Date Published: April 24, 2019
Publisher: Public Library of Science
Author(s): Kristina Georgieva, Milena Popova, Lyudmila Dimitrova, Boryana Trusheva, Le Nguyen Thanh, Diep Thi Lan Phuong, Nguyen Thi Phuong Lien, Hristo Najdenski, Vassya Bankova, Wolfgang Blenau.
Propolis produced by the stingless bee Lisotrigona cacciae was studied for the first time. Using different chromatographic procedures, a total of eighteen constituents (phenols and triterpenes) were isolated, among which flavane 1, homoisoflavanes 2–4, and xanthones 5 and 6 were new for propolis. Propolis extract was also characterized by gas chromatography/mass spectrometry and other fifteen constituents were identified. The xanthone α-mangostin (8) demonstrated significant activity against Staphylococcus aureus with MIC and MBC 0.31 μg/ml, followed by 7,4′-dihydroxy-5-methoxy-8-methylflavane (1) with MIC 78 μg/ml and MBC 156 μg/ml. 10,11- Dihydroxydracaenone C (4), a component bearing ortho-hydroxyl groups, was the only compound displaying radical scavenging ability. Triple botanical origin of the sample was defined, consisting of Dracaena cochinchinensis, Cratoxylum cochinchinense and Mangifera indica. D. cochinchinensis is a new resin source of propolis.
Propolis is a valuable beehive product containing plant secretions and beeswax. It is well known as a remedy with a wide range of biological and pharmacological properties, such as antibacterial, antioxidant, immunostimulating, antiviral, etc. [1,2]. Propolis chemistry depends on the geographical origin, plant species, and bee species, and thus various constituents contribute to its bioactivity . Because of its chemical diversity, propolis has been classified into types based on the plants that bees have chosen as resin sources. At present, the majority of scientific information concerns propolis produced by the honey bee Apis mellifera (tribe Apini), which inhabit almost all ecosystems of the world, and over twenty propolis types have been formulated [3,4]. In tropical and southern subtropical regions, however, the native bee species are stingless bees (tribe Meliponini), which are also key pollinators and producers of beneficial honey, wax and propolis [5,6].
In the present article, a phytochemical study of propolis produced by the stingless bee Lisotrigona cacciae was described for the first time. The results add new knowledge in the field of propolis research in terms of new constituents and a new plant source. The study also reveals that the propolis of L. cacciae, and stingless bee propolis in general, is a valuable product as well as a promising source of biologically active compounds.