Stingless bees in Brazil are indigenous and found all over the country. Bee pollen is used for its nutritional value in the human diet. It is made up of natural flower pollen mixed with nectar and bee secretions. In order to evaluate the chemical composition, free radical scavenging activity, and botanical origin, sample of pollen loads from stingless bee, Melipona rufiventris (Uruçu amarela) was studied. The EtOAc extract of pollen of Melipona rufiventris yielded the following compounds: p-hydroxycinnamic acid, dihydroquercetin, isorhamnetin, isorhamnetin-3-O-(6"-O-E-pcoumaroyl)-β-D-glucopyranoside, luteolin, and quercetin. This is the first report of the isolation of isorhamnetin-3-O-(6"-O-E-p-coumaroyl)-β-D-glucopyranoside from pollen. The free radical-scavenging activities of different solvent extracts of pollen were determined using DPPH assay. This activity decreases in the order: EtOAc>EtOH>Hexane extract. It appears that the EtOAc extract of the pollen is a good scavenger of active oxygen species. The botanical evaluation of pollen loads showed the composition by two pollen types, with the dominant type (97.3%) being Scoparia dulcis (L.) (Scrophulariaceae) and the minor one Senna obtusifolia (L.) Irwin & Barneby (Fabaceae). This suggests a specific foraging behavior in Melipona rufiventris bees, even in an environment with such a rich botanical diversity as the Northeastern Brazil.
The indiscriminate use of antibiotics in the treatment of caprine mastitis causes the appearance of resistant microorganisms, besides leaving residues in milk, putting at risk to human health. In this way, propolis is an alternative in the treatment of diseases because it has antimicrobial activity, mainly because of the presence of flavonoids in its composition. The aim of this study was to evaluate the antimicrobial potential of propolis to Staphylococcus spp. Isolated from cases of goat mastitis and qualify the crude ethanoic extract by high performance liquid chromatography (HPLC). In this study, the minimum bactericidal concentration values of propolis extracts in ethanol, ethyl acetate and hexane showed that the best concentrations capable of promoting the highest mortality of the isolates of Staphylococcus spp. from mastitis in goats, were 6250, 3125 and 1562.5μg/mL, respectively. By the microplate adherence test, it was found that 20.78% isolates were not able to form biofilm, 14.70% were classified as moderate and 64.70% were weak and none as a strong biofilm producer. Propolis in its different diluents was able to affect the formation of biofilm and showed a pronounced marked antimicrobial activity against Staphylococcus spp. strains and may be indicated for use in in vivo studies.
This study aimed to analyze the details of collection of floral resources (pollen and nectar) by honeybees (Apis mellifera) on male and hermaphrodite flowers of melon (Cucumis melo). The experiments were conducted in areas located at Embrapa Semiárido and Embrapa Produtos e Mercado, Petrolina, state of Pernambuco, in November and December 2011, with crop of a hybrid yellow 10/00 F1 melon. Honeybee colonies housed in Langstroth hives, uniform concerning the number of individuals and brood area were used. The four experimental areas (0.5 ha each), received respectively 0, 1, 2 and 3 hives, from the first day on which the hermaphrodite flowers appeared to the end of the flowering period of the melon crop. The results showed that the bees visited more the hermaphrodite than the male flowers, in order to collect the resources (pollen and nectar), in all areas where honeybee hives were placed. In general, independently from the number of hives, the resource most collected was nectar. Pollen collection occurred mainly at the first hours of the morning, while nectar was collected throughout the day.
Studying the pollinators' foraging behaviour is quite important for pollination. Time spent by the pollinator in floral handling is one of the aspects of this behaviour. Honeybees (Apis mellifera) are the main responsible for the pollination of melon (Cucumis melo), but there are few studies on their foraging, mainly in the region of Petrolina, state of Pernambuco, and Juazeiro, state of Bahia, in Brazil. This study aimed to compare bee visitation to hermaphrodite (HF) and male (MF) flowers in a crop area where different number of hives were used. For each floral type, 10 flowers were observed, in each experiment (0, 1, 2 or 3 hives). The duration of bee visits (n = 10) was registered in three times of the day: 8 a.m., 11 a.m., and 4 p.m. In general, HF received significantly longer visits than MF, in all experiments, except when using one hive. In fact, significant correlations were found between the duration of visits and number of hives for HF, but not for MF. This is probably related to the attractiveness of HF and to the availability of floral resources. The studies of duration of pollinator' visits are relevant in agriculture and should be considered when evaluating the efficiency of pollination in melon.
Frieseomelitta doederleini honeys from semiarid region of the Northeast of Brazil are presented. The melissopalynological analysis showed two principal pollen types of Mimosa tenuiflora (jurema preta) and Shinus sp (aroeira). The chemical profile data obtained by UPLC-DAD-qTOF-MS/MS of the Mimosa tenuiflora flowers (principal pollen of honey) and the five samples of F. doederleini honeys both flowers and honey showed similar profile. Abelha branca honeys samples had similar characteristic profile of phenolic compounds (flavonoids), and also antiradical activity. The main flavonoids identified in the honey samples in the jurema preta flowers were flavonols/flavone and flavanols/flavanones aglycones. All the flavonoids identified showing that the nectar collected by the bees may be from this plant species. The antiradical activity of the honey samples strongly correlated with their phenolic content. Among the minerals analyzed, potassium was the most abundant, followed by magnesium.
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