Oleanane-type glycosides from Pittosporum tenuifolium ``variegatum'' and P. tenuifolium ``gold star''

The phytochemical study of two cultivars of Pittosporum tenuifolium Banks & Sol. ex Gaertn, ``variegatum'' and ``gold star'', led to the isolation of eight oleanane-type glycosides: seven previously undescribed and a known one. Their aglycons are oxygenated oleanane derivatives as barringtogenol C, camelliagenin A, hederagenin, and 22 alpha-hydroxyoleanolic acid. Their structures were established by 2D NMR spectroscopic techniques and mass spectrometry as3-O-beta-D-galactopyranosyl-(1 -> 2)-[alpha-L-arabinopyranosyl-(1 -> 3)]-beta-D-glucuronopyranosyl-21-O-angeloyl-22-O-acetylbarringtogenol C, 3-O-beta-D-galactopyranosyl-(1 -> 2)-[alpha-L-arabinopyranosyl-(1 -> 3)]-beta-D-glucuronopyranosyll-21,22-di-O-angeloylbarringtogenol C, 3-O-beta-D-galactopyranosyl-(1 -> 2)-[alpha-L-arabinopyranosyl-(1 -> 3)]-beta-D-glucuronopyranosyL-22-O-angeloylcamelliagenin A, 3-O-beta-D-glucopyranosyl-(1 -> 2)-[beta-D-glucopyranosyl-(1 -> 6)]-beta-D-glucopyranosyl-22-O-[(6-0-acetyl)-beta-D-glucopyranosylIcam elliagenin A, 3-O-beta-D-galactopyranosyl-(1 -> 2)-[alpha-L-arabinofuranosyl-(1 -> 4)]-beta-D-glucuronopyranosylhederagenin 28-beta-D-glucopyranosyl ester, 3-O-beta-D-arabinofuranosyl-(1 -> 4)-beta-D-glucuronopyranosylhederagenin 28-O-beta-D-glucopyranosyl ester, 3-O-beta-D-galactopyranosyl-(1 -> 2)-[alpha-L-arabinofuranosyl-(1 -> 4)]-beta-D-glucuronopyranosyl-22 alpha-hydroxyoleanolic acid 28-O-beta-D-glucopyranosyl ester, and the known ilexoside XLIX. These results represent a significative contribution to the chemotaxonomy of the genus Pittosporum, highlighting hederagenin-type saponins as chemotaxonomic markers of R tenuifolium cultivars. (C) 2017 Elsevier Ltd. All rights reserved.