Azidolysis of C-19 diastereoisomer tosylesters of morphine derivatives possessing a bridged ring C has been studied and 4-azatetracyclo[4.4.02,4.03,8]decanes 6b, 6d and 6f were formed via the substitution and subsequent intramolecular cyclization of the (R)-C-19 tosylesters 4b, 4d and 4f, and primarily the ethylidene derivatives 7a, 7b and 7c were obtained from (S)-C-19 tosylesters 4c, 4e and 4g. According to our experience the course of the reaction depends on the configuration of the C-19 centre of chirality and on the spatial requirement of the substitutent on C-6
The formation of supramolecular polymeric aggregates with a molecular mass of 100 kDa in a nonaqueous solution from a telechelic dimer of isopropylidene guanosine in the presence of K+ ions is reported. The possible structure of macromonomers resulting from the development of G4 quartets was deduced from DOSY NMR, circular dichroism spectra, and dynamic light scattering measurements.
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Elsőkent alkalmaztunk negyszogsavesztereket uj antraciklin-glikozid (adriamicin, daunomicin, carminomicin) es glikopeptid (eremomicin,vankomicin,riszticetin, teikoplanin) antibiotikomok es szarmazekaik szintezisere.Eljarasunkat az aminodeoxi-cukrokra (es alditolokra,amino-aldonsavakra, es glikozilaminokra) is kiterjesztettuk, amely lehetőseget kinal uj ciklitol-antibiotikumok es specifikus horgony (spacer,linker) vegyuletek stb... előallitasara.Kuzuluk az adriamicin(SA-17) szarmazek jelentős sargalaz es dengue-virus ellenes hatasunak bizonyult.Egy specialis hidrofob-csoporttal szubsztitualt-aglikorisztocetin(8e) influenza ellenes aktivitasa pedig felulmulta a forgalomban levő leghatasosabb keszitmenyt az Oseltamivirt.Sikerult olyan N- glikozil- aglikorisztocetin szarmazekot keszitenunk, amely megtartotta az anyavegyulet aktivitasat, de a nem aggregalta a trombocytakat. A Xenorhabdus ssp. Var. Bicornutus (belbakteriumanak) tenyeszeteből egy arginin tartalmu heptapeptidet izolatunk es tanulmanyoztuk mezőgazdasagi felhasznalasanak lehetőseget. | We were the first to apply squaric acid esters for the synthesis of new anthracycline glycoside- (adriamycin, daunomycin, carminomycin) and vancomycin-type (eremomycin,vancomycin, ristocetin, teicoplanin) antibiotics and their derivatives. We extended the procedure also for the preparation of aminodeoxy sugars (and alditols, amino aldonic acids, glycosylamines), and this offers possibilities for obtaining new cyclitol antibiotics and specific anchor (spacer, linker, etc.) compounds. Of these substances, the adriamycin derivative SA-17 possesses significant activity against yellow fever and the dengue-virus. The anti-influenza activity of an aglyco-ristocetin derivative (8e), carrying a specific hydrophobic substituent, was higher than the most effective commercial preparation; Oseltamivir. We succeeded to synthesize an N-glycosyl aglyco-ristocetin derivative which retained the activity of the parent antibiotic but did not cause thrombocyte aggregation. We isolated an arginin-containing heptapeptide from the culture of the intestinal bacterium Xenorhabdus sp. Var. Bicornutus and studied its possible utilization in agricultural practice.
Abstract 2-Methylenecephem-1-oxides (4) or -1,1-dioxides (6) can be very conveniently obtained through the use of dimethyl(methylene)imonium salts, which can be prepared in situ or in advance from bis(N,N-dimethylamino)methane (2) and a reactive acid derivative.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
