1 Enzyme KHCO 3 HO H O O O OH OH HO Enzyme KHCO 3 HO OH HO H O OH OH 2 3 OH H HO OH HO O OH 1) S. Yu. Yunusov Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (99871) 120 64 75; 2) N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913, Moscow, B-334, Leninskii pr., 47. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 149-150, March-April, 2002. Original article submitted April 8, 2002. 0009-3130/02/3802-0179$27.00 2002 Plenum Publishing Corporation © 179 Chemistry of Natural Compounds, Vol. 38, No. 2, 2002 PHYTOECDYSTEROIDS OF PLANTS OF THE Silene GENUS. 2-DEOXYECDYSTERONE-25-ACETATE FROM Silene wallichiana N. Z. Mamadalieva, Z. Saatov, UDC 547.926 1 1 V. V. Kachala, and A. S. Shashkov 2 2 The new ecdysteroid 2-deoxyecdysterone-25-acetate was isolated from roots of Silene wallichiana Klotzsch. Key words: ecdysteroids, 2-deoxyecdysterone, 2-deoxyecdysterone-25-acetate, 5α-2-deoxyecdysterone. In continuation of the study of ecdysteroids of Silene wallichiana Klotzsch [Oberna wallichiana (Klotzsch) Ikonn., Caryophyllaceae] [1], we isolated a new ecdysteroid (1) from its roots. The IR spectrum of 1 has absorption bands for hydroxyls (3378 cm ) and an α,β-unsaturated ketone (1640 cm ) in -1 -1 addition to bands at 1721 and 1255 cm , which are indicative of an ester. This is supported by the presence in the PMR -1 spectrum of 1 of a 3H singlet at δ 1.95 ppm (Table 1). The mass spectrum of 1 lacks a peak for the molecular ion M at m/z 506 and contains peaks for products of successive + dehydration of the molecular ion at 410, 395, 392, and 377 together with fragments at 332, 285, 284 (fragments of the steroid core), 144, 99, 81, and 69 (fragments of the side chain). This indicates that 1 is a 2-deoxyecdysteroid with an acetyl in the side chain [2]. Base hydrolysis of 1 gives 2-deoxyecdysterone (2) and ecdysteroid 3, which was identified as 5α-2-deoxy- ecdysterone [1]. Enzymatic hydrolysis of 1 using total enzymes from Baker's yeast [3] gave 2-deoxyecdysterone (2) [4]. Comparison of the PMR spectra of 1 and 2 show a significant difference only for the positions of signals for the 26/27 methyls, which shift to weak field. The C NMR spectra of 1 and 2 are practically identical with the exception of the signals 13 for C-24, C-26, and C-27, which are observed at weaker field for the former, and the signal for C-25, at strong field (Table 1) [5]. The spectral data (IR, H and C NMR) indicate that the acetyl is located on the C-25 hydroxyl [6]. 1 13 An analogous weak-field shift occurs for viticosterol E [7] and integristerone A 25-acetate [8]. Therefore, we conclude that 1 is 2-deoxyecdysterone-25-O-acetate.