A UML based metamodel for Bunge-Wand-Weber (BWW) ontology is presented. BWW ontology is a generic framework for analysis and conceptualization of real world objects. It includes categories that can be applied to analyze and classify objects found in an information system. In the context of BWW ontology, the metamodel is a representation of the ontological categories and relationships among them...

A new pregnane-type steroidal glycoside (1), two new spirostane-type steroidal glycosides (2, 3), and two new furostane-type steroidal glycosides (4, 5), named allimacrosides A-E, together with four known compounds (6-9) were isolated from a 80% MeOH extract of Allium macrostemon Bunge. The identification and structural elucidation of these compounds were based on their 1D- and 2D-NMR spectra, ...