**1. Introduction**

Propolis also known as "bee glue" is a nontoxic hive product accumulated by bees from diverse plants containing compounds such as flavonoid aglycones, phenolic acids and their esters, phenolic aldehydes, alcohols, ketones, sesquiterpenes, coumarins, steroids, amino acids, and inorganic compounds. It functions in sealing holes, cracks, reconstruction, and smothering the inner surfaces of the beehive. Propolis and its extracts have application in treating diseases due its anti-inflammatory, antioxidant, antibacterial, antimycotic, antifungal, antiulcer, anticancer, and immunomodulatory properties [1,2]. Egyptians, Greeks, Romans, Chinese, Arabs, and Incas have traditionally used it as an

antiseptic to treat wounds and as an anti-pyretic agen<sup>t</sup> [1–3]. The term propolis was described in the 16th Century in France and was considered as an o fficial drug by London Pharmacopoeia [4].

Propolis contains mainly hydrophobic terpenes and phenolics compounds and can be classified in five types. The chemogeographic patterns of propolis types reflects the geographical distribution of plants species [2]. According to this distribution, the propolis produced in North America belongs to the poplar propolis and contains mainly flavonoids without B-ring substituents, such as pinocembrin, pinobanksin, galangin, and chrysin [2,5].

In recent years, it has gained wide acceptance as traditional medicine in various parts of the world where it is claimed to improve human health and to prevent diseases such as diabetes and cancer [6,7]. Nowadays, in several countries, it is possible to find propolis as liquid extracts in bottles, vaporizers, syrups capsules, tablets, candies, creams, among others [8,9].

Data about the chemical composition and biological activity of propolis fromMéxico is limited [10–12]. Propolis in Atliplano region is prepared in several forms, including syrups, tinctures, and creams as an alternative to improve health and prevent diseases. In view of the importance of propolis in Mexican traditional medicine the chemical composition and biological activities (antioxidant, antibacterial, and cytotoxic) of the ethanolic extract of Altiplano propolis (EEP) were investigated.

The aims of this study were: (a) To isolate the major compounds of brown Mexican propolis, and (b) to evaluate the antibacterial, antioxidant, and cytotoxic activities of the EEP.

#### **2. Materials and Methods**

#### *2.1. Chemicals and Reagents*

All the chemicals to investigate the antioxidant, antibacterial, and cytotoxic activities were supplied by Sigma-Aldrich (St. Louis, MO, USA). All the solvents and chromatographic supports were purchased from Merck (Darmstadt, Germany). Deuterated solvents and TMS were provided by Cambridge Isotope Laboratories (Tewksbury, MA, USA).
