Jownul of Ethnophmnacology, 26 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGF (1989) 109- 113 Eisevier Scientific Publishers Ireland Ltd. 109 zyxwvuts ANTIMICROBIAL EFFECTIVENESS OF SIX PARADOLS. 1: A STRUCTURE-ACTIVITY RELATIONSHIP STUDY J.K. OLOKE’, D.0. KOLAWOLF’ and W.O. ERHUN’ zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJI ‘DQ~r~~Qnt of Applied ~~b~~gy, ondo state University, Ado-EkW ‘~Q~r~Q~t of ~~b~~gy ad ‘DQpaMnQnt of Pha~~o~sy, Faculty of Pharmacy, ObafQmi Awolowo WniuQrsity, &+Ife (Niger&d (Accepted August 30,1988) The pattern of antimicrobial effectiveness of (Ol-, (2)_, (3)_, (4~, (Sl- and (9)_ paradols was studied. (3l- Farad01 was more active than the other homo- logues with a minimum inhibitory concentration (MIC) of 1 mglml when tested against Proteus vulgar& Pseudomonas aeruginosa, Staphylococcw aureus and Botryodiplodia theobromae. At 0.2 mglml, (3)_paradol completely inhibited the spore germination of Trkhophyton mentugrophytes and after 3 h of exposure at 0.5 mg/ml, it inhibited the growth of a heavy inoculum of Stuphy~coc~ uureus (1 x 10% cells/mll. Introduction Paradols are derivatives of alkyl-4-hydroxy-3-methoxyphenethyl ketones. They are known to be among the pungent principles of the grain of ~~rurnorn~rn mebepetu Roscoe (Zin~beraceae) (Nelson, 1917; Connell, 1970; Tackie et al., 1975) and have been shown to have some antimiffobi~ activity (Oloke et al., 1987). This paper represents an investigation into the relative antimicrobial efficacy of a series of paradols. Materials and methods The following gram-positive and gram-negative bacteria were used: Bacillus subtilis (NCIB 26101; Escherichaiz co& (NCIB 861, Proteus v&g&s (NCIB 671, Pseudomonas fluorescens (NCIB 4181, Pseudomonas aeruginosa (NCIB 9501, Serruttix murcescens (NCIB 13771, Staphylococcus aureus (NCIB 85881, Klebsiellu pneumoniae lNCIB 37561 and Yersiniu enterocolitica Fungi 0~~~1~~2.10 0 1989 Elsevier Scientific Publishers Ireland Ltd. Published and Printed in Ireland