Sterol alkaloids

Tobacco leaf has a complicated chemical composition including a variety of polymers and small molecules. The small molecules from tobacco belong to numerous classes of compounds such as hydrocarbons, terpenes, alcohols, phenols, acids, aldehydes, ketones, quinones, esters, nitriles, sulfur compounds, carbohydrates, amino acids, alkaloids, sterols, isoprenoids [48], Amadori compounds, etc. Some of these compounds were studied by pyrolysis techniques. One example of pyrolytic study is that of cuticular wax of tobacco leaf (green and aged), which was studied by Py-GC/MS [49]. By pyrolysis, some portion of cuticular wax may remain undecomposed. The undecomposed waxes consist of eicosyl tetradecanoate, docosyl octadecanoate, etc. The molecules detected in the wax pyrolysates include hydrocarbons (Cz to C34 with a maximum of occurrence of iso-Czi, normal C31 and anti-iso-C32), alcohols (docosanol, eicosanol), acids (hexadecanoic, hexadecenoic, octadecanoic, etc ). The cuticular wax also contains terpenoids such as a- and p-8,13-duvatriene-1,3-diols. By pyrolysis, some of these compounds are not decomposed and others generate closely related products such as seco-cembranoids (5-isopropyl-8,12-dimethyl-3E,8E,12E,14-pentadecatrien-2-one, 3,7,13-trimethyl-10-isopropyl-2,6,11,13-tetradecatrien-1al) and manols. By pyrolysis, c/s-abienol, (12-Z)- -12,14-dien-8a-ol, generates mainly frans-neo-abienol. 

The path from squalene (114) to the corresponding oxide and thence to lanosterol [79-63-0] (126), C qH qO, cholesterol [57-88-5] (127), and cycloartenol [469-38-5] (128) (Fig. 6) has been demonstrated in nonphotosynthetic organisms. It has not yet been demonstrated that there is an obligatory path paralleling the one known for generation of plant sterols despite the obvious stmctural relationships of, for example, cycloartenol (128), C qH qO, to cyclobuxine-D (129), C25H42N2O. The latter, obtained from the leaves of Buxus sempervirens E., has apparentiy found use medicinally for many disorders, from skin and venereal diseases to treatment of malaria and tuberculosis. In addition to cyclobuxine-D [2241-90-9] (129) from the Buxaceae, steroidal alkaloids are also found in the Solanaceae, Apocynaceae, and LiUaceae. 

Alginates, alkaloids, glycerides, gutta, phenols, rosins, rubber, saponins sterols, tall oils, tannins, terpenes, waxes... 

Experimental procedures have been described in which the desired reactions have been carried out either by whole microbial cells or by enzymes (1—3). These involve carbohydrates (qv) (4,5) steroids (qv), sterols, and bile acids (6—11) nonsteroid cycHc compounds (12) ahcycHc and alkane hydroxylations (13—16) alkaloids (7,17,18) various pharmaceuticals (qv) (19—21), including antibiotics (19—24) and miscellaneous natural products (25—27). Reviews of the microbial oxidation of aUphatic and aromatic hydrocarbons (qv) (28), monoterpenes (29,30), pesticides (qv) (31,32), lignin (qv) (33,34), flavors and fragrances (35), and other organic molecules (8,12,36,37) have been pubflshed (see Enzyp applications, industrial Enzyt s in organic synthesis Elavors AND spices). 

Note The color development depends on the temperature and duration of heating [1]. The detection limit for sterols and morphine alkaloids is in the lower nanogram range [1,2]. 

Steroid chemistry, the glamor area of natural product research in the years following World War II, was replaced by macrolides, alkaloids, and prostanoids. Sterol chemistry again became exciting when an unanticipated rich diversity of marine invertebrate sterols were isolated, notably from sponges. After pioneering research in Italy, the field was reborn in Carl Djerassi s laboratory at Stanford. As a result, we now have a better and more detailed knowledge of sterol biosynthesis than of any other class of marine natural products. The authors of Chapter 1 are Stanford alumni. 

This chapter reviews recent findings about the health benefits of phytochemicals present in fruits, vegetables, nuts, seeds, and herbs, including phenolics, carotenoids, sterols, and alkaloids. These phytochemicals are extracted using emerging technologies such as supercritical carbon dioxide (SC-CO2) extraction, PEF, MWE, HPP, UE, and OH. The impact of important parameters related to sample preparation (particle size and moisture content) and extraction process (temperature, pressure, solvent flow rate, extraction time, and the use of a cosolvent) on the efficiency of extraction and on the characteristics of the extracted products is evaluated based on an extensive review of recent literature. The future of extraction of phytochemicals is certainly bright with the... 

A large variety of phytochemicals are found within agricultural commodities. This chapter focuses on four main groups phenolics, carotenoids, sterols, and alkaloids. In addition, recent research related to the health benefits of these phytochemicals will be briefly reviewed. Table 9.1 summarizes the main chemical structure and solubility in organic solvents of phytochemicals such as phenolics (flavonoids), carotenoids, sterols, and alkaloids. 

The three most important groups of steroids are the sterols, bile acids, and steroid hormones. Particularly in plants, compounds with steroid structures are also found that are notable for their pharmacological effects—steroid alkaloids, digitalis glycosides, and saponins. 

C Spectra are also reported for some glucoside and mannoside derivatives of alcohols of a sterol type, " and for a series of steroidal Solarium alkaloids with various E/F-ring structures. ... 

N.A. Isoquinoline alkaloids (berberine), sesquiterpene lactones, sterols.157 Treat diarrhea, dysentery, jaundice, vaginal infection, skin conditions. 

N.A. Physalin, vitamin C, alkaloids, flavonoids, sterols." Diuretic, treat kidney and urinary disorder. 

N.A. Mucilage, sterols, pigments, inulin, gallic, malic, tartaric acids, tannins, pyrrolizidine alkaloids.99100 Expectorant, demulcent, astringent, antiinflammatory. 

N.A. Physalis franchetti L. P. pube scene L. Flavonoids, plant sterols, vitamins A and C, alkaloids.100-310 A diuretic for urinary and arthritic problems including kidney and bladder stones, fluid retention, and gout. 

In green plants, which contain little or no cholesterol, cydoartenol is the key intermediate in sterol biosynthesis.161-1623 As indicated in Fig. 22-6, step c, cydoartenol can be formed if the proton at C-9 is shifted (as a hydride ion) to displace the methyl group from C-8. A proton is lost from the adjacent methyl group to close the cyclopropane ring. There are still other ways in which squalene is cyclized,162/163/1633 including some that incorporate nitrogen atoms and form alkaloids.1631 One pathway leads to the hop-anoids. These triterpene derivatives function in bacterial membranes, probably much as cholesterol does in our membranes. The three-dimensional structure of a bacterial hopene synthase is known.164 1643 Like glucoamylase (Fig. 2-29) and farnesyl transferase, the enzyme has an (a,a)6-barrel structure in one domain and a somewhat similar barrel in a second domain. 

Methylation at C-4 of sterol nucleus was one of the other factors affecting activity enhancement. Thus, in general, 4-methylsterols (14,15) and 4,4-dimethylsterols (8,13) exhibited higher activity than 4-desmethylsterols. A similar structure-activity relationship was observed also in the HHPA-induced inflammation on mouse ear [35]. Whereas cholesterol (7) did not show inhibitory activity, several 4,4-dimethylcholestane derivatives, 0-12, exhibited activity. 4,4-Dimethylcholestane-3a,5a-diol (12) was the most potent inhibitor its activity was comparable to that of ursolic acid (210) [35]. Compound 12 reduced also the inflammation induced by teleocidin B (3), one of the indole alkaloid-type of tumor promoters [53]. 

Raw Materials and Extraction. The variety of natural sources of steroid raw materials is vast, and the exact details of manufacturing processes are ambiguous closely held industrial secrets. However, the most widely utilized raw materials for die partial synthesis of steroids appear to be the following (/) the sapogenins, for example, diosgenin (27). (2) the sir-ucliirally relaied sierold alkaloids, (3) sterols, such as cholesterol (8), and (4) bile acids. 

Methylation is one of the most common enzymatic modifications in plant specialized (secondary) metabolism. Almost all classes of plant specialized metabolites are known to be methylated, including amino acids, alkaloids, phenylpropanoids, sugars, purines, sterols, thiols, and flavonoids. The methyl transfer most commonly occurs on C, N, S, or O atoms. 

Starch in plants is accompanied by water, metal ions, lipids, proteins, sterols (such as saponins), and alkaloids (as in such exotic plants as Diascoracea).649 Several of these components can be washed out by the isolation of starch, some of them are extractable with organic solvents, and some are volatized by steam treatment. With the exception of metal ions (preceding article, p. 263), the foregoing components form physical mixtures with starch and do not chemically bond with either amylose or amylopectin. Therefore, one may assume that amylose and amylopectin form inclusion complexes with organic components that are similar to those mentioned in the preceding article. 

Some allelochemicals have hemolytic properties, such as saponins. If resorbed, these compounds complex membrane sterols and make the cells leaky. Steroidal alkaloids from Solanum or Veratrum species display this sort of activity as well as influencing ion channels (Table IV). 

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