PROTECTIVE ROLE of the PIGMENTS found in ST JOHNS WORT (HYPERICUM SPP.) The active UV-PROTECTIVE chemical in St. Johns Wort is called HYPERICIN, named for the Latin name of the plant, Hypericum. Hypericin is a CHROMOPHORE. A chromophore is the part of a molecule responsible for its color. The color arises when a molecule absorbs certain wavelengths of visible light and transmits or reflects others. Hypericin-like chromophores are known chemically, leading to many opportunities for comparison of pigment chemistry and photophysical cell behavior. The best characterized roles of hypericin-like pigments are in photoresponses and photoreceptors. A direct role for the pigments in UV protection is evident. However, hypericin and hypericin-like pigments more commonly serve as predator defense and the pigments are multifunctional. This observation raised the possibility that these compounds also served as antifeedants, possibly for protection of the developing seeds against insect herbivores. These compounds were found to be concentrated in the anthers, indicating that they might protect the pollen as well. Many flowers have UV patterns, invisible to humans but visible to insects such as honeybees, whose visual sensitivity extends into the near UV region of the solar spectrum. These patterns are meaningful to the pollinator. Through human eyes, we see the yellow flavonoids of the St. Johns Worts flower petals, which when extracted impart anti-inflammatory and antispasmodic properties, but lying within those yellow petals is the red chromophore, hypericin. Not surprisingly, the flowers UV patterns are displayed predominately on the exposed “facial” surface of the flower, where the pollinator makes its landing. The UV patterns sometimes differ in plants growing intermingled in potential competition and may be part of the decor that makes each flower recognizably distinct and, as a consequence, potentially memorable to the pollinator, or in human cases, to in-the-know herbalists. Interestingly, a phenomenon observed by many herbalists for millennia, Hypericum imparts a red pigment to its extracts, if the solvent is weak, such as a vegetable oil, the oil will turn red ONLY when placed in the sun, allowing for the photodynamic reaction between the light and the chromophore, hypericin, to occur. Solar-infused St. Johns Wort Oil (Hypericum Oil), extracted in organic sweet almond oil, is the primary base oil found in our Apollo Botanica NEURO~DERMAL SERUM, which is wonderfully anti-inflammatory, antiviral, and antispasmodic for nerve-related skin and muscular issues; especially helpful topically for carpal tunnel, sciatica, CHICKEN POX and SHINGLES. Sources: Photophysics and multifunctionality of hypericin-like pigments in heterotrich ciliates: a phylogenetic perspective. Lobban CS1, Hallam SJ, Mukherjee P, Petrich JW. Photochem Photobiol. 2007 Sep-Oct;83(5):1074-94. Attractive and defensive functions of the ultraviolet pigments of a flower (Hypericum calycinum), Matthew Gronquist, Alexander Bezzerides, Athula Attygalle, Jerrold Meinwald, Maria Eisner, and Thomas Eisner. PNAS, vol. 98 no. 24, 13745–13750 von Frisch K (1967) The Dance Language and Orientation of Bees (Harvard Univ. Press, Cambridge, MA). Menzel R, Backhaus W (1991) in The Perception of Colour, ed Gouras P(CRC Press, Boca Raton, FL), pp 262–293.
Posted on: Sun, 04 Jan 2015 15:50:03 +0000
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