala Lumpur isolate), and also on human corneal epithelial cells (HCEC). Experiments conducted consisting of IC50 determination by eosin dye and MTT assay, morphological observation by light microscopy, evaluation of membrane integrity by acridine orange/propidium iodide staining, mode of cell death determination by DNA fragmentation test and assessment of DNA damage by alkaline comet assay. The IC50 obtained for M1 were 6.26 μM for A. castellanii, and 9.00 μM for Acanthamoeba sp. (HKL isolate) while for M2 the values were 6.97 and 8.63 μM respectively, indicating that these compounds are cytotoxic against both Acanthamoeba. They shortened acanthopodia structures, transformed the amoeba cells to become rounded, and exhibited no distinct vacuoles and nucleus. The membrane integrity was also disrupted, making them non-intact, and promoted apoptosis in amoeba but did not significantly affected the DNA. Both thiourea derivatives showed moderate cytotoxicity toward HCEC with IC50 at 132.69 and 98.20 μM respectively. The compounds did not significantly alter corneal cells’ cellular morphology. These derivatives were found to disrupt HCEC’s membrane integrity and promoted apoptosis but non-genotoxic on HCEC’s DNA

Impak bencana banjir terhadap industri: Kes kajian di Kedah

Bencana banjir yang melanda boleh mengakibatkan impak yang besar terhadap komuniti, hartabenda serta impak yang signifikan terhadap industri. Justeru, kajian impak terhadap industri wajar dilaksanakan untuk mengenalpasti apakah impak yang ditanggung oleh pihak industri bilamana banjir melanda. Bagi maksud kertas kerja ini, metodologi kajian terhadap industri dibincangkan. Kajian ini berasaskan survei yang telah dijalankan terhadap 10 industri di daerah Kubang Pasu Kedah. Kawasan kajian merupakan kawasan perusahaan yang terlibat secara langsung ketika banjir berlaku. Selain itu, kawasan perindustrian Bukit Kayu Hitam iaitu kawasan perindustrian KEDA Napoh dan kedai-kedai sekitar Changlun juga turut dijadikan kawasan kajian. Selain survei, pendekatan temubual secara bersemuka bersama pegawai di peringkat pengurusan dan pentadbiran turut dijalankan bagi mengukuhkan dapatan kajian terhadap impak yang ditanggung oleh pihak industri akibat banjir. Selain itu, pendekatan kajian turut membantu pasukan penyelidik untuk mendapatkan cadangan-cadangan yang bersesuai dari perspektif pihak iindustri bagi tujuan mengurangkan impak banjir terhadap industri. Hasil kajian mendapati terdapat beberapa faktor yang telah menjejaskan operasi pengeluaran industri seperti pekerja tidak dapat datang bekerja, penghantaran produk terjejas, kilang dimasuki air, bekalan elektrik dan air terputus, dan penerimaan barang mentah terputus. Pemilik industri juga terpaksa menanggung segala kerugian yang dialami disebabkan tidak dapat beroperasi selama beberapa hari dan menanggung segala kos kerosakan dan pembaikan yang terlibat semasa bencana banjir. Manakala dari aspek punca berlakunya banjir bagi kawasan perindustrian adalah disebabkan oleh sistem pengaliran yang tidak terurus

1-(2-Bromo­phen­yl)-3-(4-chloro­butano­yl)thio­urea

The asymmetric unit of the title compound, C11H12BrClN2OS, consists of two crystallographically independent mol­ecules. In each mol­ecule, the butano­ylthio­urea unit is nearly planar, with maximum deviations of 0.1292 (19) and 0.3352 (18) Å from the mean plane defined by nine non-H atoms, and is twisted relative to the terminal benzene ring with dihedral angles of 69.26 (7) and 82.41 (7)°. An intra­molecular N—H⋯O hydrogen bond generates an S(6) ring motif in each butano­ylthio­urea unit. In the crystal, N—H⋯O hydrogen bonds link the two independent mol­ecules together, forming an R 2 2(12) ring motif. The mol­ecules are further connected into a tape along the c axis via N—H⋯S and C—H⋯S hydrogen bonds

Synthesis and physicochemical properties of magnetite nanoparticles (Fe3O4) as potential solid support for homogeneous catalysts

Black and dark magnetite nanoparticles (MNPs) were successfully synthesised through a co-precipitation method as a crucial material to support palladium(II) complexes as they have the potential to become a stable solid support for homogeneous systems. The two-hour synthesis was done by mixing FeCl3.6H2O and FeCl2.4H2O in an alkaline medium. To improve the properties of iron oxide nanoparticles, the process was done under inert conditions. The physicochemical properties of this support was then characterised using various spectroscopic techniques such as Fourier Transform Infrared (FTIR) spectroscopy that shows the X-ray diffraction analysis (XRD), Thermogravimetric analysis (TGA), Field Emission Scanning Electron Microscope (FESEM), and Vibrating Sample Magnetometer (VSM). The pore size distribution and the specific BET surface area were measured by N2 adsorption-desorption isotherms. The FTIR absorption spectroscopy was used to confirm the formation of Fe-O bond. The most intense peak correspond to the (311) crystallographic orientation of the spinel cubic phase of MNPs shown by XRD pattern result. The particle size of magnetite was successfully controlled in the range of 20-40 nm. All of the MNPs showed the superparamagnetic behaviour with high saturation magnetization

N-(2,6-Dimethylphenyl)-N′-propanoyl­thiourea

In the title compound, C12H16N2OS, an intra­molecular N—H⋯O hydrogen bond forms an S(6) ring motif. The propionyl­thio­urea group is approximately planar [with a maximum deviation of 0.135 (2) Å] and forms a dihedral angle of 83.39 (7)° with the benzene ring. In the crystal, mol­ecules are linked by pairs of N—H⋯S hydrogen bonds, forming centrosymmetric dimers and generating R 2 2(8) ring motifs

Quantitative structure-activity relationship (qsar) study of newly synthesized carbonyl thiourea derivatives on acanthamoeba sp.

This research aims to build a mathematical quantitative structure-activity relationship (QSAR) model, which could relate the relationship between newly-synthesized carbonyl thiourea derivatives with their anti-amoebic activities. Therefore, in this study, inhibition concentration of 50% cells population (IC50) was evaluated for 44 carbonyl thiourea derivatives on pathogenic Acanthamoeba sp. (Hospital Kuala Lumpur isolate). QSAR analysis was conducted using the obtained IC50 data with additional 4 thiourea compounds of the same group from our previous work by applying three linear regression techniques namely stepwise-MLR, GA-MLR, and GA-PLS. Results showed that these thiourea derivatives are positively active against the tested Acanthamoeba sp. with IC50 values ranging from 2.56 to 7.81 μg/mL. From the evaluation of the obtained models, the GAPLS technique is found to be the best model due to its best predictive ability. The final equation of GA-PLS model gave good statistical output with values of r2 = 0.827, r2 cv = 0.682 RMSEC=0.047, RMSECV=0.064, and r2 test =0.790 and RMSEP=0.051. Y-randomization test has confirmed that the model did not occur from the chance of correlation with r2 = 0.015- 0.372. Small residual with values less than 0.25 from the prediction in the test set proves the robustness of the model. The information generated from this study will provide an insight into designing a new lead compound from carbonyl thiourea containing highly potential anti-amoebic properties

Anti-amoebic properties of carbonyl thiourea derivatives

Thiourea derivatives display a broad spectrum of applications in chemistry, various industries, medicines and various other fields. Recently, different thiourea derivatives have been synthesized and explored for their anti-microbial properties. In this study, four carbonyl thiourea derivatives were synthesized and characterized, and then further tested for their anti-amoebic properties on two potential pathogenic species of Acanthamoeba, namely A. castellanii (CCAP 1501/2A) and A. polyphaga (CCAP 1501/3A). The results indicate that these newly-synthesized thiourea derivatives are active against both Acanthamoeba species. The IC50 values obtained were in the range of 2.39–8.77 μg·mL-1 (9.47–30.46 μM) for A. castellanii and 3.74–9.30 μg·mL-1 (14.84–31.91 μM) for A. polyphaga. Observations on the amoeba morphology indicated that the compounds caused the reduction of the amoeba size, shortening of their acanthopodia structures, and gave no distinct vacuolar and nuclear structures in the amoeba cells. Meanwhile, fluorescence microscopic observation using acridine orange and propidium iodide (AOPI) staining revealed that the synthesized compounds induced compromised-membrane in the amoeba cells. The results of this study proved that these new carbonyl thiourea derivatives, especially compounds M1 and M2 provide potent cytotoxic properties toward pathogenic Acanthamoeba to suggest that they can be developed as new anti-amoebic agents for the treatment of Acanthamoeba keratitis

Metodologi kajian impak: Kajian kes banjir

Bencana alam yang berlaku sama ada secara semulajadi atau akibat perbuatan manusia pasti memberi kesan terhadap komuniti dan negara secara keseluruhannya. Ia memberikan impak yang besar jika dilihat dari aspek kos yang perlu ditanggung oleh individu mahupun kerajaan. Ini adalah akibat daripada kemusnahan hartabenda individu dan juga hartabenda awam seperti kerosakan infrastruktur asas, bangunan dan sebagainya. Oleh itu, kajian ini mengkaji kesan banjir ke atas sosioekonomi negeri Kedah dengan berdasarkan terma rujukan kajian yang berikut: menilai dan menganggar bantuan kewangan yang diberi oleh kerajaan dan pertubuhan bukan kerajaan (NGO) semasa banjir dan kos lain seperti bantuan perubatan, sara hidup, kerosakan harta benda dan gantirugi yang berkaitan dengan banjir; menilai dan menganggar kos dan perbelanjaan yang akan berlaku jika langkah mencegah banjir tidak dilakukan; meneliti impak kepada individu, kawasan dan negeri dengan memfokus kepada sosioekonomi; mengenalpasti impak dan perubahan kualiti kehidupan kumpulan sasaran; menilai keberkesanan dan kelemahan sistem penyampaian dan mengemukakan cadangan-cadangan untuk mengatasi masalah yang dikenalpasti dalam kajian ini. Justeru metodologi kajian impak banjir adalah berasaskan pendekatan kualitatif yang disokong oleh survei dan temubual kumpulan sasaran (TKS)