Research Articles

2017  |  Vol: 2(1)  |  Issue: 1(Jan-Feb)
Cytotoxic activity of the cycloorbicoside A and its derivatives

Manzura A. Agzamova, Isa M. Isaev

Institute of the Chemistry of Plant Substances named after S. Yu. Yunusov.

Uzbekistan Academy of Sciences. Tashkent

fax (99871) 120 64 75

Address for Corresponding Author

Manzura A. Agzamova

Institute of the Chemistry of Plant Substances named after S. Yu. Yunusov.

Uzbekistan Academy of Sciences, Tashkent.

fax (99871) 120 64 75

Abstract. Cycloorbicoside A, С35Н56О9– cycloartane glycoside being the main component in the plant Astragalus orbiculatus. Сycloorbicoside A and its synthetic derivatives were tested for cytotoxic activity. Materials and Methods: Verified cultures of cancer cells of cervical carcinoma (HeLa) and mouse myeloma cells (P3X) were utilized to determine the cytotoxic activity of glycosides; studies conducted by the MTT-Test*. Results: Further evaluation of cytotoxic activity of five compounds has shown significant activity against HeLa and P3X cells of compounds and 5.

Key words: Astragalus orbiculatus, cycloartane glycosides, cytotoxic, cervical carcinoma (HeLa) and mouse myeloma cells (P3X)


The flora of Uzbekistan is rich with plants which contain biological valuable metabolites. It is found that the plants of extensive genus Astragalus (Leguminosae) produce cycloartane metylsteroids. In the world flora there are more than 2200 species of this plant, and in the flora of Uzbekistan this genus is represented by 254 species.

Cycloartane metylsteroids and glycosides possess pharmacological properties, such as cardiotonic (Tsaruk et al., 2010b; Khushbaktova et al., 1990; Khushbaktova et al., 1994), cholesterol-lowering, antihypertensive, interferon-inducing activities. A variety of chemical structures, high physiological activity and therefore possibility of creating different drugs on the basis of these compounds attract the attention of chemists and pharmacologists and study on Astragalus orbiculatus Ledeb. (Ledebur K.F.) is the objective of our study.

Plants containing cycloartane triterpenoids and glycosides, have been widely used in traditional medicine for treating various diseases. Some representatives of this plants have hypolipedemic, hypotensive, diuretic, anti-inflammatory, sedative, analgesic, immunostimulation, cardiotonic activities. Medicines on the basis of biologically active substances of Astragalus sieversianus have hypoholesterinimic activity, and due to this improve heart function, effecting the normalization of lipid metabolism. Some of compounds exhibit antitumor activity.

Glycosides of Astragalus membranaceus Bunge inhibit the formation of lipid peroxides in human and animal organisms. Some glycosides have an inhibitory effect on the central nervous system.

Materials and methods

Сycloorbicoside A (1) is the main component in the plant Astragalus orbiculatus. We carried out chemical modifications of the genin part of this glycoside, maintaining the carbohydrate component. The aim of our investigation is to create biologically active substances to determine the structure-activity relationships (Khan et al., 2006).

We carried out the synthesis of protected synthons, utilizing acetylation as the protection for secondary hydroxyl groups (Isaev et al., 2010).

Figure 1. Сycloorbicoside A (1) and its synthetic derivatives (2-5), tested for cytotoxic activity


On the basis of Сycloorbicoside A 1 which is the main glycoside of plant Astragalus orbiculatus we created derivatives 2-5, to study their biological activity. Earlier we have studied cytotoxic activity of compounds, isolated from A.orbiculatus (Agzamova et al., 2014). In this study we tested the derivatives of Сycloorbicoside A.

Cytotoxic activity of Compounds 1-5 was studied using published methods [Mosmman T]. The cells of cervical carcinoma HeLa and mouse myeloma P3X were grown in humidified atmosphere of 5% СО2 in air and fed with the culture medium supplemented with 10% fetal bovine serum and 1% penicillin - streptomycin solution and 1 mM sodium pyruvate. The MTT assay was used to measure the cytotoxicity of Compounds 1-5 in concentrations of 6.25-200 µM on cells of cervical carcinoma HeLa and mouse myeloma P3X.

No treated culture cells were used as a negative control. Briefly, 1x104 cells were seeded into 96-well plate in triplicate, and a series of drugs was added into the wells at the indicated final concentrations after 6 h. After incubation with drugs for 24 h, the medium in each well was replaced with 100 μL DMEM (Dulbecco's modified Eagle's medium) of MTT (3-[4,5-dimethylthiazol-2-yl]-2,3-diphenyltetrazodium bromide) to 5 mg/mL final concentration DMSO (150 μL /well) was added to dissolve the formed violet formazan crystals within metabolically viable cells after 4 h. The plates were incubated at 37 °C for 15 min and then read at 590nm with a microplate reader. The percent of growth inhibition was calculated as

PI= (OD of control – OD of samples)/ OD of control x100.

IC50was calculated at the concentration µM of compounds causing a 50% inhibition of cell viability.

Results and discussion

Cytotoxic activity of the compounds was determined by the percentage of reduction of color in the control samples at 590 nm. Results are listed in Table 1.

Table1. Cytotoxic activity of compounds 1-5 IC50 (µM)

S. No.


P3X IC50(µM)

HeLa IC50(µM)






Cycloorbicoside A

1-Ac-Cycloorbicoside A

4-Ac-Δ25-Cycloorbicoside A

1-Ac-Δ25-Cycloorbicoside A

Δ25-Cycloorbicoside A











*Experiments on cytotoxic activity conducted by Mamadalieva N. in Tuscia University, at the Environmental Sciences department (Viterbo, Italy)

Our researchers in the Institute of Chemistry of Plant Substances in Uzbekistan have determined the effect of Cycloorbicoside G on metabolic processes in the myocardium of rats (Tsaruk et al., 2010b). Сycloartane glucosides possess cardiotonic activity and have several advantages over cardenolides due to the lack of toxicity and cumulative effects (Khushbaktova et al., 1990; Khushbaktova et al., 1994). Cycloorbicoside A and Askendoside D have distinct interferon inducing activities. Cyclosieversioside F exhibit antioxidant, immunostimulating, hepatoprotective effects and also has an effect on the blood clotting system (Tsaruk et al., 2010a). Askendoside D and Cyclosieversioside F induce hypoglycemic effect in the tests on experimental animals with endogenous hypercholesterinemia.

Cycloorbicoside A from the Astragalus orbiculatus аnd its derivatives have been screened on cytotoxic activity on the cancer cells of cervical carcinoma (HeLa) and mouse myeloma cells (P3X). Compounds 4 and 5 have showed significant activity against HeLa and P3X cells comparing to cycloorbicoside A and its other synthetic derivatives.


Agzamova MA, Isaev IM, Terentyeva EO. 2014. Triterpene glycosides of Astragalus orbiculatus, and their biological activity. International scientific-practice conference «Pharmaceutical education, science, production, October 23-24, J. Vestnic South-Kazakhstan state Pharmaceutical Academy, 4(3): 16-19.  

Isaev IM, Agzamova MA, Isaev MI. 2010. Triterpene glycosides of Astragalus and their genins. LXXXVI. Chemical transformation of cycloartanes. YIII. Syntesis on the basis of cycloorbicosid A. Chemistry of Natural Compounds, 46(3): 600-608.

Khan MTH, Choudhary MI, Atta-ur-Rahman, Mamedova RP, Agzamova MA, Sultankhodzhaev MN, Isaev MI. 2006. Tyrosinase inhibition studies of cycloartane and cucurbitane glucosides and their structure– activity relationships. Biological & Medicinal Chemistry, 14: 6085-6088.

Khushbaktova ZA, Agzamova MA, Syrov VN, Radchenko NV, Mirsalikhova NM, Umarova FT. 1994. Influence of Cyloartanes from plants of the genus Astragalus and their Synthetic Analog on the Contractive Function of the Myocardium and the Activity of Na, K-ATPase. Khim. Prir. Soedin, 4: 510-514. Chem. Nat. Comp. (Engl. trans.), 31 (4): 469-473.

Khushbaktova ZA, Syrov VN, Agzamova MA, Isaev MI. 1990. Influence of cycloarthanic glycosides of Astragalus on myocard contractility. XI International congress of pharmacology. Amsterdam, the Netherlands, 3 July. European journal of Pharmacology, 183.

Tsaruk AV, Isaev IM, Agzamova MA, Vypova NL, Khushbaktova ZA, Syrov VN, Isaev MI. 2010a. Study of cyclosieversioside F action on the system of blood clotting. Uzbek Biological Journal, 5: 10-12.

Tsaruk AV, Iskenderov DA, Agzamova MA, Khushbaktova ZA, Syrov VN, Isaev MI. 2010b. Isolation and influence of cycloartane glycosides Cycloorbicoside G and Cyclosieversioside A on metabolic processes in myocardium. Journal of Pharmaceutical Chemistry, 44(1): 10-13.

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