Biogenesis of alkaloids

The synthesis and structural analysis of alkaloids leads to the following basic questions why are alkaloids synthesized in an organism and on which mechanism is alkaloid formation and degradation dependent in the life cycle It is known that alkaloids have a genetic nature59 and that alkaloid content is diverse inside and between the species16. In nature the same species of plants may have both high and low alkaloid content120121. Natural hybridization has been successfully used in plant...

Influence on DNA

The phenethylisoquinoline alkaloids present in some members of the Lily family (Liliaceae) are known to be toxic. Wang and Wang457 have researched the activity of veratridine on rats. This alkaloid causes persistent opening of the voltage-gate Na+ channel and reduces its single-channel conductance by 75 . However, its toxicity is concentration dependent. The toxicity of iso-quinoline alkaloid berberine is low in concentrations 0.05 for living plant cells464. In these concentrations berberine...

Cell cultures

Alkaloids can be produced by using cell culture techniques in the same or a similar way as with other molecules624. Alkaloids such as ajmalicine, serpentine (C. roseus) and berberine (Coptis japonica) can produce remarkable quantities of alkaloids in in vitro cultures625 626. Generally, cell cultures produce species-specific alkaloids. In some cases cell cultures can produce more alkaloids than the whole plant, in relation to dry weight. This occurs, for example, in the cases of nicotine,...

Regulation of acetylcholine esterase

The alkaloids which influence acetylcholine esterase activity are eserine, galan-thamine, nicotine, lobeline and tubocurarine. All of these alkaloids are very active. Eserine blocks acetylcholine esterase. This alkaloid may be used to decrease possible negative side effects connected to the use of other drugs, for example that of atropine. Galanthamine also blocks acetylcholine esterase activity. One of the new applications of galanthamine is in a treatment of Alzheimer's disease. Moreover,...

Alkaloids as biological fertilizers

Alkaloids from many plants are considered to be used as biological fertilizers in ecological cultivation. This is very important especially in cases when more attention is given to these plants, which play not only a role in production but also in the cyclical maintenance of a field, garden or forest ecosystems614'615'616. Plants containing alkaloids, for example lupines, have the ability to establish complexes with the soil and with the rhizosphere. The excretion of many chemicals from roots...

Alkaloids in food

Alkaloidal plants used as food are small in number. The reason for this is the bioactivity and traditional use of alkaloids in medicines and drugs. Moreover, food is checked and controlled with the purposes of keeping alkaloid-contaminated food off the market. However, cases where pyrrolizidine alkaloids were found in the honey produced by bees that had foraged on the flowers of Echium and Senecio species are documented475'495'591. In these relatively old studies, bees had been feeding only on...

Applications

Abstract Alkaloid applications can be found in different areas. Some alkaloids are still used in modern medicine today as natural or modified compounds. Their use is connected to the regulation of Na+ ions and channels, mescaric, cholinergic receptor, acetylcholine esterase, opioid and opiate receptors, glycine and other receptors, as well as the regulation of micro-tubules of the spindle apparatus. Moreover, alkaloids are used in the regulation of microbial and schizonticide activity and as...

Nicotinic acidderived alkaloids

Nicotini Synthesis Image

Alkaloids derived from nicotinic acid contain a pyridine nucleus. Nicotinic acid itself is synthesized from L-tryptophan via N-formylkynurenine, L-kynurenine, 3-hydroxykynurenine, 3-hydroxyanthranilic acid and quinolinic acid. The pyridine nucleus is passed to alkaloids via dihydronicotinic acid, moving from dihydropyridine to nicotine and nornicotine (Figure 47). Dihydronicotinic acid is synthesized by the enzymatic activity of NADP and subsequently becomes 1,2-dihydropyridine by a reduction...

Antimicrobial properties

It is generally recognized that alkaloids have strong antimicrobial, antibacterial and antifungal biological Moreover, some studies have evidenced anti-parasitic activity in this group of compounds392 393. Caron et al.329 have investigated 34 quasi-dimeric indole alkaloids for antimicrobial activity using 8 different test micro-organisms. It was found that all of the studied alkaloids showed activity against Staphylococcus aureus and Bacillus subtilis, which are Gram-positive bacteria. Caron et...

True alkaloids

True alkaloids derive from amino acid and they share a heterocyclic ring with nitrogen. These alkaloids are highly reactive substances with biological activity even in low doses. All true alkaloids have a bitter taste and appear as a white solid, with the exception of nicotine which has a brown liquid. True alkaloids form water-soluble salts. Moreover, most of them are well-defined crystalline substances which unite with acids to form salts. True alkaloids may occur in plants 1 in the free...

Aberrations in cells

Pyrrolizidine alkaloids are toxic to foreign organisms Figure 89 . This problem was largely studied in the Serious livestock poisoning episodes are mentioned in literature from the effects of the pyrrolizidine alkaloid of the Senecio genus especially Senecio riddellii, Senecio douglasii and Senecio jacobaea411. The toxicity of pyrrolizidine alkaloids to livestock was considered coincidental. Johnson and Molyneux501 and Johnson et al.502 have stated that experimental feedings of pyrrolizidine...

Protoalkaloids

Protoalkaloids are compounds, in which the N atom derived from an amino acid is not a part of the heterocyclic31. Such kinds of alkaloid include compounds derived from L-tyrosine and L-tryptophan see Table 1 . Protoalkaloids are those Definition, Typology and Occurrence of Alkaloids Table 1 Main types of alkaloids and their chemical groups Cocaine Hyoscyamine Scopolamine hyoscine lycopsamine Acetyl-intermedine Europine Homospermidine Ilamine Anaferine Lobelanine Lobeline N -methyl pelletierine...

The Buttercup botanical family Ranunculaceae

The Buttercup botanical family Ranunculaceae Juss. Table 13 yields both L-tyrosine and terpenoid alkaloids. This plant family, which has 50 genera and nearly 2000 species, is situated around the Globe in the temperate zones. Tyrosine-derived alkaloids, such as berberine and hydrastine, occur in the Seal genus Hydrastis L. . Fangcholine and fuzitine have been reported in the genus Thalictrum Thalictrum orientale , growing in Turkey127. Terpenoid alkaloids, such as aconitine and sinomontanine,...

The Nightshade botanical family Solanaceae

The Nightshade plant family Solanaceae Pers. , containing 90 genera and more than 2000 species distributed in all continents, particularly is abundant in alkaloids Table 7 . The plant species belonging to this family grow especially in the tropics and sub-tropics. However, the majority of the species occur in Central and South America. The L-ornithine Figures 11 and 15 derived alkaloids occur in many species of this family. Hyoscyamine and hyoscine and cuscohygrine are in the genus Nightshade...

The Ecological Role of Alkaloids

Abstract Alkaloids are a special group of secondary compounds and are part of an organism's adaptation mechanism to its living environment. They are not toxic when stored, but become toxic as a result of cell pH change. The defensive function of alkaloids is only secondary, and connected to internal immune and regulation processes. Animal responses to alkaloids are very diverse. Some animals can tolerate alkaloids relatively well, while others are harmed or even poisoned by them. Animal...

Life regulation through the high and low cytotoxicity

Alkaloids from the plant family Amaryllidaceae are known to have a wide range of biological activities. They have analgesic, antiviral, anti-malarial, antineoplastic properties and display effects on the CNS. Elgorashi et al.354 have studied 25 Amaryllidaceae alkaloids for possible inhibitory activity of their acetylcholinesterase enzyme AChE . This enzyme is biologically very important. According to the cholinergic hypothesis Alzheimer's disease symptoms result from AChE activity, which...

Animals

Alkaloids are also found in the animal kingdom, especially in millipedes, salamanders, toads, frogs, fish and mammals. They occur particularly in the genera Saxidomus, Salamandra, Phyllobates, Dendrobates, Castor and Moschus. Moreover, alkaloid molecules are found in such genera as Solenopsis, Odon-tomachus, Glomeris and Polyzonium. Many alkaloids have been recently isolated from marine environment, especially from the sponges197. The discovery of ptilomycalin A from the sponges Ptilocaulis...

Pseudoalkaloids

Pinidine From Pinus Penderosa

Pseudoalkaloids are compounds, the basic carbon skeletons of which are not derived from amino acids31. In reality, pseudoalkaloids are connected with amino Figure 6. An example of a pseudoalkaloid. Acetate-derived alkaloid pinidine is extracted from the Pinus species, for example, from Pinus penderosa. Photo T. Aniszewski . Pinidine has antimicrobial activity. Figure 6. An example of a pseudoalkaloid. Acetate-derived alkaloid pinidine is extracted from the Pinus species, for example, from Pinus...

The Borage botanical family Boraginaceae

Forget-me-not family Boraginaceae Lindl. contains L-ornithine Figure 11 and 15 derived alkaloids, such as indicine-N-oxide in the heliotrope Heliotropium indicum and southern hound's tongue Cynoglosum creticum species Table 8 . Farsam et al.46 reported on new alkaloids from Table 8 General botanical characteristics of the Borage family312,313,316 Botanical Forms and Parts Characteristics Rarely shrubs or trees Lianas rarely Regular Calyx 5-parted Regular corola 5-lobed...

Sesquiterpene pyridine alkaloids

Pyridine Alkaloids

Compounds belonging to this group of alkaloids are sourced from the Celas-traceae and Hippocrateaceae families and contain the sesquiterpene nucleus. More than 220 alkaloids are known in this group58. Sesquiterpene pyridine Claisen reaction neophilic addition dehydration and enolization Claisen reaction neophilic addition dehydration and enolization Figure 60. Structural development of acridone alkaloids. Figure 60. Structural development of acridone alkaloids. alkaloids can be divided into...

Alkaloids as secondary metabolism molecules

Keto Acid Synthesis

The precursors of true alkaloids and protoalkaloids are aminoacids both their precursors and postcursors , while transamination reactions precede pseudoalka-loids Tables 1 and 10 . It is not difficult to see that from all aminoacids only a small part is known as alkaloid precursors Table 19 . Both true and proto alkaloids are synthesized mainly from the aromatic amino acids, phenylalanine, tyrosine isoquinoline alkaloids and tryptophan indole alkaloids . Lysine is the Table 19 Amino acids and...

The Aster botanical family Asteraceae

Daisy botanical family Asteraceae Dum. is very large, containing over 900 genera and more than 20 000 species Table 3 . Their distribution is worldwide, and species belonging to this family are found everywhere. The Aster plant family contains species yielded in similar ways to some natural alkaloids. The genus Ragwort Senecio L. is especially rich in L-ornithine Figure 11 derived alkaloids senecionine, senecivernine, seneciphylline, spartioidine, intergerrimine, jacobine,...

Ornithinederived alkaloids

Ornithine is a metabolically quite active amino acid, and the important precursor of pyrrolidine nucleus, which is found in pyrrolizidine alkaloids. Ornithine itself is a non-protein amino acid formed mainly from L-glumate in plants, and synthesized from the urea cycle in animals as a result of the reaction catalyzed by enzymes in arginine. Quinoline nucleus after transformation from indole Aspidosperma C9 skeleton Figure 32. The L-tryptophan-supplied nucleus during synthesis. The synthesis of...

The Legume botanical family Fabaceae

Aconitum Karacolicum

Alkaloids derived from L-ornithine, L-lysine, and L-trypthophan occur in the Legume plant family Fabaceae Juss. Table 9 . This plant family is the third largest botanical family, with 650 genera and 18000 species in the humid tropics, sub-tropics, temperate and sub-arctic zones around the Globe118. L-ornithine-derived alkaloids such as senecionine are present in the genus Crota Crotalaria L. . The most typical alkaloids for this botanical family are L-lysine Figure 16 derived alkaloids, such as...

Fungus and bacter

The fungi Aspergillus, Rhizopus, Penicillium and Claviceps produce parasitic ergoline and ergotamine alkaloids. The ergot alkaloids derived from L-tryptophan in the fungus Claviceps purpurea, growing on grain in the ears of rye Secale cereale , wheat Triticum aestivum or triticosecale Triticale , are highly toxic Figure 20 . They have been used in the development of lysergic acid diethy-lamine, LSD, which is hallucinogenic and, in small doses, is used in the treatment of schizophrenia. Li et...

Lysinederived alkaloids

Assay Castanospermine Alkaloid

L-lysine furnishes alkaloids with at least four different nuclei. It is a protein amino acid, one of the most important alkaloid precursors. L-lysine-derived alkaloids have a basic skeleton with C5N the piperidine nucleus and C5N ____ indolizidine, quinolizidine and pyridon nuclei . 2.6.1. Pelletierine, lobelanine and piperine synthesis pathway Alkaloids with the piperidine nucleus, such as pelletierine Punica grana-tum , lobelanine Lobelia inflata and piperine Piper nigrum , have a typical...

Skeleton diversity

The skeleton nucleus of the alkaloid is the main criterion for alkaloid precursor determination. Many skeletons are produced in the process of alkaloid synthesis. Figure 24 illustrates some nuclei and skeletons supplied in the synthesis. Alkaloid Indole alkaloids Quinoline alkaloids Ergot alkalo Indolizine alkaloids Piperidine alkaloids Indolizine alkaloids Piperidine alkaloids Simple L-Tyrosine alkaloids Quinazoline ADP NAD L -Tryptophan ATP QH NADH2 -- - Tryptophan yAnthranilic C o Tyucinee...

RpLpi

Structural development of phenyl and phenylpropyl alkaloids. alkaloids e.g., eserine and ergot alkaloids e.g., ergotamine . Indole alkaloids form a very important group from the perspective of their application. The a for structural development of serotonin simple indole alkaloid is L-tryptophan, and the ft is 5-hydroxy-L-tryptophan Figure 64 . Serotonin is a monoamine. It is a bioactive alkaloid known as a neurotransmitter. It has been found in the cardiovascular system, in blood...

Tryptophanderived alkaloids

Alkaloids derived from L-tryptophan hold the indole nucleus in a ring system. The ring system originates in the shikimate secondary compounds building block and the anthranilic acid pathway. It is known that the shikimate block, in general, and anthranilic acid, in particular, are precursors to many indole alkaloids. However, there are many rearrangement reactions which can convert the indole ring system into a quinoline ring. In this pathway, L-tryptophan is enzymatically transferred to...

Quinolizidine alkaloids

The third structural group of alkaloids, from the same a, are quinolizidine alkaloids QAs . It is a large group of compounds with very different The structural development of quinolizidine alkaloids is presented in Figure 54. The a l-lysine provides the basic components of the quinolizidine nucleus and skeleton. The P is cadaverine and is synthesized in the same way as piperidine alkaloids by the activity of PLP . The transformation from P to also occurs through the activity of diamine oxidase...

Regulation of schizonticide activity

Quinidine and quinine have schizonticide activity due to the inhibition of nucleic acid synthesis through DNA intercalation. This activity is also based on carbohydrate metabolism. The action of both of these alkaloids is a result of their binding to sarcoplasmic reticular vesicles and the resulting reduced uptake of Ca2 . These alkaloids are also active on Na and K -ATPase, both in an encouraging or inhibiting sense. Both alkaloids therefore have been developed as strong anti-malarial...

Definition

The definition of the term alkaloid is not a simple one, and is in many cases a source of academic controversy. Difficulties with the definition of such a group of secondary and natural molecules as alkaloids stem from similarities of alkaloids with other secondary compounds. Attempts to define the term alkaloid originated at the time of the discovery of these compounds. Friedrich Sert rner, an apothecary's assistant from Westphalia, first isolated morphine Figure 1 , one of the most important...

List of Figures

1 Contemporary scheme of morphine. 2 2 Some alkaloids isolated by pharmaceutists Pierre Joseph Pelletier and Joseph Beiname Caventou during 1817-1821. 3 3 Schemes of taxol, vinblastine, vincristine and vincamine 5 4 An example of a true alkaloid 11 5 An example of protoalkaloids 11 6 An example of a pseudoalkaloid 12 7 The raw extraction of quinolizidine alkaloids 13 8 L-tryptophan with its aromatic side chain 15 9 The devil's-pepper genus, Rauwolfia serpentina 15 10 L-phenylalanine is a...