Related Experiment Videos
Friedolanostanes and xanthones from the twigs of Garcinia hombroniana
Saranyoo Klaiklay1, Yaowapa Sukpondma, Vatcharin Rukachaisirikul
1Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Songkhla 90112, Thailand.
Abstract:
The twigs of Garcinia hombroniana yielded six compounds: two 17,14-friedolanostanes (garcihombronanes K-L, 1-2) and four xanthones (garcihombronones A-D, 3-6) together with 14 known compounds including four friedolanostanes, one lanostane, six xanthones, two benzoic acid derivatives and one biflavonoid. Their structures were elucidated by analysis of spectroscopic data and comparison of the NMR data with those reported previously. Their antibacterial activity against methicillin-resistant Staphylococcus aureus and S. aureus was evaluated.
Related Concept Videos
Antiasthma Drugs: Methylxanthines
Theophylline is thought to inhibit phosphodiesterase enzymes, increasing intracellular levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). This rise in cAMP and cGMP concentrations stimulates cardiac function,...
Preparation of Diols and Pinacol Rearrangement
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.