Synthesis of ecdysone. 3. On insect hormones. Syntheses of 2-beta, 3-beta, 14-alpha-trihydroxy-6-keto-delta-7-A-B-cis-steroids

The synthesis of the tetracyclic skeleton of ecdysone with correct stereochemistry and substitution is described. 22,25-Didehydroxy-ecdysone and methyl (20S)-2β,3β-dihydroxy-6-oxo-5β-pregn-7-ene-20-carboxylate have been prepared. The latter is a key intermediate in the synthesis of ecdysone.     

Mass spectrometry of insect moulting hormones: Trimethylsilyl-methoxime derivatives of ecdysone and 20-hydroxyecdysone

The mass spectra of trimethylsilyl-methoxime derivatives of the two insect moulting hormones, ecdysone and 20-hydroxyecdysone are described together with some model compounds. These steroid derivatives are volatile in the gas chromatograph and their mass spectra provide a sensitive means of detection and structure recognition.     

A survey of the chromatographic analysis of natural insect juvenile hormones and the insect growth regulator, altosid.

A brief survey of gas and liquid chromatographic methods for analysis, purification and quantitation of natural insect juvenile hormones and one commercially used analoh, altosid (methoprene) insect growth regulator, includes references to the most recent literature.     

甾体植物生长激素合成的研究IV.一些中间体的合成

Steroidal plant growth hormone intermediates, I (R = H, Ac; R1 = MeC:CHMe, MeCHCOMe, MeCHQ, MeCHQ1) were prepared from hydrodeoxycholic acid (I, R = H, R1 = MeCHCH2CH2CO2H).     

Partial synthesis of 2-desoxyecdysone and 2-desoxyecdysterone,insect molting hormones

Conclusions Starting from the ketone (VIII) and specially synthesized 2-desoxypoststerone, partial syntheses of 2-desoxyecdysone and 2-desoxyecdysterone (insect molting hormones) have been carried out.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 317–325, February, 1982.     

Pyridazines. IV. The synthesis and some reactions of acetylpyridazines

Two 3-acetylpyridazines have been prepared. N-Oxidation of 3-acetylpyridazine ( 6 ) gave only 3-acetylpyridazine 1-oxide ( 7 ). During the N-oxidation of 3-acetyl-6-methoxypyridazine ( 10 ), three primary products, namely, 3-acetyl-6-methoxypyridazine 1-oxide ( 12 ), 3-acetyl-6-methoxy-pyridazine 2-oxide ( 13 ), 3-acetylpyridazin-6-one ( 14 ) and an artifact, 3-methoxypyridazine 1-oxide ( 15 ) were obtained. Furthermore, it has been shown that 3-methoxypyridazine 1-oxide ( 15 ) can be obtained in quantitative yield by treatment of 3-acetyl-6-methoxypyridazine 2-oxide ( 13 ) with dilute sodium hydroxide solution at room temperature. This represents a novel deacylation reaction. Nitration of 3-acetylpyridazine 1-oxide, ( 7 ) gave 3,4-bis(3′-pyridazinoyl)furoxan 1′,1′-dioxide ( 19 ) rather than a simple nitration product. 3-Acetyl-pyridazine ( 6 ) and 3-acetyl-6-methoxypyridazine ( 10 ) also gave furoxans ( 22 and 23 ) upon nitration.     

Side chain modified sterols as probes into insect molting hormone metabolism. I: synthesis of monofluorophytosterols

25- and 26-monofluorophytosterols were synthesized from stigmasterol as potential arthropod-activated competitive inhibitors of side chain hydroxylations occuring in ecdysone biogenesis.     

Interpretation of scoring functions using 3D molecular fields. Mapping the diacyl-hydrazine-binding pocket of an insect ecdysone receptor

A method is presented for the interpretation of receptor docking score values (rough measures of binding affinities) of ligands in terms of 3D molecular field interaction contributions. The FlexX and FlexX-Pharm methods were used to dock the structures of designed sets of ligands into the ligand-binding pocket of a selected receptor. In the next step the relationship was investigated between the FlexX and CScore scores and 3D molecular fields obtained for the docked conformations of the ligands, using the CoMFA (Comparative Molecular Field Analysis) and CoMSIA (Comparative Molecular Similarity Indices Analysis) methods. The approach yielded highly significant CoMFA and CoMSIA models demonstrating that a high portion of the variance in the docking score values of the ligands can be explained by steric, electrostatic, hydrophobic, and hydrogen bond donor and acceptor molecular field interaction contributions. The approach was exemplified by using the crystal structure of the ligand-binding domain of the ecdysone receptor (EcR) of the moth Heliotis virescens as well as virtual molecule libraries of analogues of known diacyl-hydrazine (DAH) type ecdysteroid agonists. By docking appropriately designed virtual compound libraries into the DAH binding pocket of EcR followed by CoMFA and CoMSIA of the docked conformations, hitherto unexplored regions of the receptor cavity could be mapped. By mapping the significant molecular field interaction contributions onto the model of the receptor-ligand complex, important receptor-ligand interactions could be highlighted that may help the design of novel highly scored receptor ligands. An advantage of the method is that no experimental biological activity data are required to exhaustively map the receptor-binding site.