Antibacterial and insecticidal activity of volatile compounds of three algae species of Oman Sea

Abstract

Many of the volatile oils showed important biological and pharmacological activities, these compounds as part of the traditional medicine in many cultures used as long time. Potencies of them caused these natural products gained many scientific researches in felid of natural products. The volatile oils of Actinotrichia fragilis (Forsskål) Børgesen, Liagora ceranoides J.V.Lamouroux and Colpomenia sinuosa (Mertens ex Roth) Derbes and. Solier were extracted by hydrodistillation. These volatile oils were analyzed by GC-MS and GC-FID techniques and tested for their toxicity against Oryzeaphilus mercator and Tribolium castaneum, antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus using by the disc diffusion method also free-radical-scavenging properties. The identified constituents of these volatile oils represented 92.7%, 99.9% and 93.8% of the total volatile oils, respectively, of A. fragilis, L. ceranoides and C. sinuosa. Ethyl cinnamate and Tetradecane were the main compounds in L. ceranoides, 1-dodecanol and caryophyllene oxide in A. fragilis whilst hexadecane and 7-pentadecanone were the principal components of C. sinuosa volatile oil. All three volatile oils showed 55-90% mortality of O. mercator and 60-80% mortality of T. castaneum at a dose of 12 μL/L air after 48h of exposure. Based on the observed contact toxicity of the essential oils of these species, it is fair to state that these volatile oils may have some potential as an insecticide against the crop pests, O. mercator and T. castaneum. Also antibacterial activity of L. ceranoides volatile oil against Pseudomonas aeruginosa and Staphylococcus aureus is significant.

Keywords

• antibacterial activity
• contact toxicity
• actinotrichia fragilis
• liagora ceranoides
• colpomenia sinuosa