Novel monoterpene lactones from the seeds of Nephelium lappaceum Linn. var. lappaceum (Sapindaceae)

• Main Author: De Luna, Roderick D.
• Format: text
• Language: English
• Published: Animo Repository 2006
• Subjects: Rambutan (Nephelium lappaceum); Seeds; Chemistry
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/3544; https://animorepository.dlsu.edu.ph/context/etd_masteral/article/10382/viewcontent/CDTG004352_P__1_.pdf
• Institution: De La Salle University

The dichloromethane extract of the air-dried seeds of Nephelium lappaceum Linn. var. lappaceum afforded two new diastereomeric monoterpene lactones lappaceolide A and B, and the known butenolide siphonodin [4-(hydroxymethyl)-2(5H)-furanone], by column chromatography. Their structures were elucidated by extensive 1D and 2D NMR spectral interpretation, and characterized by MS, UV and IR spectroscopy. The antimicrobial activity test using the agar cup method showed that the new monoterpenes were both moderately active against Candida albicans and slightly active against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Trichophyton mentagrophytes and Aspergillus niger. However, they were relatively inactive against the bacteria Bacillus subtilis. The new secondary metabolites represent a novel tricyclic monoterpenoid skeleton. This is also the first report that siphonodin was identified from the plant.