Balsam

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For other uses, see Balsam (disambiguation).

Balsam (also: turpentine) is the resinous exudate (or sap), which forms on certain kinds of trees and shrubs. Balsam (from Hebrew bosem בֹּשֶׂם, "spice", "perfume") owes its name to the biblical Balm of Gilead.

Chemistry[edit]

Balsam is a solution of plant-specific resins in plant-specific solvents (essential oils). Such resins can include resin acids, esters, or alcohols. The exudate is a mobile to highly viscous liquid and often contains crystallized resin particles. Over time and as a result of other influences the exudate loses its liquidizing components or gets chemically converted into a solid material (i.e., by autoxidation).[1]

Some authors require balsams to contain benzoic or cinnamic acid or their esters.[2]

Resins are difficult to classify because of their amorphous nature.[2] Even the term "resin" is not sharply defined.[3] Several attempts were made to differentiate between waxes and other classes of substance, particularly fats, resins, and high molar mass polymers, by using several criteria. These primarily physical definitions are to some extent arbitrary and are not generally accepted.[4]

Plant resins are sometimes classified as mixtures with other plant constituents, for example as pure resins (guaiac, hashish) gum-resins (containing gums/polysaccharides), oleo-gum-resins (a mixture of gums, resins and essential oils), oleo-resins (a mixture of resins and essential oils, e. g. capsicum, ginger and aspidinol), balsams (resinous mixtures that contain cinnamic and/or benzoic acid or their esters), and glycoresins (podophyllin, jalap, kava kava).[2]

There is also rubber (latex), which consists of 1,4-polyisoprene.[5]

Non-plant natural resins include fossil and mined resins (amber, Utah resin, asphaltite), and animal resins (shellac).[1]

Safety[edit]

Some balsams, such as Balsam of Peru, may be associated with allergies. In particular, Euphorbia latex (wolf's milk) is strongly irritant and cytotoxic.

List of balsams[edit]

See also[edit]

References[edit]

  1. ^ a b Klemens Fiebach; Dieter Grimm (2007), "Resins, Natural", Ullmann's Encyclopedia of Industrial Chemistry (7th ed.), Wiley, p. 2 
  2. ^ a b c Andrew Pengelly (2004), "Essential oils and resins", The constituents of medicinal plants (2nd ed.), Allen & Unwin, p. 102 
  3. ^ Gerd Collin et al. (2007), "Resins, Synthetic", Ullmann's Encyclopedia of Industrial Chemistry (7th ed.), Wiley, p. 1 
  4. ^ Uwe Wolfmeier et al. (2007), "Waxes", Ullmann's Encyclopedia of Industrial Chemistry (7th ed.), Wiley, p. 3 
  5. ^ Heinz-Hermann Greve (2007), "Rubber, Natural", Ullmann's Encyclopedia of Industrial Chemistry (7th ed.), Wiley, p. 1