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The synthesis, in vitro antimalarial assay, molecular docking, drug-likeness analysis, and ADMET prediction of substituted 3-styryl-2-pyrazoline derivatives as antimalaria have been conducted. The synthesis of N-phenyl (1a‒3a) and N-acetyl-substituted (1b‒3b) 3-styryl-2-pyrazolines was carried out using dibenzalacetone derivatives and hydrazine hydrate or phenylhydrazine. An in vitro antimalarial assay was conducted against the chloroquine-sensitive Plasmodium falciparum 3D7 strain, while molecular docking was performed toward the crystal protein of Plasmodium falciparum dihydrofolate reductase-thymidylate synthase (PfDHFR-TS) (PDB ID: 1J3I). Furthermore, the prediction of drug-like properties was determined by assessing Lipinski’s rules, and the pharmacokinetic parameters were also studied in-silico, including absorption, distribution, metabolism, excretion, and toxicity (ADMET). The in vitro assay showed that 3a (IC50 0.101 µM) has excellent antimalarial activity, followed by 2a (0.177 µM), and 1b (0.258 µM). Molecular docking has supported the in vitro assay by showing the lowest CDOCKER energy for 3a (‒56.316 kcal/mol), then 2a (‒51.2603 kcal/mol), and 1b (‒48.8774 kcal/mol). The drug-like properties showed that all of the prepared compounds were acceptable based on Lipinski’s rules and predicted to be potentially orally bioavailable. The ADMET analysis provided information that 3a and 2a could be proposed as the best lead antimalarial drugs with further modification to reduce the lipophilicity and toxicity properties.

Two vanillin-hydrazone compounds as the colorimetric amine detection during chicken meat spoilage are described. Two hydrazone compounds (1 and 2) have been synthesized from the condensation reaction of vanillin with phenylhydrazine and 2,4-dinitrophenylhydrazine. Their properties for colorimetric recognition of amine were determined by the naked eye and UV-vis spectra. Their properties as amine indicators were investigated toward primary amine: butylamine (BA); secondary amine: dimethylamine (DMA), diethylamine (DEA); tertiary amine: triethylamine (TEA), and also ammonia (Amm). The hydrazone 1 in DMSO showed no significant color changes (colorless) after the addition of amines solution. Hydrazone 2 (5×10-5 M in DMSO) showed color changes from yellow to violet in the presence of ammonia, DEA and BA, to reddish-violet for DMA, and light brown after addition of TEA solutions. The colorimetric amine detection by vanillin-hydrazone 2 could recognize the real amine during chicken meat spoilage from yellow to light brown after 24 h storage at room temperature.

Aminoalkylated chalcone compounds (4a-4c) have been designed using Quantitative Structure-Activity Relationship (QSAR) analysis, synthesized and evaluated for their in vitro antimalarial activity. The best QSAR model obtained was log IC50 = 705.132 (qC7) - 65.573 (qC3) - 24.845 (qC4) - 4.634 (qC13) - 220.479 and statistical analysis showed R2 of 0.937, suggesting that the QSAR model was able to predict the actual antimalarial activity by 93.7% accuracy. The addition of secondary amines to the chalcone compounds was successfully carried out using the Mannich reaction, which was confirmed by spectroscopic analysis. The in vitro antimalarial activity of the synthesized compounds were screened against the 3D7 strain of Plasmodium falciparum (CQ sensitive). All of the compounds exhibited strong activity with IC50 values ranging from 0.54 ± 0.649 to 1.12 ± 0.369 µM. The molecular docking studies investigated interactions of the prepared compounds to the binding site of wild-type Plasmodium falciparum dihydrofolate reductasethymidylate synthase (Pf-DHFR-TS) (PDB ID: IJ3I) and quadruple mutant Pf-DHFR-TS (PDB ID: IJ3K). Some hydrogen bond and π – π interactions were observed with the side chain of Ala16, Asp54, Cys15, Leu164, Tyr170, and Met55 in both the wild and mutant Pf-DHFR types. It has also been found that all the tested compounds were obeyed the Lipinski’s rule. This study proposed that compound 4b can be developed as the new lead of the antimalarial agent.

Fatty acid and monoglyceride are examples of lipid compounds that can be founded in vegetable oils. The fatty acid has an important role in the human diet, lubricants, detergents, cosmetics, plastics, coatings, and resin. Monoglyceride has a wide function in the food industry in particular as natural emulsifier, pharmaceuticals, cosmetics, antioxidant, and antibacterial. Therefore, isolation and preparation of fatty acid and monoglyceride are the crucial step. This article focuses on providing the chemical reaction paths of isolation fatty acid and synthesis of monoglyceride from vegetable oils. Fatty acids could be isolated by Colgate-Emery steam hydrolysis, hydrolysis of vegetable oils using inorganic base catalyst or lipase, and base-catalyzed hydrolysis of pure fatty acid methyl ester. There are three steps in the synthesis of pure fatty acid methyl ester which are neutralization, transesterification, and fractional distillation. There are four reactions paths in preparing monoglyceride from vegetable oils. They are glycerolysis, ethanolysis using lipase enzyme (sn-1,3), esterification of fatty acid with glycerol in the presence of inorganic acid catalyst or lipase, transesterification of fatty acid methyl ester with glycerol, transesterification of fatty acid methyl ester with protected glycerol (1,2-O-isopropylidene glycerol), and deprotection using an acid resin (Amberlyst-15).

An attempt of synthesis 2-monolaurin from lauric acid through trilaurin as an intermediate compound has been successfully conducted. Trilaurin has been afforded via esterification reaction of lauric acid and glycerol with yield and purity of 78 and 84% respectively. Ethanolysis reaction of trilaurin using Lipozyme TL IM enzyme resulted in the formation of 2-monolaurin in a yield of 60 % and purity of 97%.

C-4-phenacyloxy phenyl calix[4]resorcinarene (CPPCR) was synthesized by acidic condensation of 4-hydroxybenzaldehyde and resorcinol. The adsorption of CPPCR for Pb(II), Cd(II) and Cr(III) has been studied by measuring the metal concentration in aqueous solution using Atomic Absorption Spectrophotometry (AAS). The effects of solution pH, contact time and initial concentration of metal ions on the adsorption capacity of CPPCR were investigated. The adsorption kinetic of all the ions obeyed the Ho and McKay pseudo 2nd order rate law and the adsorption isotherm profile matched very well with Langmuir model. The separation factor (RL) of CPPCR for Pb(II), Cd(II) and Cr(III) were 0.190, 0.017, and 0.065, respectively, indicating the formation of monolayer behaviour. The Gibb free energy (ΔG) of the adsorption for all the metal ions have negative values indicating the adsorption process of Pb(II), Cd(II) and Cr(III) by CPPCR are spontaneous.

Resistance to antibacterial drugs is a problem in the global public health that must be conquered immediately by finding new antibacterial drugs. This study has been carried out to rationally design fluoroquinolone derivative compounds as antibacterial using QSAR method. The basis set used for molecular optimization was semiempirical Austin Model 1 (AM1) and the statistical analysis used was multilinear regression (MLR). The best QSAR equation model obtained was Log MIC50 = 473.758 – 92.342 (qC9) + 461.068 (qO11) + 192.743 (qC16) – 277.851 (qC20) + 1004.598 (LUMO).

Objective: To synthesize chalcone derivatives and investigate their antimalarial activity toward chloroquine-sensitive Plasmodium falciparum 3D7 (Pf3D7) strain; to develop quantitative structureactivity relationships (QSAR) model to estimate IC50 values for biological activity of antimalarial and compared to experimental measurement; and to determine the binding interactions of the most active compounds with targeting P. falciparum dihydrofolate reductase-thymidylate synthase using molecular docking simulation. Methods: Seven chalcone derivatives have been synthesized from substituted acetophenone and substituted benzaldehyde in ethanol with the presence of bases catalysis at reflux condition. The QSAR analysis was conducted by using Gaussian 09 software to predict IC50 value for antimalarial activity. The in vitro test was evaluated against the chloroquine-sensitive Pf3D7 strain. Finally, the docking studies were performed with the CDOCKER protocol under the receptor-ligand interaction section in Discovery Studio® 3.1 (Accelrys, Inc., San Diego, USA). Results: Among the synthesized chalcone, a prenylated chalcone 5c and an allylated chalcones 10a showed the best IC 50 values of 1.08 and 1.73 μg/mL respectively against Pf3D7 strain (1.37 and 2.33 μg/mL based on QSAR analysis). Comparison between the prediction of IC50 value generated from the QSAR and the outcome from an in vitro assay showed a similar result as seen from the r2 value (r2 = 0.99). The most active compound 5c was employed in the docking simulation to determine the potential binding interactions with active sites of P. falciparum dihydrofolate reductase-thymidylate synthase (protein data bank ID: 1J3I). The docking simulation study showed 5c bind well with Ala16, Ser108, Ile164, Trp48, and Phe58 which are the crucial interactions that could possibly interrupt the sequential catalysis reactions in the thymidylate cycle and subsequently prevent deoxythymidine monophosphate production and DNA synthesis. The formed binding interaction (H-bond) toward residues of Ala16, Ser108, and Ile164 also indicate the activity of 5c against chloroquine-resistance P. falciparum strain. Conclusions: We have successfully determined the effects of some chalcone derivatives on antimalarial activity against the chloroquine-sensitive Pf3D7 strain. Compound 5c and 10a were described a good antiplasmodial compounds. Interestingly, these in vitro results relevance with IC50 predicted QSAR studies. Moreover, molecular docking simulation provided insight into the binding modes of 5c into the anti-folate resistance from malarial P. falciparum.

The synthesis of 1-monoolein has been carried out through a two-step reaction: transesterification of ethyl oleate and 1,2-acetonide glycerol in the presence of sodium carbonate as a catalyst, and followed by deprotection using an Amberlyst-15 catalyst in ethanol. The transesterification reaction of ethyl oleate could produce 1,2-acetonide-3-oleoyl glycerol as a yellow liquid with a yield of 74%. Meanwhile, the deprotection of the intermediate compound could afford 1-monoolein as an unstable white soft solid in a yield of 59% and melting point at 35-37 °C.