A Alkaloids

R. W. Herbert in S. W. Pelletiet, A., Alkaloids, Chemical and Physiological Perspectives, Vol. 3, Wdey-Interscience, New York, 1985. 

Chemistry, pharmacology, and clinical efficacy of the Chinese nootropic agent huperzine A, alkaloid from Hupenia sermta with annulated 2-pyridone and l-amino-3-methyl-9-ethylidenebicyclo[3.3.l]nona-2,6-diene fragments 99ACR641. 

Alkalizyanid, n. alkali cyanide, alkaloidartig, a. alkaloid4ike, alkaloidal. alkaloidisch, a. alkaloidal. 

A. Alkaloids 1. Belladonna-type solanaceous tropane alkaloids [Atropine (1), (—)-Hyoscyamine (2), Scopolamine ((—)-Hysoscine)(3)] Atropa belladonna L. (belladonna), Datura metel L., D. stramonium L. (jimson weed), Hyoscyamus niger L. (henbane), Mandragora officinarum L. (European mandrake), and other solanaceous species Anticholinergics (parasympatholytics)... 

The first few steps of a synthesis of a alkaloid conessine produce D from C. Suggest a sequence of reactions for effecting this conversion. 

Figure 96. Diagram of alkaloid production by cell culture. Abbreviations A - alkaloid synthesis.

Chart 8.3.A Alkaloids (skeletons) typical of both marine and land organisms (5max=75, av=20 5/7finax=0.91, av=0.56). 

X axis biogenetic class (A = alkaloids P = amino acids, peptides, peptides, polypeptides and proteins FA/PO = fatty acids and polyketides S = shikimates C = carbohydrates). 

N.A. Alkaloids, rescrpine.99 This herb is toxic. Treat malarial fever, antispasmodic, lower blood presure, reduce high blood pressure. 

N.A. Alkaloids, tannins, saponins, pectin, oleoresin, aldehydes, dimeric indole alkaloids, vinblastine, sesquiterpenes.100114315 Treat diabetes, leukemia, reduce blood pressure, Hodgkin s disease, hypotensive, sedative and tranquillizing, anticancer. 

N.A. Alkaloids, ephedrine, 1-ephedrine, d-pseudoephedrine.106129511 Treat fevers, relieve kidney pain, asthma, nose and lung congestions, hay fever, and as a hypertensive aid. 

N.A. Alkaloids, peimine." Affects the parasympathetic nervous system. 

N.A. Alkaloids, nicotine, volatile oil." Nicotine is toxic. A good insecticide. No longer used medicinally. 

The alio series of the pumiliotoxin A class have an additional hydroxyl group that has been placed at C-7 on the indolizidine ring, without assignment of configuration. Three members of the alio series have been assigned the tentative structures (7), (8), and (9).3 Pumiliotoxins A and B are relatively toxic, and comparable in potency to strychnine. Pumiliotoxin B has a potent cardiotonic and myotonic activity.3 An enantioselective total synthesis of pumiliotoxin A alkaloids from L-proline has already been announced.4... 

A domino reaction catalyzed by AlMe3 leads to the skeleton of the Erythrina and /3-homo-/<.ry thrift a alkaloids (Scheme 49) <2004AGE5391>. The mechanism is believed to proceed via an iV-acyliminium ion and a metalled amide. 

The dendrobatid toxin 25 ID (18) has been synthesized by a new approach which utilizes an iminium-vinylsilane cyclization to produce the (Z)-6-alkylidene-indolizidine ring-system in a stereospecific manner. The key intermediate (19) was prepared from L-proline and converted into toxin 25 ID (18) by reaction with paraformaldehyde and (+)-camphor-10-sulphonic acid in refluxing ethanol. The method is potentially a general one for forming unsaturated azacyclic rings, and it provides a convenient route to the pumiliotoxin A alkaloids.7... 

Emetine in A Emetine in B Cephaeline in A Cephaeline in B Psychotrine in A Alkaloids in A Ipecac alkaloids in B Emetine Emetine in A Emetine in B Emetine in C Cephaeline Cephaeline in A Cephaeline in B Emetine Emetine Emetine in B Ipecac alkaloids in B Emetine Emetine in A Emetine in B Cephaeline Emetine Emetine in A Emetine in B Cephaeline in A Emetine Emetine in B Emetine in C Cephaeline... 

Fig. 3. HPLC chromatograms of cell liquid in Mackaya cordata root. Column NOVA-pack C g (5p.), 8 mm x 10 cm eluent 0.1 iV tartaric acid (containing 0.125% sodium dodecyl sulfate)— acetonitrile, 45 55 at 2.0 ml/min detection UV, 285 nm. (a) Alkaloid (colored) cell, (b) Colorless cell. Peaks a, protopine b, allocryptopine c, sanguinarine d, chelerythrine.

A total selectivity has been observed in the cyclization6 of l-benzyloxycarbonyl-2-(1-methylethenyl)pyrrolidine (13), a useful intermediate in the synthesis of the pumiliotoxin A alkaloid class. Thus, A -bromosuccinimide in dimethyl sulfoxide/water or iodine in acetonitrile was utilized as electrophile. 

Further analysis of the GC-FTIR spectra of class A alkaloids is usually helpful for the assignment of the unsaturation pattern of the alkyl side-chains. The most commonly observed pattern consists of a terminal acetylene unit (v h 3320 cm" and Vc=c 2100 cm ) or a terminal ethylene unit (V=CH2 3080 cm and 6=ch 990-910 cm ) and/or an internal cw-ethylene linkage (v=ch- 3020 cm ). Trans-eAiylene linkages (8=ch- 965 cm ) are rarely present. 

CiiHigNO ) and m/z 84 (CsHioN" ), due to the presence of the extra methylene group with respect to PTX-A alkaloids. Cleavage of the side-chain C-15 allylic hydroxyl group in PTX-A and a//o-PTX-A alkaloids is usually responsible for a [M-OH]" fragment in the mass spectrum of these compounds. 

The isolation and characterisation from a Panamian population of Dendrobates pumilio Schimdt of indoiizidine 223A [25], formerly identified as 1,4-dipropyl quinolizidine [5], established a new type of class A alkaloids the 5,6,8-trisubstituted indolizidines. 

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