MID SEMESTERS EXAM ANSWERS CHEMISTRY OF NATURAL PRODUCTS

NAME : DESI FEBRIANTI

NIM : RSA1C110011

1.    how to convert a compound of natural ingredients that do not have the potential (inactive) can be made into a superior compound that has the potential of high biological activity that is the way the sample determination, preparation and extraction, phytochemical screening test, test taksisitas, antioxidant test, column chromatography, and the determination molecular structure.
For example: the ant nest
The results of the study on the color reaction test showed that the extract contains phenols, polyphenols, tannins and flavonoids. TLC test showed positive extract contains tannins and flavonoids. Antibacterial test method used in this study by measuring the clear zone pitting caused by the ethanol extract of tubers anthill with a concentration of 10%, 20%, 30%, 40%, and 50%. Positive controls used were ciprofloxacin 50ppm and negative controls were: DMSO. The results showed that the average diameter of clear zone obtained from the concentration of 10% to 50% is 1.540 cm, 1.752 cm, 1.945 cm, 2.033 cm and 2.076 cm. Research data obtained was analyzed by using the non-parametric Anova test krusskal-wallis test and Mann-Whitney test. The results of this study concluded that ethanol extract of tuber anthill has antibacterial activity against Staphylococcus aureus ATCC 25923 growth and there is a power difference between the concentration of antibacterial extract given.

2.    In nature there are many chemical compounds that have benefits for humans, especially as drugs but sometimes the presence of these compounds is very limited so the chemist and pharmacy trying to make a clone of the compound in the laboratory in which we are familiar with the term synthesis. One example is the compound kalkon:
Kalkon is one of a group of flavonoids that are very limited distribution in nature and is found only in a few groups of plants in small amounts. On the other hand, this kalkon compounds have useful biological activities, such as antioxidant, anti-inflammatory and antibacterial properties, so it needs an effort to get kalkon compounds by synthesis. From several studies suggest that group-containing compound kalkon methylenedioxy (-O-CH2-O-) have activity as an antibacterial, so in this study will be the synthesis of compounds derived kalkon with piperonal and Acetophenone. Synthesis of 3,4-metilendioksikalkon through Claisen-Schmidt condensation reaction between piperonal and Acetophenone using NaOH catalyst with various Concentrations of NaOH catalyst is added at 40%, 50%, 60%, 70% and 80%. Results extracted using methylene chloride and then the solvent is evaporated using a rotary evaporator. The next stage characterization of physical properties of synthetic products and their structures analyzed using a spectrophotometer UV-Vis and FT-IR. After that tested the antibacterial activity against bacteria E. coli and S. aureus. Compounds synthesized solid form, is yellow and has a melting point of 80-85 ° C. UV-Vis Data converting the presence of two peaks, namely at λ 264 nm roomates is the absorption of benzoyl and λ 358 nm is the absorption sinamoil roomates. Data shows IR absorption spectra of the carbonyl group (C = O) at wavenumber 1658.7 cm-1, C = C aromatic absorption at wavenumber 1589.2 cm-1 and absorption at wavenumber 2923.9 cm-1 shows vibrational Csp3-H of methylene group (CH2 ). From these data it can be concluded that the compound 3,4-metilendioksikalkon been formed. Highest Yield of 72.58% was obtained at a concentration of 70% NaOH. From the results of the antibacterial test, the greatest inhibition zone Occurs at Concentrations of 3% roomates is 3 mm against E. coli and 2.5 mm against S. aureus.

3.    Determination of the principal rules of the solvent compounds is a natural material choice of solvent to be used in the extraction process. Principles underlying the selection of a solvent in the extraction process is a rule of "like dissolve like ', polar compounds roomates means should be analyzed together with polar solvents. Extraction is generally performed for the separation of the laboratories, such as the separation of organic compounds (organic phase) of the aqueous solution (water phase) by using a solvent is not miscible roomates (Harvey 2000).
In the selection of the solvent to be used, be aware of the nature of chemical Constituents (metabolites) to be extracted. Important property is polar and polar groups on the compound to be extracted as an OH group, COOH, as well as other functional groups. By knowing the nature of the metabolites be extracted, it can Easily be selected a suitable solvent by polar metabolites and solvents. Polar compounds dissolve in polar solvents and non-polar compounds dissolve in non-polar solvents. In general, the extraction is done in a row starting with non-polar solvents (hexane or benzene) and a semi-polar solvents (ethyl acetate or diethyl ether), and then with a polar solvent (methanol or ethanol). Would thus obtained crude extract containing consecutive non-polar compounds, semi-polar and polar compounds (Hostetmann et al. 1997). Extraction with non-polar solvents Usually required for the removal of fat before it is extracted with a suitable solvent. Thus, the extracts be obtained free of fat (Harborne 1996).
For example:
1) material flavonoid compounds from plants that are commonly used polar solvents such as ethanol and methanol. Flavonoids are compounds that will dissolve in the polar solvent methanol and ethanol Because it has the same polarity properties. In addition to soluble polar, several flavonoid compounds are also known to be separated by semi-polar solvent. Likely this is due to the nature of polar compounds roomates growing niche to dissolve in polar solvents with higher levels lower
2) alkaloids, caffeine such as coffee powder dissolved in diethyl ether is non-polar Because so as to dissolve the caffeine roomates is also non-polar, but is also due to the low boiling point of chloroform. Because if the high boiling point solvent means possible to approach the boiling point of caffeine can lead to caffeine obtained crystals evaporate so little. With a low boiling point solvent, allowing it to evaporate only kloroformnya.
3) terpenoids soluble organic compounds such as ethers and alcohols.
4) Steroids have semipolar properties can be extracted with chloroform. Moreover, it can also by fat solvents such as ether, benzene, carbontetrachlorida, xylene and alcohol.

4.    Examples of compounds of structural determination of caffeine, can be done with infrared spectroscopy. To produce the following data:


With infrared spectroscopy, the structure of caffeine contained in the sample can be determined, ie the typical absorption data from multiple functional groups, or with menbandingkan with standard IR spectrum of caffeine. From the results, it can spektorskopi diketahhui compound structure through cluster-Sugus functions contained therein.