Natural antimicrobial compounds plant antimicrobials

Recently, it has been demonstrated that medicinal plants contain MDR pump inhibitors that actually enhance the activity of their own natural antimicrobial compounds. Plant amphipathic cations, such as berberine, have been shown to be good MDR substrates. Recent research has shown that in addition to berberine, Berberis species produce 5 -methoxyhydnocarpin-D, Fig. 10, an MDR inhibitor that enhances the action of this compound. In addition, isoflavones isolated Ifom Lupinus argenteus were found to enhance the antibacterial activity of a-linolenic acid, also found in the same plant [99]. 

Keywords Antimicrobial Antiviral Cytotoxicity Natural compound Plant extract... 

As a conclusion, these findings provide additional evidence for the supposition that the assays mentioned above play the part of useful primary screening in the survey of bioactive natural products. For the reasons outlined above, it is very important to focus on plants to discern novel antivi-ral/antimicrobial compounds. Therefore, we truly hope that our studies, as well as similar reports by different researchers, may help find new antimicro-bials/antivirals from herbal sources. 

The family of the abyssinone natural products has been known for its interesting and promising biological properties for some time (434,435). Isolated from different plants traditionally used in folk medicines, these compounds show antimicrobial activity (434) and aromatase inhibition (435). The main challenge in the syntheses of these compounds is a chiral flavanone core. Scheidt et al. (Scheme 112)... 

Indole and its derivatives are found in many natural products as plant alkaloids that have antimicrobial [150], anti-inflammatory [151], antibacterial [152], and antidepressive activities. Many sulfur-containing compounds such as sulfates, sulfones, and sulfonomides exhibit insecticidal, germicidal, antimicrobial, and antibacterial activities [153,154] and certain phenyl sulfones show fungicidal properties [155]. 

Thousands of diverse natural products are produced by plants and many of these are involved in plant defense. The phytochemical diversity of antimicrobial compounds include terpenoids, saponins, phenolics and phenylpro-panoids, pterocarpans, stilbenes, alkaloids, glucosinolates, hydrogen cyanide, terpenoids, indole and also elemental sulphur, the sole inorganic compound (Cooper et al., 1996). Investigation of chemotaxonomic relationships provided evidence that plant families may be good proxy for the chemical composition of antimicrobial compounds for instance, Fabaceae produce primarily isoflavonoids and... 

In conclusion, flavonoids and plant extract rich in flavonoidic compounds as antimicrobial agents present two main positive features the first is their natural origin, which means more safety for consumers, and the second is that they are considered to be low risk for resistance development by pathogenic microorganisms thus they can be considered a valuable support in the treatment of infections and may contribute to the development of new and safe antimicrobial agents. 

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