Chemistry of Natural Products

SEMESTER FINAL EXAM MATERIALS CHEMISTRY CULTURE

Name                          : Yunita Rubi Lestari

NIM                            : RSA1C110007

Course                        : Chemistry of Natural Product

Credits                        : 2

Lecturer                     : Dr. Syamsurizal, M.Si

Time                           : 22-29 December 2012

 

1). Jelaskan dalam jalur biosintesis triterpenoid, identifikasilah faktor-faktor penting yang sangat menentukan dihasilkannya triterpenoid dalam kuantitas yang banyak.

Answer :

Triterpenoid
Triterpenoid carbon skeleton is a compound derived from the six units (units) and in the biosynthesis of isoprene derived from C30 acyclic hydrocarbons, ie skualena.
More than 4000 kinds of triterpenoids have been isolated with more than 40 kinds of basic framework that has been known and in principle is the cyclization of skualen. This compound is a compound colorless, crystalline, often high melting point and active optics.

Triterpenoids consisting of frame with 3 cyclic 6 which joined berupaka cyclic 5 or 6, which has a cyclic 4 functional groups on specific cyclic. While naming further simplified by giving the numbering on each carbon atom, thus facilitating the determination of the substituents on each carbon atom. Terpenoida a wide range of structures that arise as a result of subsequent secondary reactions such as hydrolysis, isomerization, oxidation, reduction and cyclization over-geranil, farnesil-and-geranil geranil pyrophosphate.

Triterpenoid widespread in resin, cork and kutin plants. Resin is a triterpenoid acid often together with xanthan gum polysaccharide in amber. Triterpenoid alcohol also are free and as glycosides. Triterpenoid acyclic hydrocarbons skualena important only for the first time isolated from shark liver oil but is also found in some nights epikutikula and vegetable oil (olive oil). Triterpenoid compound best known as lanosterol contained in wool grease, yeast and some compounds of higher plants. Triterpenoid eufol tetrasiklik like alcohol and acids from Euphorbia sp of Elemi Canarium commune.

Triterpenoids are pentacyclic triterpenoid most important thing. These compounds are found
in seprimitif sphagnum plants but the most common is the seed plants, free and glycosides. Triterpenoid nonglikosida often found as excretion and the work as a protective cuticle or cause resistance to water.
Several kinds of physiological activity of triterpenoids which is the active component of the plant has been used as a medicinal plant remedy diabetes, menstrual disorders, pecks snake, skin disorders, liver damage, and malaria.
Skualena is a steroid derivative of the basic framework has four rings as follows:


Triterpenoids have a very bitter taste, especially present in Rutaceae plants, Meliceae and Simaroubeaceae as limonin in citrus fruits (also classified as a sense of bitter alkaloids) and kukurbitasin D in Cucurbitaceae plants and diosgonin. In the form of triterpenoids found in plant sap of Euphorbia and Havea.

Triterpenoid Biosynthetic

Based on its mechanism of acetyl-CoA via the mevalonic acid pathway produces isopentyl pyrophosphate (IPP), which later became dimethyl berisomerisasi alipirofosfat (DMPP) assisted with the isomerase enzyme, which produces IPP and DMPP join geranil Pyrophosphate (GPP) to form monoterpenoid compounds, then GPP and IPP merged by the same mechanism produces farnesil pyrophosphate (FPP) to form sesquiterpenoid compound, combined with the subsequent FPP FPP with a path similar mechanisms will produce triterpenoid compounds. In this biosynthetic pathway could be modified to increase the amount of production triterpenoid more and with less time.
One of the factors that determine the quantity produced triterpenoid much on triterpenoid biosynthetic pathway enzymes. The enzyme in the biosynthesis of triterpenoids may also determine the amount that will be generated. This is because the growing number of enzymes that act on biosynthetic pathways, it will be the more triterpenoid obtained. The use of enzymes in the biosynthesis of the triterpenoids itself as a catalyst. Where it is known that the function of the use of enzymes that can accelerate the reaction, but did not participate react. But in this biosynthetic pathway inhibition also occurred that would lead to mevalonic triterpenoids produced a little.

2). Jelaskan dalam penentuan struktur flavonoid, kekhasan signal dan intensitas serapan dengan menggunakan spektrum IR dan NMR. Berikan dengan contoh sekurang-kurangnya dua struktur yang berbeda.

Answer :

Flavonoids are a group of phenolic compounds found in fruits and vegetables. Compound has 15 carbon atoms, consists of two substituted benzene rings connected by a single aliphatic chain containing three carbon atoms (Figure 1.7). The basic framework of the system structure of flavonoids is C6-C3-C6.

 

Figure 1.7. structure of Flavonoids

Flavonoids have been studied have a wide range of biological activity. Flavonoids act as anticancer, antiviral, anti-inflammatory, reducing the risk of cardiovascular disease and play a role in the capture of free radicals. The power of the antioxidant activity of flavonoids depends on the number and position of OH groups contained in the molecule. The more substitutes a hydroxy group on the flavonoid, the greater the activity antiradikalnya. The existence of ortho-catechol group (3'4'-OH) on the B ring of flavonoids is an important determinant of high antioxidant capacity (Andersen et al., 2006).

• The intensity of the IR absorption:

In the long-wave infrared spectrophotometry and wave number is the value used to indicate the position of the absorption spectrum.
Where in the intensity of the absorption of flavonoids is displayed hydroxyl (3227 cm-1) and (1628 cm-1).

• The intensity of the NMR absorption spectrum:

Samples under appropriate conditions flavonoids can adsorbing area radio frequency electromagnetic radiation, radio depends on the nature of the sample. A plot of peak frequency versus absorption peak intensity gives an NMR spectrum

3). Dalam isolasi alkaloid, pada tahap awal dibutuhkan kondisi asam atau basa. Jelaskan dasar penggunaan reagen tersebut, dan berikan contohnya sekurang-kurangnya tiga macam alkaloid.

Alkaloid is an alkaline compound containing nitrogen atoms satuatau more and usually a cyclical system. Alkaloids mengandungatom carbon, hydrogen, nitrogen, and usually contains many alkaloids oksigen.Senyawa contained in the roots, seeds, wood and leaves daritumbuhan and also of animals. Metabolismedari alkaloid compounds is the result of plant and used as a backup for the synthesis of the plant alkaloid protein.Kegunaan is as protective of pests, plants and regulator amplifier hormones work. Alkaloids have physiological effects. Source is a flowering plant alkaloid, angiosperms, animals, insects, marine organisms and microorganisms. Mengandungalkaloid plant families that are Liliaceae, solanaceae, Rubiaceae, and papaveraceae (Tobing, 1989).

Classification of Alkaloids

Alkaloids not have a systematic name, so namadinyatakan as trivial as codeine, morphine, heroin, quinine, kofein, nicotine. Almost all were given the trivial name suffix-in that characterizes alkaloid.Sistem alkaloid widely accepted classification is the division alkaloidmenjadi three groups, namely real alkaloid, protoalkaloid and pseudoalkaloid.Suatu ways of classifying alkaloid is a nitrogen based heterocyclic jeniscincin which is part of the structure molekul.Jenisnya namely pyrrolidine, piperidine, quinoline, isokuinolin, indole, pyridine dansebagainya (Robinson, 1995). The structure of the types of alkaloids presented dalamgambar
 

Isolation of Alkaloids

a.       Alkaloid extracted from the leaves of plants, flowers, fruit, bark, dried and crushed danakar. Extraction of alkaloids in umumadalah as follows:
Alkaloid extracted with certain solvents, such as ethanol, and then evaporated.

b.       Ekstrak obtained given inorganic acids to produce a quaternary garamamonium then extracted again quaternary ammonium

c.       Garam obtained reacted with natriumkarbonat to produce these alkaloids kemudiandiekstraksi free with certain solvents such as ether and chloroform.

d.       Campuran - a mixture of alkaloids obtained finally separated in various ways, such as chromatographic methods (Tobing, 1989).

There are other ways to get the alkaloids from the acid solution by absorption using Lloyd reagent, and then eluted with basaencer alkaloids. Alkaloid that is hydrophobic absorbed by XAD-2 resin and dielusidengan acid or ethanol-water mixture. Many alkaloids which can be precipitated by Mayer's reagent (potassium mercury (II) iodide) or salt Reineccke. This study used a general way that the isolation of alkaloids extracted with an organic solvent, acidification, formation of quaternary garamamonium with a base, extraction with organic solvents, and purification using column chromatography, thin layer chromatography, ataupuninstrumen-electronic instruments (IR, GC-MS, UV -Vis)

4). Jelaskan keterkaitan diantara biosintesis, metode isolasi dan penentuan struktur senyawa bahan alam . Berikan contohnya.

Answer :

Biosynthesis (also called biogenesis or "anabolism") is an enzyme-catalyzed process in cells of living organisms in which a substrate is converted to more complex products. Biosynthesis process often consists of several enzymatic steps in which the product of one step is used as substrate in the following step. An example for such a multi-step biosynthetic pathways are those for the production of amino acids, fatty acids, and natural products. Biosynthesis plays a major role in all cells, and more specifically the metabolic routes combined constitute general metabolism. Six organelles within cells that is involved in biosynthesis. Ribosomes, chloroplasts, smooth endoplasmic reticulum, rough endoplasmic reticulum, plastids, and Golgi bodies

Basically isolation of chemical compounds from natural ingredients it is a business how to separate the compounds were mixed so that we can produce a pure single senayawa. Let's take just one example, how to isolate compounds from plants. Plants that contain thousands of compounds, both of which are categorized as primary metabolites or secondary metabolites. Usually the isolation of compounds from natural ingredients ni hopes to isolate secondary metabolites, secondary metabolites due believed and has been shown to provide benefits for human life. Antaralain benefits are in the areas of agriculture, health, food, cosmetics etc.

NMR (Nuclear Magnetic Resonance) spectroscopy is a method that is very important in determining the structure of organic compounds. We know that all organic compounds metabolite natural products and bioactive both lacked the NMR, both 1H-and 13C-NMR were expressed by a number of resonance peaks and prices dimiliki.setiap NMR chemical shifts of carbon atoms in the molecule has a peak or a shift NMR chemical which depends on the position of the carbon atoms in the structure of the molecule. The position of the carbon atom gives specific conditions that lead to each carbon atom in an organic molecule has a peak or specific NMR chemical shifts as well. Trait that would distinguish one molecule with another molecule. The number of peaks and NMR price is used as the basis for the determination of a molecule.

Biosynthesis, isolation and structure determination methods that are important to know and mempelajasi compounds of natural ingredients. The third method is highly related to one another. In the process of biosynthesis of us can know the process of formation of compounds of natural ingredients that only lasted in living things. Where in this process we mangetahui that there are certain enzymes that are involved. In the biosynthesis of these different types of reactions occur to produce a compound. By studying the biosynthesis of these compounds produced as well, then we can know the properties of these compounds are natural materials, so we can design an isolation method based on the nature and reactions of these compounds. For example, we can choose a suitable solvent and other treatments to obtain pure substances. Once isolated, then the knowledge-knowledge that has been known in advance, we can carry out the procedure of determining the structure of the compound, for example by spektoskopi NMR, IR and UV.

 

CHOLESTEROL

Cholesterol is a complex molecule, a part of the family of organic molecules called sterols. It was discovered by Michel Chevreul in 1812, and has been studied by many researchers since then. Thirteen scientists have received Nobel Prizes studied, including Adolf Windaus.

Cholesterol is a very important part of cell membranes. The membrane is required to keep our cells intact, and to regulate the flow of nutrients to and fro inside and outside the cell. More cholesterol in the membrane, which is rigid. Neural networks in the brain and spinal marrow, which requires a lot of isolation cells, rich in cholesterol.

Cholesterol is made by the liver. Mostly used to make bile. Bile is a complex mixture including cholic acid, amino acid and desoxycholic cholanic. These acids are stored in the gall bladder, and released into the intestine during the digestive process. Bile emulsifies fats that we eat, so that the digestive enzymes to break them.

Cholesterol is also used to make hormones that are essential for normal body function. These include corticosteroids, which are essential for fighting infections and allergies. Cholesterol is an important precursor molecules for the synthesis of vitamin D and steroid hormones, including the adrenal gland hormones cortisol and aldosterone, as well as the sex hormones progesterone, estrogen, and testosterone, and derivatives.

So why do people talk about good and bad cholesterol?
Cholesterol is used to make bile and also to make hormones that are essential for normal body function.

Some of cholesterol made by the liver is secreted into the blood to be transported to other tissues. In the blood, it is associated with another chemical called lipoproteins. If there is a lot less lipoprotein and cholesterol, known as high-density lipoprotein (HDL). HDL is used by the body to make other types of molecules, and what is known as good cholesterol.

If the opposite is true, this is known as low density lipoprotein (LDL). LDL is not easily transported in the blood, and will be deposited in the arterial wall. These deposits are called plaques. If there is too much LDL plaque or if they are close to the heart, it can cause a stroke or heart attack. That's why it's called 'bad' cholesterol.

Lipoprotein cholesterol rich foods leads imbalance, causing the body to make more HDL than LDL. That is why it is considered safer to buy cooking oil with less or no cholesterol. Foods rich in trans-fatty acids (like margarine and butter) promotes the formation of LDL, while a diet rich in fiber (root vegetables, fruits) and omega-3 fatty acids (fish, flaxseed oil) and Vitamin B3 promotes good cholesterol. So let's go slow on fries, and eat more carrots!
Foods rich in fiber (root vegetables, fruits) and omega-3 fatty acids (fish, flaxseed oil) and Vitamin B3 promotes good cholesterol.

A bad feature is the abuse of steroids or cholesterol 'doping'. When there are high levels of testosterone in the blood, the body gains more stamina. Steroid molecules Much has been made of cholesterol that mimics the function of testosterone, such as androstendione. It's called Improving Performance Drugs (PEDs) If an athlete injects ped into the blood stream, he experienced a temporary increase stamina, which can help beat other athletes in a competition.

However, many dangers. PEDs are illegal in all sports competitions. Second, they can cause permanent damage to the body. They increase LDL, reduced immunity against infectious diseases and creates a higher risk of cancer or heart attack.

NICOTINE BIOSYNTHESIS

Nicotine biosynthesis

Nicotine biosynthesis pathway involves the reaction of cyclic coupling between the two structures that make up the nicotine. Metabolic studies indicate that the pyridine ring of nicotine from nicotinic acid while pyrrolidone is derived from the N-methyl-Δ1-pyrrollidium cations. Biosynthesis of two structural components results in two independent synthesis, NAD pathway for nicotinic acid and tropane pathway for N-methyl-Δ1-pyrrollidium cations.

NAD pathway in the genus nicotiana starting with aspartic acid oxidation to α-imino succinate by aspartate oxidase (AO). This is followed by condensation with glyceraldehyde-3-phosphate and cyclization catalyzed by quinolinate synthase (QS) to give quinolinic acid. Quinolinic acid then reacts with the acid-catalyzed pyrophosphate phosphoriboxyl quinolinic phosphoribosyl transferase (QPT). The reaction is now underway through the cycle to produce NAD rescue by converting nicotinamide nicotinic acid by the enzyme nicotinamidase.

Cation N-methyl-Δ1-pyrrollidium used in the synthesis of nicotine is an intermediate in the synthesis of tropane alkaloid derived. Biosynthesis begins with the decarboxylation of ornithine decarboxylase by ornithine (ODC) to produce putrescine. Then converted into putrescine N-methyl putrescine through methylation by SAM catalyzed by putrescine N-methyltransferase (PMT). N-methylputrescine then undergoes deamination to 4-methylaminobutanal by N-methylputrescine oxidase (MPO) enzyme, 4-methylaminobutanal then spontaneously cyclize to N-methyl-Δ1-pyrrollidium cations.

The final step in the synthesis of nicotine is the coupling between the N-methyl-Δ1-pyrrollidium cation and nicotinic acid. Although studies suggest that some forms the link between the two components of the structure, processes and mechanisms that would still not been determined. The theory agreed today involving the conversion of nicotinic acid to 2,5-dihydropyridine with 3.6-dihydronicotinic acid. The 2,5-dihydropyridine intermediate then reacts with the N-methyl-Δ1-pyrrollidium cations to form enantiomerically pure (-)-nicotine.

MID SEMESTERS EXAM ANSWERS CHEMISTRY OF NATURAL PRODUCTS

NAME                   : YUNITA RUBI LESTARI

NIM                      : RSA1C110007

1). To find compound effective Dari Yang paled MATERIAL natural compounds, in addition to using Appropriate Toxicity Data can ALSO use analytical methods Isolation. Isolated compounds can be developed outreach process Illustrations That paled find effective compounds. Know the structure of the new compound CHEMICAL nil would be a "lead compound" In, formation so you can scale the Great Illustrations synthetic. Modify Structure O compounds, compounds Which Will Able to withstand levbih On. The pure compound was isolated ALSO be tested with different bioactivity, based not only related to the use of AT New Media bioactivity customary. In addition to using the method of extraction ALSO Insulation can be used to find active compounds. Illustration order to extract only contains active compounds contained in Yang, raw MATERIALS / Experience The penyari The optimal hedge Liquids Able to attract active compounds. Pure active compounds can be administered Illustration of looping, the dose given is more accurate. My husband, of course, can be achieved when kita managed to get pure compounds role Illustration biokativitasnya and share experimental dilakuakn selnajutnya to find the dose, the dose was prepared New Articles The RIGHT Way And The right way to give. The term is not Here Again gambling. There are several methods of extraction using Natural MATERIALS raw, such as maceration, infundasi, digestion, percolation and soxletasi.

2). Utilization of Plant Medicine

Since ancient times herbs have been utilized by humans to treat various types of diseases. How traditional medicine using the natural ingredients have been recorded in various documents stored neatly in China, India and North Africa. Even to this day still plant an exclusive source for producing chemical compounds that have a variety of pharmacological activities.
Data from a scientific journal reported, there were approximately 25% of all drugs prescribed to patients, a drug compounds derived from plants, 121 of which active substance is still in use today. Of 252 basic drugs and esential set by the WHO, 11% of whom are drug compounds that are exclusively derived from plants and in significant numbers also include synthetic compounds derived from natural precursor materials (1). Some examples of essential drugs isolated from plants antaralain digoxin from Digitalis spp plants, quinine and kinidin from Chinchona spp, morphine and codeine from Papaver somniferum and atropine from Atropa Belladona.

Prior to the 19th century in the form of extracts of plants used to treat various diseases. Around the beginning of the 19th century there was a change in the era of utilization of medicinal plants. At this time, scientists have managed to isolate pure compounds from plants such as strychnine, quinine, morphine, etc., which is still used as a drug. In this period of secondary metabolites from plants being the main target of research in order to find chemical compounds that have the potential as a medicine.

Plants selected as the source material providers are important in medicine caused by several things, among others:

• Plants can produce pure compounds that can be used directly as a drug. Examples are morphine quinine, vincristine and vinblastine.
• Plants can produce chemicals that can be used as model compounds in the synthesis of total or partial synthetic (modified structure) into compounds more effective or less toxic. Examples of drugs that are based on a model of natural compounds is metformin, verapamil, morphine, etc. taxolphodophyllotoxin.

• plant extracts can be used for treatment, without having to go through the insulating phase of pure compounds. Examples include gingko biloba and herbal medicines circulating in Indonesia.

Recent years these drug compounds produced from natural materials have become of particular concern to the pharmaceutical industry. As can be seen from the development representatifnya compound taxol, etoposide and artemisin who have managed through the clinical testing phase. Taxol is a chemical compound that was first isolated from the plant Taxus brevifolia. Isolation and structure determination of these compounds is based on the results of initial laboratory research showing that extracts of this plant showed activity against cancer cells. Although the bioactivity testing has been done in the early 1960s, the isolation and determination of new chemical structures completed in 1971. After going through the various stages of research, in 1980 the successful clinical testing in the 1990s dilakukan.Sekitar compound taxol and Taxotere derivatives turned out to have been clinically proven to be effective against breast cancer (breast cancer) and ovarian cancer (ovarian cancer) (2)

Podophyllin resin was first isolated from the plant Podophyllum peltatum, are compounds that are toxic. The main component of the resin is a memepunyai phodophyllotoxin lignans aktiviatas inhibit cell division. Due to the toxic nature of these compounds are less likely to be used as medicine. But look aktvitasnya can inhibit cell division, these compounds may be indicated compounds have potential cancer chemotherapy. A semisynthetic compound etoposide were made based on model compounds phodophyllotoxin apparently been tested clinically effective against lung cancer and testicular cancer (2)

Artemisinin is a chemical compound isolated from the plant Artemisia annua. Clinical testing has shown that this compound is used as an antimalarial effective and can be used for treatment of infections caused by Plasmodium falciparum (2)

The potential of plants as a source of drug discovery compounds to date have not fully utilized. Approximately 250000-500000 plant species existing in the world today, accounting for only about 6% of its bioactivity testing that has been done, and only about 15% that have examined levels of the chemical. Given the thousands of plants containing secondary metabolites are believed to play an important role as a producer of chemical compounds that have pharmacological activity. So a challenge for scientists to explore the chemical compounds found in plants that can be used for future drugs.

Synthesis and Structure Modification

To get a more effective compound or with the aim of reducing toxicity, can be modified structure. In addition to modification of the structure, which has been isolated compounds can serve as a model compound in the total synthetic process. Total synthetic compound performed usually for memepunyai simple structure, and does not cost more expensive. Adakalnya in the drug discovery process, it will require more time and cost expensive lenih if desired compounds were isolated from the repeated nature. It is therefore necessary that the total drug can be synthesized in the laboratory. But not all natural compounds can be synthesized, because the complexity of its structure, da vinblastine vincristine is still produced from the plant, and yet can be made synthetically.

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3). Factors Influencing the Selection of Solvent

a. Selectivity

Solvents may only dissolve extract desired, not the other components of the material extraction.

b. Village

Solvents dissolve as much as possible have the ability to extract large.

c. Ability not intermingled

In liquid extraction, solvent should not dissolve in the extraction of materials.

d. Density

Especially in the extraction fluid, wherever there may be a large difference in density between the solvent and extraction materials. It is intended that both phases can be easily separated after mixing.

e. Reactivity

In general, the solvent should not cause chemical changes in the component material extraction komponent

f. Boiling point

The boiling point of the two materials should not be too close. In terms of economics, it is advantageous if the boiling point of the solvent extraction process is not too high.

g. Criteria

Solvents as much as possible should be:

    Budget

    Available in large quantities

    Non-toxic

    Not flammable

    Not korotif

    Do not cause the formation of emulsions

    Having a low viscosity

    Stable in chemical and thermal

Some of the most important solvent is water, organic acids and inorganic, saturated hydrocarbons, tolven, ether, acetone, isopropanol, ethanol, carbon disulfit (Bernasconi, et.all, 1995).

Terpenoids

Terpenoids are derivatives dehydrogenation and oxygenation of terpene compounds. Terpenes are a class of hydrocarbons produced by many plants and some animal groups. Terpenes molecular formula is (C5H8) n.
Terpenoids also called isoprenoids. This is due to the same carbon skeleton as compound isoprene. Terenoid chemical structure is a combination of the isoprene unit, can be either open-chain or cyclic, may contain a double bond, hydroxyl, carbonyl or other functional groups. The solvent used to extract the methanol terpenoid compounds.
Flavonoids
Generally most of the extraction process materials containing flavonoids is done simply with the addition of direct solvent extraction.
Powdered plant material can also be extracted using a Soxhlet, initially with hexan, to remove lipids and then with ethyl acetate or ethanol to obtain phenolic compounds. This method is unsuitable for the content of compounds that are not heat resistant. The procedure is safe and commonly used sequential solvent extraction. The first phase, with dichloromethane, to extract flavonoid aglycone and content of non-polar. The next stage of the alcohol will extract and flavonoid glycoside content of polar compounds.

Steroids

Broadly speaking, the isolation of the sea cucumber steroid compounds consisting of two phases in the extraction part of fat cucumbers, followed by extracting the steroid compounds. Here is one study conducted Sarifah Nurjanah, et al (2009) to identify steroid sand sea cucumber (Holothuria scabra) in Indonesia.

Extraction of steroid cucumbers done in two stages, namely fat extraction followed by extraction of steroids. Fat extraction performed with acetone solvent by maceration, saponification process is then performed using a solution of 1 M KOH and carried reflux at 70 ⁰ C for 1 hour. Steroids extracted using diethyl ether solvent.

Alkaloids
Alkaloids are one type of secondary metabolites.

what is of secondary metabolites??

that the metabolism of which is used by plants as a defense, but specific and limited only owned by certain plants. Alkaloids are more soluble in organic solvents than water.

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4). Infrared spectrophotometry is more widely used for identification of a compound through the group functions. For the purpose of structure elucidation, the wavenumber region 1400 - 4000 cm-1 which is at the left of the IR spectrum, an area that is particularly useful for the identification of functional groups, which is the absorption of the stretching vibration. Furthermore, the area just to the right of wave numbers 1400 cm-1 are often very complicated because in this region occurred absorption of stretching vibration and bending vibration, but any organic compound having a Characteristic absorption in this region. It is therefore part of the spectrum is called fingerprint region (fingerprint region). Currently there are two kinds of instruments, namely IR and FTIR spectroscopy (Furier Transformation Infra Red). FTIR is more sensitive and accurate example to distinguish cis and trans forms, conjugated and isolated double bonds and others are in indistinguishable IR spectrophotometer.

Furthermore, also known regions vibration of each bond held by the organic compounds can be seen in Fig. below.

 In interpreting the IR spectrum of the isolated compound / synthesis, the focus of attention focused on the major functional groups such as carbonyl (C = O), hydroxyl (OH), nitrile (CN) and others. Uptake single CC and CH sp3 should not be so confused because almost all organic compounds have absorptions in the region.

Here's a guide in analyzing the IR spectrum of an organic compound:
1. Consider whether there is a carbonyl group (C = O) in the region 1820-1600 cm-1 and a sharp peak is very characteristic.

2. If there is a carbonyl group, then consider the possibility of the following functional groups, if not then proceed to step 3.
a. Carboxylic acid will bring apda OH absorption region 3500-3300 cm-1
b. Amida will give a sharp NH absorption in the region around 3500 cm-1
c. Esther will bring a sharp and strong CO absorption at 1300-1000 cm-1
d. Anhirida will bring up the C = O absorption twins in 1810 and 1760 cm-1.
e. Aldehyde aldehyde CH will bring weak intensity sharply in 2850-2750 cm-1 both symmetry and anti-symmetry

f. Ketones, if all the above does not arise.

3. If no carbonyl absorption then:

1. Test alcohol (-OH), taking into account the wider uptake (typically once) at 3500-3300 cm-1 (confirmed with a carboxylic acid) and reinforced with CO absorption at around 1300-1000 cm-1
2. Test amine (NH), with respect to the uptake medium at about 3500 cm-1 (confirmed by amide)

3. Test ether (CO), taking into account the absorption at 1300-1000 cm-1 (confirmed with alcohols and esters)

4. C = C bond of alkenes and aromatics. For alkene absorption appears at 1650 cm-1, whereas for the aromatic around 1650-1450 cm-1. Uptake CH aliphatic alkenes will appear below 3000 cm-1, whereas CH vinilik benzene will appear above 3000 cm-1

5. Alkyne C ≡ C bond will appear sharply weaker 2150 cm-1, whereas the C ≡ N nitrile medium and sharp will appear at 2250 cm-1
6. NO2 nitro group, giving a strong absorption around 1600-1500 cm-1 of the anti-symmetric and also at 1390-1300 cm-1 for symmetric
7. When you get 1 to 6 above does not exist then the IR spectrum is strong suspicion of hydrocarbons.

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