Philippine Journal of Science 133 (2): 97-101, December 2004 ISSN 0031 - 7683 97 Antimicrobial Compounds from Artocarpus heterophyllus Consolacion Y. Ragasa *1, Karen Jorvina 1 and John A. Rideout 2 1 Chemistry Department, De La Salle University 2401 Taft Avenue, Manila 1004, Philippines 2 School of Chemical and Biomedical Sciences Central Queensland University, Queensland 4701, Queensland, Australia Keywords: Artocarpus heterophyllus Lam., Moraceae, langka, cycloartenone, cycloartenol, 2,3-butanediol, antimicrobial *Corresponding author: ragasac@dlsu.edu.ph The freeze-dried unripe fruit of Artocarpus heterophyllus Lam., common name: langka, afforded cycloartenone 1, cycloartenol 2, and a diastereomeric mixture of 2,3-butanediols 3a and 3b in a 3:1 ratio. Antimicrobial tests on 1-3 indicated that 1 has low activity against E. coli, P. aeruginosa, and T. mentagrophytes, moderate activity against C. albicans and A. niger and inactive against S. aureus and B. subtilis. 2 has no antibacterial activity and only low antifungal activity. The diastereomeric mixture of 3 exhibited high activity against P. aeruginosa, moderate activity against C. albicans, and low activity against S. aureus, T. mentagrophytes, and A. niger. 3 has the same activity as the standard antibiotic against P. aeruginosa. H H R 1 5 9 12 14 17 20 18 19 28 29 30 27 24 1 R = O 2 R = H, b-OH 3b CH 3 CH 3 HO H H OH H OH H OH CH 3 CH 3 3a INTroDUCTIoN Artocarpus heterophyllus Lam., commonly known as langka, is cultivated throughout the Philippines for its fruit which is eaten fresh or made into preserves and other sweets. The unripe fruit is used as an astringent, while the ripe fruit is used as demulcent, nutritive and laxative (Quisumbing 1978). A number of studies were conducted on A. heterophyllus which reported the isolation of cycloartenone, cycloartenol, and other tetracyclic triterpenoids (Baric et al. 1994), flavonoids (Lu & Lin 1994; Lu et al. 1995; radhakrishnan et al. 1965; Chung et al. 1995), and Diels-Alder-type adducts (Shinomiya et al. 1995; Aida et al. 1990). This paper reports the isolation of cycloartenone 1, cycloartenol 2, and a diastereomeric mixture of 2,3-butanediol 3a and 3b from the unripe fruit of A. heterophyllus. The antimicrobial test results on 1-3 are also reported. To the best of our knowledge this is the first report on the isolation of 3a and 3b from A. heterophyllus, and their antimicrobial properties.