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1. It has been established that the fragmentation of the molecular negative ions of the diacetates of sclareol and of 13-episclareol takes place with the splitting out of the fragments Ac, OAc, CH2CO, AcOH, CH3, and CH=CH2 without skeletal rearrangements. 2. The relative yields of the negative ions formed depend on the stereochemistry of the molecules of… (More)
Inclusion complexes of salicylic acid (SA) and acetylsalicylic acid (aspirin, ASA) with polysaccharide arabinogalactan (AG) from larch wood Larix sibirica and Larix gmelinii were synthesized using mechanochemical technology. In the present study, we have investigated physicochemical properties of the synthesized complexes in solid state and in aqueous… (More)
The synthesis of new betulin and ursolic acid derivatives and evaluation of their antiviral activity in vitro is reported. Betulin was modified at positions C-3, C-20 and C-28 to afford the derivatives with nicotinoyl-, methoxycynnamoyl-, alkyne and aminopropoxy-2-cyanoethyl-moieties. The two stage conversion of betulin to the new ursane-type triterpenoid… (More)
Two new triterpenoid saponins 1 and 2 were isolated from the methanol extract of the roots of Acanthophyllum gypsophiloides Regel. These saponins have quillaic acid or gypsogenin moieties as an aglycon, and both bear similar sets of two oligosaccharide chains, which are 3-O-linked to the triterpenoid part trisaccharide… (More)
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.
Derivatives of glycyrrhyzic acid (GA), a triterpene glycoside, exhibit a wide spectrum of pharmacological activity in advantageous combination with low toxicity [1 -5 ] . This article reports on the synthesis of new GA amides (II), synthesized by acylation of biogenic amines with glycyrrhyzic acid in the presence of N,N'-dicyclohexylcarbodiimide (DCHC). The… (More)
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.