Plant antimicrobials

The use of herbal antimicrobials has a long history. Archaeologists discovered flower fragments from several different medicinal plants in 

Medicinal plants synthesize antimicrobial compounds as part of their defence against invasion by microbial pathogens. It is estimated that almost 50% of synthetic medicines are derived from or patterned after phytochemicals (Canadian Pharmaceutical Association, 1988). In the medicinal plant family secondary metabolites such as alkaloids, phenolics and other compounds have contributed the largest number of antimicrobial drugs in the pharmacological industry. The safer, biodegradable plant-derived compounds offer a promising solution to the problem of resistant microbes (Citarasu, 2010). 

2 Plant active compounds involved in microbial control 

Plants produce primary and secondary metabolites with various functions. The primary metabolites - amino acids, simple sugars, nucleic acids and lipids - are compounds that are essential for their cellular processes. Secondary metabolites are compounds such as phenols, alkaloids, terpenoids and fiavonoids, which are produced in response to stress. 

Phenolics make up a class of chemical compounds consisting of a hydroxyl group (-OH) attached to an aromatic hydrocarbon group they serve as a defence against attack by microorganisms. Phenolic acids are widely distributed in plants and make up a diverse group that includes the widely 

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Mitscher, L., et al. "Antimicrobial Agents from Higher Plants. Antimicrobial Isoflavionoids and Related Substances from Glycyrhiza glabra L. var. typica." J Nat Prod 43 259269, 1980. Abstract. 

Stermitz, RR., P. Lorenz, J.N. Tawara, L.A. Zenewicz, and K. Lewis. 2000. Synergy in a medicinal plant Antimicrobial action of berberine potentiated by 5 -methoxyhydnocar-pin, a multidrug pump inhibitor. Proc. Natl. Acad. Sci. U.S.A. 97(4) 1433-1437. 

Al-Shamma A, Drake S, Flynn DL, Mitscher LA, Park YH, Rao GSR, et al. Antimicrobial agents from higher plants. Antimicrobial agents from Peganum harmala seeds. J Nat Prod 1981 44 745-7. 

Mitscher, L.A., YH. Park, D. Clark, and J.L. Beal Antimicrobial Agents from Higher Plants. Antimicrobial Isoflavonoids and Related Substances from Glycyrrhiza glabra L. var. typica. J. Nat. Prod., 43, 259 (1980). 

Cammue BP, De Bolle MF, Terras FR, Ptoost P, Van Damme ], Rees SB, Vanderleyden J, Broekaert WE Isolation and characterization of a novel class of plant antimicrobial peptides Irom Mirohilis jalapa L. seeds, j Biol Chem 1992 267 2228-2233. 

Sydiskis, R., Owen, D., Lohr, J., Rosier, K. and Blomster, R. 1991. Inactivation of enveloped vimses by anthraquinones extracted from plants. Antimicrobial Agents and Chemotherapy, 35 (12), pp. 2463-2466. 

Historical Overview of Plant Antimicrobials as a Food Preservative... 

Padovan L, Scocchi M, Tossi A (2010) Structural aspects of plant antimicrobial peptides. Curr Protein Pept Sc 11(3) 210-219... 

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