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Antitumor and antimetastatic effects of betulonic acid amides in mice with transplantable Lewis carcinoma

“…Betulinic acid derivatives differ from natural cytostatics by low toxicity and selectivity of action on tumor cells [10]. New derivatives of betulonic acid synthesized at the Novosibirsk Institute of Organic Chemistry contain fragments of long-chain amino acids and peptides at C-28 and exhibit antiviral activity relative to human immunodeficiency virus type 1 and herpes simplex virus [4,5]. Previous experiments on cultured tumor cells of human melanoma and epidermal carcinoma showed that introduction of amino acid fragments into the molecule of betulinic acid (C-29) potentiates the cytotoxic effect of this compound [9].…”

Synthesis of 30-Amino Derivatives of Lupane Triterpenoids

“…In addition to the expected 30-bromo derivatives of betulin (11) and the methyl ester of betulinic acid (12), the 30-methoxy derivatives 13 and 14, respectively, were formed. The ratio of 30-bromo derivatives 11 (12) and 30-methoxy derivatives 13 (14) depended on the reaction conditions. Thus, after 3 d of hydrolysis at room temperature, the ratios of 11 to 13 and 12 to 14 were 1:1 and 1:2, respectively, according to PMR spectra.…”

“…Increasing the hydrolysis time to 15 d gave practically the 30-methoxy derivative. The 30-bromo derivative of the methyl ester of betulinic acid (12) could not be isolated pure from the mixture so this compound was synthesized directly from the methyl ester of betulinic acid (6).…”

“…The structures of all newly synthesized compounds (2, 3a-h, 4d, [9][10][11][12][13][14] were confirmed by elemental analyses and mass and NMR spectra. Signals in the 13 C NMR spectra were assigned based on 2D spectra of 2, 3a, b, d, f, 4d, 9, 10, and 14 and the literature [10].…”