A new cyclitol derivative influences inositol metabolism in Neurospora crassa.

Cyclitol derivatives have been synthesized and screened for growth inhibitory effect upon prokaryotic and eukaryotic organisms. One derivative, (2S,3R,5R)-3-azido-2-benzoyloxy-5-hydroxycyclohexanone, was studied in detail: it has no effect upon bacteria, but it is inhibitory to Neurospora crassa. In Neurospora crassa it increased the amount of myo-inositol-1-phosphate synthase and inhibited the activity of myo-inositol-monophosphatase. The enhanced synthesis of myo-inositol-1-phosphate synthase was the consequence of lowering the intracellular inositol concentration. Li+ treatment of Neurospora crassa has effects similar to those of P.I.-658.

13C NMR study of actinoidins: carbohydrate moieties and their glycosidic linkages.

The configuration of the glycosidic linkages and the conformation of the carbohydrate moieties in the molecules of the glycopeptide-type antibiotics actinoidins A and B (1a, 1b) have been determined by means of two-dimensional 13C/1H correlation NMR technique and with the application of model compounds 2-4.

Synthesis of hypolipidemic silybin analog 3',4'-ethylenedioxyflavonoids.

For pharmacological investigation various types of silybin analogues have been synthesized. According to the results of preliminary tests, many of the prepared benzodioxane analogues of chalcones, chalcone epoxides, isoflavones, flavanones and aurones possessed hypolipidemic activity.

Synthesis, antibacterial and antifungal activity of 4-hydroxycoumarin derivatives, analogues of novobiocin.

3-Acylamino-, -arylsulfonylamino-, -(N'-arylureido)-, -arylideneamino- and -arylcarbamoyl-4-hydroxycoumarins have been synthesized and tested for antibacterial and antifungal activity. 3-Arylcarbamoyl-4-hydroxycoumarins have been shown to possess significant activity against Gram-positive bacteria; 3-acylamino-4-hydroxycoumarins have moderate antibacterial and antifungal effects whereas the additional compounds are inactive.

High performance liquid chromatography (HPLC) of antibiotics of vancomycin type. Comparative studies.

Comparative HPLC examination of seven antibiotics of vancomycin type has been undertaken. Investigation has shown that on column I in eluent system B, ristomycin A (ristocetin A) can be not only separated from vancomycin, but both antibiotics can be quantitatively determined. Under these conditions the lowest detectable quantities of the individual antibiotics have been also stated. By the application of this column and eluent system A, ristomycin A (ristocetin A) and the major component of the A-35512 B antibiotic complex can be readily separated from one-another and from avoparcin alpha and beta.

Structural investigation of the antibiotic ristomycin A. 13C-NMR spectral analysis of the interglycosidic linkages of the heterotetrasaccharide side-chain.

By 13C-NMR studies on Ia, IIa, IIb and IVa obtained by the chemical degradation of ristomycin A and on several synthetic model compounds it has been proved that an O-beta-D-arabinopyranosyl-(1 leads to 2)-O-alpha-D-mannopyranosyl-(1 leads to 2)-O-[alpha-L-rhamnopyranosyl-(1 leads to 6)]-D-glucopyranosyl heterotetrasaccharide moiety is connected to the aglycone of the antibiotic.

[Study of the antibiotic parvulomycin. The isolation of alpha,alpha-trehalose and L-glutamic acid]. / Issledovanie antibiotika parvulomitsina. Vydelenie al'fa,al'fa-tregalozy i L-glutaminovoi kisloty.

A non-reducing disugar and amino acid were isolated in the studies on the structure of parvulomycin. The acid hydrolysis of the disugar revealed the presence of 2 moles of D-glucose. Acetylation of the disugar resulted in formation of octa-O-acetyl-alpha,alpha-tregalose, saponification of which resulted in formation of alpha,alpha-tregalose. Its physical parameters, i.e. melting point of the mixed sample, optical rotation, IR-spectrum coincided with those of the authentic alpha,alpha-tregalose. The isolated amino acid proved to be L-glutamic acid on thin-layer chromatography with witness and comparison of the physico-chemical properties of their hydrochlorides.

Study of the antitumoral activity of S-carbamoyl-L-cysteine derivatives in animal experiments.

The antitumoral activity of three amino acid derivatives, S-carbamoyl-L-cysteine, S-ethyl-carbamoyl-L-cysteine, and S-chloroethyl-carbamoyl-L-cysteine, was studied. The ethyl and chloroethyl derivatives had a pronounced curative effect on certain animal tumors. It is interesting in the case of S-carbamoyl-L-cysteine that N-ethylization of the substance resulted in increased chemotherapeutic effectivity with no simultaneous change of the toxicity. According to various studies this effect is different in many respects from that of the known cytostatics, and a possibility of a specific selective or surface activity is raised.

Structural investigation of the antibiotic ristomycin A. Synthesis of ristobiose and ristotriose.

Proof is given by synthesis confirming the structure of ristobiose as 2-O-alpha-D-mannopyranosyl-D-glucose (IV) and ristotriose as O-alpha-L-rhamnopyranosyl (1 leads to 6)-O-[alpha-D-mannopyranosyl (1 leads to 2)]-D-glucose (X) which are obtained from ristomycin A upon mild acid hydrolysis. Both oligosaccharides, IV and X, have been detected for the first time as the components of an antibiotic.

[Structure of the carbohydrate moiety of actinoidins A and B]. / Stroenie uglevodnoi chasti aktinoidinov A i B

The structure of the carbohydrate moiety of actinoidins A and B was found with partial acid hydrolysis (metanolysis) of the antibiotics and their methyl derivatives and the method of periodate oxidation. Actinoidins A and B had 3 carbohydrate branches presented by the residues of monosugars of D-mannopyranose and 2, 3, 6-tridesoxy-3-amino-4-O-methyl-L-arabinopyranose(L-actinosamine) and disaccharide of 2-O-(2, 3, 6-tridesoxy-3-amino-L-arabinopyranosyl)-D-glucopyranose.