[Synthesis of dihydroquinopymaric acid conjugates with amino acids].

Synthesis of dihydroquinopymaric acid amides and their 2beta-succinyl and 2beta-phthalyl derivatives containing residues of amino acids was carried out for the first time. Antiviral properties of the compounds synthesized were investigated.

[Synthesis of olean-18(19)-ene derivatives from betulin].

The rare olean-18(19)-ene triterpenoids moradiol and moronic acid were synthesized from betulin, and their antiviral properties were investigated.

[Betulonic amides modified at the ring A by amino acids: synthesis and inhibition of influenza A virus reproduction].

The Beckman rearrangement of carboxy- and alkyloxycarbonylalkylamides of 3-hydroxyiminobetulonic acid led to derivatives of 3a-homo-4-aza-3-oxolup-20(29)-ene and 3,4-seco-2-cyanolupa-4(23),20(29)-diene. An X-ray analysis showed methyl 3-(N-acetoximino)lup-20(29)-enoate is the E-isomer. The compounds synthesized exhibited inhibiting activity toward the reproduction of flu A virus in cell culture.

[Synthesis and antiviral activity of lupane triterpenoids with modified cycle E].

A reductive transformation of the peroxide products of ozonolysis of derivatives of 3beta-O-acetyl-22(17-->28)-abeo-lupa-17(28),20(29)-diene and the subsequent intramolecular ketalization led to a compound with a trioxane fragment. This is a new approach to a skeletal modification of triterpenoid cycle E. An activity of the synthesized compounds was found toward the viruses of type A influenza and herpes simplex.

[Biological activity and pharmacological prospects of lupane terpenoids: II. Semisynthetic lupane derivatives].

The discussion of lupane triterpenoids as prospective medicinal preparations is continued, and semisynthetic triterpenoids are being discussed. Acyl derivatives that mainly exhibit high anti-HIV, antitumor, and organo-protective activities are described. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2006, vol.

[Biological activity and pharmacological prospects of lupane terpenoids: I. Natural lupane derivatives].

The biological activity of natural and semisynthetic lupane triterpenoids is discussed in a two-part review. The first part is devoted to the pharmacological properties of natural lupane triterpenoids. Betulinic acid has proven to be the most effective antitumor agent among more than fifty natural lupanes.

[Synthesis and antiviral activity of amides and conjugates of betulonic acid with amino acids].

Betulonic acid amides with aliphatic and heterocyclic amines and with L-amino acids were synthesized by the acid chloride method. Betulonic acid amide and L-methionine derivatives of betulonic acid and its 3-oxime effectively inhibit the influenza A virus. Betulonic acid octadecylamide is active against the herpes simplex type 1 virus.

[Synthesis and antiviral activity of ureides and carbamates of betulinic acid and its derivatives].

Ureides and carbamates of betulinic acid and its derivatives were prepared in good yields by interaction of betulinic acid, betulonic acid, and betulonic acid 3-oxime with amines, amino acids, and alcohols. Ureides of betulonic acid containing L-Val and L-Met residues were found to be effective against herpes simplex type 1 virus. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2003, vol.

[Study of pharmacological properties of betulin bishemiphthalate].

The results of pharmacological tests showed that betulin bishemiphthalate possesses hepatoprotector, antioxidant, and immunotropic properties. Administered in combination with hydroxymethyluracil, that betulin bishemiphthalate prevented the loss of experimental animals upon irradiation.

Lupane triterpenes and derivatives with antiviral activity.

Betulin and betulinic acid have been modified at the C-3 and C-28 positions and the antiviral activity of derivatives has been evaluated in vitro. It was found that simple modifications of the parent structure of lupane triterpenes produced highly effective agents against influenza A and herpes simplex type 1 viruses.

[Synthesis and antiviral activity of hydrazides and substituted benzalhydrazides of betulinic acid and its derivatives].

New nitrogen-containing derivatives of betulinic and betulonic acids, hydrazides and N'-benzalhydrazides, were synthesized. Their antiviral activities toward of influenza A virus, herpes simplex type I virus, enterovirus ECHO6, and HIV-1 were studied in vitro. Betulinic acid 3-oxime was found to have the highest activity against the influenza virus.

Antiviral activity of betulin, betulinic and betulonic acids against some enveloped and non-enveloped viruses.

Antiviral properties of betulin, betulinic and betulonic acids were investigated in cell cultures infected with herpes simplex type I, influenza FPV/Rostock and ECHO 6 viruses. All studied triterpenes were active against herpes simplex virus. Betulin and especially betulinic acid also suppressed ECHO 6 virus reproduction.

Glycals in the stereoselective synthesis of triterpene 2-deoxy-alpha-L-glycosides under conditions of acidic catalysis.

3beta-Hydroxy triterpenes of the oleanane, ursane, and lupane types were successfully glycosylated with acetylated L-glucal and L-rhamnal under conditions of acidic catalysis (anhydrous cation-exchange resin and LiBr). The 2-deoxy- and 2, 6-dideoxy-alpha-L-arabino-hexopyranosides (1-5) were stereoselectively prepared in 83-90% yields, following deacetylation under mild conditions, which led to the target triterpene 2-deoxy-alpha-L-glycosides (6-10).

[Synthesis of the lupane group triterpenoids and there hepatoprotective activity].

Hemisuccinates, hemiphthalates, acetylsalicylates, cinnamates, and p-methoxycinnamates of lupeol, betulin, and 3-O-acetylbetulin were synthesized via interaction with corresponding acid anhydrides or acid chlorides. A number of betulin esters in position 3 and 28 were shown to exhibit a pronounced hepatoprotective effect similar to that of betulin and silibor. These experimental data were in a good agreement with the computer prediction of their biological activity.

[Synthesis of triterpene 2,6-dideoxy-alpha-L-arabino-hexopyranosides from L-rhamnal. Their pharmacological properties].

Triterpene 2,6-dideoxy-alpha-L-arabino-hexopyranosides were synthesized by the glycosylation of oleanane triterpene alcohols with L-rhamnal acetate in the presence of cationite KU-2-8 and lithium bromide. 2,6-Dideoxy-alpha-L-arabino-hexopyranosides of allobetulin and methyl glycyrrhetinate showed pronounced antiulcerous activity; the latter also stimulated reparative skin regeneration in rats and was effective as a hepatoprotectant.

[Synthesis of triterpene 2-deoxy-alpha-D-hexopyranosides on the basis of glycals and their effect on reparative processes].

Triterpene 2-deoxy-alpha-D-hexopyranosides were synthesized by the glycosylation of oleanane triterpene alcohols with D-glucal and D-galactal acetates in the presence of di(sym-collidine)iodonium perchlorate with subsequent deiodination and deacetylation of the resulting 2-deoxy-2-iodo-alpha-D-glycosides. 2-Deoxy-alpha-D-arabino- and -lyxo-hexopyranosides of methyl glycyrrhetinate demonstrated pronounced antiulcer activity and stimulated reparative skin regeneration in rats more effectively than glycyrrhizic acid and methyluracil.