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One of the secondary metabolites contained in the leaf of Fig (Ficus carica L.) is flavonoid type, which has the potential as pancreatic lipase inhibitors, so it can inhibit lipid adsorption and act as anti-obesity drug. The aims of this study are to 1) isolate flavonoid from fig leaf that has activity as pancreatic lipase inhibitor; 2) determine the inhibitory power of the isolate relative to the orlistat (a commercial anti-obesity drug); and 3) determine the type of flavonoid isolate based on its UV and IR Spectra and molecular mass. This study was conducted in four stages, namely 1) extraction, isolation, and phytochemical analysis of flavonoids isolate, (2) in vitro analysis to determine the inhibition power of flavonoid isolates against pancreatic lipase; (3) identification and structure determination of flavonoid isolates using UV-Vis, FTIR and LC-MS/MS spectroscopy, and (4) in silico analysis using flavonoid isolate structure as ligand and porcine pancreatic lipases as receptor. This study was able to isolate some of the flavonoid compounds from ethanol extracts of fig leaf and all of them have a higher inhibitory power against pancreatic lipase than Orlistat has. Flavonoid isolate with highest inhibitory power of fig leaf contains luteolin, that has greater binding affinity than Orlistat, in silico analysis, but at different position. [ABSTRACT FROM AUTHOR]

The 9-(4-bromophenyl)-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione (Compound 1) was successfully synthesized using the green synthesis method. The purpose of the use of a green catalyst lemon juice and ultrasound-assisted method was to reduce temperature, time, and hazardous waste reaction. Uncatalyst reaction produced the yield of compound 1 47.31 % when water was used as the solvent. On the other hand, there was an increase in yield when lemon juice was used as an acidic catalyst, and the yield changed to 59.14%. Meanwhile, another product was formed in significant amounts when we used these methods. The product was 2-(4-bromo benzylidene) cyclohexane-1,3-dione (Compound 2). These reaction results will be discussed further in the talk. The antibacterial test shows that compound 1 has no antibacterial activity against Staphylococcus aureus and Escherichia coli. [ABSTRACT FROM AUTHOR]

The purpose of this research are to synthesis methyl ester from used cooking oil refined with zeolite and activated pumice and to investigate its potential as biodiesel. The research stages were activating the natural zeolite and pumice with temperature variations of 500 and 600 °C, refining waste cooking oil with various concentrations, trans-esterification of refined waste cooking oil, characterization and identification of methyl esters by using Gas Chromatography-Mass Spectrometry (GC-MS). The best refining was resulted from free fatty acids and clarity at a concentration of 30% natural zeolite with a yield of 67.17%. The trans-esterified methyl esters have a density of 0.881 g/mL, refractive index of 1.447, viscosity of 4.92 cSt, acid number of 0.49 mg-KOH/g, and saponification number of 198.8 mg-KOH/g, which have high potential as biodiesel. The main components of trans esterified methyl ester from refined waste cooking oil are methyl palmitate, methyl oleate, and methyl stearate with the compositions of 46.27, 40.26, and 5.19%, respectively. [ABSTRACT FROM AUTHOR]

Potassium and sodium fatty acid salts as an alkali soap are a type of surfactant potentially used for their antibacterial activity. Traditionally, this material is prepared from triglyceride oil with potassium or sodium hydroxide through a saponification reaction. The research synthesized potassium fatty acids salt (potassium soap, K-soap) from olive oil and examined the antibacterial activity. Potassium soap was prepared by reacting olive oil with potassium hydroxide through the saponification reaction. Properties of the as-synthesized soap are a yellowish-white solid, melting point of 200- 204 ℃, and soluble in water, methanol, and ethanol. Antibacterial activity against Staphylococcus aureus and Escherichia coli with MIC < 1% indicated that it possessed great potential as antibacterial agent. [ABSTRACT FROM AUTHOR]

One of the factors that determine the effectiveness of an alcohol esterification reaction is the group attached to the acyl chain. The study of the esterification reaction of menthol with acetic acid and its derivatives has been carried out with success. The esterification reaction of menthol was carried out with glacial acetic acid, acetic anhydride, and acetyl chloride. The effectiveness of esterification, both from the yield and the resulting content of menthyl acetate, shows that acetyl chloride is best effective, followed by acetic anhydride and acetic acid in its esterification against menthol. [ABSTRACT FROM AUTHOR]

The characteristics of yogurt are influenced by the concentration of the starter and incubation time. This study aims to determine the effect of variations in starter concentration and incubation time on the characteristics of yogurt. To achieve this objective, the study was carried out through several stages, namely sample preparation (pasteurization of cow's milk); incubation of cow's milk yogurt with variations in starter concentration and incubation time; characterization of the physical and chemical properties of yogurt. The physical properties were investigated through organoleptic tests of color, aroma, taste, and texture, along with pH and viscosity tests. In contrast, the chemical properties were analyzed from the total acid levels and protein levels. The results show that the variation in the treatment of yogurt production significantly affects the physical and chemical characteristics of the yogurt produced. The produced yogurt's pH is in the range of the standard value set by Food Standards Australia New Zealand (FSANZ). Besides, the amount of produced yogurt's total acid and protein concentration in this study are also met in the standard value set by the Indonesian national standard of yogurt. Moreover, the Mann-Whitney test results show excellent characteristics of yogurt produced. It has a soft texture, a distinctive aroma of yogurt, sour flavor, and white color. [ABSTRACT FROM AUTHOR]

The 1,8-dioxo-octahydroxantene has many derivates. One of those is 9-(4-hydroxyphenyl)-3,4,6,7-tetrahydro-2H-xanthene-1,8(5H,9H)-dione. This compound has been successfully synthesized from 4-hydroxybenzaldehyde and 1,3-cyclohexanedione. This reaction has been catalyzed by lime and lemon juice under the free solvent condition. It is assumed that citric acid in both materials has a role in catalyzing this reaction. The advantages of using them as catalysts are biodegradable, environmentally safe, and cheap. Besides that, the synthesis of this compound only required one reaction stage, and the product was easily purified. The structure of the pure product was determined by FT-IR, H-NMR, and GC-MS. The antioxidant activity of this compound was investigated by the DPPH method. This compound had an antioxidant activity with inhibition percentage over 53.42%. [ABSTRACT FROM AUTHOR]

Synthesis of 9-(4-bromophenyl)-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione (compound 1) using lime and lemon juices as catalyst under free solvent condition has been successfully done. Both fruits contained citric acid, which operates as an acidic catalyst. The structure of compound 1 was confirmed by IR, H-NMR, and MS spectra. The use of the natural product as a green catalyst has some advantages, that is eco-friendly, cheap, high availability, and biodegradable. DPPH methods were used as methods to determine the antioxidant properties of compound 1. This compound has properties as antioxidant with inhibition percentage of 59.20%, 65.38%, 67.41%, 68.53%, 70.0% at 2, 4, 6, 8, and 10 ppm respectively. [ABSTRACT FROM AUTHOR]

The heterogeneous catalysts in biodiesel synthesis is more environmentally friendly and reusable. Alkaline earth oxides are less alkaline than alkaline oxides. Biodiesel is an alternative fuel, which has been started to be developed as a renewable energy. The aim of this study was to synthesize biodiesel from low-quality crude palm oil (CPO) with heterogeneous catalyst of MgO-K2O using ultrasonic waves. The stages in this study were (a) activation of natural zeolites, (b) refining of low quality of CPO, (c) synthesis of MgO-K2O catalyst at ratio of 10 : 1, 10 : 2, 10 : 3 (MgO : KOH) and (d) transesterification of esterified CPO (variations in the amount of catalyst 10%, 15%, and 20%). This research achieved the optimum conditions for methyl ester synthesis at ratio of 10 : 2 (MgO : KOH) of catalyst composition (15% w/w of oil), and the yield was 88.086%. The character of the methyl ester was in accordance of Indonesian biodiesel standard, therefore, the methyl ester obtained has the potential as biodiesel. The composition of the synthesized methyl ester were 1.96% methyl myristate, 40.42% methyl palmitate, 44.32% methyl oleate, and 7.46% methyl stearate. [ABSTRACT FROM AUTHOR]

The research objectives are the antibacterial activity of peanut oil and its derivatives determination. The derivatives are potassium salt (K-salt or K-soap), free fatty acids (FFAs), and fatty acid methyl esters (FAMEs) against Staphylococcus aureus and Escherichia coli bacteria. Peanut oil is a liquid light yellow, having density of 0.9372 g.cm−3, viscosity of 230.88 cSt, boiling point of 188 °C, refractive index of 1.4689, soluble in n-hexane, chloroform, and ethanol, but insoluble in methanol and water. The fatty acid contents are palmitic, and stearic acids of 11.46, 16.14, 67.44, and 4.96% respectively. Synthesized K-salts are solid-state and white, have melting point of 208-217 °C, are soluble in water, ethanol, and methanol, but are insoluble in n-hexane and chloroform. There are two FFAs, namely liquid and soft solid. Liquid FFAs are yellowish-white, have density of 0.9560 g.cm−3, viscosity of 462.17 cSt, boiling point of 192 °C, and refractive index of 1.4683. Soft solid FFAs are yellowish-white, and have melting point of 30-35 °C. The FAMEs are liquid yellowish-white, have density of 0.9009 g.cm−3, viscosity of 23.50 cSt, boiling point of 170 °C, and refractive index of 1.4580. The FFAs (liquid and soft solid) and FAMEs are soluble in ethanol, methanol, chloroform, and n-hexane, yet insoluble in water. FFAs and K-salt are active as antibacterial with MIC < 0.2%. [ABSTRACT FROM AUTHOR]

The aim this study is to perform synthetic compound of 9-(4-hydroxy-3-methoxyphenyl)-3,3,6,6-tetramethyl- 3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione (1a) and 9-(3-ethoxy-4-hydroxyphenyl)-3,3,6,6-tetramethyl- 3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione (1b) (1,8-dioxo-hydroxanthene derivates) derivate from vanillin and to determine their antibacterial activity against various bacteria such as Staphylococcus epidermidis, Propionibacterium acnes, Staphylococcus epidermidis, Bacillus subtilis, Salmonella typhimurium, and Pseudomonas aeruginosa. Compound 1a and 1b were synthesized from dimedone and aromatic aldehyde (vanillin and ethyl vanillin) in the presence of concentrated sulfuric acid and ethanol as solvent. Their antibacterial activity was determined by well diffusion assay method with measuring zone of inhibition in mm. Two derivatives of 1,8-dioxo-octahydroxanthene (compound 1a and 1b) has been successfully synthesized. Compound 1b has very strong antibacterial activity against Staphylococcus epidermidis with inhibition zone 23,38 mm and compound 1a has medium antibacterial activity against P. acnes, S. epidermidis, B. subtilis, S. typhimurium, and P. aeruginosa. The susbtitution of the methoxy group attached to the aromatic aldehydes with an ethoxy group enhance the antibacterial activity of 1,8-dioxo-hydroxanthene compounds. [ABSTRACT FROM AUTHOR]

Enhancement of bacterial resistance has not been comparable by the development of new antibacterial, therefore the search for substances that have the potential as antibacterial needs to be developed. One of the substances that have antibacterial activity is fatty acids obtained through the hydrolysis of triglyceride acids (oils or fats). Triglyceride oils are contained in many plants, especially in their seeds. Candlenut seeds (Aleurites moluccana) contain triglycerides, reaching 55-66% of the weight of the seeds. This study aims to determine the antibacterial activity of candlenut oil derivatives, namely potassium soap, fatty acids, and their methyl esters. Stages of the research carried out include: (1) synthesis, characterization, and identification of potassium soap (2) synthesis, characterization, and identification of fatty acids, (3) synthesis, characterization, and identification of methyl esters, and (4) antibacterial activity test for potassium soap, fatty acids, and methyl esters against Staphylococcus aureus and Escherichia coli. The results showed that potassium soap, fatty acids, and methyl esters had antibacterial activity. Inhibition zone diameters produced by potassium soap, fatty acids, and methyl esters at a concentration of 1% against Staphylococcus aureus respectively 12.07, 8.75, and 6.67 mm and against Escherichia coli 12.18, 11.02, 7.32 mm, while at a concentration of 2% against Staphylococcus aureus respectively 13.20, 9.77, 7.33 mm and against Escherichia coli 14.00, 13.23 and 8.70 mm. [ABSTRACT FROM AUTHOR]

This paper describes the first-year chemistry students’ attitude towards chemistry subject. 49 first-year students participated in the study. A set of questionnaire consisted of 30 statements was applied to map chemistry students’ attitude towards chemistry. The Likert scale ranging from 1 (strongly disagree) to 5 (strongly agree) was employed in each statement. The study revealed a strong belief among most first-year chemistry students that chemistry knowledge contributes significantly to their daily life. The students declared a positive attitude towards chemistry in term of the importance, usability, attractive and relevance of chemistry. For the difficulty aspect, the students exhibited a neutral attitude. [ABSTRACT FROM AUTHOR]