Further antibacterial diterpenes from the bark and leaves of Juniperus procera hochst. ex Endl

Abstract

The bark of Juniperus procera yielded three antibacterial diterpenoids, (+)‐E‐communic acid (1), (+)‐Z‐communic acid (2) and (+)‐totarol (3). Compound 2 exhibited significant activity against Gram‐positive bacteria, while 1 was found to be less active. Compound 3, on the other hand, demonstrated potent activity against Mycobacterium organisms, while its corresponding 3β‐hydroxy‐derivative 4 was found to be inactive. The chromatographic separation of (+)‐Z‐communic acid (2) from (+)‐E‐communic acid (1) and those previously unreported spectral data of 1 and 2 are described. In addition, the leaves yielded (+)‐8α‐acetoxyelemol, β‐peltatin A methyl ether and deoxypodophyllotoxin. Copyright © 1995 John Wiley & Sons, Ltd.