790 0009-3130/18/5404-0790  2018 Springer Science+Business Media, LLC Chemistry of Natural Compounds, Vol. 54, No. 4, July, 2018 LUPANE AND URSANE-TYPE TRITERPENOIDS FROM Pergularia tomentosa Halima S. Al Hinai, 1 Wafaa M. Al-Subhi, 1 Fatma Rashid S. Al-Rubaiai, 1 Syed I. Hassan, 1 Neelam Sherwani, 2 and Majekodunmi O. Fatope 1* Pergularia tomentosa L. (Apocynaceae) grows naturally as a perennial twining herb with much milky latex in semi-arid zones of the Sahel and Arabian Peninsula where preparations from its root and shoot are used to treat skin diseases and other ailments [1]. It is a member of the subfamily Asclepiadoideae [2] and is often classified as a toxic plant that causes spasm and gastroenteritis when eaten [3]. P. tomentosa showed antitumor [4], molluscicidal [5], and hypoglycemic [6] properties. Cardenolides [4, 7] and taraxasterol-type triterpenes [8] have been isolated from the root and leaf. The cardenolides and alkaloids pergularinine and tylophorinidine are responsible for the cytotoxic, antitumor, and antimicrobial properties [7, 9] of the Asclepiadaceous plants. In this paper we report lupane 1, ursane triterpenoids 2 and 3, and a triacylglycerol (4) as new analogues from this plant, along with stigmast-5-en-3-O--glucoside ( 5). The stem of P. tomentosa was collected from the plant growing in Al-Rusayl Muscat near the armed forces hospital in September 2015. The plant was identified by comparison with a voucher specimen previously deposited at the herbarium of Biological Sciences Department at Sultan Qaboos University. The air-dried powdered stem of P. tomentosa (1 kg) was extracted sequentially by maceration with petroleum ether (7.5 L  2), EtOAc (7.5 L  2), and EtOH (7.5 L  2), each for one week, to afford 33.5 g residue of petroleum ether, 64.0 g of EtOAc, and 4.2 g of EtOH extract, respectively. The EtOAc extract (15.8 g) was purified on silica gel (120 g) and eluted using gradients of Me 2 CO in hexane as mobile phase to give fractions 1–30. Fraction 10 (10.6 g) eluted with petroleum ether– Me 2 CO (9:1) had a distinctive ester smell. It was further purified on silica gel (120 g), eluting with gradients of CHCl 3 in petroleum to give fractions 10-1–10-44. Fraction 10-22 gave 20.9 mg of 3-O-acetyl lupeol (1) [10], with R f 0.85 (CHCl 3 –hexane, 1:3), and fraction 10-15 gave 11.27 mg of 3-O-acetyl--amyrin (2), R f 0.47 (CHCl 3 –hexane, 1:3). A portion of fraction 12–14 (63.0 mg, yellowish brown semisolid) gave 6.0 mg of triacylglycerol (4) [11] after purification by prep TLC. The MALDI-TOF mass spectral data revealed the molecular formula C 56 H 96 O 6 for compound 4. The ion peak at m/z 886.690 amu [M + Na] + confirmed the presence of a C 3 glyceryl substructure and two C 18 and one C 17 fatty acyl groups in compound 4. The peaks at m/z 638.451 and 378.416 resulted from loss of the C 17 fatty acyl group at  (2) from [M + Na] + and C 18 fatty acyl group at  (1 or 3) from the resulting daughter ion. The EtOH extract (4.2 g) was loaded on silica gel (20 g) and eluted with hexane, CHCl 3 , EtOAc, and EtOAc–EtOH (9:1) in that order. The fraction eluted with EtOAc afforded a white solid (6.6 mg) of stigmast-5-en-3-O--glucoside (5) [12] after trituration with Me 2 CO, CHCl 3 and EtOAc. The petroleum ether fraction (11.9 g) was also loaded on silica gel (120 g) and eluted with gradients of Me 2 CO in hexane to give fractions PT-1–PT-24. Fraction PT-10 (3.2 g) was purified on silica gel (40 g) using gradients of CHCl 3 in hexane as mobile phase to afford fractions PT-10-1–PT-10-56. Fractions PT-10-41–PT-10-44 gave 11.2 mg of compound 3 [10], R f 0.07 (hexane–CHCl 3 , 3:2). Compounds 1–3 are low-level oxidation triterpenes and are reported for the first time from P. tomentosa. In contrast to the leaf and root, the stem of the plant is rich in triterpenoids. 1) Department of Chemistry, College of Science, Sultan Qaboos University, P. O. Box 36, Postal Code 123, Al Khod, Muscat, Oman, e-mail: majek@squ.edu.om; 2) Department of Biology, College of Science, Sultan Qaboos University, P. O. Box 36, Postal Code 123, Al-Khod, Muscat, Oman. Published in Khimiya Prirodnykh Soedinenii, No. 4, July–August, 2018, pp. 668–669. Original article submitted November 22, 2016. DOI 10.1007/s10600-018-2477-x