Biogenetic aspects

Alkaline hydrolysis of 57 gave benzaldehyde and neopilosinine. After treatment with acetic acid anhydride and pyridine, anhydroepiisopiloturine was obtained, isolated as its nitrate. Biogenetic aspects were discussed (117). 

The chemistry of the Daphniphyllum alkaloids has focused on the biogenetic aspects of their occurrence. The search for proposed biosynthetic intermediates among the minor alkaloids of these plants has resulted in the isolation and structure elucidation of five new bases. Accomplishments have included interconversions of the Daphniphyllum alkaloids by bond formation or fission. The compounds isolated thus far have been divided into five structural types and are reviewed as diterpenoids... 

Barton DHR, Cohen T (1957) Some Biogenetic Aspects of Phenol Oxidation. In Festschrift Professor Dr. Artur Stoll. Basel Birkhauser... 

Barton, D.H.R Cohen, T. Some biogenetic aspects of phenol oxidation. In Festschrift Artur Stoll. Birkhauser Basel, 1957, 117-143. 

Barton, D. H. R., and T. Cohen Some Biogenetic Aspects of Phenol Oxidation. Festschrift A. Stoll, p. 117. Basel Birkhauser 1957. 

In his thorough review (385 references), Voigt (55-57) covers the literature up to 1967. The article also comprises microbiological aspects of alkaloid synthesis in saprophytic cultures as well as in vivo studies. Biogenetic interrelationships between different species of clavine alkaloids apart from the main pathway are also discussed there. 

A useful review of diterpenoid chemistry has appeared.1 Some aspects of the distribution of diterpenoids in plants have been discussed.2 An interesting feature of the new diterpenoids described over the past few years is the increase in the number with skeleta based on the macrocyclic ring formed by the cyclization of geranylgeranyl pyrophosphate at the distal double bond. This mode of cyclization has formed the basis of a biogenetically patterned synthesis3 of ( )-nephthenol (2) and ( )-cembrene A from the distal epoxide of geranylgeranyl phenyl thioether (1). 

Some of the most interesting applications of organic structural theory to the elucidation of biosynthetic pathways were stimulated by efforts to formulate mechanisms for the biosynthesis of alkaloids. Conversely, consideration of implied biogenetic relations have occasionally helped structural determination. An important aspect of theories concerning alkaloid biosynthesis has been the assumed role of the aromatic amino acids in their formation. Only limited experimental evidence is available in this area. The incorporation of tyrosine- 8-C into morphine has been shown to be in accordance with a theory for its formation from 3,4-dihydroxyphenyl-alanine plus 3,4-dihydroxyphenylacetaldehyde. A stimulating theory of the biosynthesis of indole alkaloids, based on a condensation between trypt-amine and a rearrangement product of prephenic acid, has recently been published. The unique stereochemistry of C15 of these alkaloids had an important part in the formulation of the theory. Experimental proof of this theory would be valuable for several areas of alkaloid chemistry and biosynthesis. 

The majority of natural acetylenes known today are polyacetylenes. This name encompasses what now appears to be a biogenetically uniform group of secondary metabolites, usually not strictly poly-ynes (c.g. the esters 2 and 3), which originate from oleic acid and are found in the roots and the aerial parts of plants and in fungi. In what follows, aspects of their cjjemistry are discussed prefaced by a survey of natural acetylenes of different origin. 

This volume covers the synthetic and structural aspects of all types of terpenoids and steroids based on the increasing importance of biogenetic theory in this work. It covers the period September 1963 to August 1970. 55 pp 11-00... 

Polycyclic amine alkaloids (3-alkylpiperidine alkaloids) containing a complex skeleton with several macrocyclic rings have been isolated from marine sponges. They include manzamines, sarains, haliclamine A and ingenamines. Their structures, synthesis and biochemical aspects have been recently reviewed [35]. Our focus, therefore, is on the biogenetic origin of the bis-pyridinium macrocycle and on the role of precursors in their biosynthesis, as summarized in the retrosynthetic analysis for manzamines demonstrated schematically in Fig.(23). 

General reviews have appeared on aspects of terpenoid biosynthesis " and on the use of biogenetic arguments in the elucidation of the structure of naturally occurring compounds. 

Ellipticin, biogenetic, synthetic, and biochemical aspects, antitumor activity of 86T2388 85H(23) 1277 81 H( 16) 1357. 

Winterhalter, P. 1996. Carotenoid-derived aroma compounds Biogenetic and biotechnological aspects. In Biotechnology for improvedfoods and flavors, ed. G. R. Takeoka, R. Teranishi, P. J. Williams, and A. Kobayashi, 295-308. ACS Symposium Series 637. Washington, DC American Chemical Society. 

Carotenoid-Derived Aroma Compounds Biogenetic and Biotechnological Aspects... 

As yet not one single compound has been found to co-occur in the two populations. The five compounds from the Canadian collection arc all characterized by the presence of the inverted isoprene unit (2-methyl-3-buten-2-yl) in the 3a position. Of the tricyclic structures from the Scandinavian collection only three compounds (1, 5, and 6) encompass this configuration. Therefore, even if I and 8 only differ in this aspect they are clearly biogenetically different. Likewise, even if the N-oxide of flustramine B (2-VI-oxide) participates in an acid-base catalyzed equilibrium with flustrarine B (9) (45) analogous to the geneserine and geneseroline equilibria with hexahydropyrrolo[2,3-6] indole V-oxides and hexahydro-1,2-oxazino[5,6-fe]indoles (46) there is no possibility of transforming IV to 9. 

V.K.Kansal and P.Potier, The Biogenetic, Synthetic and Biochemical Aspects of Ellipticine, an Antitumour Alkaloid, Tetrahedron, 1986, 42, 2389. 

Table IV lists those yeasts (other than the aforementioned Sporobolomyces sp.) that synthesize polysaccharide-like 0 -phos-phonoglycans along with the various a-g-glycose 1-phosphate end groups found thus far (50). A new aspect of the phosphomannan story is introduced in this table When grown in the absence of added orthophosphate, almost all such yeasts alternatively synthesize neutral a-D-mannans and glucoraannans. Common biogenetic origin of the neutral and phosphorylated mannans and glucomannans is evidenced by similar amounts of g-glucose or its absence in the biopolymers produced by a given strain of yeast.

The main monolignols are coniferyl, sinapyl, and p-coumaryl alcohols. Cinnamic aldehydes and acids that are biogenetic precursors to the monolignol can also take part in the biosynthesis. This chapter is concerned with the topological aspects of the structnral organisation of lignin. 

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