scholarly journals Synthetic Studies of Pyridomycin. IV. Syntheses of Some Twelvemembered Ring Compounds Designed for Construction of Intact Ring System with Exocyclic (Z)-s-Butylidene Side Chain in Pyridomycin

1985 ◽  
Vol 58 (11) ◽  
pp. 3298-3308 ◽  
Author(s):  
Mitsuhiro Kinoshita ◽  
Yasuharu Mori
Keyword(s):  
Ring System ◽  
Side Chain ◽  
Ring Compounds ◽  
Synthetic Studies

Synthetic Studies on Maitotoxin. 1. Stereoselective Synthesis of the C′D′E′F′-Ring System Having a Side Chain

2008 ◽  
Vol 10 (9) ◽  
pp. 1675-1678 ◽  
Author(s):  
Masayuki Morita ◽  
Seishi Ishiyama ◽  
Hiroyuki Koshino ◽  
Tadashi Nakata
Keyword(s):  
Stereoselective Synthesis ◽  
Ring System ◽  
Side Chain ◽  
Synthetic Studies ◽  
F Ring

scholarly journals The role of side chains in the interaction of new antitumor pyrimidoacridinetriones with DNA: molecular dynamics simulations.

2000 ◽  
Vol 47 (1) ◽  
pp. 47-57 ◽  
Author(s):  
J Mazerski ◽  
I Antonini ◽  
S Martelli
Keyword(s):  
Molecular Dynamics ◽  
Rational Design ◽  
Md Simulations ◽  
Ring System ◽  
Side Chain ◽  
Side Chains ◽  
Intercalation Complex ◽  
Highly Active ◽  
Simulation Techniques ◽  
Dynamics Simulations

Pyrimidoacridinetriones (PATs) are a new group of highly active antitumor compounds. It seems reasonable to assume that, like for some other acridine derivatives, intercalation into DNA is a necessary, however not a sufficient condition for antitumor activity of these compounds. Rational design of new compounds of this chemotype requires knowledge about the structure of the intercalation complex, as well as about interactions responsible for its stability. Computer simulation techniques such as molecular dynamics (MD) may provide valuable information about these problems. The results of MD simulations performed for three rationally selected PATs are presented in this paper. The compounds differ in the number and position of side chains. Each of the compounds was simulated in two systems: i) in water, and ii) in the intercalation complex with the dodecamer duplex d(GCGCGCGCGCGC)2. The orientation of the side chain in relation to the ring system is determined by the position of its attachment. Orientation of the ring system inside the intercalation cavity depends on the number and position of side chain(s). The conformations of the side chain(s) of all PATs studied in the intercalation complex were found to be very similar to those observed in water.

scholarly journals The intercalation of imidazoacridinones into DNA induces conformational changes in their side chain.

2000 ◽  
Vol 47 (1) ◽  
pp. 65-78 ◽  
Author(s):  
J Mazerski ◽  
K Muchewicz
Keyword(s):  
Conformational Changes ◽  
Ring System ◽  
Van Der Waals Interactions ◽  
Side Chain ◽  
Intercalation Complex ◽  
Highly Active ◽  
Antitumor Compounds ◽  
Chemical Constitution ◽  
Modelling Techniques ◽  
Dynamics Simulations

Imidazoacridinones (IAs) are a new group of highly active antitumor compounds. The intercalation of the IA molecule into DNA is the preliminary step in the mode of action of these compounds. There are no experimental data about the structure of an intercalation complex formed by imidazoacridinones. Therefore the design of new potentially better compounds of this group should employ the molecular modelling techniques. The results of molecular dynamics simulations performed for four IA analogues are presented. Each of the compounds was studied in two systems: i) in water, and ii) in the intercalation complex with dodecamer duplex d(GCGCGCGCGCGC)2. Significant differences in the conformation of the side chain in the two environments were observed for all studied IAs. These changes were induced by electrostatic as well as van der Waals interactions between the intercalator and DNA. Moreover, the results showed that the geometry of the intercalation complex depends on: i) the chemical constitution of the side chain, and ii) the substituent in position 8 of the ring system.

scholarly journals Crystal structure of ethyl (2S,2′R)-1′-benzyl-3-oxo-3H-dispiro[1-benzothiophene-2,3′-pyrrolidine-2′,11′′-indeno[1,2-b]quinoxaline]-4′-carboxylate

2015 ◽  
Vol 71 (3) ◽  
pp. o195-o196
Author(s):  
J. Govindaraj ◽  
R. Raja ◽  
M. Suresh ◽  
R. Raghunathan ◽  
A. SubbiahPandi
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Ring System ◽  
Side Chain ◽  
Dihedral Angles ◽  
Pyrrolidine Ring ◽  
Compound C ◽  
Dimensional Network ◽  
Centroid Distance ◽  
Quinoxaline Ring

In the title compound, C35H27N3O3S, the spiro-linked five-membered rings both adopt twisted conformations. The pyrrolidine ring makes dihedral angles of 80.5 (1) and 77.4 (9)° with the benzothiophene ring system and the quinoxaline ring system, respectively. The S atom and C=O unit of the benzothiophene ring system are disordered over two opposite orientations in a 0.768 (4):0.232 (4) ratio. The atoms of the ethyl side chain are disordered over two sets of sites in a 0.680 (16):0.320 (16) ratio. In the crystal, molecules are linked by C—H...O, C—H...N and π–π interactions [shortest centroid–centroid distance = 3.4145 (19) Å], resulting in a three-dimensional network.

Synthetic studies related to mycobactins. III. Approaches to the synthesis of the cobactin ring system

1972 ◽  
Vol 25 (11) ◽  
pp. 2429 ◽  
Author(s):  
DSC Black ◽  
RFC Brown ◽  
AM Wade
Keyword(s):  
Primary Amine ◽  
Ring Expansion ◽  
Hydroxamic Acids ◽  
Ring System ◽  
Ethyl Benzoate ◽  
Yield Reduction ◽  
Similar Reaction ◽  
Oxidation Reactions ◽  
Cyclic Hydroxamic Acids ◽  
Synthetic Studies

The synthesis of several seven-membered cyclic hydroxamic acids has been carried out in low yield. Reduction of diethyl 2-hydroxyiminoheptane-l,7-dioate afforded ethyl 1-hydroxy-7-oxohexahydroazepine-2-carboxylate, together with related acyclic products. The cobactin precursor 3-bromo-1-hydroxyhexahydro-azepin-2-one was obtained by the ring expansion of 2-bromocyclohexanone with benzenesulphonohydroxamic acid and also by the peracid oxidation of 6-bromo-7-ethoxy-3,4,5,6-tetrahydro-2H-azepine. The methyl and cinnamyl imidates of hexanolactam were oxidized by peracid to 1-hydroxyhexahydroazepin-2-one, in addition to the related imino- and nitroso-hexanoic esters. In a similar reaction, 1-hydroxypiperidin-2-one was obtained from 2-methoxy-3,4,5,6-tetrahydropyridine. During the course of these oxidation reactions, the intermediate oxaziridines 7-methoxy-8-oxa-1-azabicyclo[5,1,0]octane and 6-bromo-7-ethoxy-8-oxa-1-azabicyclo[5,1,0]octane were isolated and identified. The peraoid oxidation of ethyl N-cyclohexylbenzimidate yielded cyclohexylhydroxylamine and ethyl benzoate in reasonable yields. This reaction suggests a useful method for the conversion of a primary amine into the related hydroxylamine.

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