Bioactive 0-heterocyclic compounds

Intramolecular cycloadditions of chiral nitrones provide a useful tool for the preparation of bioactive heterocyclic compounds.63 Shing et al. demonstrated that 1,3-dipolar cycloaddition of nitrones derived from 3-0-allyl-hexoses is dependent only on the relative configuration at C-2,3, as shown in Scheme 8.16. Thus 3-0-allyl-D-glucose and -D-altrose (both with threo-configuration at C-2,3) produce oxepanes selectively, whereas 3-O-allyl-D-allose and -D-man-nose (both with erythro-configuration at C-2,3) give tetrahydropyranes selectively.80... 

Synthesis and biological activity of heteroprostanoids 92UK456. Synthesis of natural bioactive heterocyclic compounds 92YZ516. 

Darwish, Y., Cserhati, T., and Forgacs, E. (1994). Reversed phase retention characteristics of some bioactive heterocyclic compounds. J. Chromatogr. A 668 485-494. 

Dolzhenko and Dolzhenko have presented a comprehensive review on the use of green solvents for eco-friendly S5mthesis of bioactive heterocyclic compounds in Chapter 5. Use of safer solvents is considered as one of the most... 

Green Solvents for Eco-friendly Synthesis of Bioactive Heterocyclic Compounds... 

J. Dinges, C. Lamberth, Bioactive Heterocyclic Compound Classes Pharmaceuticals and Agrochemicals, Wiley-VCH Verlag GmbH Co, 2012. 

Chromenes and their benzofused derivatives are ubiquitous in natural products and pharmaceuticals [25]. Moreover, the 2//-chromene skeleton is an important substructure moiety in a wide range of bioactive heterocyclic compounds, which have been used as traditional medicine for the treatment of hypertension and diabetes [26]. Consequently, tremendous efforts have been devoted to the synthesis of these compounds. 

Nobuhiro Sato was born in Niigata, Japan, in 1945. He received his B.Sc. degree from Yokohama City University in 1968 and his Ph.D. degree from Tokyo Metropolitan University in 1981. After a postdoctoral position with E. C. Taylor at Princeton University, he returned to japan, where he is now professor of chemistry at Yokohama City University. His research interests include synthesis and reactivity of heterocyclic compounds, particularly pyrazines and pteridines, as optically functional materials or bioactive products. 

This section covers the synthesis of aziridines, oxiranes, /J-lactams and oxetanes. Aziridines are fairly important moieties in bioactive molecules and thus new routes for their synthesis are constantly being developed. /1-Lactams are probably the most important heterocyclic compounds that contain a single nitrogen atom, due to their importance in penicillin and cephalosporin chemistry. Their synthesis and chemistry has received much attention and much of this work has been reviewed544. The oxygen-containing heterocycles are much less commonly synthesized from double-bonded functional groups. 

A Influence of the heterocycle in the germination of le ttuce. Note how heterocyclic compounds Heliannuol A and C are active, whereas open chain compounds Helibisabonol A and B are inactive. B Influence of the ring size in the germination of lettuce. Note how the bioactivity decreases with the size of the ring 8 > 7 > 6... 

As part of the series Topics in Heterocyclic Chemistry, this volume titled Bioactive Heterocycles II presents comprehensive and up-to-date reviews on selected topics concerning flavonoids and anthocyanins in plants, and heterocycles such as bioactive phenothiazines, phenoxazines, and related compounds. The volume is separated into two sections mainly concentrating on these two topics. 

The hybrid molecules, comprised of sydnones and other heterocyclic compounds, constitute one of the more promising approaches for the design of bioactive compounds. 3-Aryl-4-formylsydnones (22) are attractive starting compounds for several 4-heterocycle-substituted sydnones, such as thiazo-lidinone (23) and thiazoline (24, 25) [14,15], imidazoles (26) [16], thiadia-zolines (27), thiadiazoles (28) [17], and indoles (29) [18]. Some sydnonyl-substituted thiazolidinone (23) and thiazoline (30) derivatives exhibited a potent l,l-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, comparable to that of vitamin E [14,15]. 

Phenothiazine (PH), a three-ring fused heterocyclic system with an - NH -group and a sulphur atom (- S -) in the central six-membered ring, is the parent molecule of several series of bioactive, heterocyclic derivatives which present wide and various properties of biological and pharmaceutical interest (Fig. 1A). It is worthwhile noting that, unlike anthracene, acridine and phenazine, which constitute 14 jt-electron systems, phenothiazine contains 16 jt electrons and thus is not jt-isoelectronic with the above compounds. 

The third chapter, Quantitative Structure-Cytotoxicity Relationship of Bioactive Heterocycles by the Semi-empirical Molecular Orbital Method with the Concept of Absolute Hardness by Mariko Ishihara, Hiroshi Sakagami, Masami Kawase, and Noboru Motohashi, presents the relationship between the cytotoxicity (defined as 50% cytotoxic concentration) of heterocycles such as phenoxazine, 5-trifluoromethyloxazoles, O-heterocycles such as 3-formylchromone and coumarins, and vitamin K2 derivatives against some tumor cell lines and 15 chemical descriptors. The results suggest the importance of selecting the most appropriate descriptors for each cell type and compound. The review is of interest as it represents the relationship of the molecular structures with the cytotoxic activity of these heterocycles. 

We have been investigating the feasibility of using metathesis to prepare heterocyclic compounds such as quinolines and indoles [12] (Scheme 10.5) and its application to the synthesis of bioactive natural products [13],... 

Tandem cyclizations based on the novel reactions of allenic compounds useful for preparation of bioactive heterocycles 05CPB1211. 

Synthetic organic chemistry of bioactive heterocycles based on small ring compounds 07CPB961. 

Recently, a variety of heterocyclic compounds containing nitrogen and sulfur atoms have been developed as useful and practical agrochemicals. Our attention was directed to these heterocycles as screening targets to create novel bioactive compounds (7). 

The book is organized into seven chapters. In the introductory chapter, the synthetic pathways of some natural products illustrating the basic common reactions in secondary metabolites are described. In Chapter 2, methods and techniques involved in the biosynthesis of heterocycles are dealt with. The subsequent four chapters deal with three- to six-membered heterocycles starting from the natural products to approach the preparation of imnatural heterocyclic compounds with particular attention to bioactive molecules. In Chapter 7, seven- and eight-membered heterocycles are treated, as well as larger ones, using the same approach as used in the preceding four chapters. 

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