O. B. Kazakova

Betulin and ursolic acid synthetic derivatives as inhibitors of Papilloma virus

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 by treatment of allobetulin with Ac(2)O-HClO(4) is suggested. Cyanoethylation of ursonic acid oxime led to cyanoethyloximinoderivative. According to the results of antiviral screening against human papillomavirus type 11 the selectivity index for tested triterpenoids has a range from 10 to 35 with no cellular cytotoxicity, the most remarkable activity was found for 3beta,28-di-O-nicotinoylbetulin. 3Beta,28-dihydroxy-29-norlup-20(30)-yne was also active against HCV replicon (EC(50) 1.32; EC(90) 16.82; IC(50) 12.41; IC(90) >20; SI(50) 9.4; SI(90) >1.19). 28-O-methoxycynnamoylbetulin was active against influenza type A virus (H1N1) (EC(50) 2; IC(50) >200; SI >100).

Synthesis, structure, and pharmacological activity of (7r,8s)-epoxy-(13r,17r)-trioxolane abietic acid

The synthesis of (7R,8S)-epoxy-(13R,17R)-trioxolane abietic acid was carried out and its structure was established by X-ray diffraction. The antineoplastic activity and the ability to induce apoptosis that were predicted by a PASS computer system, correlate well with the experimentally found cytotoxic activity towards the MeWo malignant cell line. The results of tests on animals showed that abietic acid and its (7R,8S)-epoxy-(13R,17R)-trioxolane derivative have anti-inflammatory and antiulcer activities in the absence of side effects.

Synthesis, modification, and antimicrobial activity of the N-methylpiperazinyl amides of triterpenic acids

N-methylpyperazinyl amides of betulinic, platanic, glycyrrhetic, oleanolic, ursolic, and moronic acids were synthesized and modified. Betulin and betulonic acid showed antimicrobial activity against Staphylococcus aureus at a concentration of 90 mg/ml, and betulin manifested a bacteriostatic effect against Klebsiella pneumoniae at a concentration of 60 mg/ml. Among the studied N-methylpyperazinyl amides, the highest activity against S. aureus was observed for a betulonic acid derivative.

Synthesis and pharmacological activity of amides and the ozonolysis product of maleopimaric acid

The synthesis of a new group of maleopimaric acid amides containing fragments of methyl ethers of amino acids, aliphatic amines, imidazole, and N-methylpiperazine was carried out. The ozonolysis of methylmaleopimarate occurs via the cleavage of the double bond C18(19) and the opening of an anhydrous ring with the formation of secotriacid. As a result of the screening of the anti-inflammatory and antiulcer activity of maleopimaric acid derivatives, new effective compounds such as maleopimaric acid and its methyl ether, a product of ozonolysis—diterpenic secotriacid—and maleopimaric acid amide with L-leucine were found. An important advantage of the studied compounds is the low toxicity and the presence of bidirectional activity in the absence of adverse effects on the animal.

Synthesis and cytotoxicity of triterpene seven-membered cyclic amines

Abstract3-Deoxy-3a-homo-3a-aza derivatives of betulin and erythrodiol have been synthesized from betulonic and oleanonic acids. 3-Deoxy-3a-homo-3a-aza-28-hydroxy-12(13)-oleanene showed the highest antineoplastic activity of the broad spectrum in vitro; the results of an extensive examination of the derivative in vitro enable one to recommend it for in vivo tests. The modification of the compound in the position C28 by the introduction of a methoxycinnamoyl fragment led to the loss of the antineoplastic activity. As a whole, 3-deoxy-3a-homo-3a-aza derivatives of betulin [3-(aminopropyl)-, 28-(2-carboxyethyl)carboxy-, and 28-cinamoyloxy-] exhibited a moderate antineoplastic activity toward large intestine cancer, breast cancer, and leukemia cells.

Synthesis and antitumor activity of aminopropoxy derivatives of betulin, erythrodiol, and uvaol

Aminopropoxy derivatives of betulin, erythrodiol, uvaol, and oleantriol have been synthesized by the cyanoethylation of the hydroxyl groups of triterpenoids with the subsequent reduction of cyanoethyl fragments. It has been found that 3β,28-di-O-[3-(aminopropoxy)]lupa-20(29)-ene and 3β-O-hydroxy-28-O-[3-(aminopropoxy)]olean-12-ene possess high in vitro antitumor activity toward a wide range of human tumor cell lines. It has been shown that the aminopropoxy fragment is a novel promising pharmacophore group in the synthesis of anticancer agents based on triterpenoids.

The synthesis and anti-inflammatory activity of quinopimaric acid derivatives

Under the action of PCl5, the Beckman rearrangement of a 3: 1 mixture of Z- and E-isomeres of 18β-hydro-xydihydroquinopimaric acid resulted in 5′-caprolactam and isomeric caprolactams containing fragments of cyclic ether. Z- and E-ketoximes were separated as acetates. Using a carrageenan inflammation model, we demonstrated that the anti-inflammatory activity of quinopimaric acid derivatives was comparable with that of diclofenac.

Anomalous ozonolysis product of 3β,28-di-O-acetyl-29-norlupan-20-one-O-methyloxime

Ozonolysis of 3β,28-di-O-acetyl-29-norlupan-20-one-O-methylketoxime in the presence of ketones was used as an example to show that secondary ozonides at the C20 position of betulin are unstable and decompose to form the “anomalous product” methyl-3β,28-di-O-acetyl-29,30-bisnorlupan-20-oate, the structure of which was proved by an x-ray crystal structure analysis.

Synthesis and anticancer activity of aminopropoxytriterpenoids

Triterpenoids with aminopropoxy groups in C-28 or C-3 and C-28 positions were synthesized from betulin, erythrodiol, uvaol, oleantriol and betulinic acid N-methylpiperazinylamide by cyanoethylation and the following catalytic hydrogenolysis. Computational estimating activity spectra of the designed compounds pointed out on their probable antineoplastic and proapoptotic activities. Their in vitro cytotoxic activity was evaluated at the National Cancer Institute, USA. Aminopropoxy derivatives of betulin, erythrodiol and oleantriol demonstrated the highest cytotoxic activity toward the most of 60 used tumor cell lines. Bisaminopropoxyerythrodiol revealed in vivo significant antineoplastic activity toward five mouse solid transplantable tumors. The results of in silico investigations and the efficacy of compounds in a broad panel of cell lines in vitro and the activity of bisaminopropoxyerythrodiol on the in vivo tumor models strongly suggest aminopropoxytriterpenoids as promising compounds for further investigation as anticancer agents.Graphical Abstract

Synthesis and cytotoxicity of allobetulin derivatives

A variety of oxygen-, nitrogen-, sulfur-, and platinum-containing allobetulin derivatives, including those with different positions of double bonds in rings A and B, the penta- and hexacyclic ring A, and the 21-acetyl-20,28-epoxy-18α,19βH-ursanoisomeric cycle E, have been synthesized, and the screening of their antineoplastic activity in vitro (cytotoxicity) has been carried out. A significant cytotoxic activity was exhibited by (3R,5R)-19β,28-epoxy-4,5-seco-18α-olean-3(5)-ozonide toward MeWo melanoma cells and by 2,3-indolo-21β-acetyl-20β,28-epoxy-18α,19βH-ursane toward SR leukosis cells. The 3S,5S-diastereoisomer of the former compound showed no cytotoxicity.