MID SEMESTERS EXAM ANSWERS CHEMISTRY OF NATURAL PRODUCTS

Name  : VEBRIA ARDINA

NIM    : RSA1C110020

1.      The way to obtain a preparation containing an active compound from a natural material with an appropriate solvent. Why should it be removed? In order to extract only contains the active compounds contained in the raw ingredients / natural that were penyari the fluid most optimal able to attract the active compound.
Method of extraction. There are several methods of extraction of crude natural materials, such as maceration, infundasi, digestion, percolation and soxletasi.

Active a pure compound can be administered in the form of repetition, more accurate dose given. This, of course, can be achieved when we managed to get a pure compound plays a role in biokativitasnya and share experimental dilakuakn selnajutnya to find the dose, dose prepared in the right way and the right way to give. The term is no longer gambling here. Everything is scientifically proven.
The compound was isolated can be more developed in the process of finding the most effective compounds. By knowing the chemical structure of the compound will be a "lead compound" in formation so that it can be synthetically on a large scale. O modification of the structure of the compound will be able to withstand the compounds that can be more active.

Pure compounds which have been isolated can also be tested against a variety of bioactivity, not only based on the bioactivity associated with traditional uses. The possibility is always there, that the slogan for researchers.

2.      New drugs found from nature usually find obstacles in the industry because their numbers are very limited, especially when the drug is derived from marine invertebrates or microbes. For it is made ​​of natural materials synthesis memperlajari how to produce compounds of natural materials en masse and clearly this is not easy because of the diversity of natural products is very high and complicated (especially marine natural ingredients). Ingredients sourced from wild plants and animals is not only widely used in traditional medicine, but also increasingly valued as raw material in the manufacture of modern medicine and herbal preparations. Greater demand and increasing human population which leads to an increased level and often unsustainable exploitation of wild sourced ingredients.

Plants and animals have been used as a source of medicines from ancient times, and even in modern times, animal and plant-based systems continue to play an essential role in health care .  Additionally, a significant portion of the currently available non-synthetic and/or semi-synthetic pharmaceuticals in clinical use is comprised of drugs derived from higher plants, followed by microbial, animal and mineral products, in that order.

Over 50% of commercially available drugs are based on bioactive compounds extracted (or patterned) from non-human species, including some lifesaving medicines such as cytarabine, derived from a Caribbean sponge, which is reputed as the single most effective agent for inducing remission in acute myelocytic leukemia. Other examples of drugs from biological sources include: quinidine to treat cardiac arrhythmias, D-tubocurarine to help induce deep muscle relaxation without general anesthetics, vinblastine to fight Hodgkin's disease, vincristine for acute childhood leukemias, combadigitalis to treat heart failure, ranitidine to fight ulcers, levothyroxine for thyroid hormone replacement therapy, digoxin to treat heart disease, enalapril maleate to reduce high blood pressure, and even aspirin.

A great number of these natural products have come to us from the scientific study of remedies traditionally employed by various cultures, most of them being plant-derived.

There has been increasing attention paid to animals, both vertebrates and invertebrates, as sources for new medicines. Animals have been methodically tested by pharmaceutical companies as sources of drugs to the modern medical science, and the current percentage of animal sources for producing essential medicines is quite significant. Of the 252 essential chemicals that have been selected by the World Health Organization, 11.1% come from plants, and 8.7% from animals.

One excellent example of successful drug development from a component of snake venom (Bothrops jararaca [Wied 1824]) is that of the inhibitors of angiotensin-converting enzyme (ACE). This enzyme is responsible for converting an inactive precursor into the locally active hormone angiotensin, which causes blood vessels to constrict and hence raises blood pressure [62]. Other excellent example is the work initially conducted by Daly during the 1960s of the skin secretions of dendrobatid frogs from Ecuador, and of other "poison dart" frog species in Central and South America. This work has led to the identification of a number of alkaloid toxins that bind to multiple receptors in the membranes of nerve and muscle cells. One compound derived from these studies, which binds to nicotinic acid receptors associated with pain pathways, the synthetic ABT 594 (Abbott Laboratories), is in Phase II clinical trials, and has generated a great deal of interest, as it has been shown to be 30–100 times more potent as an analgesic than morphine [10]. The marine environment is a rich source of biologically active natural products of diverse structural types, many of which have not been found in terrestrial sources [63]. The sponge Luffariella variabilis (Poléjaeff, 1884) produces relatively large amounts of a chemical with anti-inflammatory activity known as monoalide. It was found that monoalide inhibits the action of an enzyme called phospholipase A2. The powerful immunosuppressive agent discodermolide originates from another sponge, Discoderma sp. [64].

Ingredients sourced from wild plants and animals are not only widely used in traditional medicines, but are also increasingly valued as raw materials in the preparation of modern medicines and herbal preparations. Greater demand and increased human populations are leading to increased and often unsustainable rates of exploitation of wild sourced ingredients.

http://www.ethnobiomed.com/content/3/1/14

3.      Criteria for selection of the solvent:

a.       The solvent dissolves the material easily extract

b.      The solvent does not mix with the juice extracted

c.       Solvent extract impurities that there are little or no

d.      Solute easily separated from the solvent

e.       The solvent does not react with the solute through any means

Type of solvent used

Related to the type of solvent polarity of the solvent. Things to be considered in the extraction process is a compound that has the same polarity will be easier interested / dissolved by the solvent that has the same polarity. Correlated to the polarity of the solvent, there are three classes of solvents, namely:

a.       polar solvents

It has a high level of polarity, suitable for extracting polar compounds from plants. Polar solvents tend to be used universally because normally if polar, can still cite compounds with lower levels of polarity. An example is the polar solvents: water, methanol, ethanol, acetic acid.

b.      semipolar solvent

Semipolar polarity solvent has a lower rate than the polar solvent. It is a good solvent for semipolar compounds from plants. Examples of these solvents are: acetone, ethyl acetate, chloroform

c.       nonpolar solvents

Non-polar solvents, almost completely polar. It is a good solvent to extract the compounds do not dissolve in polar solvents. The compound is better to extract different types of oils. Example: hexane, ether

The flavonoids possess a less polar, if extracted with a non-polar solvent, then it will not be possible to obtain the compound to be our extraction. To extract flavonoids we use polar or semi-polar solvents. As methanol.

Alkaloids, such as coffee powder caffeine dissolved in diethyl ether is because non-polar so as to dissolve the caffeine which 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 koroformnya.

Terpenoid polar nature so that it can be used semi-polar or polar solvents such as methanol and ethanol.

Steroids have properties that can be used polar solvents polar or semi-polar such as acetone, chloroform.

4.      Covering ultraviolet spectroscopic methods, infrared and nuclear magnetic resonance.
In essence, the explanation structure using spectroscopic methods of UV / Vis, IR, MS and NMR. However, in practice, is in the head NMR, integrated by MS. MS is sometimes become very important in the elucidation especially for long-chain compounds. IR is not so helpful in the elucidation of the structure, while the dereplikasi UV / Vis more useful.

NMR as the primary means of generating NMR spectra for H and C (typical), the data are called 1D NMR. While 2D NMR correlation gives date2 H / C with H / C in the form of HSQC, HMBC, COSY, TOCSY, ADEQUATE, etc.
NMR data obtained through the planar structure of a compound and from here is to determine the stereochemistry (if it contains a chiral atom) whose methods are divided into three: chemical reactions, physical (NMR and circular dichroism), and X-ray chrystallography .

Determination of the stereochemistry of the end of the elucidation of structure-activity.
Throughout the process structure elucidation, there are two important things were done. The first is a test of bioactivity that can be done at the beginning / middle (for screening) or at the end of pure compound (for the determination of the activity) and dereplikasi.

In summary, dereplikasi is a method to quickly identify known compounds. Since the objective laboratory natural materials is usually a new compound, the compound is not new, all the work, must be identified as soon as possible, in order not to lose time (with membuang2 resources of compounds which are no longer new).

Biosynthesis Of Cholestrol

Cholesterol Is Made from Acetyl-CoA in Four Stages

Cholesterol, like long-chain fatty acids, is made from acetyl-CoA, but the assembly plan is quite different in the two cases. In early experiments animals were fed acetate labeled with 14C in either the methyl carbon or the carboxyl carbon. The pattern of labeling in the cholesterol isolated from the two groups of animals (Fig. 20-30) provided the blueprint for working out the enzymatic steps in cholesterol biosynthesis.

Figure 20-30

Figure 20-30 The origin of the carbon atoms of cholesterol, deduced from tracer experiments with acetate labeled in the methyl carbon (black) or the carboxyl carbon (red). The individual rings in the fused-ring system are designated A through D.

The process occurs in four stages (Fig. 20-31). In stage 1 the three acetate units condense to form a six-carbon intermediate, mevalonate. Stage 2 involves the conversion of mevalonate into activated isoprene units, and stage 3 the polymerization of six 5-carbon isoprene units ta form the 30-carbon linear structure of squalene. Finally (stage 4, the cyclization of squalene forms the four rings of the steroid nucleus, and a further series of changes (oxidations, removal or migration of methyl groups) leads to the final product, cholesterol.

Figure 20-31

Figure 20-31 A summary of cholesterol biosynthesis, showing the four stages discussed in the text. The isoprene units in squalene are set off by red dashed lines.

1. Synthesis of Mevalonate from Acetate

The first stage in cholesterol biosynthesis leads to the intermediate mevalonate (Fig. 20-32). Two molecules of acetyl-CoA condense, forming acetoacetyl-CoA, which condenses with a third molecule of acetyl-CoA to yield the six-carbon compound β-hydroxy-β-methylglutaryl-CoA (HMG-CoA). These first two reactions, catalyzed by thiolase and HMG-CoA synthase, respectively, are reversible and do not commit the cell to the synthesis of cholesterol or other isoprenoid compounds.

The third reaction is the committed step: the reduction of HMGCoA to mevalonate, for which two molecules of NADPH each donate two electrons. HMG-CoA reductase, an integral membrane protein of the smooth endoplasmic reticulum, is the major point of regulation on the pathway to cholesterol, as we shall see.

Figure 20-32

Figure 20-32 Formation of mevalonate from acetyl-CoA. The origin of C-1 and C-2 of mevalonate from acetyl-CoA is shown in red.

2. Conversion of Mevalonate to Two Activated Isoprenes In the next stage of cholesterol synthesis, three phosphate groups are transferred from three ATP molecules to mevalonate (Fig. 20-33). The phosphate attached to the C-3 hydroxyl group of mevalonate in the intermediate 3-phospho-5-pyrophosphomevalonate is a good leaving group; in the next step this phosphate and the nearby carboxyl group both leave, producing a double bond in the five-carbon product, Δ³-isopentenyl pyrophosphate. This is the first of the two activated isoprenes central to cholesterol formation. Isomerization of Δ³-isopentenyl pyrophosphate yields the second activated isoprene, dimethylallyl pyrophosphate (Fig. 20-33)

Figure 20-33

Figure 20-33 Conversion of mevalonate into activated isoprene units. Six of these units will combine to form squalene. The leaving groups of 3-phospho-5-pyrophosphomevalonate are shaded in red.

3. Condensation of Six ActiUated Isoprene Units to Form Squalene

Isopentenyl pyrophosphate and dimethylallyl pyrophosphate now undergo a "head-to-tail" condensation in which one pyrophosphate group is displaced and a 10-carbon chain, geranyl pyrophosphate, is formed (Fig. 20-34). (The "head" is the end to which pyrophosphate is joined.) Geranyl pyrophosphate undergoes another head-to-tail condensation with isopentenyl pyrophosphate, yielding the 15-carbon intermediate farnesyl pyrophosphate. Finally, two molecules of farnesyl pyrophosphate join head to head, with the elimination of both pyrophosphate groups, forming squalene (Fig. 20-34). The common names of these compounds derive from the sources from which they were first isolated. Geraniol, a component of rose oil, has the smell of geraniums, and farnesol is a scent found in the flowers of a tree, Farnese acacia. Many natural scents of plant origin are synthesized from isoprene units. Squalene, first isolated from the liver of sharks (genus Squalus), has 30 carbons, 24 in the main chain and 6 in the form of methyl group branches.

Figure 20-34

Figure 20-34 Formation of squalene (30 carbons) by successive condensations of activated isoprene (five-carbon) units.

4.Conversion of Squalene to the Four-Iling Steroid Nucleus

When the squalene molecule is represented as in Figure 20-35, the relationship of its linear structure to the cyclic structure of the sterols is apparent. All of the sterols have four fused rings (the steroid nucleus) and all are alcohols, with a hydroxyl group at C-3; thus the name "sterol." The action of squalene monooxygenase adds one oxygen atom from O₂ to the end of the squalene chain, forming an epoxide. This enzyme is another mixed-function oxidase (Box 20-1); NADPH reduces the other oxygen atom of O₂ to H₂O. The double bonds of the product, squalene2,3-epoxide, are positioned so that a remarkable concerted reaction can convert the linear squalene epoxide into a cyclic structure. In animal cells, this cyclization results in the formation of lanosterol, which contains the four rings characteristic of the steroid nucleus. Lanosterol is finally converted into cholesterol in a series of about 20 reactions, including the migration of some methyl groups and the removal of others. Elucidation of this extraordinary biosynthetic pathway, one of the most complex known, was accomplished by Konrad Bloch, Feodor Lynen, John Cornforth, and George Popjak in the late 1950s.

Cholesterol is the sterol characteristic of animal cells, but plants, fungi, and protists make other, closely related sterols instead of cholesterol, using the same synthetic pathway as far as squalene-2,3-epoxide. At this point the synthetic pathways diverge slightly, yielding other sterols: stigmasterol in many plants and ergosterol in fungi, for example (Fig. 20-35).

Figure 20-35

Figure 20-35 Ring closure converts linear squalene into the condensed steroid nucleus. The first step in this sequence is catalyzed by a mixed-function oxidase (a monooxygenase), for which the cosubstrate is NADPH. The product is an epoxide, which in the next step is cyclized to the steroid nucleus. The final product of these reactions in animal cells is cholesterol, but in other organisms, slightly different sterols are produced

http://www.bioinfo.org.cn/book/biochemistry/chapt20/sim6.htm

http://www.chembio.uoguelph.ca/educmat/chm452/lectur16.htm

Identification of Isoflavonoid

Isoflavones are found in dried fruits, in particular soya is believed to have estrogenic properties, anticancer, antiosteoporoisitik, antioksidan.Pada processed soy isoflavone-containing compounds, that is to say have a temperature aktivitasantioksidan and anti-haemolytic, these compounds are called by a factor of 2, genisten, and daidzein.Isoflavon are flavonoids which act as phytoestrogens are very useful for the health. Flavonoids and isoflavonoida is one satugolongan secondary metabolites are found in many plants, in particular by groups Leguminoceae (butterflies flower plants). The content of flavonoid compounds in the plant itself is very low, approximately 0.25%. These compounds are generally in keadaanterikat / conjugated with sugars.Isoflavones are compounds that many secondary metabolites synthesized by the plants. However, it is not so metabolitsekunder as compounds because these compounds are not synthesized by microorganisms. Dengandemikian, microorganisms do not have the content of these compounds. For karenaitu, plants are the main source of isoflavones compounds in nature. Of the different types of crops, high content of isoflavones contained in tanamanLeguminoceae, especially in soybean plants. In soybean, a higher content of isoflavones present in soy, especially in hipokotil (germ) that will grow into plants. Some lagiterdapat the cotyledons which will be the first leaf of the plant.These compounds isoflavones generally form complex compounds or conjugated sugar dengansenyawa through glucoside bond. This type of compound terutamaadalah isoflavones genistein, daidzin and glisitin. This form of such compounds mempunyaiaktivitas physiological small.During the process, either through a process of fermentation and prosesnon-fermentation, isoflavone compounds may undergo, hydrolysis process terutamamelalui so that it can be obtained free yangdisebut compounds isoflavone aglycone of greater activity. The adalahgenistein aglycone compounds, glisitein and daidzein

Isolation of Cinnamaldehyde from Cinnamon

Introduction

Commercial cinnamon consists of dried, ground bark from the cinnamon tree, and contains about 2% cinnamaldehyde, which is responsible for its distinct flavor and odor.

The isolation will be accomplished by steam distillation. This means that the solid cinnamon will be boiled in water, and the steam will be condensed and collected. Since cinnamaldehyde is soluble in steam (but not in water), it will be carried up with the distillate and form a finely distributed emulsion, which will appear milky upon cooling. Many other essential oils can be isolated in this way – anisole from anise, camphene from nutmeg, carvone from caraway and spearmint, cuminaldehyde from cumin, eugenol from cloves, safrole from sassafras, and limonene from citrus peel.
A common way of isolating cinnamonoil along with cinnamaldehyde fromcinnamon bark, even in industrial scale, isthrough steam distillation. The cinnamon oilisolated through steam distillation containsroughly around 90% trans-cinnamaldehyde.Cinnamaldehyde contains a formylgroup, and is therefore an aldehyde. Itsstructure has a phenyl group attached to an
unsaturated aldehyde. It named throughIUPAC nomenclature as 3-phenyl-2-Propenal.The experiment aimed to isolatecinnamon oil from cinnamon bark by steamdistillation. From cinnamon oil,cinnamaldehyde could be extracted bymultiple extractions using DCM as a solvent,through aqueous dispersion. In theexperiment done, cinnemaldehyde wasanalyzed by subjecting it to Tollen’s test andPhenylhydrazone test, both of which test forthe presence of aldehydes

Procedure

Steam distillation of the cinnamon:

• Obtain a 100 ml Erlenmeyer flask with a 14/20 ground glass joint from the instructor.

• Add 15 ml of distilled water, 2 drops of Triton X-100 (a surfactant which reduces

foaming), 2.0 g of cinnamon, and a long stir bar.

• Attach a Hickman still to the flask, then top it with a reflux condenser. Attach the reflux

condenser to the water hoses and turn on the water. Insulate the top of the flask below the

neck of the still with aluminum foil.

• Turn on the stirrer and begin to heat the cinnamon mixture slowly until it begins to boil.

• If it foams up into the still, you are heating too quickly – if the foam gets into the lip of

the still, you'll have to take it off and clean it before continuing.

• Remove the distillate with a pipet as it collects and place it in a beaker or flask.

• If, after collecting some distillate, the still begins to look dry, add up to 1 ml of water (no

more!). Try not to bake the cinnamon onto the glassware, as it is hard to clean out.

• You should collect about 5 ml of distillate; once it no longer turns milky on cooling, most

of the cinnamaldehyde has been removed.

Isolation of the cinnamaldehyde from the distillate:

• Place a sep funnel on the clamp and put a beaker underneath it. After making sure the

stopcock is closed, transfer the distillate to the sep funnel.

• Extract it by adding about 5-10 ml of dichloromethane, shaking, allowing it to separate,

and draining off the dichloromethane.

• Repeat two more times, combining all of the dichloromethane layers that you drain off.

Don't throw away anything until you are sure you have what you want!

• Dry the dichloromethane solution by adding sodium sulfate until it is free flowing.

• Transfer the solution to a tared (preweighed) round bottom flask and rinse the solid

sodium sulfate with a little more dichloromethane. Evaporate the solution on the rotovap.

• Observe the product that you have obtained and record your observation. Authentic

cinnamaldehyde is a clear, slightly yellow liquid with a strong odor of cinnamon.

• When the flask is cool, obtain the mass of the cinnamon oil that you have extracted.

Calculate the % recovery of cinnamaldehyde.

• Discuss the odor, appearance, mass, and percent recovery of the cinnamaldehyde in your

conclusion.