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Malaria is an endemic disease in Indonesia caused by infection from the Plasmodium parasite. Recently, antimalarial resistance significantly contributed to the decline in the cure rate of malaria sufferers. In this work, three calix[4]resorcinarenes have been synthesized from 2-methylresorcinol and different benzaldehyde derivatives, i.e., 4-chlorobenzaldehyde, 4-methoxybenzaldehyde, and 4-dimethylaminobenzaldehyde through the one-pot synthesis procedure. The calix[4]resorcinarenes synthesis was done through a cyclo-condensation reaction by using HCl 37% as the catalyst and ethanol as the solvent in an one-pot reaction. The structures of the synthesized products were confirmed using Fourier transform infrared, proton-nuclear magnetic resonance, and liquid chromatography-mass spectrometry techniques. The antimalarial activity assay was evaluated against the Plasmodium falciparum FCR-3 strain through an in vitro study. Three synthesized compounds, i.e., C-4-chlorophenylcalix[4]-2-methylresorcinarene, C-4-methoxyphenylcalix[4]-2-methylresorcinarene and C-4-dimethylaminophenylcalix[4]-2-methylresorcinarene have been successfully synthesized in up to 97% yield. The C-4-chlorophenylcalix[4]-2-methylresorcinerene exhibited the most potent antimalarial activity with a half-maximal inhibitory concentration (IC50) value of 2.66 µM against P. falciparum FCR-3 while the C-4-methoxyphenylcalix[4]-2-methylresorcinarene and C-4-dimethylaminophenylcalix[4]-2-methylresorcinarene gave the IC50 values of 23.63 and 13.82 µM, respectively. From the results, it could be concluded that the antimalarial activity of calix[4]-2-methylresorcinarenes was influenced by the type of substituent of aromatic rings at the para position.

Epidermal growth factor receptor (EGFR) is found to be overexpressed in cancer cells as it controls angiogenesis, cell signaling, and proliferation mechanisms. Therefore, EGFR has been known as a common target for the initial screening of new anticancer agents. Either xanthone or chalcone has been evaluated as the anticancer agents, and their activity strongly depends on the type and position of the attached functional group. Therefore, molecular hybridization between xanthone and chalcone could yield novel anticancer agents through the EGFR inhibition mechanism. Herein, a series of xanthone-chalcone derivatives with hydrogen-bond-acceptor or hydrogen-bond-donor substituents at ortho, meta, and para positions was evaluated as the EGFR inhibitor. Thirty-seven xanthone-chalcones were designed and docked in the active site of EGFR. Compared to the native ligand, pristine xanthone-chalcone gave a 1.215× stronger binding energy and a 13.97× lower binding constant. Compound 3SH was found to be the most promising candidate due to its strongest binding energy (−9.71 kcal/mol) and the lowest binding constant (0.08 µM). Furthermore, molecular dynamic studies demonstrated that complex EGFR-3SH was stable for 100 ns simulation. These in silico investigations show that the xanthone-chalcone derivative is a promising novel anticancer agent to be examined through in vitro and in vivo assays.

This work aimed to study the energy efficiency of the synthesis process of carbonated hydroxyapatite (CHA) nanoparticles using microwave heating treatment and its effect on material characteristics. Microwaves can provide heat quickly, so it is expected to increase the efficiency of CHA synthesis through the heat provided. The CHA nanoparticles were synthesized using precipitation and heated using a microwave oven. The unheated and hydrothermal-heated precipitation methods were also conducted for comparison purposes. The microwave-heated precipitations were done at 270 W for 0.05, 0.10, and 0.15 h, while the hydrothermal-heated precipitations were done at 100 °C for 1, 2, and 3 h. The CHA materials were characterized using an infrared spectrophotometer, X-ray diffractometer, and electron microscope. The X-ray diffractogram and infrared spectra confirmed that the synthesized materials had a hydroxyapatite crystal phase with a CO32− functional group in their spectra. Microscopic images revealed that the materials were nanometer-sized grain aggregates. The heat treatment and duration increased the material characteristics, i.e., crystallinity, crystallite, and grain size. The CHA with microwave heat treatment had the highest crystallinity and crystallite size. The electrical energy calculation revealed microwave heating had better energy efficiency than hydrothermal heating.

Malaria is an endemic disease in tropical countries, including Indonesia, with a high annual mortality rate. Because of that, serious attention shall be given to find new antimalarial agents that are highly active for medical treatment. In this work, we designed and synthesized three calix[4]resorcinarene derivatives and evaluated them as antimalarial agents through in vitro heme polymerization inhibitory assay. The calix[4]resorcinarenes were prepared from resorcinol and corresponding aldehyde derivatives in ethanol media through a cyclo-condensation reaction. The calix[4]resorcinarene products were obtained in 31.1–85.1% yield. The synthesized compounds were subjected to structure elucidation using spectroscopy techniques. The antimalarial activity of calix[4]resorcinarene with aromatic substituent (IC50 = 0.198 mg/mL) was higher than the aliphatic ones (IC50 = 0.282–0.814 mg/mL). It was found that all calix[4]resorcinarenes in this work exhibited stronger antimalarial activity than chloroquine diphosphate as the positive control (IC50 = 1.157 mg/mL). The calix[4]resorcinarenes could interact with hydrogen bonding, thus inhibiting the heme polymerization process. These findings demonstrate that calix[4]resorcinarene derivatives are potential antimalarial agents to be developed for effective medical treatment in the near future.

Cancer is one of the three biggest causes of death in the world. The development of new drugs against this disease is a serious study that must be carried out in order to reduce mortality and extend the life span of sufferers. The aim of this research was to develop a new anti-cancer drug based on halogenated imidazole chalcones have been conducted. A 18 The halogenated imidazole chalcone compound was designed and performed molecular docking. Potential compounds of molecular docking are then carried out molecular dynamics. The results of molecular docking show that the potential chalcones based on bond affinity and specific interactions are chalcones B5, B6, C5, and C6. Analysis of the molecular dynamics result parameters are root mean standard deviation (RMSD) complex, root mean square fluctuation (RMSF), Radius of Gyration, Protein-ligand hydrogen bonding, and complex stability with generalized born surface area (GBSA) method, where the potential chalcone compounds are chalcones B5 and B6.

A new series of xanthyl-cinnamate hybrid compounds (4a-d) have been synthesized and screened through in vitro assay against four human cancer cell lines, i.e., HeLa, T47D, A549, and WiDr. The results revealed that xanthone hybridization with cinnamic acid increases the selectivity of the compounds with SI values of 2.75–209.03 compared to its parent oxygenated-xanthone. Compound 1,3-dihydroxyxanthen-6-yl cinnamate (4c) showed high cytotoxic activity against WiDr cell lines with an IC50 value of 39.57 µM. Molecular docking studies revealed the possible binding modes of all hybrid compounds with EGFR protein. A complex of 3,6-dihydroxyxanthen-1-yl cinnamate (4d)-EGFR, as the best binding model, exhibited higher predicted EGFR inhibitory activity than erlotinib and oxygenated-xanthone with a ΔG and Ki value of -35.02 kJ/mol and 0.74 µM, respectively. Compounds 4c and 4d were chosen as the most potent derivates from the study.

Vernonia amygdalina was reported to be used as a therapy for Diabetes Mellitus (DM). One of the mechanisms of therapy DM was to inhibit the action of the α-amylase enzyme. This study aimed to prove the presence of compounds that could inhibit the action of α-amylase. Vernonia amygdalina leaves were macerated with methanol and partitioned into n-hexane, dichloromethane (DCM), and ethyl acetate (EtOAc). Furthermore, they were tested for α-amylase inhibitory activity and analyzed using liquid chromatography-high resolutions mass spectrometry (LC-HRMS). Molecular docking and molecular dynamics simulation (MD simulation) examined unique compounds in the extract with good activity and chromatogram results. The EtOAc extracts showed potential as α-amylase inhibitors indicated by their IC50 values, namely 3.0 μg/mL. There are five unique compounds in the EtOAc extract predicted as 3-[(2Z)-3,7-dimethylocta-2,6-dien-1-yl]-2,4-dihydroxy-6-(2-phenylethyl)benzoic acid (compound 1), 2-hexylpentanedioic acid (compound 2), (2E,4E)-5-[1-hydroxy-2,6-dimethyl-4-oxo-6-({3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl] oxy}methyl)cyclohex-2-en-1-yl]-3-methylpenta-2,4-dienoic acid (compound 3), 3,5,5-trimethyl-4-(3-{[3,4,5-trihydroxy-6-(hydroxymethyl)oxan-1-yl)oxy}butyl)cyclohex-2-en-1-one (compound 4), and 2-{[(6E)-2,10-dihydroxy-2,6,10-trimethyldodeca-6,11-dien-3-yl]oxy}-6-(hydroxymethyl)oxane-3, 4,5-triol (compound 5). The molecular docking analysis showed that compound 3 had better interaction energy (Ei) (-8.59 kcal/mol) and inhibition constant (Ki) values (0.503 μM) than acarbose. These data were supported by MD simulations based on the parameters of RMSD value, the radius of gyration, and protein-ligand interaction energy.

Abstract In the present work, three hydroxyxanthones were synthesized in 11.15–33.42% yield from 2,6-dihydroxybenzoic acid as the starting material. The chemical structures of prepared hydroxyxanthones have been elucidated by using spectroscopic techniques. Afterward, the hydroxyxanthones were evaluated as antioxidant agents through radical scavenging assay; and anticancer agents through in vitro assays against WiDr, MCF-7, and HeLa cancer cell lines. Hydroxyxanthone 3b was categorized as a strong antioxidant agent (IC50 = 349 ± 68 µM), while the other compounds were categorized as moderate antioxidant agents (IC50 > 500 µM). On the other hand, hydroxyxanthone 3a exhibited the highest anticancer activity (IC50 = 184 ± 15 µM) and the highest selectivity (SI = 18.42) against MCF-7 cancer cells. From the molecular docking study, it was found that hydroxyxanthone 3a interacted with the active sites of Topoisomerase II protein through Hydrogen bonding with DG13 and π–π stacking interactions with DA12 and DC8. These findings revealed that hydroxyxanthones are potential candidates to be developed as antioxidant and anticancer agents in the future.

Plasmodium falciparum (P. falciparum) is the most fatal among the other Plasmodium parasites that infect humans with the malaria disease. Currently, the resistance of P. falciparum against some antifolate drugs has become a severe problem. On the other hand, xanthone and thioxanthone derivatives have been reported to have remarkable antimalarial activity. However, molecular docking studies have not evaluated thioxanthone derivative compounds as antimalarial agents. Accordingly, this research investigated the binding pose and inhibition mechanism of several thioxanthone derivatives against P. falciparum proteins DHFR (PDB ID: 1J3K) and DHODH (PDB ID: 1TV5) through molecular docking study. The compound structures were geometrically optimized using Gaussian 09 software and docked to the receptors using AutoDock4 software. The results showed that the free binding energy of thioxanthone derivatives ranged between -6.77 to -7.50 and -8.45 to -9.55 kcal mol–1 against pfDHFR and pfDHODH, respectively, with RMSD values of less than 2 Å. Compound F (4-iodo-3,4-dihydroxy-thioxanthone) gave the most substantial free binding energy against both proteins. Furthermore, the hydrogen bond interaction of compound F was the same as the native ligands of pfDHFR and pfDHODH. These results suggested that compound F has a more robust interaction in pfDHFR and pfDHODH. Thus, it is promising to further evaluate the compound as a candidate for a new antimalarial agent.

Context: Vernonia amygdalina has been reported as a potential antidiabetic agent. One of the mechanisms in diabetes mellitus treatment is the inhibition of the α-amylase enzyme’s action. Objective: This study is aimed to identify the presence of secondary metabolites in Vernonia amygdalina leaf extract, which has the potential as α-amylase inhibitors through phytochemical screening combined with metabolomic analysis. Materials and methods: Methanol extract from Vernonia amygdalina leaf was partitioned into n-hexane, dichloromethane (DCM), and ethyl acetate. From this process, methanol, hexane, DCM, and ethyl acetate extracts were obtained. These extracts were then being tested for phytochemical screening, α-amylase inhibition, and FTIR. Then FTIR data were used for metabolomic analysis (PCA and PLS). Results: The results of the α-amylase inhibition test showed that the ethyl acetate extract had the smallest IC50 average value, which was 3.00 μg/mL. Based on the phytochemical screening test results, the extract showed positive for the presence of compounds such as flavonoids, phenols, tannins, alkaloids, and saponins. From the PCA analysis (Bi-plot), the wavenumbers that were influential in the ethyl acetate extract were 1436 to 1681 and 3341 to 3348 cm−1. In theory, functional groups such as CH, CC, CO, NH, and OH appeared on the absorption. From the PLS analysis, these wavenumbers affected the activity. Conclusion: The most potential extract as an α-amylase inhibitor was the ethyl acetate extract. Based on phytochemical screening tests and metabolomic analysis, it was proven that this extract contained compounds as hypoglycemic agents.

Potential energy curves (PECs) and energy profiles of atomic O attack on coronene as a model for graphene/graphitic surface and interstellar reaction surface have been computed at the unrestricted B3LYP/cc-pVDZ level of theory to elaborate on atomic O attack mechanism and chemisorption on coronene. The PECs were generated by scanning the O atom distance to the closest carbon atom on "top" and "bridge" positions in the coronene, while fully relaxed geometries in the triplet state were investigated to gain the energy profile. We found that the most favorable geometry as the final product was the chemically bound O on the "bridge" site in the singlet state with an interaction energy of –29.2 kcal/mol. We recommended a plausible mechanism of atomic O attack and chemisorption reaction on coronene or generally graphitic surface starting from the non-interacting O atom and coronene systems into the chemically bound O atom on coronene.

A carbonate-hydroxyapatite-based antibacterial implant material with low cytotoxicity was synthesized. The silver ion (Ag+) was incorporated into CHA material, resulting in silver-doped carbonate hydroxyapatite (CHA-Ag). The microwave-assisted precipitation method was used to synthesize the CHA-Ag material. The amount of Ag+ was varied at 0.005, 0.010, and 0.015 mol fractions (χAg). The XRD results showed that the diffractograms corresponded with hydroxyapatite (ICSD 98-05-1414), without any additional phase. The presence of carbonate ions was indicated by vibrations at wavenumber of 871, 1411, and 1466 cm−1 in the infrared spectra. The CHA-Ag materials were agglomerates of nanosized particles with low crystallinity. The particle size and crystallinity of the materials decreased due to the incorporation of CO32− and Ag+. The incorporated Ag+ successfully inhibited peri-implant-associated bacterial growth. The antibacterial ability increased alongside the increase in the Ag+ amount. The pre-osteoblast MC3T3E1 cell could grow up to >70% in the MTT assay, despite the use of Ag+ as a dopant. The cell viability was higher in the CHA-Ag-containing media than in the CHA-containing media. The MTT assay also revealed that the CHA-Ag cytotoxicity decreased even though the Ag+ amount increased. The CHA-Ag-15 had the lowest cytotoxicity and highest antibacterial activity. Therefore, the optimal amount of Ag+ in the CHA-Ag formulation was χAg = 0.015.

Erlotinib, Afatinib, and WZ4002 are quinazoline derivative compounds and classified as first, second, and third-generation EGFR inhibitor. All inhibitors have been given directly to cancer patients for many years but find some resistance. These three compounds are candidates as the lead compound in designing a new inhibitor. This work aims to design a new potential quinazoline derivative as an EGFR inhibitor focused on the molecular docking result of the lead compound. The research method was started in building a pharmacophore model of the lead compound then used to design a new potential inhibitor by employing the AutoDock 4.2 program. Molecular dynamics simulation evaluates the interaction of all complexes using the Amber15 program. There are three new potential compounds (A1, B1, and C1) whose hydrogen bond interaction in the main catalytic area (Met769 residue). The Molecular Mechanics Generalized Born Surface Area (MM-GBSA) binding energy calculation shows that B1 and C1 compounds have lower binding energies than erlotinib as a positive control, which indicates that B1 and C1 are potential as EGFR inhibitor.

Stability and hydrogen bond occupancy analysis of flavonol derivative docked in DAPK1 have been carried out using molecular dynamics simulation approach. Six flavonol derivatives were docked in DAPK1 as protein target, then continued with molecular dynamics simulation. NVT and NPT ensembles were used to equilibrate the system, followed by 20 ns sampling time for each system. Structural stability and hydrogen bond occupancy analyses were carried out at the NVT ensemble, while free binding energy analysis was done at NPT ensemble. From all compounds used in this work, compound B (5,7-dihydroxy-2-(4-hydroxyphenyl)-6-methoxy-4H-chromen-4-one) has a similar interaction with reference ligands (quercetin, kaempferol, and fisetin), and the most stable complex system has the maximum RMSD around 2 Å. Compound C complex has -48.06 kJ/mol binding free energy score, and it was slightly different from quercetin, kaempferol, and fisetin complexes. Even though complex C has similar binding free energy with the reference compound, complex B shows more stable interactions due to their hydrogen bond and occupancy.

Objectives: The objective of this work was to predict anti-colon and anti-hepatoma cancer activity of newly designed substituted 4-anilino coumarin derivatives using quantitative structure–activity relationship (QSAR). Methods: The optimization of the derivatives including molecular and electronic properties data to generate the QSAR were resulted from H-GGA DFT/BPV86 method calculation combined with Hartree-Fock 6-31G basis set. The QSAR models were delivered in multiple linear regression (MLR) and the drug design was accomplished by considering the descriptors constructing the best QSAR models for each biological activity. Results: This research accomplished two best validated QSAR models for predicting anti-colon cancer and anti-hepatoma activities of substituted 4-anilino coumarin derivatives. There were 17 of newly designed substituted 4-anilino coumarin derivatives which their anticancer activity (Log IC50) were predicted using our both QSAR models. The QSAR predictions inform that the compound 25 and compound 19 have the best predicted anti-colon cancer and anti-hepatoma activities, respectively. Conclusion: The results revealed that this approach can be used to assist in the action of anticancer drug discovery. Moreover, the retrosynthesis analysis of both compounds are also explained in a logic reverse of organic synthetic steps through Knoevenagel and Perkin reactions.

Compound of 3,3'-(4-(2-amino-4,5-dimethoxyphenyl)pyridine-2,6-diyl)dianiline (CHP) has been synthesized via three-step synthetic procedure from veratraldehyde as starting material and 4-(4,5-dimethoxy-2-nitrophenyl)-2,6-bis(3-nitrophenyl)pyridine (CHP-1) as an intermediate compound. The CHP-1 was reduced using hydrazine hydrate catalyzed by 10% Pd/C to the final target of CHP. The spectroscopic study revealed that CHP in acetonitrile could detect formaldehyde through fluorescence enhancement and showed color change from yellow to blue under the 365 nm portable ultraviolet lamp as a response. Based on the fluorescence spectra, the emission wavelength of CHP in acetonitrile was shifted from 526 to 480 nm after addition of formaldehyde. Limit detection (LOD), selectivity, sensitivity, and computational study geometry of CHP as a chemosensor for formaldehyde has also been investigated. CHP could also be applied as a test paper for the detection of formaldehyde qualitatively.

In this study, the chloro-substituted hydroxyxanthones were prepared by cyclodehydration of acid derivatives and substituted phenol in the presence of Eaton reagent, followed by halogenations step to electrophilic substitution of chlorine in a moderate yield. The in vitro anticancer activity study on various cell lines revealed that the chloro functional group increases the anticancer activity of the hydroxyxanthone derivatives. The molecular docking study showed that there was a binding interaction between chloro-hydroxyxanthone and the amino acid residues such as Asp810, Cys809, Ile789, His790, and Leu644 of protein tyrosine kinase receptor (1T46.pdb).

Resistance to the traditional antifolates is now widespread in Plasmodium falciparum and Plasmodium vivax. To find the interaction model of some compounds derived from 1,6-dihydro-1,3,5-triazine-2,4-diamine, molecular docking technique was carried out using these compounds ligand and pDHFR as the receptor. Complex ligand and the receptor from Protein Data Bank (PDB ID 1J3K) were chosen as an interaction model between a ligand and its receptor. Each compound was optimized using ab initio methods with 6-311G basis set. Partial charges of ligand were added using AM1-BCC methods. Each ligand was docked to the receptor utilizing Dock6 software. Theoretical prediction based on the binding energy between these compounds as the ligand with pDHFR as receptor resulted in 1 compound, namely 6,6-dimethyl-1-[3-(2-chloro-4,5-dibromophenoxy)propoxy]-1,6-dihydro-1,3,5-triazine-2,4-diamine possessing binding affinity better than that of WR99210 which was known to have good antimalarial activity.

Lung cancer was a second common cancer case due to the high cigarette smoking activity both in men and women. One of protein receptor which plays an important role in the growth of the tumor is Epidermal Growth Factor Receptor (EGFR). EGFR protein is the most frequent protein mutation in cancer and promising target to inhibit the cancer growth. In this work, the stability of the hydrogen bond as the main interaction in the inhibition mechanism of cancer will be evaluated using molecular dynamics simulation. There were two compounds (A1 and A2) as new potential inhibitors that were complexed against the EGFR protein. The dynamic properties of each complexed were compared with respect to erlotinib against EGFR. The result revealed that both compounds had an interaction in the main catalytic area of protein receptor which is at methionine residue. Inhibitor A1 showed additional interactions during simulation time but the interactions tend to be weak. Inhibitor A2 displayed a more stable interaction. Following dynamics simulation, binding free energy calculation was performed by two scoring techniques MM/GB(PB)SA method and gave a good correlation with the stability of the complex. Furthermore, potential inhibitor A2 had a lower binding free energy as a direct consequence of the stability of hydrogen bond interaction.

Study of substituent effect on properties of platinum(II) porphyrin had been performed using DFT method. The aim of the study is to investigate the effect of substituent group on the electronic and optical properties of the platinum(II) porphyrin. Geometry optimization was conducted using DFT/B3LYP/LANL2DZ to obtain molecular structure, electronic structure and energy profile. Band gap energy (Eg), the density of states (DOS), and UV-visible spectra are the semiconductor parameters to study. Computational results show that platinum(II) porphyrin and substituted platinum(II) porphyrin have properties of semiconductor based on Eg value, DOS, and UV-visible spectra. The results show that Mulliken partial charges of electron withdrawing substituents are higher than the electron donating substituents (CH3, OH, and NH2). Eg values of the complexes with respect to the substituents follow this order: NH2 < OH < NO2 < COOH < I < CH3 < Br < F < H, for DOSHOMO values, the order is CH3 < NO2 < I < OH < F < NH2 < COOH < Br < H and the maximum wavelength (λmax) for UV-visible adsorption spectra follows this order: NH2 > OH > COOH > NO2 > I > Br > CH3 > F > H. Molecules with smaller Eg and DOSHOMO values and higher λmax are considered as the most appropriate semiconductor materials. Our results show that Pt(II)P-NH2 has the smallest Eg and the highest λmax among other substituted platinum(II) porphyrin molecules. Therefore, Pt(II)P-NH2 are the most suitable semiconductor material based on the aforementioned criteria.

Ab initio of Quantum Mechanics Charge Field Molecular Dynamic (QMCF-MD) of K(I) ion in liquid ammonia has been studied. A Hartree-Fock level of theory was coupled with LANL2DZ ECP basis set for K(I) ion and DZP (Dunning) for ammonia. Two regions as first and second solvation shell were observed. In the first solvation shell at distance 3.7 (Å), K(I) ion was coordinated by four to eight ammonia molecules dominated by K(NH3)6+ species. Second shell of solvation was ranging between 3.7 Å to 7.3 Å. Within simulation time of 20 ps, the frequent exchange processes of ligands indicating for a very labile solvation structure. Four mechanism types of ligand exchange between first and second solvation shell were observed. Mean residence time of ligand is less than 2 ps confirming weak in ion-ligand interaction. Evaluation of K(NH3)6+ using natural bond orbital analysis shows that the Wiberg bond Index is less than 0.05 indicating weak electrostatic interaction of K-N.

The annual number of cancer deaths continues increasing every day; thus, it is urgent to search for and find active, selective, and efficient anticancer drugs as soon as possible. Among the available anticancer drugs, almost all of them contain heterocyclic moiety in their chemical structure. Xanthone is a heterocyclic compound with a dibenzo-γ-pyrone framework and well-known to have “privileged structures” for anticancer activities against several cancer cell lines. The wide anticancer activity of xanthones is produced by caspase activation, RNA binding, DNA cross-linking, as well as P-gp, kinase, aromatase, and topoisomerase inhibition. This anticancer activity depends on the type, number, and position of the attached functional groups in the xanthone skeleton. This review discusses the recent advances in the anticancer activity of xanthone derivatives, both from natural products isolation and synthesis methods, as the anticancer agent through in vitro, in vivo, and clinical assays.

Quantitative Structure-Activity Relationship (QSAR) analysis of organophosphate derivatives, and their insecticide activities, was performed using electronic and molecular parameters. The series of organophosphate derivatives and their activities were obtained from literature. The semi-empirical AM1 method was used to model the structure of organophosphate derivatives and calculate the parameters of QSAR. Multiple linear regression (MLR) analysis was performed on the electronic and molecular parameters as well as the activities of the organophosphate insecticides to derive the QSAR model. The best QSAR equation model was used to design, in silico, new insecticide molecules of organophosphate derivatives with higher insecticidal activity. A new insecticide molecule, 4-(diethoxy phosphoryloxy) benzene sulfonic acid, -Log LD50 = 7.344, had the highest insecticidal activity. Lastly, we recommend synthesizing and testing the new insecticide molecule further in the laboratory.

The interactions between sensor chalcone of 3-(4-hydroxy-3-methoxyphenyl)-1-phenyl-2-propen-1-one (1) and anions (F–, Cl–, Br–, CN–, CO32–, and SO42–) have been experimentally and TD-DFT theoretically investigated. Sensor (1) showed a naked-eye detectable color change from yellow to red upon addition of F–, CO32–, CN–, and SO42– anions in DMSO, whereas no significant color change was observed upon addition of Cl– and Br– anions. The interaction models were predicted by optimizing (1)-anion complex using DFT/B3LYP method. Optimized (1)-anion complexes showed that sensor (1) was deprotonated by CO32–, CN–, F–, and SO42–. The formation of deprotonated sensor (1)– was responsible for the colorimetric signaling. Absorption spectra of neutral and deprotonated sensor were calculated using TD-DFT method. The calculated spectra were in good agreement with experimental results.

Mahkota dewa plant (Phaleria macrocarpa (Scheff.) Boerl.) which is belong to family of Thymelaeaceae is one of Indonesia's traditional medicines. The aim of this research is to isolate secondary metabolites from ethyl acetate extract of leave and fruit of mahkota dewa and to determine the molecular structure of isolated compounds using spectroscopic method and to know the antibacterial activity of the isolated compound. Sample was extracted with methanol, concentrated then extracted by n-hexane, chloroform and ethyl acetate. The compounds were separated and purified with column chromatography. The compound 1 was isolated from ethyl acetate extract of leave as white needle amorphous solid as 45 mg. The compound was identified by spectroscopic as 4,6-dihydroxy-4’-methoxybenzophenon-2-O-β-D-glucopyranoside and named isophalerin B. From the test results of antibacterial activity showed that the compound 1 (10 mg/mL) in ethanol has a weak activity against the bacteria S. aureus and E. coli. The compound 2 was isolated from ethyl acetate extract of fruit as peach needle crystal as 10 mg. The compound was identified by spectroscopic as 4,6-dihydroxy-4’-methoxybenzophenon-2-O-α-D-glucopyranoside and named isophalerin A.

A QM/MM molecular dynamics (MD) simulation has been carried out using three-body corrected pair potential to investigate the structural and dynamical properties of Zr4+ in dilute aqueous solution. Structural data in the form of radial distribution function, coordination number distribution, and angular distribution function were obtained. The results indicate eight water molecules coordinate to zirconium ion and have two angles of O-Zr4+-O, i.e. 72.0° and 140.0° with a Zr4+-O distance of 2.34 Å. According to these results, the hydration structure of Zr4+ ion in water was more or less well-defined square antiprismatic geometry. The dynamical properties have been characterized by the ligand’s mean residence time (MRT) and Zr4+-O stretching frequencies. The inclusion of the three-body correction was important for the description of the hydrated Zr4+ ion, and the results indicated in good agreement with experimental values.

Characterisation and catalytic ativities investigation of modified natural zeolite on cyclisation acetylation reaction of (R)-(+)-citronellal was performed. The experimental work involved isolation of (R)-(+)-citronellal from Java Citronella oil (Cymbopogon winterianus) by vacuum fractional distillation, determination of its enantiomer, preparation and characterisation of different catalysts i.e. H-natural zeolite (H-Za), Fe3+-natural zeolite (Fe3+-Za), and Zn2+-natural zeolite (Zn2+-Za), followed by examination of catalytic activity and selectivity. Isolated citronellal contained 88.21% ee of (R)-(+)-citronellal. The main products of cyclisation-acetylation of (R)-(+)-citronellal was IPA (isopulegyl acetate) and NIPA (neo-isopulegyl acetate). Although the highest yield of IPA and NIPA was obtained by Fe3+-Za catalyst (78.69%) at 80oC and 120 min, the stereoselectivity of Fe3+-Za slightly lower than that of Zn2+-Za. Structure elucidation of citronellal and products was carried out by means of GC and GC-MS. Lewis acidity plays the role of acetyl ionic formation from acetic anhydride. The Activity and stereoselectivity of catalysts depended on Lewis acidity and cation distribution on the catalyst surface. © 2014 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)

The roles of counterions, solvent types and extraction temperatures on the selectivity of 18-crown-6 (L) toward alkaline earth salts MX2 (M = Ca, Sr, Ba; X = Cl-, NO3-) have been studied by density functional method at B3LYP level of theory in gas and solvent phase. In gas phase, the chloride anion Cl- is the preference counterion than nitrate anion NO3-. This result is confirmed by the interaction energies, the second order interaction energies, charge transfers, energy difference between HOMO-LUMO and electrostatic potential maps. The presence of solvent reversed the gas phase trend. It is found that NO3- is the preference counterion in solvent phase. The calculated free energies demonstrate that the solvent types strongly change the strength of the complex formation. The free energies are exothermic in polar solvent while for the non polar solvent the free energies are endothermic. As the temperature changes the free energies also vary where the higher the temperatures the lower the free energy values. The calculated free energies are correlated well with the experimental stability constants. This theoretical study would have a strong contribution in planning the experimental conditions in terms of the preference counterions, solvent types and optimum extraction temperatures.

Design of new potent insecticide compounds of organophosphate derivatives based on QSAR (Quantitative Structure-Activity Relationship) analytical model has been conducted. Organophosphate derivative compounds and their activities were obtained from the literature. Computational modeling of the structure of organophosphate derivative compounds and calculation of their QSAR descriptors have been done by AM1 (Austin Model 1) method. The best QSAR model was selected from the QSAR models that used only electronic descriptors and from those using both electronic and molecular descriptors. The best QSAR model obtained was: Log LD50 = 50.872 - 66.457 qC1 - 65.735 qC6 + 83.115 qO7 (n = 30, r = 0.876, adjusted r2 = 0.741, Fcal/Ftab = 9.636, PRESS = 2.414 x 10-6) The best QSAR model was then used to design in silico new compounds of insecticide of organophosphate derivatives with better activity as compared to the existing synthesized organophosphate derivatives. So far, the most potent insecticide of organophosphate compound that has been successfully synthesized had log LD50 of -5.20, while the new designed compound based on the best QSAR model, i.e.: 4-(diethoxy phosphoryloxy) benzene sulfonic acid, had log LD50 prediction of -7.29. Therefore, the new designed insecticide compound is suggested to be synthesized and tested for its activity in laboratory for further verification.

The hydration of α-pinene has been studied in the presence of Y-zeolite (Si/Al = 2.89) as a solid acid catalyst. The reaction was performed in batch reactor in isopropyl alcohol at various temperature and reaction time with magnetic stirrer. The acid catalyst hydration reaction of a-pinene yields a complex mixture of monoterpenes, alcohols and hydrocarbons. The selectivity of α-terpineol (the monocyclic alcohol) as main product was 59.20% with a conversion of 83.83% and the non alcoholic as the isomerization co-product as 30% after 60 min at 65 °C. The conversion and selectivity to α-terpineol increase significantly with in increase in temperature and reaction times.

Chalcone, an α,β-unsaturated ketone, has been shown have many biological activities such as anticancer and antifungi. This research was conducted to synthesize the chalcone derivatives and to obtain their cytotoxic activity on human cervix cancer cell lines. Synthesis of chalcone and its derivatives, 4II-methylchalcone, 4II-methoxychalcone, and 3II,4II-dichlorochalcone was carried out using starting materials of benzaldehide and acetofenon, p-methylacetophenone, p-methoxyacetophenone, as well as m,p-dichloroacetophenone through Claisen Schmidt condensation catalized by NaOH in ethanol at 15 °C. The purity of synthesized compounds were analyzed by thin layer chromatography, melting range, and gas chromatography. Structure elucidations were conducted by UV spectrophotometer, IR spectrometer, 1H-NMR spectrometer, as well as mass spectrometer. Cytotoxic activities were determined by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) microculture tetrazolium viability assay. The results showed that chalcone and derivatives compounds have been able to be synthesized and purified and had the same structure as a predicted structure. Chalcone had highest cytotoxic activity compared to that of its derivatives, with the IC50 values of chalcone, 4II-methylchalcone, 4II-methoxychalcone, and 3II,4II-dichlorochalcone were 9.49, 14.79, 11.48, and 24.26 µg/mL respectively. It was concluded that methyl, methoxy as well as chlorine substitution at 3 II and 4II position decrease the cytotoxic activity of chalcone.

The structures, energetic and thermodynamic parameters of crown ethers with different cavity size, electron donating/withdrawing substituent groups and donor atoms have been determined with density functional method at B3LYP level of theory in gas and solvent phase. Small core quasi-relativistic effective core potentials was used together with the accompanying SDD basis set for Sr2+ and DZP basis set was used for crown ether atoms. Natural bond orbital (NBO) analysis was evaluated to characterize the distribution of electrons on the complexes. The interaction energy is well correlated with the values of Strontium charge after complexation, the second order interaction energies (E2) and HOMO-LUMO energy gab (∆Egab). The interaction energy and thermodynamics parameters in gas phase are reduced in solvent phase as the solvent molecules weaken the metal-crown ether interaction. The thermodynamic parameters indicated that less feasibility to extract Sr2+ ion directly from pure water without presence of organic solvent. The theoretical values of extraction energy for Sr(NO3)2 salt from aqueous solution in different organic solvent is validated by the experimental trend. This study would have strong contribution in planning the experiments to the design of specific host ligand and screening of solvent for extraction of metal ion.

The capability of 15-crown-5 ethers to form complexes with some metal cations (Li+, Na+, K+, Zn2+, Cd2+ and Hg2+) was investigated by an ab initio quantum mechanical method. The calculations were performed at the RHF/lanl2mb level of theory. The interaction energies were used to evaluate the metal binding capability of the crown ether. The effect of nature of the metal on the binding properties was also studied. The results of the calculations showed that the interaction energy of the complexes increased in proportion with the ratio of ion charge, electronegativity and ionization potential to the cation diameter. In addition, based on the extraction distribution coefficient in the gas phase, it is found that the 15-crown-5 could not extract metal cations investigated.

Mahkota dewa (Phaleria macrocarpa (Scheff.) Boerl.) which is belong to family of Thymelaeaceae is one of Indonesian traditional medicines. Chemical constituent has been isolated from bark of mahkota dewa. Sample was extracted with methanol. Concentrated methanol extract was extracted by n-hexane, chloroform and ethyl acetate. A Compound that separated and purified by column chromatography from ethyl acetate extract is a red spherical crystal (m.p. 94-95 °C). Its spot gave yellow fluorescence at TLC plate (UV366) and has optical rotation of -9.3°(c. 2 mg/mL, methanol). Structure elucidation by UV, IR, 1H-NMR, 13C-NMR and NMR 2 dimension (HMQC, COSY, HMBC and DEPT-135) spectroscopy show that the compound gives a name macronone. Computational chemistry calculation using Hyperchem on the level of semiempirical method PM3 was confirmed the conformation of macronone. DPPH method shows that macronone has lower antioxidant activity compare to the ethyl acetate extract.

The hydration of a-pinene has been studied in the presence of TCA/Y-Zeolite catalyse. The catalyst was prepared by impregnating trichloroacetic acid (TCA) on support of Y-Zeolite. The TCA/Y-Zeolite catalyst converted a-pinene into hydrocarbons, while the TCA/Y-Zeolite catalyst was active and selective for producing alcohols, with a conversion of 66% and showed 55% selectivity for α-terpineol at 10 min. The reaction taken place in a solid-liquid mode and most of the α-terpineol is extracted out by the organic phase during the course of the reaction. TCA/Y-Zeolite was found as good catalyst for hydration of α-pinene to produce α-terpineol.

Ni(II) doped titanium dioxide has been prepared by using sol-gel process. Ni(II) ion was incorporated into titanium dioxide by reacting Ni(II) chloride with titanium tetraisopropoxide (TTiP)-acetyl acetone mixture in isopropanol solvent. The effects of transition metal ion doping on the physical properties have been investigated. UV/Vis spectrophotometer, TGA-DTA, X-ray diffraction (XRD) and DR-UV/Vis were used to investigate the spectra absorption of nanosol, nanoparticle thermal transition, structure of crystal and band edge absorption, respectively. The results at addition of 5% Ni/Ti revealed that absorbance of nanosol increased from 0.811 (λmax: 342 nm) to 2.283 (λmax: 350 nm). The crystallization temperature transition from anatase to rutile decreased from 500 °C to 475 °C. The particle size increased from 18.51 nm to 20.35 nm, while the band gap energy (Eg) decreased from 2.73 eV to 2.51 eV.

Mahkota dewa plant (Phaleria macrocarpa (Scheff.) Boerl.) which is included into family of Thymelaeaceae is one of Indonesia's traditional medicines. Chemical constituent has been isolated from ethyl acetate extract of leaves of mahkota dewa. Sample was extracted with methanol, concentrated then extracted by n-hexane, chloroform and ethyl acetate. The ethyl acetate extract was separated and fractionated by column chromatography. The first fraction was purified by TLC preparative and recrystalization. Compound was isolated as red-brown spherical crystal in 8 mg (m.p. 129-131 °C). Its spot gave dark fluoroscence at TLC plate (UV366) with Rf of 0.3 at TLC chromatogram with eluent of n-hexane : ethyl acetate (7:3); 0.6 with n-hexane : ethyl acetate (1:1); 0.9 with -hexane : ethyl acetate (4:6). This compound was dissolved in methanol. Compound was identified by UV, IR, 1H NMR, 13C NMR and NMR 2 dimension (HMQC, COSY, HMBC and DEPT-135) spectroscopic as 2,6,4'-trihydroxy-4-methoxybenzophenon. This compound as well as the ethyl acetate extract showed antioxidant activity on DPPH with IC50 was 10.57 and 101.06 μg/mL, respectively. This compound showed strong antioxidant activity on DPPH, almost to the standard antioxidant activity of quercetin (IC50 of 2.93 μg/mL)

Kinetic in cyclisation-acetylation of (R)-(+)-citronellal with acetic anhydride was investigated over Zn2+-Natural zeolite (Zn2+-Natzeo) as a catalyst. (R)-(+)-citronellal has been isolated from citronella oil by fractional distillation under reducing pressure. Enantioselective capillary GC on a Supelco β-DEX 225 column has been used for analysis the enantiomers ratio of citronellal. Catalyst Zn2+-Natzeo has prepared through acid activation of natural zeolite from Malang using HF 1% and HCl 6 M, followed by ion-exchange with 3 M NH4Cl and calcination at 450 °C for 1 h under nitrogen to obtained H-natural zeolite (H-Natzeo). H-Natzeo was modified to Zn2+-Natzeo by ion exchange with 0.1 M ZnCl2. Cyclisation-acetylation reaction was carried out by heating (R)-(+)-citronellal (CIT), acetic anhydride (AA), and 1 g catalyst in glass batch reactor with vigorous stirring at 80 °C. Molar ratio CIT/AA that used, i.e. 0.25; 0.5; 1.0; 1.2 and 1.5. As the reaction proceeded, 1 mL sample was taken off at 10; 20; 30; 60; 120; 180 min and extracted using n-hexane for every molar ratio. Structure analysis of product was conducted by GC-MS. Kinetic of the cyclisation-acetylation reaction was analyzed according to the Langmuir-Hinshelwood mechanism. Increasing molar ratio of CIT/AA will decrease the isopulegyl acetate (IPA) and neo-isopulegyl acetate (NIPA) formation. Rate constant of cyclisation-acetylation reaction catalyzed by Zn2+-Natzeo was 30.964-47.619 mmol(min. g cat)-1 at 80 °C, 30 min and the ratio adsorption equilibrium constant KCIT/KAA was 7.09. Keywords: Cyclisation-acetylation, (R)-(+)-citronellal, Zn2+-natural zeolite, kinetic

The computational chemistry calculation to determine the stabilization energy and ligand-ligand repulsion energies of [Co(NH3)n]2+ system was done by using LANL2DZ basis set for Co2+ and 6-31G* basis set for NH3 at the level theory of unrestricted Hartree-Fock (UHF). Result from the calculation shows that the larger number of NH3 ligand present in the complex give the effect of the lower average binding energy per ligand molecule, i.e. -503,29 kJ/mol for [Co(NH3)]2+ and then decrease to -338,025 kJ/mol for octahedral [Co(NH3)6]2+ complex. A correlation between the number of ligand and the metal ion-ligand bond distance was studied. The result shows that the metal ion-ligand bond distance increases along with the larger number of the ligand. The calculation of average pair interaction energies between Co2+ and NH3 in [Co(NH3)n]2+ complexes were done in order to determine the error possibility caused by the neglect of non-additivity contribution. The results indicate that the maximum relative error with respect to the pair potential, %ΔEavpi, is 17,64 % [Co(NH3)6]2+ complex. Keywords: unrestricted Hartree-Fock (UHF); basis set; many-body effect Corresponding Author : Harno Dwi Pranowo (harnodp@ugm.ac.id)

The effect of substituent on dibenzo-16-crown-5 (DBz16C5) and interaction between these crown ether with metal cations was evaluated using computational chemistry calculations. Substituens where are connected to the benzene ring on the DBz16C5 are -COOH, -Br, -COOC2H5, -CHO, -CH=CHCO2H, -CH=CHCO2C2H5 and -CH(OH)CH3. The analysis based on computational chemistry calculation using MNDO/d semi empirical method was done. The first step is structure optimization of crown ether followed by optimization of crown ether-metals cation complexes Mn+.[DBz16C5], where M is Li+, Na+ and Zn2+. Interactions of the crown ether and cation were discussed in term of the structure parameter of crown ether, atomic charges and energy interaction of the crown ether-metals cation. Electron donating groups increase the capability of crown ether to bind cation by means of induction effect, while electron withdrawing groups reduce the ability of crown ether to bind cation. Any substituent on the benzene in DBz16C5 which can be make the symmetrical form of the crown ether-metals cation complexes will increase the selectivity of the crown ether to bind the cation. Selectivity of the crown ether to bind cation also depends on the compatibility of the diameter of cation and cavity of crown ether. DBz16C5 has higher selectivity to bind the Na+ compare to the Li+ and Zn2+. Keywords: selectivity, dibenzo-16-crown-5, MNDO/d

The effect of water molecule addition into modeling structure of complex of substituted dibenzo-18-crown-6 ether with metal ion Na+ was studied. The aim of this research is to find information about geometrical conformation of substituted DB18C6 and its selectivity to complex/coordinate metal ion Na+ in the presence of water molecule. In this research semi empirical method was used for calculation. To find the best conformation, trial and error experiments were conducted using semi empirical method available in HyperChem 6.0, finally MNDO/d method was selected. The result of geometry optimization showed that addition of water molecule improve the stability of the conformation of substituted DB18C6 and increase the selectivity of this compound to complex metal ion Na+. The presence of electron-withdrawing substituents decreased the binding energy while that of electron-donating one increase the binding energy (value of DE more negative). Cavity radii of DB18C6 in the presence of water molecule extended from 2.3 Å to 2.6 Å. This figure is almost similar to that of experimental data. Keywords: Crown ether, molecular modelling, semiempirical method

The Quantitative Structure-Activity Relationship (QSAR) study was established on curcumin and its derivatives as glutathione S-transferase(s) (GSTs) inhibitors using atomic net charges as the descriptors. The charges were resulted by semiempirical AM1 and PM3 quantum-chemical calculations using computational chemistry approach. The inhibition activity was expressed as the concentration that gave 50% inhibition of GSTs activity (IC50). The selection of the best QSAR equation models was determined by multiple linear regression analysis. This research was related to the nature of GSTs as multifunctional enzymes, which play an important role in the detoxification of electrophilic compounds, the process of inflammation and the effectivity of anticancer compounds. The result showed that AM1 semiempirical method gave better descriptor for the construction of QSAR equation model than PM3 did. The best QSAR equation model was described by : log 1/IC50 = -2,238 - 17,326 qC2' + 1,876 qC4' + 9,200 qC6' The equation was significant at 95% level with statistical parameters : n = 10, m = 3, r­ = 0,839, SE = 0,254, F = 4,764, F/Ftable = 1,001. Keywords: QSAR analysis, curcumin, glutathione S-transferase(s) (GSTs), atomic net charge

A Monte Carlo simulation was performed for Co2+ in 18.6 % aqueous ammonia solution at a temperature of 293.16 K, using ab initio pair potentials and three-body potentials for Co-H2O-H2O, Co-NH3-NH3 and Co-H2O-NH3 interactions. The first solvation shell consists average of 2.9 water and 3.2 ammonia molecules, and the second shell of 10.4 water and 11.2 ammonia molecules. The structure of the solvated ion is discussed in terms of radial distribution functions, angular distributions and coordination number. Keywords: Molecular simulation, Monte Carlo simulation, solvation, ab initio

Quantitative Electronic Structure Activity Relationship (QSAR) analysis of a series of benzalacetones has been investigated based on semi empirical PM3 calculation data using Principal Components Regression (PCR). Investigation has been done based on antimutagen activity from benzalacetone compounds (presented by log 1/IC50) and was studied as linear correlation with latent variables (Tx) resulted from transformation of atomic net charges using Principal Component Analysis (PCA). QSAR equation was determinated based on distribution of selected components and then was analysed with PCR. The result was described by the following QSAR equation : log 1/IC50 = 6.555 + (2.177).T1 + (2.284).T2 + (1.933).T3 The equation was significant on the 95% level with statistical parameters : n = 28 r = 0.766 SE = 0.245 Fcalculation/Ftable = 3.780 and gave the PRESS result 0.002. It means that there were only a relatively few deviations between the experimental and theoretical data of antimutagenic activity. New types of benzalacetone derivative compounds were designed and their theoretical activity were predicted based on the best QSAR equation. It was found that compounds number 29, 30, 31, 32, 33, 35, 36, 37, 38, 40, 41, 42, 44, 47, 48, 49 and 50 have a relatively high antimutagenic activity. Keywords: QSAR; antimutagenic activity; benzalaceton; atomic net charge

D6-anhidroeritromisin-A is a new derivative of erythromycin which is synthesized through biosynthetic engineering technique. The molecular docking in rRNA 23S Deinoccocus radiodurans are accomplished to determine the model and strength of binding to the target macromolecule. The molecular docking of erythromycin-A and 6-deoksieritromisin-A to the same macromolecule is used as a control. The docking result of the D6-anhidroeritromisin-A shows that it occupies the same cavity as of the experimental erythromycin-A in the same macromolecule. The binding position of D6-anhidroeritromisin-A is not exactly same as erythromycin-A and 6-deoksieritromisin-A due to the presence of D6 unsaturated double bond. However the hydroxyl group(OH) at C-6 does not have an apparent effect on the binding model to rRNA23S D. radiodurans. Keywords: D6-anhidroeritromisin-A, rRNA 23S D. radiodurans, molecular docking, antibiotic potency

Monte Carlo simulations were performed for I-, Br- and Cl-, in water using ab initio pair potential. The systems consisting of one anion in 215 solvent molecules have been simulated at 298 K. Anion-water pair potentials have been newly developed based on ab initio calculations of split valence basis set plus polarization quality. The structure of the solvated ion is discussed in terms of radial distribution functions, coordination number and pair potential distribution. Structural properties were investigated by means of radial distribution functions and their running integration numbers, leading for the first solvation shell to an average 12.60 H2O around I- with I--O distance of 3.74 Å and I--H distance of 2.86 Å, 11.84 H2O around Br- with Br--O distance of 3.40 Å and Br--H distance of 2.42 Å, and 10.68 H2O around Cl- with Cl--O distance of 3.20 Å and Cl--H distance of 2.24 Å, respectively. The structure of the water-anion complexes are agreed with dipole orientation. Pair energy distribution of hydrated anions showed that the pair interaction energy are increase from I-, Cl-, to Br-, namely, -6.28, -9.98 and -13.67 kcal/mol, respectively. The coordination number distribution analysis for the first solvation shell of the all hydrated anions indicated a high exchange rate for the first solvation shell ligands. Keywords: Monte Carlo simulation, halogen anion, ab initio

The structure and binding energies of 12-crown-4 and benzo-12-crown-4 complexes with Li+, Na+, K+, Zn2+, Cd2+, and Hg2+were investigated with ab initio calculations using Hartree-Fock approximation and second-order perturbation theory. The basis set used in this study is lanl2mb. The structure optimization of cation-crown ether complexes was evaluated at HF/lanl2mb level of theory and interaction energy of the corresponding complexes was calculated at MP2/lanl2mb level of theory (MP2/lanl2mb//HF/lanl2mb). Interactions of the crown ethers and the cations were discussed in term of the structure parameter of crown ether. The binding energies of the complexes show that all complex formed from transition metal cations is more stable than the complexes formed from alkali metal cations. Keywords: 12-crown-4, benzo-12-crown-4, alkali metals, transition metals

Research on comparison between Hartree-Fock method and electron correlation methods as well as the effect of size of basis sets on representing interaction of Co2+-NH3 observed from complex energy parameters and optimum geometric parameters have been carried out.The first step is screening basis sets based on charge transfer effect and BSSE value. The selected basis set does not yield charge transfer at 1,4 Å

Electronic structure and inhibition activity relationship study of curcumin analogs has been established for 29 curcumin analogs on Ethoxyresorufin O-Dealkylation (EROD) reaction using atomic net charge descriptor based on AM1 semiempirical calculations. The QSAR (Quantitative Structure and Activities Relationships) equation model was determined by statistical parameter from multiple regression analysis and leave-one-out cross validation method. The best QSAR equation was described: Keywords: curcumin, QSAR, descriptor, atomic net charge, semiempirical methods.

The aim of this research is to find information about the substituent effect to the structure of crown ether benzo-15-crown-5 (Bz15C5), dibenzo-16-crown-5 (DBz16C5) and dibenzo-18-crown-6 (DBz18C6), and also crown ether selectivity to coordinate a Li+ metal cation. The presence of substituent could change the conformations flexibility of crown ether during interact with metal cation. In this research semi empirical MNDO/d method was used for calculations. Firstly, geometry optimization was conducted to crown ethers structure using MNDO/d methods. The next steps were running the geometry optimization of complexes between cation Li+ with crown ethers. Data were produced from these calculation are the parameter of crown ether structures, structures of the complexes, and the binding energy of the cation-crown ethers. The presence of electron-withdrawing substituents decreased the binding energy while that of electron-donating one increase the binding energy (value of ΔE more negative). The substituents which are increase the degree of symmetry of the cation-crown ether complexes could give the increase of crown ether selectivity to bind the cation. Selectivity of crown ether to bind the cation depends on the structural match between ionic radii of crown ether cavity (the ion-cavity size concept). Bz15C5 what has higher selectivity to bind Li+ than DBz16C5 and DBz18C6. Keywords: selectivity, crown ether, MNDO/d.