A simple route for renewable nano- sized arjunolic and asiatic acids and self- assembly of arjuna- bromolactone

• Braja G. Bag,
• Partha P. Dey,
• Shaishab K. Dinda,
• William S. Sheldrick and
• Iris M. Oppel

Beilstein J. Org. Chem. 2008, 4, No. 24, doi:10.3762/bjoc.4.24

• self-assembly of nano-sized arjuna-bromolactone are reported. Keywords: arjunolic acid; nanochemistry; renewable; self-assembly; triterpene; Introduction Triterpenes are an important class of plant secondary metabolites derived from C30 precursors [1][2]. More than 100 triterpenoids with different

• triterpenoids having a β-amyrin skeleton with certain amounts of α-amyrins is common in nature and has been explained by 1,2-CH3 migration during their biosynthesis [11]. The mixture of the triterpenic acids extractable from Terminalia arjuna contains arjunolic acid as the major component along with asiatic

• -bromolactone 3 was isolated in pure form leaving 1.2 g of methyl asiatate (4) in the mother liquor (see Figure 1 for HPLC profiles). Arjuna-bromolactone 3 (3.6 g) on stirring with Zn-dust (20 equivalents) in acetic acid at room temperature for 30 min produced arjunolic acid (3 g) in 97% isolated yield [12