Non-quassinoid constituents from the twigs and thorns of Castela polyandra Paul A. Grieco a, *, Jalal Haddad b , Marta M. PinÄeiro-NuÂnÄez b , John C. Human c a Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA b Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA c Department of Molecular Structure Center, Indiana University, Bloomington, Indiana 47405, USA Received 1 September 1998; accepted 31 December 1998 Abstract The structures of two new constituents, a b-glycoside (1) and a steroid (2), isolated from the twigs and thorns of Castela polyandra, were established by a combination of spectroscopic and single-crystal X-ray analysis. # 1999 Elsevier Science Ltd. All rights reserved. Keywords: Castela polyandra; Simaroubaceae; twigs; thorns; quassinoids; steroids; b-glycosides; spectroscopy; X-ray crystrallography 1. Introduction Castela polyandra is one of many plant species belonging to the botanical family Simaroubaceae which has played a prominent role in folk medicine (Simao Barreiro, Das, DaSilva & Gottliebet, 1991; Grieve, 1971; Polonsky, 1968]. We have studied exten- sively the root bark (Grieco, VanderRoest & PinÄeiro- NuÂnÄez, 1995) and twigs (thorns) (Grieco, Haddad, PinÄeiro-NuÂnÄez & Human, 1998) of C. polyandra. Over a dozen quassinoids have been isolated, identi®ed and characterized. In a continuation of our work with this species, two new non-quassinoid constituents, a b- glycoside (1) and a steroid (2), have been isolated from the twigs and thorns. Their structures were determined by a combination of spectral analysis and single-crystal X-ray diraction. 2. Results and discussion The methanol extracts of the twigs and thorns of Castela polyandra aorded two new natural products, a b-glycoside (1) and a steroid (2). In addition, 15-O- acetyl-D 4,5 -glaucarubol (Grieco, Haddad, PinÄeiro- NuÂnÄez & Human, 1998), glaucarubol (Khan & Shamsuddin, 1980) and 1-epi-glaucarubolone (Grieco, Haddad, PinÄeiro-NuÂnÄez & Human, 1998) were iso- lated and identi®ed by comparison of their respective 1 H and 13 C NMR spectra with those obtained from the authentic natural materials. The structure of 1 was elucidated by a combination of 1 H and 13 C NMR spectroscopy, mass spectrometry, IR spectroscopy and X-ray crystallography. The mass spectrum and elemental analysis of 1 indicated a mol- ecular formula of C 19 H 28 O 8 . The requisite number of carbon atoms was present in the 13 C NMR spectrum. Compound 1 proved to be highly crystalline and the structure was de®nitively established by single-crystal X-ray analysis (Complete crystallographic data etc.). Compound 1, mp 248±2508C, crystallized in space group P2 1 2 1 2 1 with unit cell dimensions of a=6.718(2) A Ê , b=12.641(4) A Ê , c=22.101(7) A Ê and Z=4. The volume of the crystal was 1876.83 A Ê 3 with a density of 1.361 gcm 3 . The absolute con®guration of 1 was not determined. An ORTEP view of 1 is shown in Fig. 1. The structure of 2 was established by a combination of IR, 1 H and 13 C NMR, mass spectrometry and X- Phytochemistry 51 (1999) 575±578 0031-9422/99/$ - see front matter # 1999 Elsevier Science Ltd. All rights reserved. PII: S0031-9422(99)00060-6 * Corresponding author.