2014, 19, 19610-19632; doi: 10. 3390/molecules191219610 molecules

 

 

12. The Plant Sources of Propolis 

The current opinion is that propolis is collected from resins of trees such as poplars and conifers, and 

therefore propolis is sometimes classified after the name of the source plant [2–4]. The plant source is 

identified by observing the collection activities of bees, and comparing the chemical profiles of propolis 

and plant materials. Other researchers found that honeybees collect plant material by cutting fragments 

of vegetative tissues, so the anatomical characteristics of plant tissue in the propolis can be used as 

evidence of propolis origin [65]. 

As mentioned in the last section, Populus species are considered to be the main plant origin of 

propolis all over the world, especially in the temperate zone. Most propolis collected from Europe, North 

America, non-tropical region of Asia, New Zealand [3] and even Africa (mainly the east area of Nile 

Delta region) [35] contains the characteristic poplar chemical profile: high level of flavanones, flavones, 

low phenolic and their esters [98].   

In the tropical and subtropical area, there are few poplar trees. Honeybees have to search for new 

plant source for propolis. For the propolis collected from southeast of Brazil, Baccharis dracunculifolia 

turns out to be the main botanical source [66,99]. Artepillin C as the salient chemical composition makes 

it easy to distinguish this propolis from other types of propolis. It is reported that propolis from 

Venezuela, Amazon and Cuba contains prenylated benzophenones, which is originated from the 

exudates of Clusia flower [9,100].   

Macaranga plants have been demonstrated to be the plant source of Taiwan [95], Okinawan [101] 

that was classified as Pacific propolis [3]. High concentration of diterpenoids in Mediterranean  

propolis may originate from Cupressus plants for Sicilian, Cretan propolis [29] and Maltese propolis [74], 

Pinus  plants for Greek propolis [39]. In Kangaroo Island (Australia), bees collect propolis from the 

sticky exudate on the stem shoots and seed pods of an endemic Australian plant, Acacia paradoxa [45]. 

Red Brazilian propolis and Nepalese propolis have various biologically active neoflavonoids that 

primarily come from the genus Dalbergia [24,50]. 

However, some of plant sources are just surmised by observing the bees’ foraging behaviors,  

not comparing chemical identity of secondary plant metabolites in propolis and in the plant source.  

For example, Eucalyptus species are considered as the source plant in Australia, south Anatolia  

(Turkey) [102], Ismailia (Egypt) [61] and Brazil

, but no real proof has been presented for this origin. 

Therefore, it still needs further study to compare chemical compounds in propolis and the plants, in order 

to confirm the exact botanic origin. 

13. Summary and Future Perspectives 

The biological activities of propolis are attributed to a variety of major chemical constituents 

including phenolic acids, phenolic acid esters, flavonoids, and terpenoids, such as CAPE, artepillin C, 

caffeic acid, chrysin, and galangin quercetin, apigenin, kaempferol, pinobanksin 5-methyl ether, 

pinobanksin, pinocembrin, pinobanksin 3-acetate.   

Over 500 compounds have been identified in propolis from many countries up to 2012. They belong 

to flavonoids, phenylpropanoids, terpenoids, stilbenes, lignans, coumarins and their prenylated derivatives. 

Molecules 2014, 19 19626 

 

 

However, other common chemical components such as alkaloids, iridoids have not been reported in 

propolis. This characteristic is often explained by the plant sources. 

We recommend that bee varieties and subspecies need to be considered together with geographical 

factors and plant species around the beehive in future studies on propolis. The priorities of future 

research lie on the influence of species and behaviour on propolis, together with feeding experiments to 

identify the plant part source, which will advance our understanding of the chemistry and quality of 

propolis, as well as honey bee biology. Characterization of propolis from various locations and plant 

sources is warranted to define acceptable quantitative standards for different types of propolis. 

Furthermore, the biological activities of each type of propolis need to be correlated with their chemical 

composition, and eventually, standardized products should be used in clinical studies.   

Acknowledgments 

This work was supported by the Grant from the National Natural Science Foundation of China  

(No. 31272512) and the earmarked fund for Modern Agro-industry Technology Research System from 

the Ministry of Agriculture of China (CARS-45). 

Author Contributions 

S.H.: conception, data collection, and manuscript preparation; C.P.Z.: review of the manuscript; 

K.W.: data collection; G.Q.L.: manuscript preparation and review of the manuscript; F.L.H.: conception 

and reciew of the manuscript. 

Conflicts of Interest 

The authors declare no conflict of interest. 

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