Herbs - Plant Constituents - Phenols / Phenolic Glycosides

These chemical structures are classified by the presence of a benzene ring combined with an alcohol. Most members of this class of compounds have antiseptic activity and are also anthelminitic and caustic. In order for the body to absorb this compound, they are usually naturally combined with a sugar to form a glycoside.

A familiar example of this compound is Salicylic acid, which is found free or as methyl salicilyte in many plants such as Meadowsweet and Willow. This is the basis of aspirin and a whole class of non-steriodal anti-inflammatory drugs (NSAIDs). It is here that may best show how the chemical may have a whole range of properties that are not necessarily those of the plant. Salycilates are well known to cause severe stomach irritation, even leading to stomach hemorrhage. However, in a plant such as Meadowsweet, the whole remedy can actually stop bleeding in the stomach. It is thus important to realize that the actions of a whole plant cannot always be predicted by knowledge of their constituents.

Other actions related to this class of compounds include fever reduction, general anti-inflammatory effect, increased volume and concentration of bile, and rubefacient actions when used externally. It is now known that this anti-inflammatory effect is due to an anti-prostaglandin and bradykinin action, which would also explain the use of salicylates as anti-blood-clotting agents. In summary, these are generally useful compounds that are quite safe when used in their natural plant context. Two other familiar examples are Eugenol from Cloves, which helps tooth aches, and Thymol from Thyme and other aromatic remedies which is a useful anti-septic and anti-fungal oil.