Ujian
mid semester kimia bahan alam
Pauline
Dewi Trian 2010
Pgsbi
2010
1. Put
forward your ideas how to convert a compound of natural ingredients that do not
have the potential (inactive) can be made into superior compounds that have a
high potential for biological activity. Give the example.
answer
Way
of altering a compound derived from nature such as methane (CH4) from organic
waste that was originally an inactive compound. Methane formed by the
fermentation process is anaerobic (without air) by methane bacteria called
biogas, anaerobic bacteria and bacteria that reduce waste that contains organic
matter (biomass), forming methane (CH4), which when burned to produce heat
energy . Actually, in some places this process occurs naturally as a gas
explosion incident that formed beneath a pile of garbage in the landfill (TPA).
Methane gas with LPG (liquidified petroleum gas / LPG), the difference is that
methane has one C atom, whereas LPG more.
Culture
of Egypt, China and ancient Rome have been known to take advantage of this
natural gas is burned to produce heat. However, the first to link the gas fuel
with vegetable material decomposition was Alessandro Volta (1776), while Willam
Henry in 1806 identified a gas that can burn such as methane. Methane in the biogas,
when the fire will be relatively more cleanly than coal and produce more energy
with carbon dioxide emissions less. Carbon in biogas is carbon taken from the
atmosphere by photosynthesis of plants, so releasing it into the atmosphere
will not increase the amount of carbon in the atmosphere when compared with
burning fossil fuels.
2.
Explain
how the idea of a compound of natural ingredients that have a high biological
potency and prospective for the benefit of sentient beings can be synthesized
in the laboratory
answer
example
in turmeric, kurkulin can be found on the two tautomer forms, the enol form.
keto structure more stable or more found in the solid phase, while the enol
structure is dominant in the liquid phase or in solution.
to isolate curcumin from turmeric powder
dissolved in dichloromethane kenyit. as a solvent, used solvent dichloromethane
which is non-polar because the compounds present in turmeric is an organic
compound that tends to be it will dissolve non-polar compounds present in
turmeric include kurkulum the solvent.
3. Explain the basic rules in choosing a solvent for the isolation and
purification of a compound of natural ingredients. Give the example for 4
classes of compounds of natural products: terpenoids, alkaloids, flavonoids,
and steroids.
isolation of the compound alkoloid, research was conducted at the Research Laboratory of the Department of Chemistry and Laboratory UM Faculty and Plant Pests BALITAS, Coral Ploso, Malang. Virginia tobacco leaf type and armyworms as test animals obtained from BALITAS, Coral Ploso, Malang. Isolation of nicotine is done by maceration-extraction by maceration time variation performed at 24 hours, 48 hours and 72 hours, and the volume variation at optimum maceration performed on volume 250 mL, 500 mL, 750 mL, 1000 mL, and 1250 mL. Optimization of maceration time and volume is determined by the method of determining the optimum nicotine yield obtained by acid-base titration method. Filtrate results maceration called rough isolates, tested its activity as insecticides against armyworms (Spodoptera litura). Identification of nicotine conducted by Thin Layer Chromatography with developer solution and NH4OH CH3OH (200:3).
insulation on the crown of God for flavonoid.Sebanyak compound 1 gram of powder in 100 ml of boiling hot water for 15 minutes and then filtered. By 5 ml of filtrate added Mg powder and add 2 ml of ethanol-HCl solution and shaken vigorously amilalkohol then allowed to separate. Positive observations arise when the red / yellow / orange on the top layer (layer amilalkohol).
isolation of terpenoids, Isolation is the separation process components - chemical components contained a material organism. insulation consists of the separation, purification, identification and determination. one commonly used method is the chromatographic isolation. of chromatographic separation is based on the nature of the adsorption or partition that separated the compound adsorbent and liquid pengulasi.
Adlah chromatographic separation of the components in the preparation method is penyarian factionalism, absorption, ion exchange in a porous substance, or by using a liquid or a gas diverter. separation occurs because the components move footage different distances in sebabka by different retention components are separated. pemisaha the components caused by the difference between the two phases distribusidi, the stationary phase and mobile phase.
Some chromatographic technique that is often done is paper chromatography, thin layer chromatography, column chromatography usual, vacuum liquid chromatography column and liquid chromatography-Gais.
insulation for a total of 1 gram of steroid compounds dimeserasi powder with 20 ml of ether for 2 hours, then filtered, the filtrate evaporated as much as 5 ml in a petri evaporator, the residue is added 2 drops into the Lieberman-Buchard reagent. When the red-purple color formed showed triterpenoid and when formed blue-green color indicates steroid.
isolation of the compound alkoloid, research was conducted at the Research Laboratory of the Department of Chemistry and Laboratory UM Faculty and Plant Pests BALITAS, Coral Ploso, Malang. Virginia tobacco leaf type and armyworms as test animals obtained from BALITAS, Coral Ploso, Malang. Isolation of nicotine is done by maceration-extraction by maceration time variation performed at 24 hours, 48 hours and 72 hours, and the volume variation at optimum maceration performed on volume 250 mL, 500 mL, 750 mL, 1000 mL, and 1250 mL. Optimization of maceration time and volume is determined by the method of determining the optimum nicotine yield obtained by acid-base titration method. Filtrate results maceration called rough isolates, tested its activity as insecticides against armyworms (Spodoptera litura). Identification of nicotine conducted by Thin Layer Chromatography with developer solution and NH4OH CH3OH (200:3).
insulation on the crown of God for flavonoid.Sebanyak compound 1 gram of powder in 100 ml of boiling hot water for 15 minutes and then filtered. By 5 ml of filtrate added Mg powder and add 2 ml of ethanol-HCl solution and shaken vigorously amilalkohol then allowed to separate. Positive observations arise when the red / yellow / orange on the top layer (layer amilalkohol).
isolation of terpenoids, Isolation is the separation process components - chemical components contained a material organism. insulation consists of the separation, purification, identification and determination. one commonly used method is the chromatographic isolation. of chromatographic separation is based on the nature of the adsorption or partition that separated the compound adsorbent and liquid pengulasi.
Adlah chromatographic separation of the components in the preparation method is penyarian factionalism, absorption, ion exchange in a porous substance, or by using a liquid or a gas diverter. separation occurs because the components move footage different distances in sebabka by different retention components are separated. pemisaha the components caused by the difference between the two phases distribusidi, the stationary phase and mobile phase.
Some chromatographic technique that is often done is paper chromatography, thin layer chromatography, column chromatography usual, vacuum liquid chromatography column and liquid chromatography-Gais.
insulation for a total of 1 gram of steroid compounds dimeserasi powder with 20 ml of ether for 2 hours, then filtered, the filtrate evaporated as much as 5 ml in a petri evaporator, the residue is added 2 drops into the Lieberman-Buchard reagent. When the red-purple color formed showed triterpenoid and when formed blue-green color indicates steroid.
4.
Explain
the basic starting point for the determination of the structure of an organic
compound. When the compounds of natural ingredients such as caffeine tersebuat
is. Put forward your ideas matter - whatever the subject matter is required in
determining the overall structure
answer
Caffeine
is a natural ingredient compounds that are widespread and belong to the
alkaloid compound with molecular formula C8H10N4O2, is a weak base, white
powder crystals are long, bitter, has a melting point of 234-2390C and
menyublin at temperatures of 180-2000. at a pressure of 1 atm be sublimed
without decomposition at temperatures of 176 ° C and does not smell. Caffeine
solubility: soluble in both chloroform, boiling water and alcohol, slightly
soluble in cold water and ether. Caffeine have the molecular formula:
(1,3,7-trimetilxantin)
Caffeine
can be isolated from the tea plant with water and chloroform solvent because
the solubility of caffeine in both solvents was great. Water as a solvent has
many advantages, besides cheap too easily obtained and no damage during
isolation of caffeine although at high temperatures. Difficulties arise because
it uses water as the extracting is a long time isolation, breakdown of caffeine
salts plant difficult, it menyakibatkan caffeine that can be extracted very
little.
As
it is known that caffeine is a xanthine derivative that can provide major
effect in terms of stimulating the central nervous system, especially the
respiratory center, stimulates cardiac muscle, smooth muscle relaxation and may
increase diuresis, but it can constrict blood vessels in the brain are both
headache and migrants . Keep in mind that too much consumption of caffeine
causes hardening of the arteries that can lead to heart attacks and strokes, so
need to be careful and not excessive in taking it.
Determination
of caffeine content in coffee, as in this experiment based on the distribution
of solute in this case the caffeine in coffee between two phases, namely the
organic phase (chloroform) and the inorganic phase (water). Because coffee is
well-soluble in hot water, so it must be dissolved in boiling hot water.
Furthermore refluxed for 35 minutes. The function of this reflux is to homogenize
the coffee and solvents with a long time, other than that it also aims to
attract perefluksan compound caffeine from coffee because caffeine is easily
soluble in hot water.
Subsequently
after a refluxed, the mixture was filtered using a funnel into the Erlenmeyer.
The function of this filter is that the caffeine contained in coffee mixture
can be separated from the filtrate or coffee grounds, so the caffeine does not
re-bound with the dregs kopi.Sehingga screening experiments performed up to 4
times to menghilankan coffee grounds. Once cooled, the mixture was then etched
by a solution of lead acetate drop by drop, until the precipitate formed. The
function of the addition of acetic solution is to menyendapkan coffee mixture
and precipitate impurities contained in the filtrate in the form of salts other
than caffeine, such as albumin, amino acids, tannins, and so on.
Once
formed precipitate, then filtered. Inserted into the funnel and the filtrate
was added 25 mL of chloroform. The addition of chloroform serves to separate
the caffeine in the filtrate. Filtrate separation of caffeine in coffee is
characterized by the formation of two layers of the filtrate, where the top
layer is a layer of water phase containing residual salt and Pb and lower layer
or layers merupan organic phase containing caffeine in chloroform. The
formation of two layers was caused because the density between the two
solutions is the solution of coffee have a lower density when compared with
chloroform, and differences in polarity, where the coffee solution is polar
while the bottom layer which is non polar CHCl3.
The
bottom layer containing caffeine accommodated in the evaporating dish and top
layer rinsed again with chloroform. At the time of extraction equilibrium
process occurs after penggocokan process, therefore a new solution can be
separated after the solution is stable. In this case we use the funnel must be
strong to be shaken by the two solutions distributed in the two phases of polar
and non-polar so that at a fixed temperature and pressure chemical equilibrium.
Then the cooling process performed intended to stabilize the molecules to be
extracted at the time the penggocangan, then formed two phases. The top layer
is a mixture of coffee with water, while the bottom layer is a solution of
chloroform-soluble caffeine contained therein, so that the bottom layer is
taken and placed on a saucer evaporation. To avoid the caffeine that remains on
the top layer, then re-added chloroform extracted again later. The results
re-accommodated on a saucer evaporation.
The
liquid was removed from the funnel was then evaporated in the vaporizer cup
with a low temperature of 70 - 1000C to anticipate the melting caffeine. This
is because the nature of caffeine can melt at high temperatures. The purpose of
the provision of filter paper is used as a cover plate that caffeine crystals
are dissolved is not out of the cup. Crystalline forms of caffeine in this
experiment is a glowing crystal berpentuk needle attached to a saucer
evaporation. These crystals do not evaporate and stick to the filter paper due
to the msih coffee grounds left over from screening or still bayaknya
impurities inherent .. Caffeine in this experiment is having sebasar caffeine
content of 1.5% is 0.3 grams or 20 grams of caffeine from coffee. Meanwhile,
according to Malato et al (2001) robusta coffee caffeine levels theoretically
is 1.5-2% by weight of coffee and coffee shows suitable for consumption
