We studied cytotoxic activity of new tetranitrosyl NO-generating binuclear iron—sulfur [Fe—S] complexes containing different ligands in the molecule against tumor cells in vitro. Cytotoxic activity of the most active complex with cysteamine (CysAm) was compared with that of antitumor drug cisplatin. Caspase activation and morphological changes in cells were visualized by fluorescence microscopy. Fluorescence of active caspases 3 and 7 and changes in nuclear DNA in cells in the presence of CyAm were detected by using fluorochrome-labeled inhibitor of caspases (FLICA) and Hoechst and propidium iodide reagents. Similar cytotoxic activities of CyAm and cisplatin were demonstrated in various human tumor cell lines of different histogenesis. Therefore, a new class of NO-donating [Fe—S] complexes can provide the base of potential drugs for chemotherapy with a new mechanism of action.

Objective: to evaluate the prospects of the glycosides of indolocarbazole containing amino acid residues as potential antitumor compounds. Materials and methods. For 32 compounds by structural formulas using the methods of chemoinformatics, a number of molecular descriptors and the probability of manifestation of various types of biological activity were calculated, the cytotoxic activity was evaluated in vitro by methylthiazole tetrazolium (MTT) assay using five human tumor cell lines. Results. For the studied amino acid derivatives of glycosides of indolocarbazole, a high probability of antitumor activity with a low probability of cytotoxic activity in vitro is predicted by computer method. Low cytotoxic activity was confirmed in the MTT test on 5 cell lines. Computer methods were used to predict the mechanisms of possible antitumor activity and to calculate a number of molecular descriptors that are important for the qualification of substances as potential drugs. Conclusion. It is expedient to study the antitumor activity of amino-acid derivatives of glycosides of indolocarbazole in experiments on animals with transplanted tumors.

Осуществлен синтез и скрининг противоопухолевой активности in vitro (цитотоксичности) разнообразных кислород-, азот-, серо- и платиносодержащих производных аллобетулина, в том числе – с различным расположением двойных связей в кольцах А и В, пента- и гексациклическим кольцом А, 21-ацетил-20,28-эпокси-18 19 -урсано-изомерным циклом Е. Значимую цитотоксическую активность проявили (3R,5R)-19 28-эпокси-4,5-секо-18 -олеан-3(5)-озонид в культуре клеток меланомы MeWo и 2,3-индоло-21 -ацетил-20 28-эпокси-18 19 -урсан в культуре клеток лейкоза SR. 3S,5S-Диастереоизомер первого из них цитотоксичности не проявил.

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 (3 R ,5 R )-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 3 S ,5 S -diastereoisomer of the former compound showed no cytotoxicity.

В качестве потенциальных противоопухолевых агентов синтезированы N6-производные N12-рибозилиндоло[2,3-а]пирроло[3,4-с]карбазол-5,7-диона, в которых атом N6 пиррольной части гетероцикла включен в дипептидный остаток общей формулы >N6-(CH2)n-CO-Ala/ Ala-OMe (n = 2 или 3). Данные соединения получены путeм взаимодействия 13-метил-12-(2,3,4-три-О-ацетил-?-D-рибопиранозил)индоло[2,3-а]фурано[3,4-с]карбазол-5,7-диона с дипептидами, имеющими свободную N-концевую аминогруппу, в DMF при 130°С, при этом атом азота аминогруппы пептида замещает кислород О6 в фурановом кольце гетероцикла и встраивается в виде имидного атома азота пиррола N6. Изучена способность полученных соединений подавлять рост клеток карциномы яичников человека линии SKOV3, только производное с радикалом >N6-(СН2)3--L-Ala-ОМе проявило цитотоксическую активность с ингибирующей концентрацией IC50 = 8 мкМ.

N 6-derivatives of N 12-indolo[2,3- a ]pirrolo[3,4- c ]carbazole-5,7-dione are synthesized as potential antitumor agents. The pyrrol N 6 atom of these compounds is included into the dipeptide residue of the general formula > N 6-(CH 2 ) n -CO-Ala/βAla-OMe ( n = 2 or 3). These compounds are synthesized by the reaction in DMF at 130°C between 13-methyl-12-(2,3,4-tri- O -acetyl-β-D-ribopyranosyl)indolo[2,3- a ]furano[3,4- c ]carbazole-5,7-dione and dipeptides containing the free N -terminal amino group. The nitrogen atom of the peptide amino group replaces O6 in the furan ring and is embedded as the N 6 imide nitrogen atom of pyrrol. The ability of the compounds obtained to inhibit the growth of the SKOV3 human ovarian carcinoma cells was studied. The only derivative containing the > N 6-(CH 2 ) 3 -CO- L -Ala-OMe radical showed the cytotoxic activity with an inhibitory concentration of IC 50 = 8 μM.

N6-derivatives of N12-indolo[2,3-a]pirrolo[3,4-c]carbazole-5,7-dione are synthesized as potential antitumor agents. The pyrrol N6 atom of these compounds is included into the dipeptide residue of the general formula > N6-(CH2) (n) -CO-Ala/beta Ala-OMe (n = 2 or 3). These compounds are synthesized by the reaction in DMF at 130A degrees C between 13-methyl-12-(2,3,4-tri-O-acetyl-beta-D-ribopyranosyl)indolo[2,3-a]furano[3,4-c]carbazole-5,7-dione and dipeptides containing the free N-terminal amino group. The nitrogen atom of the peptide amino group replaces O6 in the furan ring and is embedded as the N6 imide nitrogen atom of pyrrol. The ability of the compounds obtained to inhibit the growth of the SKOV3 human ovarian carcinoma cells was studied. The only derivative containing the > N6-(CH2)(3)-CO-L-Ala-OMe radical showed the cytotoxic activity with an inhibitory concentration of IC50 = 8 mu M.

The synthesis of (7 R ,8 S )-epoxy-(13 R ,17 R )-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 (7 R ,8 S )-epoxy-(13 R ,17 R )-trioxolane derivative have anti-inflammatory and antiulcer activities in the absence of side effects.

Осуществлен синтез (7R,8S)-эпокси-(13R,17R)-триоксоланабиетиновой кислоты и методом рентгеноструктурного анализа установлена ее структура. Прогнозируемые с помощью компьютерной системы PASS антинеопластическая активность и способность индуцировать апоптоз, коррелируют с экспериментально показанной цитотоксической активностью по отношению к злокачественным клеткам линии MeWo. Результаты испытаний на животных показали, что абиетиновая кислота и ее (7R,8S)-эпокси-(13R,17R)-триоксолановое производное обладают противовоспалительной и противоязвенной активностью при отсутствии побочных эффектов.

ABSTRACT Background Lignans is one of the main group phytoestrogens, natural compounds with estrogenic activity. Data of experimental studies suggest that lignans can exhibit tumor-protective properties and inhibit tumor growth. Here we studied the effect of lignan, secoisolariciresinol (Knotolan®) isolated from new nonfood vegetable raw material (Abies sibirica) on proliferation of hormone-dependent breast cancer cells in vitro. Material and methods Knotolan® was obtained from Abies sibirica wood. Commercial enterolaktone (Sigma) was as positive control. The final concentration of Knotolan and enterolactone in samples 1000-fold surpassed the concentration of 17-estradiol (E2) and was 1 µM, because previous studies showed that higher concentrations of enterolactone produced a growth-stimulating effect in vitro. The MCF7 cells were used as test object. The number of estrogens receptors was determined by a modified radioligand method. Cells were grown in RPMI 1640 medium without phenol red and 10% FCS containing estrogens. For the experiments cells were grown in the same conditions but without estrogens. Cell proliferation in samples was measured by MTT-test. Microscope examination was performed using Axiolmager invertal microscope. Results MCF7 cells revealed 6.1 ± 0.5 3H-E2 binding sites per cells. On day 5, incubation of cells with E2 in concentration 1nM increased proliferation of MCF7 cells by 41.7%. Incubation with Knotolan® or enterolactone in concentration 1 µM for 5 days had no effect on cell proliferation. Pre-incubation with Knotolan® or enterolactone for 2 days followed by incubation with E2 did not stimulate cell proliferation. The capacity of Knotolan® to abolish the growth stimulating effect of E2, i.e. to exhibit its antiestrogen properties was similar to the effect of enterolactone. We hypothesized that this effect can be realized in vivo and Knotolan® from Abies sibirica can serve as basis for the creation of new plant preparation with protective properties. Disclosure All authors have declared no conflicts of interest.

Новые 2,3-секо-тритерпеновые амиды получены взаимодействием хлорангидрида 2,3-секо-1-циано-19 28-эпокси-18 -олеан-3-овой кислоты с первичными аминами, синтетическими и биогенными аминокислотами. Среди синтезированных азотсодержащих производных выявлен цитотоксичный тритерпеновый конъюгат с остатком этилового эфира -аланина, при 100 мкM-концентрации которого в среде выживаемость клеток меланомы составила 45.5%.

Here we present antiestrogenic effects of Knotolan ® , a new dietary lignan from Abies sibirica raw material. Knotolan abolished growth-stimulating effects of 17β-estragiol on hormonedependent MCF-7 cells.

Novel 2,3-seco-triterpenic amides were prepared by the interaction of the chloride of 2,3-seco-l-cyano-19beta,28-epoxy-18alpha-oleane-3-oic acid with primary amines and synthetic and biogenic amino acids. A cytotoxic triterpenic conjugate with a residue of the ethyl ester of beta-alanine was found among the synthesized nitrogen-containing derivatives. Treatment with this conjugate in a concentration of 100 muM resulted in the 45.5% survival of melanoma cells in the medium.

Novel 2,3-seco-triterpenic amides were prepared by the interaction of the chloride of 1-cyano-19β,28-epoxy-18α-oleane-3-oic acid with primary amines and synthetic and biogenic amino acids. A cytotoxic triterpenic conjugate with a residue of the ethyl ester of β-alanine was found among the synthesized nitrogen-containing derivatives. Treatment with this conjugate in a concentration of 100 μM resulted in the 45.5% survival of melanoma cells in the medium.

We studied the ability of lymphokine-activated killer cells to lyse A549 human non-small cell lung cancer cells after preincubation with cisplatin. Lymphokine-activated killer cells obtained after incubation of human blood lymphocytes with interleukin-2 were characterized by high expression of natural killer cell antigens and activation molecules. Lymphokine-activated killer cells produced potent cytotoxic effect on intact A549 cells and lysed tumor cells survived after treatment with cisplatin in concentrations of IC 50 and IC 30 . Cisplatin in noncytotoxic concentrations did not increase lytic activity of lymphokine-activated killer cells.

We compared cytotoxic activity of blood mononuclear leukocytes from healthy donors and lymphokine-activated killer cells generated from them towards tumor and normal cells. Lymphokine-activated killer cells exhibited higher (in comparison with blood mononuclear leukocytes) killer activity towards tumor cells. Lymphokine-activated cells and mononuclear leukocytes had no lytic effect on non-transformed eukaryotic cells. Hence, we demonstrated selective cytotoxic activity of effector cells (lymphokine-activated killers) towards tumor cells of different origin (but not normal cells).