Rabu, 26 Desember 2012

Chemistry of Natural Products Test


Chemistry of Natural Products
Name                       :  Lina Purwanti
Student number        :  RSA1C110009
Study Program         :  Chemistry Education of ISSTE

     1. Jelaskan dalam jalur biosintesis triterpenoid, identifikasilah faktor-faktor penting yang sangat menentukan  dihasilkannya triterpenoid dalam kuantitas yang banyak. 
Answer :
Triterpenoid carbon skeleton is a compound derived from six isoprene units and the biosynthesis derived from C30 acyclic hydrocarbons, ie skualena.
SYNTHESIS TERPENOID
Terpenoids is a form of the compound with large structures in natural product-derived and isoprene unit (C5) are coupled in the model head to tail, whereas isoprene units derived from acetic acid metabolism by mevalonic acid pathway (MVA). The reaaksinya are as follows:





Figure 1 Line Acetate is the formation of IPP formation of terpenoids Via Bricks mevalonic acid (http://nadjeeb.wordpress.com).
In general, the biosynthesis of terpenoids with the three basic reactions, namely:
1. Formation of active isoprene derived from acetic acid via mevalonic acid.
2. Merging head and tail of two isoprene units to form mono-, seskui-, di-. Sester-,      and poly-terpenoids.
3. The incorporation of the tail and the tail unit C-15 or C-20 produces triterpenoids and steroids.
The mechanism of the reaction steps of terpenoid biosynthesis is activated by acetic acid as coenzyme A did produce acid Claisen type condensation asetoasetat.
Compounds produced by the condensation of acetyl coenzyme A did produce aldol type branched carbon chains as found in mevalinat acid, subsequent reactions are fosforialsi, elimination of phosphoric acid and dekarboksilasi produce isopentenyl (IPP) who later became dimethyl allyl berisomerisasi piropospat (DMAPP) by the enzyme isomeriasi. IPP as active isoprene unti joined head to tail with DMAPP and this merger is the first step of the polymerization of isoprene to produce terpenoids.
This merger occurs because electrons attack the double bond carbon atoms of IPP to DMAPP electron deficient followed by the removal of ions that produce geranil. pirofosfat pyrophosphate (GPP) is an intermediate for all monoterpenoid compounds. Merger between one unti further IPP and GPP with the same result menaisme Farnesil pyrophosphate (FPP), which is an intermediate for all compounds seskuiterpenoid. Diterpenoid compounds derived from geranil-geranil Pyrophosphate (GGPP) derived from the condensation between one unti IPP ​​and GPP by the same mechanism. The mechanism of biosynthesis of terpenoid compounds are as follows:




         From that picture in biosynthesis we can get if there is enzyme such as isomeriasi enzyme to help reaction faster, Co-A to make active acetic acid so will happen condensation, H2O, and acetic acid 

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 :
IR Spectroscopy  : This section takes you through typical IR spectra of compounds with different functional groups to help you recognize distinctive, characteristic IR bands. The final section outlines how to analyze any IR spectrum.
Infrared spectrophotometer can be used for the following:
a.      Identfcation functional group
b.      Taking into account the presence of other information such as melting point, boiling point, molecular weight and refractive index to determine the structures and to identify compounds
c.       By using a computer, can identify compounds even mixture of compounds.


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-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 that ir spectroscopy and FTIR (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 the ir spectrophotometer indistinguishable.


The Theory of NMR: This section explains the theory of NMR spectroscopy at a level appropriate for the sophomore organic chemistry student. Both proton and carbon NMR are covered.
As the name implies NMR (nuclear magnetic resonance, nuclear magnetic resonance), NMR spectroscopy related to the core character of an atom in a molecule is analyzed. NMR spectrometry is basically another form of absorption spectroscopy as well as UV-VIS and IR. The difference with IR and UV-VIS is
Absorption system under the influence of a magnetic field and it is not on UV-VIS and IR. In the NMR energy electromagnetic radiation in the radio frequency region.
  kafein



Working Principle of NMR Spectroscopy
This type of spectroscopy method is based on the absorption of energy by spinning particles in a strong magnetic field. The energy used in the measurement by this method is in the region from 75 to 0.5 m or radio waves at a frequency of 4-600 MHz, depending on the type of core that is measured.
Core that can be measured by NMR, namely:
a. spherical shape
b. spin
c. Spin quantum number = ½
d. Odd number of protons and neutrons, for example: 1H, 19F, 31P, 11B, 13C
In the magnetic field, NMR active nuclei (eg 1H or 13C) absorb at a frequency characteristic of an isotope. The resonant frequency, energy absorption and the signal intensity is proportional to the strength of the magnetic field. For example, at 21 tesla magnetic field, protons resonate at 900 MHz. value of 21 T magnet is considered equivalent to a 900 MHz magnet, although different nuclei resonate at different frequencies.
At the Earth's magnetic field, the same core resonate at audio frequencies. This phenomenon is exploited by the Earth's field NMR spectrometers, which are cheaper and easier to carry. This instrument is used for field work and teaching purposes.

IR/NMR Spectroscopy Problem : This section takes you through the steps that you will need to do to solve for the structure of an organic compound given the IR, NMR, and molecular formula. Each common functional group is discussed in turn and many examples are presented.


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.
answer : 

An alkaline compound, derived from plants and animals, generally have cicncin heterocyclic (not all members have cincicn nitrogen) and often have biological activity in humans. Not all diklasifikasan nitrogenous compounds as pyridine alkaloids example. Alkaloids kbasaannya different in nature, some properties amfore cntohnya cephalin and psychotrin or even acid recini example. Most dtemukan in plants, although it has now been recorded as also found in fungi (ergot alkaloids), in animal musk deer (muscopyridin), in bacteria p.aeruginosa and some synthetic products.
1. Presipitas Alkaloids
Most alkaloids are precipitated from neutral or acidic solution by a number of reagents containing heavy metals such as mercury (Hg), platinum (Pt), bismuth (Bi) and gold (Au), to form a bond with their salt
Examples of precipitating reagent alkaloid
a. Mayer's reagent (potassium mercury iodide)
Providing the most precipitation creamy besa alkaloid
Caffeine and efredin only at high concentrations.
Ricinin not give precipitation
b. Wagner's reagent (I / KI)
Providing brick red precipitate against almost all alkaloids
c. Hager's reagent (picric acid solution is concentrated)
              Give a yellow precipitate
d. Dragendroff's reagent (solution of potassium bismuth iodide)
Giving up brownish reddish orange color. Also used as a spray reagent for TLC    identification alakaoit
e. Another Reagenisia using acid
Tannat, fosfomolibdat acid, fosfotungstat

2. Specific color reagents
a. Erlich's reagent (Van-Urk reagent)
Solution of p-dimethylaminobenzaldehide in acid, giving distinctive colors birun gray or greenish with Ergot
b. Cerric ammonium sulphate (CAS) under acidic
Alakaoid typical reagents for indole, giving a yellow or reddish orange.
c. Vitali-Mari reagent: characteristic for alkaloids tropan
d. Thaleoquine reaction: typical for alkaloid sinkona
e. Murexide reaction: typical for purine bases
in the first step alkoloid isolation we need acid and base condition. In acid because adding organic acid will make extract produces salt and adding base to lose salt bonding to be free alkaloida


4. Jelaskan keterkaitan diantara biosintesis, metode isolasi dan penentuan struktur senyawa bahan alam . Berikan contohnya.
Answer :
between the three aspects are closely linked, the boisintesis used to obtain new compounds or techniques such as structural changes in the biosynthesis of catechins using 3 x malonyl-CoA will result coas. the biosynthesis of these alone we can use in determining the structure of such ir, uv, and nmr. and for the isolation itself is to recall the components or the active ingredient by using certain solvents. of the insulation itself, we can also determine its structure. if the structure between isolation and biosynthesis have been obtained, the results can be compared
example :

EXTRACTION
Extraction is a way to separate a mixture of several substances into separate components (Winarno et al. 1973). According to Hunt (1988), extraction is a method of separation of one or more of the desired compound or solid solution containing a mixture of such compounds both physically and chemically.
In the process of extraction, solvent diffusion event occurs in the cell material. Solvent into the cell material will dissolve the compound when the solubility of the compound, which is extracted with solvents. In this way will be achieved equilibrium between the solute and solvent. Spending the active ingredient of the material depends on the rate of diffusion of the substance of substances into the solvent, the contact time, and the rate of solvent through the material (Bombardelli 1991).
Harborne (1987) states that the solubility of a substance in a solvent depends on the polarity. The only polar substances soluble in polar solvents as well as non-polar substances only soluble in nonpolar solvents. Selection of solvent in the extraction solvent should pay attention selectivity, the ability to extract the target component, toxicity, ease evaporated, and the price of solvent.

 Isolation of Alkaloids
Alkaloid extracted from the leaves of plants, flowers, fruit, bark, and roots are dried and then crushed. Extraction of alkaloids in general are as follows:
a. Alkaloid extracted with solvents, eg ethanol, and then evaporated.
b. Extracts were obtained inorganic acids to produce a quaternary ammonium salt and then extracted again.
c. Quaternary ammonium salt obtained was treated with sodium carbonate to produce these alkaloids were then extracted with a solvent-free such as ether and chloroform.
d. Mixture - 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 dilute alkali alkaloids. Alkaloid that is hydrophobic absorbed by XAD-2 resin and then eluted with 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 ammonium salts with bases, extraction with organic solvents, and purification using column chromatography, thin layer chromatography, or electronic instruments (IR, GC-MS , UV-Vis)
So after we get isolation results obtained then the structure can be determined




Minggu, 25 November 2012

Chemistry of Natural Products Mid Test

Chemistry of Natural Products

Name                         :  Lina Purwanti
Student number          :  RSA1C110009
Study Program           :  Chemistry Education of ISSTE

3.  Jelaskan kaidah-kaidah pokok dalam memilih pelarut  untuk isolasi dan purifikasi suatu senyawa bahan alam. Berikan dengan contoh untuk 4 golongan senyawa bahan alam : terpenoid, alkaloid, flavonoid dan steroid !
Answer :  The solvent selected for the extraction seen by the ability of interesting secondary metabolites from plants. As the fluid used to perform the extraction of water, ether, or a mixture of ethanol and water. Alcohol, however, is a versatile solvent for extraction.
            Methods of isolation steroid
Procedures for isolation of steroids differ according to the chemical nature of the steroids and the scale and purpose of the isolation. Steroids are isolated from natural sources by extraction with organic solvents, in which they usually dissolve more readily than in the aqueous fluids of tissues. The source material often is treated initially with an alcoholic solvent, which dehydrates it, denatures (renders insoluble) proteins associated with the steroids, and dissolves many steroids. Saponification either of whole tissues or of substances extracted from them by alcohol splits the molecules of sterol esters, triglycerides, and other fatty esters and permits the extraction of the sterols by means of water-immiscible solvents, such as hexane or ether, with considerable purification. Intact sterol esters or hormonal steroids and their metabolites (compounds produced by biological transformation) that are sensitive to strong acids or alkalies, however, require essentially neutral conditions for isolation, and, although some procedures for analysis of urinary steroids employ acid treatment, milder hydrolysis, as by enzymes, is preferred. The acidity of some steroids allows them to be held in alkaline solution, while nonacidic impurities are extracted with organic solvents.
Commercially, abundant steroids usually are purified by repeated crystallization from solvents. Small-scale laboratory isolations for investigative or assay purposes usually exploit differing polarities of the steroid and of its impurities, which may be separated by partitioning between solvents differing in polarity or by chromatography. Occasionally, special reagents may selectively precipitate or otherwise sequester the desired steroid. A classical example is the precipitation of 3β-hydroxy sterols such as cholesterol by the natural steroid derivative digitonin. New steroids of great physiological interest often are isolated from tissue only with extreme difficulty, because they are usually trace constituents. In one example, 500 kg (1,100 pounds) of silkworm pupae yielded 25 mg (0.0008 ounce) of pure molting hormone, the steroid ecdysone (i.e., 20 × 106-fold purification). In such cases each isolation step is followed by an assay for the relevant physiological activity to ensure that the desired material is being purified. The percentage recovery of known steroid hormones during their assay in small biological samples usually is assessed by adding a trace of the same steroid in radioactive form to the initial sample, followed by radioassay (analysis based on radioactivity) after purification is complete. The efficiency of recovery of the radioactive steroid is assumed to be the same as that of the natural substance.
extraction of Flavonoids
Flavonoid metabolites (mainly glycosides) can be degraded by the activity of enzymes in plant material has not been dried or fresh ingredients. Thus it is recommended to use dried, lyophilized or frozen samples. The use of dried botanicals commonly milled into powder first. In the solvent extraction process should choose the appropriate type of flavonoid required so should consider the polarity of the solvent. Types of non-polar flavonoids (eg, isoflavones, flavanones, flavones and flavonols alcohol) was extracted using chloroform, dichloromethane, diethyl ether, or ethyl acetate, while the flavonoid glycoside and aglycone would be more appropriate extracted with alcohol or alcohol-water mixture. To glycosides increased solubility if the water or alcohol-water mixture. 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.
Chalcone glycosides specific flavanones and difficult to soluble in methanol, ethanol, or a mixture of alcohol and water. Flavanones solubility depends on the pH of the water as a solvent. Flavan-3-ol (like catechin, proanthocyanidin, and condensed tannins) can generally be extracted directly with water. However, the content of the compounds in the extract is not much different, either using water, methanol, ethanol, acetone, or ethyl acetate. In this case, can not be claimed that methanol is the best solvent for catechins and procyanidin acetone 70%, and so on.
Anthocyanins can be extracted with cold acidified methanol. The acid used is usually acetic acid (approximately 7%) or trifluoroacetic acid (TFA) (about 3%).

Anthocyanin extraction (include in flavonoid)
Using solvent extraction based on the solubility of the component to other components in the mixture. stating that polar solvents will dissolve polar solutes and non-polar solvents will dissolve the non-polar solute or so-called "like dissolve like".
In the fruit or vegetable, anthocyanin pigments are generally located in the cells near the surface. Extraction of anthocyanin pigments from plant materials commonly used solvent extractors HCl in ethanol. HCl in ethanol plants will denaturation of the cell membrane and then dissolving the pigment anthocyanin out of the cell. Anthocyanin pigments soluble in ethanol because both polar.
In research for the extraction of anthocyanins from flowers girlfriend water, the best solvent used is ethanol 95%. So is the research on the extraction of pigment from the skin of the fruit rambutan. This is due to the level of anthocyanin polarity similar to the 95% ethanol that can dissolve well in ethanol 95%. In addition to the solvent, the factors that can affect the outcome of anthocyanin extraction is the extraction time, pH and temperature extraction.
Methods Isolation of Compounds Alkaloids (Nicotine)
Alkaloids are usually isolated from the plant by using the method of extraction. Solvents are used when extracting the compound mixture is acidified water molecules. This solvent will be able to dissolve the alkaloid salts.
It also can alkalinize alkaloid-containing plant material by adding sodium carbonate. Bases are formed can then extraction by organic solvents such as chloroform or ether
For alkaloids that are not heat resistant, insulation can be done using techniques alkalinize the solution concentration by first. By using this technique the alkaloid will evaporate and then be purified by steam distillation method.
Each compound in the extract (extraction) based on the level of polarity (solubility)
Extraction is usually performed in stages ranging from non-polar compounds >> semi-polar polar >>
Polar compounds will tersari with polar solvents (eg, ethanol, methanol, water) as did so. examples of semi-polar solvent (ethyl acetate), an example of a non-polar solvent (n-hexane)
Compounds tersari with non-polar solvents >> Lipids, Steroids, Tannins
Compounds tersari the semi-polar solvents >> Alkaloids, Flavonoids, Glycosides
Compounds with a polar solvent tersari >> flavonoid Glycosides
Extractions are often used to separate organic compounds are liquid extraction, the separation of substances based on the comparison of the distribution of substances dissolved in the two solvents are not mutually dissolve.
It's best in a solvent in which the solubility is one greater than the concentration of solutes in the other solvents, the price of K should be larger or smaller than the short-term extraction process called pengorokan, whereas in the long-term use and the heating soxhlot.
Solvent selection criteria:
- Solvents dissolve easily extracted material
- The solvent does not mix with the juices extracted
- Solvent extract little or no impurities that exist
- Solvent easily separated from the solute
- The solvent does not react with the solute through any means

4.  jelaskan dasar titik tolak penentuan struktur suatu senyawa organic. Bila senyawa bahan alam tersebut adalah kafein misalnya. Kemukakan gagasan anda tentang hal-hal pokok apa saja yang diperlukan untuk menentukan struktur secara keseluruhan !
Answer :  I chose the determination structure of tobacco (nicotine).
            To know the strycture we should have solvent like methanol, and the tools for identification the structure.
We can identification structure based on some method like Using Column Chromatography, Using TLC, Infrared Spectrophotometer (IR), UV spectrophotometer, GC-MS.
Example in Results Identification of Compounds in Tobacco Leaf Extract Using TLC. in this method we can use developer solution of methanol. At this stage the results of the chromatography column (more concentrated solutions) that have been obtained and identified by thin layer chromatography using the solvent methanol developers.
From the analysis of thin-layer chromatography separation obtained only one peak each sample, it means that it has produced a compound perfectly separated.
Results Infrared Spectrophotometer (IR) in the Tobacco Leaf Extract Fraction Methanol. In this method we can use methanol as a solvent. Infrared spectrophotometer was used to analyze the functional group of chemical compounds found in tobacco leaves with the solvent methanol. results of Infrared Spectrophotometer (IR) was also determined from the use of solvent in column chromatography for example in one result of identification structure using infrared spectrophotometer produce The existence of absorption at 3398.3 wavenumber indicates the-OH group. This is because the use of methanol as column chromatography. So chromatography column was first performed will affect the outcome of the determination of the method used for the next.
Test results with a UV spectrophotometer Tobacco Leaf Extract Fraction methanol. UV spectrophotometry is used for organic compounds associated with electronic transitions in electron energy levels given. Usually measured compounds having conjugated double bonds. Nicotine has a conjugated double bond in the ring of piridin. Maximum absorption difference may be due to differences in the solvent used. In this method we can use different solvent and that will make difference absorption.
                The results of GC-MS Fraction Methanol Extracts of Tobacco Leaves.  The end of for identification is using GC-MS, from the first step until the end step have relationship like using the same solvent, from one to another will affect result for the next identification structure.

2.  jelaskan bagaimana idenya suatu senyawa bahan alam yang memiliki potensi biologis tinggi dan prospektif untuk kemaslahatan makhluk hidup dapat disintesis di labortorium !

Answer :  For this question I choose calkon (calkon synthesis of pyridine compounds as potential drug candidates)
calkon natural materials including compound flovonoid group, calkon compounds have a wide range of interesting activities such biolgi antioxidant, antitumor, anti-inflammatory, and others. calkon content at relatively low in extrack of plant with limited structural variation, because calkon an intermediate product in the process of formation of the biosynthesis of other flavonoid compounds. this is one of the factors to conduct molecular synthesis calkon well to study the physico-chemical properties and understand the relationship between structure and activity, and as an effort to find new bioactive compounds of potential used modern medicine. synthesis of compounds has been carried out in the presence of pyridine calkon various combinations of functional groups and pyridine core with several other heterocyclic core. calkon some synthesized compounds turned out to exhibit strong antibacterial activity.
calkon compound pyridine synthesis approach with combinatorial chemistry to produce a compound with a structure that varies in a relatively short time and using a simple method.

1-      synthesis of pyridine calkon compounds were calculated using grinding or mixing by using a simpler tool.
2-   synthesis of pyridine compounds calkon done by eliminating or minimizing the use of organic solvents.
3-      synthesis of pyridine calkon compounds can produce high redeman a relatively short time.
4-     some calkon pyridine compounds showed strong antibacterial activity.
5-      calkon pyridine compounds potentially have other activities such as antioxidant and anti-inflammatory.

From synthesis calkon can obtain potential new drugs and useful for life in the community, in addition to the method used is also simple, environmentally friendly, and the compound structure of the new calkon.
  

1. kemukakan gagasan anda bagaimana cara mengubah suatu senyawa bahan alam yang tidak punya potensi (tidak aktif) dapat dibuat menjadi senyawa unggul yang memiliki potensi aktifitas biologis tinggi. Berikan dengan contoh !
Answer :  the way 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 is activated by using pengaktifasi functional groups.
One example is an important alkaloid found in mengkudu  fruit is xeronine. Xeronine also produced by the human body in a limited number of functions to activate enzymes and regulate fungtion of  proteins in the cell.
            other than that to activate it can also be reacted with an enzyme that is sensitive to a reaction that takes place