"A man would do nothing;
if he waited until he could do it so well
that no one would find fault
with what he has done. "
“It is cocaine," he said, "a seven-per-cent solution. Would you
care to try it?"
"No, indeed," I answered brusquely. "My constitution has not got
over the Afghan campaign yet. I cannot afford to throw any extra
strain upon it."
He smiled at my vehemence. "Perhaps you are right, Watson," he
said. "I suppose that its influence is physically a bad one. I find
it, however, so transcendently stimulating and clarifying to the
mind that its secondary action is a matter of small moment.”
― Arthur Conan Doyle, The Sign of Four
Tropane derivatives are among the economically most important pharmaceuticals (Rates 2001; Raskin 2002). Various pharmaceutical industries are manufacturing over 20 active pharmaceutical ingredients (APIs) containing the tropane moiety in their structures; they are applied as mydriatics, antiemetics, antispasmodics, anesthetics, and bronchodilators (Grynkiewicz and Gadzikowska, 2008). The first tropane derived API was homatropine, it was introduced by E. Merck Company as a new mydriatic in 1883.
Duboisia are native to the Kingaroy district of Queensland, Australia. In 1940 collection of Duboisia from the wild commenced. Commercial production of scopolamine began in 1941, that of hyoscyamine /atropine in 1942 (Barnard 1952). Propagation of plants and plantations was limited in the early years due to the abundance of naturally occurring trees when land was cleared and burnt. For the harvest of Duboisia leaf for extraction, the trees are cut, the complete branches with the leaves are air dried and then the dry leaves removed (traditional method), or the fresh branches are chopped, the leaf separated from the wood chips and dried artificially (common industrial method). The stumps normally regrow and can be harvested again after about 12 months. The first large- scale plantations did not occur until the late 1950s, and then they were mainly from seedlings transplanted from natural germination in the wild.
Plant-related research initially focused on plant propagation, on identification of alkaloid-rich genotypes, and the elucidation of the reasons of alkaloid variation (Barnard and Finnemore 1945). These activities gained a new dimension when, in the area where the habitats of D. myoporoides and D. leichhardtii overlap, intermediate types were found that appeared to be natural interspecific hybrids. Artificial hybridization experiments started, and by 1945 the first hybrid plants were established in the field (Groszman 1949; Hills 1954). After the end of World War II, commercial alkaloid extraction and government-supported research continued until about 1954 when the export embargo on Duboisia leaf was lifted. Commercial extraction was no longer competitive in the international market; research was considerably reduced if not ceased. Exportation ofDuboisia leaf from collection of wild material and increasingly from cultivation commenced and continued with a steadily growing level, one of the main buyers being Boehringer Ingelheim.In 1976 Boehringer Ingelheim has established its own Duboisia plantations within coastal forests from southern New South Wales to Northern Queensland. Since then the company has acquired several other properties, bringing the total acreage of our properties to around 990 hectares. The leaf of the Duboisia tree is harvested, dried and packaged in Australia, and then shipped to the Chemicals division of Boehringer Ingelheim in Germany, where extraction of active ingredients takes place. Today Boehringer Ingelheim, the manufacturer of Buscopan, is the world's leading producer of Duboisia, delivering 90% of the global requirement of the ingredient in 2010s.
The additional carbon atoms required for the synthesis of cocaine are derived from acetyl-CoA, by addition of two acetyl-CoA units to the N-methyl-Δ1-pyrrolinium cation. The first addition is a Mannich-like reaction with the enolate anion from acetyl-CoA acting as a nucleophile towards the pyrrolinium cation. The second addition occurs through a Claisen condensation. This produces a racemic mixture of the 2-substituted pyrrolidine, with the retention of the thioester from the Claisen condensation. In formation of tropinone from racemic ethyl [2,3-13C2]4(N methyl- 2-pyrrolidinyl)-3-oxobutanoate there is no preference for either stereoisomer. In the biosynthesis of cocaine, however, only the (S)-enantiomer can cyclize to form the tropane ring system of cocaine. The stereoselectivity of this reaction was further investigated through study of prochiral methylene hydrogen discrimination. This is due to the extra chiral center at C-2. This process occurs through an oxidation, which regenerates the pyrrolinium cation and formation of an enolate anion, and an intramolecular Mannich reaction. The tropane ring system undergoes hydrolysis, SAM-dependent methylation, and reduction via NADPH for the formation of methylecgonine. The benzoyl moiety required for the formation of the cocaine diester is synthesized from phenylalanine via cinnamic acid. Benzoyl-CoA then combines the two units to form cocaine.
Tropane alkaloid biosynthesis in Datura mainly takes place in the roots (Conklin, 1976). From the site of synthesis the compounds are translocated to upper parts of the plant. Changes in alkaloid content of leaves follow the fluctuation of roots, with a delay of approximately one month (Demeyer and Dejaegere, 1989). Degradation and transformation seems to take place continuously in stems and leaves during molecule translocation to green plant parts (van de Velde et al., 1988). Within cells, the alkaloids most likely occur in the form of crystals in the vacuoles (Verzár-Petri, 1973).
1. Humphrey AJ, O’Hagan D: Tropane alkaloid biosynthesis. A century old problem unresolved. Nat Prod Rep, 2001, 18, 494–502.
Hairy roots result from the transfer and integration of the genes located on the Ri (root-inducing) plasmid of Agrobacterium rhizogenes into the plant genome and their expression therein (White and Nester, 1980). The transferred genes are involved in the synthesis of plant hormones, expressing in the plant cell and giving rise to rooty tumors at the infection site. These types of roots are characterized by fast growth, frequent branching, plagiotropism, and the ability to synthesize the same compounds as the roots of the intact plant (David, 1984).
Agrobacterium rhizogenes is a gram negative soil bacterium. It incites hairy root disease of many dicotyledonous plants (Brown, 1929; DeCleene and DeLey, 1981; Riker et al.,1930; Siegler, 1928). The ability of A. rhizogenes to incite hairy root disease is determined by a virulence plasmid (Chilton. et al.,1982; Moore et al.,1979; White and Nester, 1980) similar to Ti (tumor inducing) plasmid found in Agrobacterium tumefaciens which causes Crown gall tumors of plants. The virulence plasmid of A. rhizogenes is known as the Ri-plasmid to distinguish it from the tumor-inducing (Ti) plasmid.
The Ri–plasmid contains a distinct segments of DNA which is transferred to plant genome during infection (Chilton et al.,1982; White et al.,1982; Willmitzer et al.,1982). The transfer of the DNA (T-DNA) to the plant genome is mediated by another segment on the plasmid known as the virulence (vir) region. Hairy root induction and morphology are controlled by the rol (A, B, C and D) genes from the A. rhizogenes Ri plasmid (White et al. 1985). The rol genes have also been found to affect secondary metabolite production (Sevón et al., 1997; Bonhomme et al., 2000; Bulgakov et al., 2004). The T-DNA confers on the plant cells the ability to grow in the absence of exogenous plant hormones. The T-DNA also confers on the transformed tissue the ability to produce modified amino acids (opines), which, in turn, are utilized only by the inciting bacteria as the carbon, nitrogen and energy source. The Agrobacterium species thus establish a unique ecological niche by genetically engineering the host plant—a highly sophisticated parasitism! Modern Agrobacterium mediated gene transfer to plants utilizes binary vectors in which the T-DNA and the vir region can reside on separate plasmids (Hellens et al., 2000).
Fig. Tropane (all equivalent)
The wide range of tropane alkaloids occurring in the Solanaceae family arises from the esterification of acids, such as acetic acid, propanoic acid, isobutyric acid, isovaleric acid, 2-methylbutyric acid, tiglic acid, (+)-α-hydroxy-β-phenylpropionic acid, tropic acid, and atropic acid)
with various hydroxytropanes (α-tropanol, α− tropane-diol or α-tropane-triol).
Fig: Various types of carboxylic acids found in tropane alkaloids
The most important natural tropane alkaloids hyoscyamine and scopolamine (Figure 1) are esters of tropane-3α-ol (and the 6-7 epoxide of tropane-3α-ol) and tropic acid. The asymmetric α-carbon of tropic acid allows the formation of two stereoisomers.
a. Sodium in ethanol or sodium amalgam can be used for reducing tropinone to pseudotropine.
b. Catalytic hydrogenation (Pt), electrolytic reduction or Zn/HI can be used to reduce tropinone to tropine.
c. Complex metal hydrides are the best reducing agents for the preparation of tropine from tropinone in the laboratory. Lithium aluminium hydride and sodium borohydride give a mixture of two, with pseudotropine predominating.
01. Tropinone can be synthesized by classic one pot Robinson synthesis. In 1917 Robinson imagined that tropinone could be broken down into three units: succindialdehyde, methylamine, and acetone. He also thought that these units could be joined by means of double Mannich reaction to form tropinone in one step.
Robinson, R. J. Chem. Soc. 1917, 111, 762-768.
R. Robinson, The Structural Relations of Natural Products, Clarendon Press, Oxford, 1955, p. 59.
When the mixture was allowed to stand in water for thirty minutes, tropinone was produced in very small yield. The yield was extremely low due to low acidity of acetone.
- Nucleophilic addition of methylamine to succinaldehyde, followed by loss of water to create an imine
- Intramolecular addition of the imine to the second aldehyde unit and first ring closure
- Intermolecular Mannich reaction of the enolate of acetone dicarboxylate
- New enolate formation and new imine formation with loss of water for
- Second intramolecular mannich reaction and second ring closure
- Loss of 2 carboxylic groups to tropinone
A similar to Robinson synthesis, synthesis of Pseudopelletierine can be helpful for comparison. In tropinone synthesis succindialdehyde is used, while glutaraldehyde is used in the synthesis of Pseudopelletierine.
02. Willstätter synthesis was the first synthesis of tropinone in 1901. It began with cycloheptanone and the final yield was only 0.75%.
R. Willstätter, Annalen., 1903, 317, 204.
03. Decarboxylation of 2-carboxytropinone or 2,4-dicarboxytropinone with concentrated HCl gives Tropinone. Bakers yeast can also be used for this purpose.
01. Willstäter´s Preparation
Cocaine was first prepared in 1923 by Willstäter. This synthesis is very remarkable because, although at this time both the relative and the absolute stereochemistry of cocaine were unknown, they were able to prepare this alkaloid in optically active form.
WILLSTÄTTER, R.; WOLFES, O.; MÄDER, H. Annalen 1923, 434, 111
02. Preobrazhenskii´s Preparation
In 1958 a group of Soviet chemists made improvements to Willstäter's synthesis by the in situ generation of the unstable butandial by acidic hydrolysis of dimethoxytetrahydrofuran.
BAZILEVSKAYA, G.I.; BAINOVA, M.S.; GURA, D.V.; DYUMAEV, K.M.; PREOBRAZHENSKII, N.A. Isvest.Vysshikh.Ucheb.Zavedenii, Khim. i Khim.Tekhnol. 1958, 2, 75-81 (Chem.Abstr. 1959, 53, 423h).
BAINOVA, M.S.; BAZILEVSKAYA, G.I.; DYUMAEV, K.M.; PREOBRAZHENSKII, N.A. Zh.Obshch.Khim. 1960, 30, 1120-1123 (Chem.Abstr.1961, 55, 530f)
BAINOVA, M.S.; BAZILEVSKAYA, G.I.; PREOBRAZHENSKII, N.A. Zh.Obshch.Khim. 1960, 30, 3258-3261 (Chem.Abstr. 1961, 55, 21155d)
02. Tufariello synthesis using nitrone
TUFARIELLO, J.J.; TEGELER, J.J.; WONG, S.C.; ALI, S.A. Tetrahedron Lett. 1978, 30, 1733-1736
TUFARIELLO, J.J.; MULLEN, G.B.; TEGELER, J.J.; TRYBULSKI, E.J.; WONG, S.C.; ALI, S.A. J.Am.Chem.Soc. 1979, 101, 2435-2442
04. Carroll´s Preparation
LEWIN, A.H.; NASEREE, T.; CAROLL, F.I. J.Heterocycl.Chem. 1987, 24, 19-21
CARROLL, F.I.; COLEMAN, M.L.; LEWIN, A.H. J.Org.Chem. 1982, 47, 13-19
05. Rapoport´s Preparation
LIN, R.; CASTELLS, J.; RAPOPORT, H. J.Org.Chem. 1998, 63, 4069-4078
PETERSEN, J.S.; FELS, G.; RAPOPORT, H. J.Am.Chem.Soc. 1984, 106, 4539-4547
06. Cha´s Preparation
LEE, J.C.; LEE, K.; CHA, J.K. J.Org.Chem. 2000, 65, 4773-4775
03. Pearson synthesis
01. Cocaethylene can be prepared from cocaine and ethanol by an ester exchange reaction.
List of generics and non-generics manufactured by various pharmaceuticals companies
|03||Atrovent Nasal Spray||Ipratropium Bromide|
|05||Atrovent HFA||Ipratropium Bromide|
|08||Buscopan Plus||ButylScopolamine & acetaminophen|
|09||Cogentin|| Benztropine Mesylate Injection
|10||Combivent||Ipratropium Bromide and Albuterol Sulfate|
|11||Duoneb||Ipratropium Bromide and Albuterol Sulfate|
|12||Enlon Plus|| Edrophonium Chloride & Atropine Sulfate
|14||Hycodan|| Hydrocodone Bitartrate and Homatropine Methylbromide
|15||Iprex|| Ipratropium Bromide
|17||Iprasol||Salbutamol & Ipratropium Bromide|
|18||Lomotil|| Diphenoxylate & Atropine
|19||Motofen||Difenoxin & Atropine|
|20||Norvent|| Tiotropium Bromide
|22||Spiriva|| Tiotropium Bromide
|23||Sulprex||Salbutamol & Ipratropium Bromide|
|24||MARK I NAAK||
MARK I Kit, is United States military nomenclature for the "Nerve Agent Antidote Kit". It is a dual-chamber auto-injector: Two anti-nerve agent drugs — atropine sulfate and pralidoxime chloride — each in injectable form, constitute the kit. The kits are only effective against the nerve gents tabun (GA), sarin (GB), soman (GD) and VX.
Fig. MARK I kit
|01||Atropine||Lomotil, Atropen, Adenocard, Motofen, Prosed DS|
|03||Atropine Sulphate|| Enlon Plus
|05||ButylScopolamine|| Buscopan, Hyospasmol, Lotanal, Oportunin, Scop, Scopoderm T , Spasmofen
|00||Cocaine Hydrochloride||Cocaine is used to temporarily numb the lining of the mouth, nose, and throat (mucous membranes) before certain medical procedures (e.g., biopsy, stitches, wound cleaning). It is an anesthetic that works quickly to numb the area about 1-2 minutes after application. Cocaine also causes blood vessels to narrow, an effect that can decrease bleeding and swelling from the procedure.|
|08||Ipratropim Bromide||Sulprex, Iprex, Atrovent, Combivent, Duoneb, Ipramid|
|09||Tiotropium Bromide|| Norvent, Spiriva
|| A de-cocainized extract of coca leaf is one of the flavoring ingredients in Coca-Cola.
|02||Coca tea||Coca tea, also known as mate de coca, is a type of herbal tea that is made using the dry, raw leaves of the coca plant soaked in hot water so that the phytonutrients are extracted from the leaf.
|03||Agwa de Bolivia|| A herbal liqueur made with Bolivian de-cocainized coca leaves and 37 other natural herbs and botanicals.
|04||Red Bull Cola|| A liqueur made with de-cocainized coca leaves and other natural herbs and botanicals.
|05||Coca Colla||An energy drink produced in Bolivia with the use of coca extract as its base.|
|06||Triple 3x Coca Tea||An iced tisane made from natural coca leaves, raw cane sugar, honey and lemon juice.|
|07||Piscoca|| Liquid Extract from coca leaves in PISCO (distilled fresh grapes juice from Inca Valley in Peru).
|08||Coca Liquor|| Typical liquor of coca leaves can be found with alcohol grade 20%.
COCA LEAF, COCA TEA, COCA LEAVES, COCA DELISSE FROM PERU
|01||Coca biscuit Courtesy CocaShop|| Cookies are made with coca powder, flour, soya, yogurt and sugar.
|02||Cocamelos|| Candies are made from coca leaves.
|03||Energetic Bar||Energetic bars are made with Coca Powder, Maca, Linseed, Kiwicha (amaranto), Sesame, Raisins , Oats, Chestnuts, Dried grapes, Honey Bee, Honey Fruit.
|04||Llipta / llicta / llupta|| A Supplement for use of coca leaves. Mass formed by a mixture of lime and/or vegetable ash normally of kiwicha or quinua cereals.
|06||Coca soap|| Soaps are made with olive oil, palm oil, coconut oil, distilled water and coca leaf.
|07||Coca Cream|| Cream of coca leaves.
Meeting cocaine farmers - Alex James - BBC
How cocaine is made in the Amazon - Bruce Parry- BBC