# Chemical Composition of Volatile and Extractive Components of Canary (Tenerife) Propolis
## 1 Introduction  
Propolis is one of the most valuable beekeeping products, but a honeybee colony's need for it is not very great. Therefore, only a small proportion of worker bees are involved in collecting raw plant materials for its production. Meanwhile, the role of propolisis in ensuring the survival of the colony in a far-from-sterile environment cannot be overestimated: it has high activity against various pathogens [1; 2; 3] and plays a key role in the'social immunity' of bees [4; 5]. In recent years, increasing attention has been paid to propolisols as an antidote to human microbial pathogens. In terms of antisepticity, propolisols stands out among most other beekeeping products, second only to bee venom in terms of potency [6; 7; 8]. It exhibits a wide range of medicinal properties, which are not limited to antimicrobial action, as reflected in a number of recent comprehensive reviews [9; 10; 11; 12]. In particular, its beneficial effects on the human digestive system, in the treatment of a number of gynecologicaldiseases, and in the healing of wounds and burns, as well as in dermatology and a number of oncological diseases, have been shown [13; 14; 15; 16; 17]. It is generally accepted that the antibacterial activity and other medicinal properties of propolisis are due primarily to phenolic compounds of plant origin, flavonoids, phenolcarboxylic acids and their esters [9; 10; 18]. These natural compounds are found not only in plant tissues but also in their external secretions in the form of resin, exudates and leakage from wounded tissues, and perform protective functions against pathogens and parasites. It is these properties that encourage bees to collect these materials, in need of a means of combating pests and pathogens in their hives. Bees are selective and preferential in relation to plant sources of raw materials for the production of propolisis [2; 19; 20; 21], and when searching for them, they are guided by various insufficiently studied olfactory and optical signals. A consequence of the selectivity of bees that deliver raw materials is the existence of certain regional 'types' or varieties of propolisis [22]. For example, the middle latitudes of Eurasia and North America are characterized by the 'poplar type', the plant precursor of which is exudates on the buds of different types of poplar containing the flavonoid aglycone, phenylcarboxylic acids and their derivatives [18; 19; 23]. In boreal regions, outside the growing range of poplar, bees collect resin from the buds of downy birch (_Betula pubescens_), which are not only rich in flavonoids but also contain large amounts of sesquiterpenol esters of phenylpropenoid acids [23; 24]. Another source of resin are aspen (_Populus tremula_ and _P. tremuloides_) buds, characterized by a high content of phenylpropenoid glycerides [23; 25; 26]. In the boreal zone, a mixed 'birch-aspen type' of propolisis is often found [23], and on the border with the mid-latitude zone, poplar markers are also found in its composition [27]. In other phytogeographical zones and regions, there are local sources of resin acceptable to foraging bees, and there they produce specific types of propolisis, such as green Brazilian propolisis from the tropical zone [28] or Argentine Andean propolisis [29]. The botanical predecessor of the former is _Bacclaris dracunculifolia_, and that of the latter is _Larrea nitida_. In isolated island areas, often rich in endemic plant species, one can also expect the existence of propolisis with a specific chemical composition that allows it to be considered a separate variety. This applies to diterpenoids-rich propolisis from the Greek islands [30] and to Pacific propolisis from Okinawa and Taiwan [31]. Such isolated areas include the islands of the Canary archipelago, where beekeeping has long been practiced, but its products still remain poorly understood. In particular, there is only one report on the chemical composition of two propolisis samples from the island of Gran Canaria [32].