Steroidal Alkaloids and Amines

A. Steroidal Alkaloids and Amines.—Conessine (1) is found in the bark of all the Holarrhena species which have been studied. It is accompanied by other derivatives of conanine thus, holarrhenine (2), holarrheline (3), holadienine (4), holaromine (5) (possibly an artefact), and holaline (6) are found in H.ftoribunda." Conkurchine (7) has been extracted from the leaves and bark of H. crassifolia7 Conessine, the nor-conessines, and holadienine have been isolated from the bark of H. mitis. Holarrhimine (8) and methylholarrhimine II (9) have also been isolated in fairly large quantity from the same plant. 

A. Steroidal Alkaloids and Amines.—Lanitine (1), 2a-hydroxy-A-methylpara-vallarine,3 and its 2/ -hydroxy isomer (2), have been isolated from the stem bark of Kibatalia gitingensis.4... 

Marine natural products have been extensively reviewed in many monographs and journals (1-17). Kobayashi and Ishibashi have reviewed marine alkaloids in general in this series (16), and our recent review (17) provides an account of toxic alkaloids of marine origin. This chapter is intended to provide the reader a brief description of the isolation, structure elucidation, synthetic studies, and biological screening of important classes of steroidal alkaloids and amines of marine origin. 

Steroidal Alkaloids and Amines.—Synthesis, Reactions, and Transformations of Steroidal Amines. 5a-Androstanols and (hydroximino)-5a-androstanes give, by standard procedures, the amino- and the acetamido-Sa-androstanes at the positions 3,4, 6, 7, 11, 16, and 17. ... 

Steroidal Alkaloids and Amines Synthesis, Reactions, and Transformations of Steroidal Amines Photochemistry... 

Steroidal Alkaloids and Amines.—Phytochemistry. Maingayine (1) was extracted from the bark of Paravallaris maingayi. This represents the first reported isolation of an alkaloid of the conanine group from the genus Paravallaris. ... 

Asymmetric synthesis ch41 and protect sensitive functional groups How to make and manipulate sugars and their derivatives Lipids form the basis of membrane structures The main sorts of natural products are alkaloids, polyketides, terpenes, and steroids Alkaloids are amines made from amino acids Fatty acids are built up from acetyl CoA and malonyl CoA subunits ... 

Three of the classes of compounds found from the skin of amphibians have been identified from the skin of bufonids, including Bufo marinus. These are steroids (bufadienolides), biogenic amines (catecholamines, indolylalkylamines and alkaloids) and bioactive peptides and proteins. 

Analytical Properties (i-Cyclodextrin (cycloheptamylose) normal phase separation of positional isomers of substituted benzoic acids reverse phase separation of dansyl and napthyl amino acids, several aromatic drugs, steroids, alkaloids, metallocenes, binapthyl crown ethers, aromatics acids, aromatic amines, and aromatic sulfoxides this substrate has seven glucose units and has a relative molecular mass of 1135 the inside cavity has a diameter of 0.78 nm, and the substrate has a water solubility of 1.85 g/ml, although this can be increased by derivatization Reference 13-28... 

The majority of alkaloids have been found to be derived from amino acids, such as tyrosine, phenylalanine, anthranilic acid, tryptophan/tryptamine, ornithine/arginine, lysine, histidine and nicotinic acid (Fig. 2.1). However, alkaloids maybe derived from other precursors such as purines in case of caffeine, terpenoids, which become aminated after the main skeleton has been synthesized i.e. aconitine or the steroidal alkaloids, are found in the Solanaceae and Liliaceae. Alkaloids may also be formed from acetate-derived polyketides, where the amino nitrogen is introduced as in the hemlock alkaloid, coniine. 

Most of the work reported with amino-substituted steroids has been concerned with the removal of the nitrogen function from the molecule. Interest has centred mainly on the peculiarities of the reaction between nitrous acid and steroidal primary amines. The naturally-occurring steroidal alkaloids have been studied mainly with a view to establishing their structures and usefulness as sources of nitrogen-free steroids, and are not included in the present survey. 

The types of compounds that can be separated by liquid-liquid chromatography include fatty acids, amino acids, organometallics, chelates, alcohols, amines, hydrocarbons, pesticides, herbicides, steroids, hormones, alkaloids, and antilnotics. A number of such separations have been illustrated by Schmit. ... 

Six steroidal ketones have been isolated from the leaves of Paravallaris micro-phylla " These ketones [(78)—(82)] have a 18— (20S) lactone function, characteristic of the alkaloids found in this plant, namely paravallarine and para-vallaridine. The co-occurrence of both steroidal ketones and steroidal amines... 

Hundreds of applications have been mentioned in the Zweig (1968) review acids, alkaloids, amino acids, antibiotics, antioxidants, food and feed additives, bases and amines, bile acids, carbonyls, dyes, enzymes, lipids, hydrocarbons, hormones, indoles, natural products, peptides, proteins, pesticides, plant growth regulators, pharmaceutical products, phenols, pigments (chlorophylls, xanthophylls, porphyrins, melanin, pterins, pteridines, anthocyanins, ilavonoids, etc.), polymers, purine and pyrimidine derivatives, quinones, RNA, DNA, organic sulfur compounds, steroids, sugars, toxins, vitamins, inorganic ions, and others. 

Fales and Pisano (1964) have discussed the gas chromatography of amines, alkaloids, and amino acids. Pollock and Kawauchi (1968) have resolved derivatives of serine, hydroxyproline, tyrosine, and cysteine, as well as racemic aspartic acid and tryptophan. VandenHeuvel and Horning (1964) have listed derivatives of steroids that can be separated. VandenHeuvel et al. (1960) first described the separation of bile acid methyl esters and Sjovall (1964) has extended the methods to bile acids. Gas liquid chromatography (GLC) is useful in the analysis of pesticides, herbicides, and pharmaceuticals (Burchfield and Storrs, 1962). Analysis of alkaloids, steroids, and mixtures of anesthetics and expired air are other examples of the application of this very useful technique. Beroza (1970) has discussed the use of gas chromatography for the determination of the chemical structure of organic compounds at the microgram level. 

Some of the innumerable reagents used in TEC are based on reactions with more or less well-established mechanism. Eor example, sodium iodobismuthate (Dragendorff reagent) is widely used among others for alkaloids and quaternary ammonium compounds, 4-dimethylaminobenzaldehyde for primary amines and amino acids, 2,4-dinitrophenylhydrazine for aldehydes and ketones, ninhydrin for amino acids and some antibiotics, fluorescamine for primary and secondary amines, phosphomolybdic acid for lipids, various steroids, and other compounds, chlorine vapor followed by Kl/starch for amines and amides. More complex is the mechanism of the reactions with some other reagents, containing high concentrations of sulfuric acid, vanillin/sulfuric acid, phosphoric acid, aluminum chloride, antimony(III)... 

Numerous species of amphibians contain substances in their skin that render them noxious or toxic to potential predators. The active substances in the skin include amines (norepinephrine and histamine), piperidines, steroidal alkaloids, bufodienolides, and tetrodotoxin (reviews in Daly et al. 1978 Daly 1982). 

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