This study investigated the chemical composition and antimicrobial activity of propolis collected from two stingless bee species Tetragonula laeviceps and Tetrigona melanoleuca (Hymenoptera: Apidae). Six xanthones, one triterpene and one lignane were isolated from Tetragonula laeviceps propolis. Triterpenes were the main constituents in T. melanoleuca propolis. The ethanol extract and isolated compounds from T. laeviceps propolis showed a higher antibacterial activity than those of T. melanoleuca propolis as the constituent α-mangostin exhibited the strongest activity. Xanthones were found in propolis for the first time; Garcinia mangostana (Mangosteen) was the most probable plant source. In addition, this is the first report on the chemical composition and bioactivity of propolis from T. melanoleuca.

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Electrospinning of propolis / polylactic acid (PLA) fibres was investigated for propolis concentrations from 0-10% (w/v). Solutions could not be spun when the amount of propolis was over 8% (w/v). Mechanical characterization indicated that propolis reduced the tensile strength. The fibre mats exhibited poorer mechanical performance when the propolis concentration was increased. At propolis concentrations of 2-6% (w/v), the fibres were smooth, bead-free and homogeneous. When the concentration of propolis was more than 6% (w/v), the fibres changed from ductile to brittle. The fibres containing 2% (w/v) propolis showed bactericidal effects on Staphylococcus aureus, Staphylococcus epidermidis, Proteus mirabilis and Escherichia coli. At a propolis concentration of 4% (w/v) they also inhibited Bacillus cereus. Efectos bactericidas de nanofibras de propóleos/ácido poliláctico (APL) obtenidas mediante electrohilado (electrospinning) ResumenEl electrohilado de fibras de propóleos/ácido poliláctico (APL) se ha investigado con concentraciones de propóleos de 0-10% (w/v). Las disoluciones no pudieron ser hiladas cuando la cantidad de propóleos fue superior al 8% (w/v). La caracterización mecánica indicó que el propóleos reduce la resistencia a la tracción. Las esteras de fibra tuvieron un comportamiento mecánico más pobre cuando se aumentó la concentración de propóleos. A concentraciones de propóleos de 2-6% (w/v), las fibras eran lisas, sin bolitas y homogéneas. Cuando la concentración de propóleos fue de más de 6% (w/v), las fibras cambiaron de dúctil a frágil. Las fibras con 2% (w/v) de propóleos mostraron efectos bactericidas sobre Staphylococcus aureus, Staphylococcus epidermidis, Proteus mirabilis y Escherichia coli. A una concentración de propóleos de 4% (w/v) también inhibieron Bacillus cereus.

Recent years, propolis has plenty of biological and pharmacological properties and its mechanisms of action have been widely investigated. There is a substantive database on the biological activity and toxicity of propolis indicating it may have many antibiotic, antifungal, antiviral and antitumor properties, among other attributes. The one-step incorporation of propolis into nanofibrous mats of polycaprolactone (PCL) by electrospinning was demonstrated. In this research, the preparation of the PCL nanofibers films added ethanolic extract propolis (EEP) by electrospinning technique was studied. The EEP content was varied from 0, 2, 4, 6, 8 and 10%. The morphology was observed by a scanning electron microscope (SEM). The functional group was investigated by FT-IR

Propolis is the mixture of resins that honeybees collect from plant buds, leaves and exudates. Antimicrobial and antioxidant properties of propolis have been widely studied, however, there have few reports on Thai propolis. To increase the efficient extraction of organic propolis compounds, extraction methods have been developed. We applied the ultrasound technology to reduce extraction time and increase extraction yields of propolis. The propolis was extracted using ultrasound technology for 15-60 minutes and the propolis extracts were examined to compare their biological activities. Antimicrobial activities of the propolis were investigated using the agar well diffusion method. The free radical-scavenging and antioxidant activities of propolis extracts were measured using the DPPH and FolinCiocalteau colorimetric methods. The propolis extracted using ultrasound for 15 and 30 minutes showed inhibitory effects on tested fungi and bacteria as well as antioxidant activities.