Codeine chemical structure

An alkaloid is a complex organic chemical substance found in plants, which characteristically combines nitrogen with other elements, has a bitter taste, and typically has some toxic, stimulant, analgesic effects. There are many different alkaloids, 30 of which are found in the opium plant. While morphine is the most important alkaloid in opium—for its natural narcotic qualities as well as providing the chemical structure for heroin—another alkaloid, codeine, is also sought after for its medicinal attributes. Other alkaloids include papaverine, narcotine, nicotine, atropine, cocaine, and mescaline. While the concentration of morphine in opium varies depending on where and how the plant is cultivated, it typically ranges from 3 percent to 20 percent. 

There are many legal medicines that use opiates or opiate-like substances. Most of the opiate-based medicines used today are not made from natural opiates, but are either synthetic or semi-synthetic. Synthetic opiate drugs are not actually opiates at all they are merely different chemicals that act like opiates. Semi-synthetics are those drugs that involve changing the chemical structure of a natural opiate. An example of this is heroin, which is a human-made variation of morphine. Morphine and codeine are the principal natural opiates used as medicines and what follows are descriptions of the other most frequently used opiate-based medicines. 

I o find new and more effective medicines, chemists use various models that J. describe how drugs work. By far, one of the most useful models of drug action is the lock-and-key model. The basis of this model is the connection between a drugs chemical structure and its biological effect. For example, morphine and all related pain-relieving opioids, such as codeine and heroin, have the T-shaped structure shown in Figure 14.1. 

FIGURE 27.3 Chemical structures of physostigmine, galanthamine, and codeine. 

Oxycodone is available alone or in combination with either acetaminophen or aspirin. Its chemical structure is most closely related to codeine, but it has strong painkilling effects equal to those of morphine. 

The gold standard of opiate pain relievers is morphine. It was one of the first compounds extracted, isolated, and purified from the opium poppy, and it continues to be one of the most widely used pain relievers today. Morphine and other opiate drugs such as heroin, codeine, oxycodone, and hydrocodone have very similar chemical structures (Figure 3.2). However, other opiates such as fentanyl and meperidine (Demerol) have a slightly different structure (Figure 3.3). 

Figure 3.2 This diagram illustrates the chemical structures of morphine, codeine, oxycodone, hydrocodone, and heroin. Notice how each molecule differs from the others by only a few atoms.

The chemical structures of morphine and heroin in relation to other closely related opiates such as codeine and dihydrocodeine are shown in Figure 2. Morphine has a "phenolic" -OH group in the 3 position and an aliphatic (alcoholic) -OH group in the 6 position. When both -OH groups (3 and 6 positions) are acetylated, diacetyl morphine, better known as diamorphine or heroin is produced. Codeine is the 3-methyl derivative of morphine by substituting the phenolic -OH group with a methyl group in the... 

Although a large variety of compounds can reduce tris(2,2 -bipyridyl)ruthenium(III), only certain species (e.g., aliphatic amines, amino acids, NADH, some alkaloids, aminoglycoside or tetracycline antibiotics, and the oxalate ion) will produce the characteristic orange luminescence with this reagent. Subtle differences in chemical structure can have a dramatic effect on chemiluminescence intensity. This is exemplified by the determination of the papaver alkaloid codeine (11) compared to structurally similar morphine (12). At pH 6.8, codeine can be determined down to a concentration of 10 mol 1 whereas morphine produces a chemiluminescent response equivalent to that of the blank. In many applications this degree of selectivity is most desirable. 

Fig. 36.4 Chemical structures of morphine (M), codeine (C), oripavine (O), thebaine (T), and pseudomorphine (P) and their separation by cyclodextrin-modified CZE using different CDs. Conditions (a) HP-PCD, (b) yCD, (c) pCD, and (d) aCD. Buffer 100 mM Tris-phosphate, pH 2.8 CD concentration of 30 mM except for pCD (10 mM due to limited solubility) applied voltage of 25 kV 2 s injection at 50 mbar 20 °C capillary 50 cm x 50 pm i.d. UV absorption detection at 214 nm (Modified from ref. [47])...

The opium poppy (Papaver somniferum L. [Papaveraceae]) latex contains benzylisoquinoline alkaloids and is a widely known source of the analgesic drugs morphine and codeine. The biosynthesis of benzylisoquinoline alkaloids begins with a condensation reaction catalyzed by norcoclaurine synthase of DA [161]. The structural features of benzylisoquinoline alkaloids derived from DA might provide some explanation for the documented affinity of some natural alkaloids of this class, and some synthetic derivatives, for DA receptors [162]. Indeed, the chemical structure of morphine has been used as a template for the development of the PD drug, apomorphine (47). Apomorphine includes a catecholaminergic moiety in its... 

In relation to their chemical structure and action, they can be classified into two categories. The first are phenanthrene alkaloids and are under international control morphine (MO), codeine (COD), and thebaine (TB), which act on the central nervous system and are used as analgesics, narcotics, and potentially addicting compounds (pain relievers). Heroin is synthesized from MO. The second group is isoquinoline alkaloids Papaverine (PV) and narcotine (also known as noscapine). Narcotine acts only to relax involuntary smooth muscles, for which it is considered an antitussive, and lacks addictive, analgesic, respiratory, narcotic, depressant, and sedative properties. Next to MO, which constitute about 10% by weight of raw opium, is the second most abundant alkaloid present in opium. The three last alkaloids (PV, narcotine, and narceine) are not under international control specially, narcotine and narceine which have scarcely any medical or other uses. Consequently, the five economically significant alkaloids of opium are MO, COD, TB, PV, and narcotine. 

Although far less numerous than the terpenoid/isoprenoid or polyketide NPs, the alkaloids (with an estimated 20,000 different structures) have a special place in NP research because a few are of great value to humans—for example, morphine, theobromine, caffeine, vincristine, quinine, codeine, cocaine, nicotine and strychnine. These often complex chemicals are found in about 20% of vascular plants and a smaller number of fungi, marine invertebrates and a few bacteria. ... 

Opium typically contains between 0.5% and 3.0% codeine by weight. Chemically, codeine is nearly identical in structure to morphine. The only difference between the two is that codeine contains an extra methyl group (two hydrogen atoms bound to a carbon atom) at one end of the molecule. In fact, once absorbed in the body, an enzyme removes the methyl group (demethyla-tion) from codeine to produce morphine. Thus, codeine itself is not an analgesic. 

Cancentrine (43) is a complex alkaloid that embodies within its structure a modified codeine skeleton and a cularine skeleton. Its 13C spectrum along with that of some derivatives was studied (36) in order to obtain chemical... 

The correct structure of morphine was proposed in 1925. Ultimate proof of its correct structure had to await its total synthesis, accomplished three decades later. The lack of the correct structure of morphine did not discourage the synthesis of several morphine congeners and derivatives by chemical reaction with the known peripheral functional groups, specifically the phenolic hydroxyl (C-3), and allylic alcohol (C-6), and the double bond (C-7-8) (Fig. 5-8). Among the derivatives introduced before 1930 and still in common usage today are codeine,6 ethylmorphine (Dionin), diacetylmorphine (heroin), hydromor-phone (Dilaudid), hydrocodone (Dicodid), and methyldihydromorphinone (Metopon). 

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