Two New Disulfated Triterpenoids from Zygophyllum fabago by Saleha S. Khan a ), Afsar Khan b ), Amir Ahmed a ) d ), Viqar U. Ahmad* a ), Umar Farooq b ), Saima Arshad a ), Sadia Bader a ), Aqib Zahoor a ), Imran N. Siddiqui a ), Bilge Sener c ), and Nurgun Erdemoglu c ) a )H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan (phone: þ 92-21-34819020; fax: þ 92-21-34819018-9; e-mail: vuahmad@hotmail.com) b )Department of Chemistry, COMSATS Institute of Information Technology, Abbottabad-22060, Pakistan c )Department of Pharmacognosy, Faculty of Pharmacy, Gazi University, Ankara-06330, Turkey d ) Pharmaceutical Division, Pakistan Council of Scientific and Industrial Research Laboratories Complex, Karachi 75280, Pakistan From the aerial parts of Zygophyllum fabago, two new monosodium salts of sulfated derivatives of ursolic acid, along with two known quinovic acid glycosides were isolated. The structures of the new compounds were determined as (3b,4a)-3,23,30-trihydroxyurs-20-en-28-al 3,23-di(sulfate) sodium salt (1 : 1) (1) and of (3b,4a)-3,23,28-trihydroxyurs-20-en-30-yl b-d-glucopyranoside 3,23-di(sulfate) sodium salt (1 : 1) (2) with the molecular formula C 30 H 47 NaO 10 S 2 and C 36 H 59 NaO 15 S 2 , respectively. The structures of the known compounds were 3-O-(2-O-sulfo-b-d-quinovopyranosyl)quinovic acid 28-b-d-glucopyr- anosyl ester ( 3) and 3-O-(b-d-glucopyranosyl)quinovic acid 28-b-d-glucopyranosyl ester (4) (quinovic acid ¼ (3b)-3-hydroxyurs-12-ene-27,28-dioic acid). The structures of all these compounds were determined by using 1D- and 2D-NMR spectroscopic techniques. Introduction. – Chemical studies carried out on the family Zygophyllaceae have revealed the occurrence of important secondary metabolites such as sulfated triterpenoid saponins [1]. In an ongoing search for the bioactive compounds from Zygophyllaceae plants, the EtOH extract of Zygophyllum fabago was selected for investigation. From previous studies, several unusual disulfated ursane derivatives with a double bond at C(20)¼C(21) have been reported which might have good potential in various biological activities. Compounds isolated in the present study include the two new disulfated triterpenoids 1 and 2, as well as two known compounds 3-O-(2-O-sulfo- b-d-quinovopyranosyl)quinovic acid 28-b-d-glucopyranosyl ester (¼ zygophyloside E; 3) [2] and 3-O-( b-d-glucopyranosyl)quinovic acid 28-b-d-glucopyranosyl ester (¼ guettarda saponin II; 4) [3] (quinovic acid ¼ (3b)-3-hydroxyurs-12-ene-27,28-dioic acid). Results and Discussion. – Compound 1 was isolated as a white amorphous powder. Its molecular formula was determined as C 30 H 47 NaO 10 S 2 on the basis of HR-FAB-MS which showed the quasi-molecular-ion peak at m/z 653.2435 ([ M  H]  ). The IR spectra of 1 showed absorption bands for OH groups (3408 cm 1 ), CH stretch (2925 cm 1 ), an aldehyde C¼O (1710 cm 1 ), an olefinic bond (1627 cm 1 ), and a band Helvetica Chimica Acta – Vol. 93 (2010) 2070  2010 Verlag Helvetica Chimica Acta AG, Zürich