KIMIA BAHAN ALAM

CODEINE

Codeine or 3-methylmorphine (a natural isomer of methylated morphine, the other being the semi-synthetic 6-methylmorphine) is an opiate used for its analgesic, antitussive, antidiarrheal, antihypertensive, antianxiety, sedative and hypnotic properties, to suppress premature labor contractions,myocardial infarction, relief of skin irritation from itching, as well as many other uses. Codeine is the second-most predominant alkaloid in opium, at up to three percent; it is much more prevalent in the Iranian poppy (Papaver bracteatum), and codeine is extracted from this species in some places although the below-mentioned morphine methylation process is still much more common. It is considered the prototype of the weak to midrangeopioids (tramadol, dextropropoxyphene, dihydrocodeine, hydrocodone, oxycodone).

Codeine is marketed as both a single-ingredient drug and in combination preparations with paracetamol (as co-codamol, e.g. brands Paracod, Panadeine, Paramol, and the Tylenol with codeine series including Tylenol 3 and 4); with aspirin (as co-codaprin); or with ibuprofen (as Nurofen Plus). These combinations provide greater pain relief than either agent alone (drug synergy). Codeine is also commonly marketed in products containing codeine with other pain killers or muscle relaxers, as well as codeine mixed with phenacetin (Emprazil With Codeine No. 1, 2, 3, and 4), naproxen,indomethacin, diclofenac and others as well as more complex mixtures including such mixtures as aspirin + paracetamol + codeine ± caffeine ± antihistamines and other agents such as those mentioned above.

Codeine-only products can be obtained with a prescription as a time release tablet (e.g., Codeine Contin 100 mg and Perduretas 50 mg). Codeine is also marketed in cough syrups with zero to a half-dozen other active ingredients, and a linctus (e.g., Paveral) for all of the uses for which codeine is indicated.

Injectable codeine is available for subcutaneous or intramuscular injection; intravenous injection can cause a serious reaction that can progress to anaphylaxis. Codeine suppositories are also marketed in some countries

KIMIA BAHAN ALAM

FLAVONOID

WHAT IS FLAVONOID . . .

flavonoids are the largest in the natural phenolic compounds, commonly found as natural dyes.

flavonoid color caused by the electrons in the conjugated system of the aromatic compounds

Flavonoids (or bioflavonoids) (from the Latin word flavus meaning yellow, their colour in nature) are a class of plant secondary metabolites.

Flavonoids were referred to as Vitamin P (probably due to the effect they had on the permeability of vascular capillaries) from the mid-1930s to early 50s, but the term has since fallen out of use. According to the IUPAC nomenclature, they can be classified into:

• flavones, derived from 2-phenylchromen-4-one (2-phenyl-1,4-benzopyrone) structure (examples: quercetin, rutin).
• isoflavonoids, derived from 3-phenylchromen-4-one (3-phenyl-1,4-benzopyrone) structure
• neoflavonoids, derived from 4-phenylcoumarine (4-phenyl-1,2-benzopyrone) structure.

Human health

Flavonoids (specifically flavanoids such as the catechins) are "the most common group of polyphenolic compounds in the human diet and are found ubiquitously in plants". Flavonols, the original bioflavonoids such as quercetin, are also found ubiquitously, but in lesser quantities.

The widespread distribution of flavonoids, their variety and their relatively low toxicity compared to other active plant compounds (for instance alkaloids) mean that many animals, including humans, ingest significant quantities in their diet. Preliminary research indicates that flavonoids may modify allergens, viruses, and carcinogens, and so may be biological "response modifiers". In vitro studies show that flavonoids also have anti-allergic, anti-inflammatory, anti-microbial, anti-cancer, and anti-diarrheal activities.

STEREOCHEMICAL

Keisomeran due to the asymmetric carbon atom, optical keisomeran.

Before there was the theory of valence, chemist / physiologically French Louis Pasteur (1822-1895) have recognized the influence of molecular structure on the properties of individual molecules combined. He managed to separate the racemic tartaric acid (sodium ammonium salt actually) to (+) and (-) under the direction of hemihedral crystal face (1848).
Both compounds have physical properties (eg melting point) and the same chemical, but there are differences in the optical properties in solution of each compound. Both rotate the plane of polarization of light, in other words having an optical activity. Rotation of the second type of compound, which mengkur rotational strength of both compounds, have the same absolute value but opposite sign. Because the molecules are free in solution, this difference can not be explained by differences in crystal structure. Unfortunately at that time, although the existing atomic theory, theory of valence has not been there. With these conditions can not explain the Pasteur discovery.

In the 1860's, the German chemist Johannes Adolf Wislicenus (1835-1902) found that two types of lactic acid is known at that time are both α-hidroksipropanoat acid CH3CH (OH) COOH, instead of acid β-hidroksipropanoat HOCH2CH2COOH. He further suggested that a new concept for menjelaskna stereoisomer should be made for this phenomenon. Konse recently stated that the two compounds that have the same structural formula can be in two dimensu stereoisomer when the arrangement of the atoms in different rooms.
In 1874, van't Hoff and Le Bel independently proposed the theory of tetrahedral carbon atom. According to this theory, the lactic acid that can be depicted in Figure 4.4. One of the lactic acid lactic acid is the mirror image of them. In other words, relations between the two compounds as a relationship right hand and left hand, and therefore called the antipodes or enantiomers. Thanks to the theory of van't Hoff and Le Bel, a new chemistry, stereochemistry, is growing rapidly.

Both isomers or the antipodes, as related to the right and left hand
In the central carbon atom in lactic acid, four different atoms or gigus bound. Carbon atoms are called the asymmetric carbon atom. Generally, the number of stereoisomers will be as many as 2n, n is the number of asymmetric carbon atoms. Tartaric acid has two asymmetric carbon atoms. However, due to the presence of molecular symmetry, the number stereoisomernya less than 2n, and another one is optically inactive stereoisomer (Figure 4.5). All these phenomena can be consistently explained by the theory of tetrahedral carbon atom.

However, because of symmetry, meso-tartaric acid is optically inactive.

Geometrical isomers

Van't Hoff explains fumaric acid and maleic keisomeran because of restrictions on the double bond rotation, a different explanation for the optical keisomeran. Isomers of this type is called the geometrical isomers. In the trans form subtituennya (in the case of fumaric and maleic acid, carboxyl group) are located on different sides of the double bond, while the cis isomer was subtituennya located on the same side.
Of the two isomers are diisoasi, van't Hoff was named isomer which readily releases water into maleic anhydride cis isomer because the cis isomer the two carboxy groups are close to each other. By heating to 300 ° C, acid fuarat turned into maleic anhydride. This is quite logical because the process must involve cis-trans isomerization process of the shipyard which is sufficiently high energies (Figure 4.6) ï ¼ Ž
Because some couples have been known geometrical isomers, geometric isomers theory gives a good dukunagn van't Hoff for the structural theory.

Figure 4.6 maleic acid geometrical isomers (cis form) has two carboxyl groups are close, and easy to release water into anhydride (maleic anhydride).

NITRILE

NITRILE

A nitrile is any organic compound that has a -C≡N functional group. The prefix cyano- is used interchangeably with the term nitrile in industrial literature. Nitriles are found in many useful compounds, including methyl cyanoacrylate, used in super glue, and nitrile butadiene rubber, a nitrile-containing polymer used in latex-free laboratory and medical gloves. Organic compounds containing multiple nitrile groups are known as cyanocarbons.

Inorganic compounds containing the -C≡N group are not called nitriles, but cyanides instead. Though both nitriles and cyanides can be derived from cyanide salts, most nitriles are not nearly as toxic.

Synthesis

Industrially, the main methods for producing nitriles are ammoxidation and hydrocyanation. Both routes are green in the sense that they do not generate stoichiometric amounts of salts.

Ammoxidation

In ammonoxidation, a hydrocarbon is partially oxidized in the presence of ammonia. This conversion is practiced on a large scale for acrylonitrile

CH₃CH=CH₂ + 3/2 O₂ + NH₃ → NCCH=CH₂ + 3 H₂O

A side product of this process is acetonitrile. Most derivatives of benzonitrile as well as Isobutyronitrile are prepared by ammoxidation.

Hydrocyanation

An example of hydrocyanation is the production of adiponitrile from 1,3-butadiene:

CH₂=CH-CH=CH₂ + 2 HCN → NC(CH₂)₄CN

From organic halides and cyanide salts

Often for more specialty applications, nitriles can be prepared by a wide variety of other methods. For example, alkyl halides undergo nucleophilic aliphatic substitution with alkali metal cyanides in the Kolbe nitrile synthesis. Aryl nitriles are prepared in the Rosenmund-von Braun synthesis.

Cyanohydrins

The cyanohydrins are a special class of nitriles that result from the addition of metal cyanides to aldehydes in the cyanohydrin reaction. Because of the polarity of the organic carbonyl, this reaction requires no catalyst, unlike the hydrocyanation of alkenes.

Dehydration of amides and oximes

Nitriles can be prepared by the Dehydration of primary amides. Many reagents are available, the combination of ethyl dichlorophosphate and DBU just one of them in this conversion of benzamide to benzonitrile:

Two intermediates in this reaction are amide tautomer A and its phosphate adduct B.

In a related dehydration, secondary amides give nitriles by the von Braun amide degradation. In this case, one C-N bond is cleaved. The dehydration of aldoximes (RCH=NOH) also affords nitriles. Typical reagents for this transformation arewith triethylamine/sulfur dioxide, zeolites, or sulfuryl chloride. Exploiting this approach is the One-pot synthesis of nitriles from aldehyde with hydroxylamine in the presence of sodium sulfate.

• from aryl carboxylic acids (Letts nitrile synthesis)

Sandmeyer reaction

Aromatic nitriles are often prepared in the laboratory form the aniline via diazonium compounds. This is the Sandmeyer reaction. It requires transition metal cyanides.

ArN₂⁺ + CuCN → ArCN + N₂ + Cu⁺

Other methods

• A commercial source for the cyanide group is diethylaluminum cyanide Et₂AlCN which can be prepared from triethylaluminium and HCN. It has been used in nucleophilic addition to ketones. For an example of its use see: Kuwajima Taxol total synthesis