Materials, Methods & Technologies ISSN 1314-7269, Volume 12, 2018 Journal of International Scientific Publications www.scientific-publications.net Page 137 SYNTHESIS AND SPECTRAL CHARACTERIZATION OF NEW SALVADORICINE ANALOGUES Yordan Stremski 1 , Stela Statkova-Abeghe 1 , Iliyan Ivanov 1,2 , Mladen Naydenov 3 1 University of Plovdiv “Paisii Hilendarski”, Department of Organic Chemistry, 24 Tzar Asen Str., Plovdiv 4000, Bulgaria 2 University of Plovdiv “Paisii Hilendarski”, Branch-Smolyan, 32 Dicho Petrov Str., Smolyan 4700, Bulgaria 3 University of Plovdiv “Paisii Hilendarski”, Department of Human Anatomy and Physiology, 24 Tzar Asen Str., Plovdiv 4000, Bulgaria Abstract Salvadoricine is an indole alkaloid isolated from the leaves of Salvadora persica Linn. This natural product has interesting and diverse biological profile. An effective one-pot synthesis of Salvadoricine analogues via multicomponent reaction of α-amidoalkylation is proposed. The conditions for the reaction of benzothiazole, alkyl chloroformates and 3-acetylindole were found. The structure of the obtained in good yields analogues of natural alkaloid - Salvadoricine was proved by spectral methods. Keywords: Salvadoricine, Benzothiazole derivatives, α-amidoalkylation, multicomponent reactions 1. INTRODUCTION Salvadora Persica Linn (Miswak) is an evergreen tree one of the most frequently mentioned plants in Islamic literature [1] due to the diverse profile of the biologically active components contained therein [2, 3]. The chemical analysis of S. persica shows the content of a total of 19 natural substances which are applicable in dentistry [4]. Aqueous and alcoholic extracts from different parts of the plant exhibit a variety of biological activities including antimicrobial, antioxidant, antitumor, anticonvulsant, antihyperglycemic, anti-inflammatory etc. [5, 6]. Indole alkaloid Salvadoricine (Fig. 1) was first isolated in 1987 from the leaves of the tree Salvadora Persica Linn by initial extraction with 1% sulfuric acid in ethanol and subsequent treatment of the distillate with ethyl acetate [7]. Salvadoricine - (2-acetyl-3-methyl indole) shows activity in the treatment of various dental diseases, scurvy, rheumatism, etc. It has been found to exhibit antibacterial activity against several pathogenic cariogenic bacteria of the teeth [8]. The preparation of the alkaloid in vitro was described in 2011 [4]. Fig. 1. Salvadoricine Several methods for the synthesis of Salvadoricine are described in the literature including decarboxylation of 2-acylindol-3-acetic acid [9], direct Friedel-Crafts acylation of 3-methylindole in the presence of Lewis acids [10, 11] and intramolecular McMurry cyclization [12]. In connection with our interest in the synthesis of new indole derivatives via multicomponent reactions of α-amidoalkylation [13], a new approach for the synthesis of structural analogues of this alkaloid is proposed.