Monoterpenoids structures

The sex ph eromone of the obscure mealybug. Pseudococcus viburni Signoret (Homoptera Coccidae), consists of (li , 2i , 35 )-(2,3,4,4-tetramethylcyclopentyl)methyl acetate. This compound is interesting because it is the first example of a new monoterpenoid structural motif in which the two isoprene units forming the carbon skeleton are joined... 

A 4-nor-7,8-dehydro-10-hydroxy-skytanthine (10) has been obtained from A. radiata [22]. Compotmd 10 and actinidine-type compound 5 are the alkaloid compounds that have been isolated from this plant species for the first time, and it is a reasonable hypothesis that the monoterpenoid structures of 10 and 5 should be derived from the previously isolated iridoids in this plant, which are known to be the biogenetic precursors of this type of alkaloids [50]. A novel skytanthine-type alkaloid named delavayine A (11) that comprises a benzoate ester has been isolated from 7. delavayi [25]. Similarly, another novel skytanthine-type alkaloid, incarviUateine E (12), possessing three incarvilline moieties has been isolated and characterized from the aerial parts of 7. sinensis [26]. Incarvine E (13) and incarvine F (14) [27] isolated from 7. sinensis and isoincarvilline (15) [28] and mairines A-C (16-18) [29] from 7. mairei are other new skytanthine-type monoterpenoid alkaloids. Compounds 16 and 18 contain a rare (5-skytanthine Af-oxide in the structure [29]. 

The terpenoid precursor isopentenyl diphosphate, formerly called isopentenyl pyrophosphate and abbreviated IPP, is biosynthesized by two different pathways depending on the organism and the structure of the final product. In animals and higher plants, sesquiterpenoids and triterpenoids arise primarily from the mevalonate pathway, whereas monoterpenoids, diterpenoids, and tetraterpenoids are biosynthesized by the 1-deoxyxylulose 5-phosphate (DXP) pathway. In bacteria,... 

In section 9.4 we described some of the transformations that are employed in the manufacture of valuable steroids. Sterols and steroids are, however, only a small fraction of the total range of terpenoids produced within the biosphere. Others include monoterpenoids based on the structures ... 

Since the last major review of the biosynthesis of the monoterpenoid indole alkaloids (97), there have been several full and partial 98-104) reviews of various aspects of the work that has been conducted since 1974. Two major developments have dominated the field in this period, namely, the demonstrations that (i) strictosidine (33) is the universal precursor of the monoterpenoid indole alkaloids and (ii) selected cell-free systems of C. roseus have the ability to produce the full range of alkaloid structure types, including the bisindoles. This section traces some aspects of these developments, paying particular attention to work been carried out with C. roseus, and omitting work, important though it may be, on other monoterpenoid indole alkaloid-producing plants, e.g., Rauwolfia, Campto-theca, and Cinchona. 

The discussion of a series displacement index for classifying mass spectra and for correlation with structural stability includes some monoterpenoids e.g. myrcene limonene, santene). ... 

Kuwahara, Y. (1982). Pheromone study on acarid mites VII. Structural requisites in monoterpenoids for inducing the alarm pheromone activity against the mold mite, Tyrophagus putrescentiae (Schrank) (Acarina Acaridae). Applied Entomology and Zoology 17 127-132. 

Sakata, T, Okabe, K. and Kuwahara, Y. (2001). Structure elucidation of twelve novel esters between five fatty acids and three branched new alcohols along with four monoterpenoids from Sancassania shanghaiensis (Acari Acaridae). Bioscience, Biotechnology and Biochemistry 65 919-927. 

Terpenoids are structurally based on the isoprenoid (C5) unit and include monoterpenoids, sesquiterpenoids, diterpenoids, triterpenoids, steroids and carotenoids. These compounds can be further modified to generate greater structural complexity. Thus the saponins are surface active amphiphiles deriving from the glycosylation of steroid (C27) or triterpenoid (C30) entities. Plant triterpenoids with very specific biochemical effects include those that mimic the effects of mammalian steroid hormones or of insect developmental hormones. 

Monoterpenoid Alkaloids.—Aristotelia Alkaloids. Fruticosonine is a novel alkaloid, containing an unrearranged monoterpene unit, which occurs48 in Aristotelia fruticosa Hook, f the structure (54) (relative stereochemistry only) was deduced by X-ray crystallography, and confirmed by the synthesis of ( )-fruticosonine... 

Tables 2-5 list monoterpenoids (Mo), sesquiterpenoids (Sq), diterpenoids (Di), and retinoids (Re), sesterterpenoids (St), meroterpenoids and miscellaneous terpenoids (Me), respectively, discussed in this review. The bioassay systems in which the compounds exhibited inhibitory effects, together with the major sources of the compounds, are included in the Tables. Most of these terpenoids are isolated from natural sources, and their structures are shown in Figs. (2)-(5). Some terpenoids which exhibit significant and/or a broad range of chemopreventive and anti-inflammatory activities are discussed below.

Ishikawa et al. (2003) could obtain 33 compounds, including two new monoterpenoids, four new monoterpenoid glycosides, two new monoterpenoid glucoside sulphates and two new aromatic compound glycosides, from the water-soluble portion of the methanol extract of coriander fruit. Their structures were clarified by spectral investigation. The major constituents of coriander essential oils (dried fruits, herb prior to flowering and flowering herb) are listed below. 

The iridoid monoterpenoid part of the structure C-1-C-9-C-5-C-6-C-7 (B) is confirmed by the ////COSY plot ... 

Monoterpenoid Alkaloids.—Corynantheine-Heteroyohimbine- Yohimbine Group, and Related Oxindoles. The leaves of Strychnos decussata (Pappe) Gil. contain a new glycosidic alkaloid for which the gross structure (78) has been proposed 52 so far, nothing is known about its stereochemistry. Nevertheless it seems distinctly possible that this alkaloid is a close biosynthetic relative of vallesiachotamine. 

Xylostosidine is a novel sulphur-containing monoterpenoid glucosidic alkaloid that occurs in the water-soluble extract of Lonicera xylosteum L. Its structure (17) has been elucidated by mass and n.m.r. spectroscopy.23 Two additional alkaloid glucosides, loxylostosidines A and B, have been isolated from the same source. They are the two geometrical isomers of xylostosidine sulphoxide, the former with a P S—O bond and the latter with an a, on n.m.r. spectral evidence.24... 

Monoterpenoid Quinoline Alkaloids.—The first examples of monoterpenoid quinoline alkaloids were isolated from Haplophyllum bucharicum some time ago, but the structures proposed on the basis of chemical and spectroscopic studies are not yet secure (cf. Vol. 1, p. 97 Vol. 2, p. 88 and Vol. 4, p. 119). The constitution... 

Monoterpenoid Alkaloids.—Aristotelia Alkaloids. Details of the elucidation of the structure of aristone by the X-ray method have been published.39" Aristoserratine, a new, minor alkaloid of A. serrata and A. peduncularis39b is 15-oxoaristoteline (59). Since aristoserratine could not be reduced to aristoteline, the absolute configuration expressed in (59) was deduced from its c.d. spectrum. 

A large amount of structural information is available that describes the variety of indole alkaloids produced in plants. This has recently been followed by significant increases in our knowledge of the biosynthetic pathways that lead to their production and of the genes involved. Several reviews have appeared recently that describe the chemistry, biochemistry, cell and molecular biology of alkaloid biosynthesis.1 3 This chapter will selectively review recently characterized genes that appear to be responsible for the diversity and complexity of monoterpenoid indole alkaloids produced by plants. A particular focus will be on the reactions leading to the biosynthesis of vindoline (Fig. 8.1) in Catharanthus roseus. 

A useful volume on the chemistry of terpenoids and steroids has appeared.1 Nineteen topics in monoterpenoid chemistry are reviewed with a literature coverage to early 1973 the topics are particularly suitable for use in advanced lecture courses and cover biosynthesis, structural elucidation, and synthesis. Monoterpenoid alkaloid chemistry has been reviewed.2... 

The structure of the monoterpenoid alkaloid alangiside (115 R = H) has been confirmed by synthesis of the O-methyl ether (115 R = Me) from secologanin and 3-hydroxy-4-methoxyphenethylamine 202 the isolation of loganic acid from the same plant (Alangium lamarckii) is consistent with biosynthetic theory. 

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