Investigation of chemical keys for relationship between plants and their unifloral honeys by hydrodistillation and SPME and biological activities of honeys

Bioactivity and Chemical Characterization of Sudanese Bee Honey: Crude Acacia and Its Organic Extracts

Honey has recently been rediscovered as an antibacterial and wound-healing natural product. The medicinal properties of honey originate from the floral source used by bees. The objective of the current study was to evaluate the antimicrobial activity of Sudanese crude acacia bee honey and its solvent extracts regarding its biological activity and chemical characterization. To verify the nature of the antibacterial agent(s) of honey, sample (A) Sudanese crude unprocessed acacia bee honey obtained from west of Sudan (Nyala) during October 2019 was tested in vitro for antibacterial activity against 10 standard microorganisms Enterobacter aerogenes: ATCC: 13048, Enterococcus faecalis: ATCC: 29212, Escherichia coli: ATCC: 25922, Klebsiella pneumoniae: ATCC: 700603, Pseudomonas aeruginosa: ATCC: 27853, Serratia marcescens: ATCC: 8100, Staphylococcus aureus: ATCC: 29213, Staphylococcus epidermidis: ATCC: 12228, Staphylococcus Methicillin Sensitive MSSA: ATCC: 29213, and Staphylococcus Methicillin-Resistant MRSA: ATCC: 23591. Extraction of honey sample was carried out by petroleum ether followed by ethyl acetate using liquid/liquid extraction technique, using separating funnels. All organic extracts in addition to their aqueous residue were tested in vitro for antibacterial activity against the10 standard microorganisms. Ethyl acetate extract was subjected to gas chromatography-mass spectrometer (GC-MS) for chemical characterization. Sudanese crude unprocessed acacia honey showed inhibitory effects against the 10 standard microorganisms. Petroleum ether extract showed no antibacterial activity against the tested organisms, while its water residue exhibited remarkable activity. The ethyl acetate extract exhibited strong antibacterial activity against the tested organisms, while its aqueous residue showed no activity. Ethyl acetate extract subjected to gas chromatography-mass spectrometer (GC-MS) showed twenty-one chemical constituents. The GC-MS showed twenty-one chemical compounds, and phenolic compound was the highest concentration. Ethyl acetate extract exhibited strong antibacterial activity which can be formulated as topical dressing for wounds and burns. The usage of honey in a professional context should be taken into consideration while treating burns and wounds.

Quality, composition and health-protective properties of citrus honey: A review

Citrus honey is one of the most important monofloral honeys produced and consumed worldwide. This honey has pleasant sensorial characteristics, which include light color and typical aroma and flavor. Besides that, several constituents such as minerals, phenolic and volatile compounds, amino acids, sugars, enzymes, vitamins, methylglyoxal and organic acids are found in citrus honey. Moreover, potential biological properties have been associated with citrus honey. All these factors make it highly desired by consumers, increasing its market value, which can stimulates the practice of fraud. Also, citrus honey is susceptible to contamination and to inadequate processing. All these factors can compromise the quality, safety and authenticity of citrus honey. In this sense, this review aims to update and to discuss, for the first time, the data available in the literature about the physicochemical and the sensorial characteristics, composition, health properties, contamination, authenticity and adulteration of citrus honey. With this background, we aim to provide data that can guide future researches related to this honey.

Strong insecticidal potential of methanol extract of Ferulago trifida fruits against Anopheles stephensi as malaria vector

Many researchers have focused on controlling pest insects and vectors by natural products because of their low environmental pollution. The present study was conducted to evaluate the antioxidant and larvicidal activities of chloroform and methanol extracts of the leaves, fruits, roots, and isolated coumarin compounds (prantschimgin, oxypeucedanin, and 6-hydroxymethylherniarin) of Ferulago trifida from the Apiaceae family against Anopheles stephensi as one of the main malaria vectors. For insecticidal evaluation, A. stephensi larvae were exposed to different concentrations of the extracts and pure compounds (0.625-1280 ppm) according to the WHO protocol. The mortality percentages were measured 24 h after treatment and lethal concentration values were calculated. In addition, radical scavenging activities of the mentioned extracts and compounds were measured by the DPPH method. The methanol extract of fruits showed potent insecticidal properties with LC₅₀ and LC₉₀ values of 2.94 and 18.12 ppm, respectively. The chloroform extracts of the fruits and leaves were the second and third extracts with larvicidal effects. Among pure compounds, only oxypeucedanin showed moderate toxicity against A. stephensi with LC₅₀ and LC₉₀ values of 116.54 and 346.41 ppm, respectively. The antioxidant activities of the methanol extracts of leaves and fruits were stronger than other extracts with IC₅₀ values of 155.83 and 159.32 ppm, respectively. In conclusion, the methanol extract of F. trifida fruits can be used as a potent bio-insecticide in green control programs of mosquitoes, especially A. stephensi.

Comparative analysis of volatile compound profiles of propolis from different provenances

BACKGROUND

Propolis is a complex mixture that honey bees produce from the exudates of various plants and presents many medicinal properties. Its chemical composition varies according to the phytogeography characteristics of each region, among others. The aim of this study was to identify and characterize the volatile organic compounds (VOCs) present in Venezuelan propolis and compare with reference samples such as Brazilian and Argentinian propolis.

RESULTS

A total of 90 VOCs were identified in a series of propolis samples using both solid-phase microextraction and dynamic headspace (DHS), both coupled to a gas chromatograph-electron ionization mass spectrometer. In the case of Venezuelan propolis, sesquiterpenes, esters, aromatic compounds, and aliphatic hydrocarbons were identified. Limonene was found only in Venezuelan samples, this being the first time it has been identified in samples from this country. In the case of green propolis, β-caryophyllene and nerolidol were the major compounds. As for the Argentinian samples, prenyl acetate, benzyl acetate, and 2-phenylethyl acetate were detected only in these samples.

CONCLUSIONS

Possible chemical markers of natural sources such as limonene were detected using DHS extraction. Several compounds have also been identified for the first time in Venezuelan propolis. Cluster analysis allowed the relating of the propolis VOCs profile to their provenance. © 2017 Society of Chemical Industry.