The Biochemistry of Alkaloids

Robinson, Trevor

doi:10.1007/978-3-642-61830-7

Cited by 34 publications

(3 citation statements)

References 67 publications

(123 reference statements)

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“…2,5 Caffeine (1,3,7-trimethyl-2,6-purinedione) is a natural product widely distributed in coffee beans and several other plants. 6,7 Coffee beans contain relatively high concentrations of caffeine, which is perceived by some as having adverse effects on health. 8 Nevertheless, caffeine is extensively used as a smooth muscle relaxant; it is often included in small doses in analgesics and cold remedies because of its stimulant action; and it is consumed in beverages such as coffee, tea, and a variety of soft drinks.…”

Section: Introductionmentioning

confidence: 99%

Theoretical and pH dependent surface enhanced Raman spectroscopy study on caffeine

et al. 2002

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ABSTRACT:The surface enhanced Raman spectroscopy (SERS) spectrum of caffeine is recorded on a silver colloid at different pH values. It is discussed on the basis of the SERS "surface selection rules" in order to characterize its vibrational behavior on such a biological artificial model. To improve the previous assignments in the Raman spectrum and for a reliable, detailed analysis of SERS spectra, density functional theory calculations (structural parameters, harmonic vibrational wavenumbers, total electron density, and natural population analysis of the molecule) are performed for the anhydrous form of caffeine and the results are discussed. The predicted geometry and vibrational Raman spectra are in good agreement with the experimental data. The flat orientation of the mainly chemisorbed caffeine attached through the electrons and the lone pair of nonmethylated N atoms of the imidazole ring are proposed to occur at neutral and basic pH values. At acid pH values caffeine is probably adsorbed on the Ag surface through one or both oxygen atoms, more probably through the O atom of the conjugated carbonyl group with an end-on orientation. However, the changes in the overall SERS spectral pattern seem to indicate the electromagnetic mechanism as being the dominant one.

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Section: Introductionmentioning

confidence: 99%

Theoretical and pH dependent surface enhanced Raman spectroscopy study on caffeine

et al. 2002

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“…The biosynthesis of most piperidine alkaloids starts with L-Lys, 8b,9 whereas the formation of a pyridine alkaloid by oxidation of a piperideine precursor is uncommon. 10,11 A rare example of the formation of a pyridine from a piperideine ring is the biosynthesis of α,β-dipyridyl in the tobacco plant Nicotiana tabacum from anatabine. 11 A comparable step has been unknown in insects so far, but these results unambiguously demonstrate that it is possible in Stenus beetles.…”

Section: ' Results and Discussionmentioning

confidence: 99%

Biosynthesis of the Defensive Alkaloid (Z)-3-(2-Methyl-1-butenyl)pyridine in Stenus similis Beetles

et al. 2011

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Most rove beetles of the genus Stenus protect themselves against microorganisms and predators such as ants and spiders by producing the alkaloid stenusine (1) in their pygidial glands. The biosynthesis of 1 was previously investigated in S. bimaculatus, where L-lysine forms the piperidine ring, L-isoleucine the side chain, and acetate the N-ethyl group. In addition to 1, S. similis keeps the pyridine alkaloid (Z)-3-(2-methyl-1-butenyl)pyridine (2) in its pygidial glands. Feeding S. similis beetles with [D,15N]-labeled amino acids followed by GC/MS analysis showed that L-Lys yields the pyridine ring and L-Ile the 2-methyl-1-butenyl side chain. Thus the alkaloids 1 and 2 probably share two precursor molecules in their biosynthesis.

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“…Many indole alkaloids have been known for years and used in ancient cultures as psychotropic, stimulants and poisons. All these natural products derive from the amino acid tryptophan (1) 4 and show wide structural diversity, going from the simplest compound tryptamine (2), a non-selective serotonin receptor agonist and serotonin-norepinephrine-dopamine releasing agent, 5 to, for instance, harmine (3), a fluorescent harmala alkaloid which reversibly inhibits monoamine oxidase which shows also cytotoxicity against different cell lines, 6 and lysergic acid (4), a precursor of different ergoline alkaloids. Amide derivatives of 4 were used as psychedelic drugs.…”

Section: Introductionmentioning

confidence: 99%

Stereoselective Synthesis of 2-(2-Aminoalkyl)- and 1,3-Disubstituted Tetrahydro-1H-pyrido[4,3-b]- Benzofuran and Indole Derivatives

2016

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ABSTRACT. The addition of an allenyl indium intermediate to chiral N-tert-butanesulfinyl imines7 proceeds with high levels of diastereocontrol. The resulting homopropargylic amine derivatives 10 were transformed into 2-(2-aminoalkyl)benzofuran and indole derivatives 13 and 19, after Sonogashira-coupling with o-iodophenol or o-iodoaniline, followed by formation of the heteroaromatic ring through an intramolecular cyclization. Enantioenriched tetrahydropyridobenzofuran and indole derivatives 16 and 21 were prepared through a Picted-Spengler condensation of the free amines derived from compounds 15 and 20, involving the nucleophilic 3-position of the benzofuran or indole moiety.

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The Biochemistry of Alkaloids

Cited by 34 publications

References 67 publications

Theoretical and pH dependent surface enhanced Raman spectroscopy study on caffeine

Theoretical and pH dependent surface enhanced Raman spectroscopy study on caffeine

Biosynthesis of the Defensive Alkaloid (Z)-3-(2-Methyl-1-butenyl)pyridine in Stenus similis Beetles

Stereoselective Synthesis of 2-(2-Aminoalkyl)- and 1,3-Disubstituted Tetrahydro-1H-pyrido[4,3-b]- Benzofuran and Indole Derivatives

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