Intrapilosins I-VII, pentasaccharides from the seeds of Ipomoea intrapilosa.

Purification of a CHCl3-soluble extract from seeds of the Mexican medicinal arborescent morning glory, Ipomoea intrapilosa, by means of preparative-scale recycling HPLC, yielded seven new resin glycosides, intrapilosins I-VII (1-7). Their structures were established through the interpretation of their NMR spectroscopic and FABMS data. All pentasaccharides were found to be macrolactones of the known operculinic acid A with different fatty acids esterifying the same positions: C-2 on the second rhamnose unit and C-3 and C-4 on the third rhamnose moiety. The lactonization site of the aglycon could be placed at C-2 of the second saccharide. The fatty acid components of 1-7 were identified as (+)-(2S)-methylbutanoic, octanoic (caprylic), dodecanoic (lauric), and trans-cinnamic. The less common (-)-(2R)-methylbutanoic acid was also isolated as one of the saponification-liberated residues from intrapilosin IV (4). The presence of the (2R)- and (2S)-methylbutanoyl enantiomers bonded to the same oligosaccharide core in intrapilosins IV (4) and V (5) represents an example of diastereoisomerism due to a chiral esterifying moiety in the resin glycoside mixtures of a morning glory species.

New triterpene and triterpenoid glycosides from Ilex brevicuspis

From the leaves of Ilex brevicuspis were isolated a new triterpene, 20(S)-3"BETA", 19"ALFA"-dihydroxyurs-12-en-23,28-dioic acid, named here brevicuspic acid, and two new triterpenoid glycosides, 3-O-"ALFA"-L-arabinopyranosyl-20(S)-pomolic acid-28-O-"BETA"-D-glucopyranosyl ester; named brevicuspisaponin 3, and the 23-sodium salt of (20S)- 3"BETA", 19"ALFA", 24-trihydroxyurs-12-en-23,28-dioic acid-28"BETA"-O-"BETA"-D-glucopyranosyl ester; along with the known compound 3-O-"ALFA"-L-arabinopyranosyl-20(S)-19"ALFA",24-dihydroxyursolic acid- 28-O-"BETA"-D-glucopyranosyl ester; already described for Ilex argentina. Their structures were established on the basis of chemical and spectroscopic methods...