Bullatenone, 1,3-dione and sesquiterpene chemotypes of Lophomyrtus species

The only known natural source of the volatile bioactive compounds bullatenone 1 and 4-methyl-1-phenylpentane-1,3-dione 2 is the New Zealand endemic shrub Lophomyrtus bullata (Myrtaceae). GC and NMR analyses of essential oils and solvent extracts of L. bullata, L. obcordata and the hybrid L. "ralphii" showed several chemotypes, which did not correlate with species. Levels of 1 and 2 varied from dominant to low/undetectable and the most common chemotype was rich in allo-aromadendrene and other sesquiterpenes. The rare natural product E-4-methyl-1-phenyl-1-penten-3-one 4 was detected for the first time in this genus. The non-volatile cytotoxic compound bullataketal 5 co-occurred with bullatenone 1. An essential oil from the relatively rare bullatenone 1 chemotype showed antifungal activity against Candida albicans and Cladosporium resinae, and an oil from the 4-methyl-1-phenylpentane-1,3-dione 2 chemotype showed antibacterial activity against Bacillus subtilis.