The bees are opportunists, picking what they need from available sources, and a detailed analysis shows that the chemical composition of propolis varies considerably from one region to another, with the vegetation. In northern climates, for example, bees collect resins from trees such as poplars and conifers (the biological role of the resin of trees is to heal the wounds and defend against bacteria, fungi and insects).
Poplar is a resin rich in flavonoids. "Typical" northern temperate propolis has approximately 50 constituents, primarily resins and vegetable balsams (50%), waxes (30%), essential oils (10%) and pollen (5%).
In the neotropics, as well as a variety of trees, bees may also collect the resin from the flowers of the genera Clusia and Dalechampia, which is the type of plants are known to produce resins of flowers to attract pollinators. Clusia resin containing benzophenone polyprenylated.
In some areas, the Chilean propolis contains viscidone, Baccharisshrubs terpene away, and Brazil, naphthoquinone epoxide recently isolated from propolis red and prenylated acids, such as 4-hydroxy-3 ,5-cinnamic acid diprenyl have been documented.
Analysis of propolis undertaken in Henan, China found sinapic acid, isoferulic acid, caffeic acidand Chrysin, where the first three compounds have shown antibacterial properties .. In addition, the Brazilian Red Propolis (primarily resin plant Dalbergia ecastaphyllum) is a large number of isoflavonoids 3-hydroxy-8-0.9 and medicarpin dimethoxypterocarpan.
Sometimes even bees collect different caulks man-made, when the usual sources are more difficult to achieve. The properties of propolis depend exact sources used by each hive, and therefore have medicinal properties that may be present in a hive with propolis may be absent from the other, and the distributors of propolis can control these factors. This may be the cause of multiple and varied demands for their medicinal properties, and the difficulty of repeating the allegations of scientific studies.
The propolis taken a colony can vary, so in controlled clinical trials difficult, and the results of any search can not be reliably generalized to Propolis samples from other regions.