Rapid Determination of Major Compounds in the Ethanol Extract of Geopropolis from Malaysian Stingless Bees, Heterotrigona itama, by UHPLC-Q-TOF/MS and NMR

Metabolomics analysis of (Geo)propolis from Brazilian stingless bees by FIA and UHPLC-HRMS (Orbitrap)

Native stingless bees (Meliponini) from Brazil make (geo)propolis which is largely used in folk medicine, specially by indigenous and quilombos communities and beekeepers´ families but are progressively being recognized for their pharmacological activities. In this study, the ethanolic extracts of (geo)propolis (EEGs) from Melipona marginata, M. quadrifasciata, M. scutellaris, and Tetragonisca angustula were analysed by Flow injection analysis (FIA) and Ultra-high performance liquid chromatography (UHPLC) in a high resolution Orbitrap mass analyser (HRMS) to investigate and compare their chemical profile. Untargeted metabolomic approach based on UHPLC-HRMS experiments, and bioinformatic tools, allowed to annotate 59 compounds from diverse classes such as: flavonoids, phenolic compounds, sugars, terpenoids, and lipids. In addition, using multivariate tools and Flow injection- high resolution mass spectrometry (FIA-HRMS), it was possible to classify samples and identify marker ions related to the bee species or genus and to the geographical origin as a proof of concept.

Antimicrobial, Cytotoxic, and α-Glucosidase Inhibitory Activities of Ethanol Extract and Chemical Constituents Isolated from Homotrigona apicalis Propolis-In Vitro and Molecular Docking Studies

The chemical investigation of Homotrigona apicalis propolis collected in Binh Dinh province, Vietnam, led to the isolation of nine compounds, including four sesquiterpenes: spathulenol (1), 1αH,5βH-aromandendrane-4β,10α-diol (2), 1β,6α-dihydroxy-4(15)-eudesmene (3), and 1βH,5βH-aromandendrane-4α,10β-diol (4); three triterpenes: acetyl oleanolic acid (5), 3α-hydroxytirucalla-8,24-dien-21-oic acid (6), and ursolic acid (7); and two xanthones: cochinchinone A (8) and α-mangostin (9). Sesquiterpens 1-4 and triterpene 6 were isolated for the first time from stingless bee propolis. Plants in the Cratoxylum and Aglaia genus were suggested as resin sources of the propolis sample. In the antibacterial activity evaluation, the EtOH extract only showed moderate activity on S. aureus, while the isolated compounds 7-9 showed good antibacterial activity, with IC50 values of 0.56 to 17.33 µg/mL. The EtOH extract displayed selective cytotoxicity against the A-549 cancer cell line, with IC50 values of 22.82 ± 0.86 µg/mL, and the xanthones 8 and 9 exhibited good activity against the KB, HepG-2, and A-549 cancer cell lines, with IC50 values ranging from 7.55 ± 0.25 µg/mL to 29.27 ± 2.07 µg/mL. The cytotoxic effects of xanthones 8 and 9 were determined by the inhibition of the EGFR and HER2 pathways using a molecular docking study. Compounds 8 and 9 displayed strong binding affinity with EFGR and HER2, with values of -9.3 to -9.9 kcal/mol. Compounds 5, 8, and 9 showed potential α-glucosidase inhibitory activities, which were further confirmed by computational studies. The binding energies of compounds 5, 8, and 9 were lower than that of arcabose.

Bee Species, Botanical Sources and the Chemical Composition of Propolis from Yucatan, Mexico

Propolis is used by corbiculated bees to protect the bee hive; it is mostly used to seal cracks, to reduce or prevent microbial growth and to embalm invaders. Different factors have been reported to influence the chemical composition of propolis, including bee species and the flora surrounding the hive. Nevertheless, the majority of the studies are focused on propolis produced by Apis mellifera, while studies on the chemical composition of propolis produced by stingless bees are still limited. In this investigation, the chemical composition of 27 propolis samples collected in the Yucatan Peninsula from A. mellifera beehives, together with 18 propolis samples from six different species of stingless bees, were analyzed by GC-MS. Results showed that lupeol acetate and β-amyrin were the characteristic triterpenes in propolis samples from A. mellifera, while grandiflorenic acid and its methyl ester were the main metabolites present in samples from stingless bees. Multivariate analyses were used to explore the relationship between bee species and botanical sources on the chemical composition of the propolis samples. Differences in body size and, therefore, foraging abilities, as well as preferences for specific botanical sources among bee species, could explain the observed variation in propolis chemical composition. This is the first report on the composition of propolis samples from the stingless bees Trigona nigra, Scaptotrigona pectoralis, Nannotrigona perilampoides, Plebeia frontalis and Partamona bilineata.

LC-MS/MS Characterization of Phenolic Metabolites and Their Antioxidant Activities from Australian Native Plants

Polyphenols are considered vital bioactive compounds beneficial for human health. The Australian flora is enriched with polyphenols which are not fully characterized yet. Thus, the main objective of this study was to identify and characterize the Australian native sandalwood nuts, wattle seeds, lemongrass, and old man saltbush for phenolic compounds and their antioxidant activities. In this study, we tentatively identified a total of 155 phenolic compounds including 25 phenolic acids, 55 flavonoids, 22 isoflavonoids, 22 tannins, 22 lignans, 33 stilbenes, 33 coumarins and derivatives, 12 tyrosols and derivatives, and 6 phenolic terpenes. The highest total phenolic content (TPC) (15.09 ± 0.88 mg GAE/g) was quantified in lemongrass, while the lowest TPC (4.17 ± 0.33 mg GAE/g) was measured in wattle seeds. The highest total flavonoid content (TFC) and total condensed tannins (TCT) were measured in lemongrass and wattle seeds, respectively. A total of 18 phenolic metabolites were quantified/semi-quantified in this experiment. Lemongrass contains a vast number of phenolic metabolites.

A Comparative Study for Nutritional and Phytochemical Profiling of Coffea arabica (C. arabica) from Different Origins and Their Antioxidant Potential and Molecular Docking

Coffee is the most widely used beverage globally and contains many bioactive compounds, including phenolic compounds, alkaloids, triterpenes, organic acids, amino acids, hormones, and fatty acids. The main objective of this study was the comparative profiling of Australian, Colombian, Ethiopian, and Peruvian C. arabica using LC-ESI-QTOF-MS/MS. In this study, we tentatively identified 136 bioactive metabolites, including five (05) organic acids, six (06) alkaloids, three (03) amino acids (l-phenylalanine, l-tyrosine, and l-pyroglutamic acid), two (02) hormones (melatonin and serotonin), two fatty acids, one (01) furopyrans (goniothalenol), one (01) carotenoid (crocetin), three (03) terpenoids, thirty-eight (38) phenolic acids, forty-one (41) flavonoids, five (05) stilbenes, three (03) lignans and twenty-three (23) other polyphenols in C. arabica. The highest TPC value (17.74 ± 0.32 mg GAE/g) was measured in Colombian coffee while the lowest TPC value (10.24 ± 0.73 mg GAE/g) was in Peruvian coffee. Colombian coffee has a higher antioxidant potential than other studied coffee samples. A total of nineteen phenolic metabolites were mapped through LC-MS/MS. Quinic acid derivatives were quantified in higher concentrations than other metabolites. Furthermore, molecular docking predicted that chlorogenic acid is a main bioactive compound that contributes to anti-Alzheimer and anti-diabetic activities of C. arabica. The obtained results indicate that C. arabica contains a vast number of bioactive compounds which have potential health benefits. Furthermore, research could be conducted to validate the effect of these metabolites on the flavor profile of coffee beverages.

Rapid LC-MS/MS detection of different carbapenemase types in carbapenemase-producing Enterobacterales

Klebsiella pneumoniae carbapenemase (KPC)-2, metallo-beta-lactamases (MBL), and oxacillinase (OXA)-48-like carbapenemases are considered the most important carbapenemases. In vitro studies have demonstrated that the carbapenemase activity of KPC-2 and MBL can be inhibited by 3-aminophenylboronic acid and ethylenediaminetetraacetic acid (EDTA), respectively. Understanding the carbapenemase types expressed in carbapenem-resistant Enterobacterales (CRE) is of great significance to clinical therapies. Liquid chromatography-coupled tandem mass spectrometry (LC-MS/MS) is fast, stable, and specific; and is considered the gold standard method for measuring small molecules. In this study, we developed carbapenemase inhibition tests combined with LC-MS/MS to rapidly identify carbapenemase types. A total of 295 clinical isolates were examined, including 212 KPC-2 producers, 29 MBL producers, 15 OXA-48-like producers, 3 KPC-2 + OXA-232 producers, and 36 carbapenem-sensitive strains. We used LC-MS/MS to determine the carbapenemase types by measuring the ratio of the hydrolyzed meropenem peak areas in the presence and absence of different inhibitors. The sensitivity and specificity of LC-MS/MS in detecting single KPC-2 producers were 97.64% and 100.00%, respectively, and 96.55% and 100.00% for MBL producers, respectively. In addition, the sensitivity and specificity of LC-MS/MS in detecting single OXA-48-like producers were both 100.00% when extending incubation time up to 2.5 h. LC-MS/MS showed excellent agreement in detecting carbapenemase types using the modified carbapenem inactivation (mCIM)/EDTA-carbapenem inactivation assay (eCIM) (kappa = 0.93 for serine carbapenemases and kappa = 0.98 for MBL carbapenemases). In this study, LC-MS/MS demonstrated excellent detection of different carbapenemase types, showing potential reliability in future clinical applications.

Antiviral, Antibacterial, Antifungal, and Antiparasitic Properties of Propolis: A Review

Propolis is a complex phytocompound made from resinous and balsamic material harvested by bees from flowers, branches, pollen, and tree exudates. Humans have used propolis therapeutically for centuries. The aim of this article is to provide comprehensive review of the antiviral, antibacterial, antifungal, and antiparasitic properties of propolis. The mechanisms of action of propolis are discussed. There are two distinct impacts with regards to antimicrobial and anti-parasitic properties of propolis, on the pathogens and on the host. With regards to the pathogens, propolis acts by disrupting the ability of the pathogens to invade the host cells by forming a physical barrier and inhibiting enzymes and proteins needed for invasion into the host cells. Propolis also inhibits the replication process of the pathogens. Moreover, propolis inhibits the metabolic processes of the pathogens by disrupting cellular organelles and components responsible for energy production. With regard to the host, propolis functions as an immunomodulator. It upregulates the innate immunity and modulates the inflammatory signaling pathways. Propolis also helps maintain the host's cellular antioxidant status. More importantly, a small number of human clinical trials have demonstrated the efficacy and the safety of propolis as an adjuvant therapy for pathogenic infections.

Propolis of stingless bees: A phytochemist's guide through the jungle of tropical biodiversity

BACKGROUND

Stingless bees (Meliponini), like honeybees Apis mellifera, collect plant resins in order to produce propolis (cerumen, geopropolis). This type of propolis has long been used in traditional medicine in Mexico, Brazil, Argentina, India, and Vietnam, as a remedy for improving health and treating various diseases. The scientific and commercial interest in stingless bee propolis has been steadily increasing over the last few years. The new and growing knowledge in this field requires systematising, as a basis for further work. Recent reviews of Meliponini propolis deal only with the South American and Mesoamerican species, while reviews of the Asian, Australian and African species are missing. Furthermore, the chemical composition has not been thoroughly reviewed since 2007.

PURPOSE

This review summarises and discusses the available data about the chemical composition of propolis from the stingless bee species (Meliponinae) of the Americas, Asia and Australia, published after 2007. The published information on the biological action of chemically characterised Meliponini propolis, and of individual constituents, is addressed. The plant sources of this propolis are also considered.

CONCLUSION AND PERSPECTIVES

Chemical studies of Meliponini propolis has resulted in the discovery of new natural molecules, some of them with valuable bioactivity. Moreover, finding known molecules in propolis stimulates the study of their pharmacological properties. The enormous chemical variability of stingless bee propolis is a challenge to chemists, entomologists and pharmacologists. It is essential to perform pharmacological studies with only chemically characterised propolis of stingless bees. Further studies are required to chemically characterise and scientifically support the medicinal properties of stingless bee propolis and to clarify the potential for its commercial use. This could lead to increased prices for Meliponinae propolis and provide an additional source of income for farmers in rural communities with most serious social needs.

Untargeted Ultrahigh-Performance Liquid Chromatography-Hybrid Quadrupole-Orbitrap Mass Spectrometry (UHPLC-HRMS) Metabolomics Reveals Propolis Markers of Greek and Chinese Origin

Chemical composition of propolis depends on the plant source and thus on the geographic and climatic characteristics of the site of collection. The aim of this study was to investigate the chemical profile of Greek and Chinese propolis extracts from different regions and suggest similarities and differences between them. Untargeted ultrahigh-performance liquid chromatography coupled to hybrid quadrupole-Orbitrap mass spectrometry (UHPLC-HRMS) method was developed and 22 and 23 propolis samples from Greece and China, respectively, were analyzed. The experimental data led to the observation that there is considerable variability in terms of quality of the distinctive propolis samples. Partial least squares - discriminant analysis (PLS-DA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) models were constructed and allowed the identification of significant features for sample discrimination, adding relevant information for the identification of class-determining metabolites. Chinese samples overexpressed compounds that are characteristic of the poplar type propolis, whereas Greek samples overexpress the latter and the diterpenes characteristic of the Mediterranean propolis type.

The Strong Anti-Kinetoplastid Properties of Bee Propolis: Composition and Identification of the Active Agents and Their Biochemical Targets

The kinetoplastids are protozoa characterized by the presence of a distinctive organelle, called the kinetoplast, which contains a large amount of DNA (kinetoplast DNA (kDNA)) inside their single mitochondrion. Kinetoplastids of medical and veterinary importance include Trypanosoma spp. (the causative agents of human and animal African Trypanosomiasis and of Chagas disease) and Leishmania spp. (the causative agents of the various forms of leishmaniasis). These neglected diseases affect millions of people across the globe, but drug treatment is hampered by the challenges of toxicity and drug resistance, among others. Propolis (a natural product made by bees) and compounds isolated from it are now being investigated as novel treatments of kinetoplastid infections. The anti-kinetoplastid efficacy of propolis is probably a consequence of its reported activity against kinetoplastid parasites of bees. This article presents a review of the reported anti-kinetoplastid potential of propolis, highlighting its anti-kinetoplastid activity in vitro and in vivo regardless of geographical origin. The mode of action of propolis depends on the organism it is acting on and includes growth inhibition, immunomodulation, macrophage activation, perturbation of the cell membrane architecture, phospholipid disturbances, and mitochondrial targets. This gives ample scope for further investigations toward the rational development of sustainable anti-kinetoplastid drugs.

Lessons from Exploring Chemical Space and Chemical Diversity of Propolis Components

Propolis is a natural resinous material produced by bees and has been used in folk medicines since ancient times. Due to it possessing a broad spectrum of biological activities, it has gained significant scientific and commercial interest over the last two decades. As a result of searching 122 publications reported up to the end of 2019, we assembled a unique compound database consisting of 578 components isolated from both honey bee propolis and stingless bee propolis, and analyzed the chemical space and chemical diversity of these compounds. The results demonstrated that both honey bee propolis and stingless bee propolis are valuable sources for pharmaceutical and nutraceutical development.

Optimized extraction based on the terpenoids of Heterotrigona itama propolis and their antioxidative and anti-inflammatory activities

Terpenoids are the main components of stingless bee propolis, their biological activities have not been fully quantified and investigated. In this study, the single-factor design and response surface methodology were applied to optimize the terpenoids extraction process in Heterotrigona itama (also called H. itama) propolis. Furthermore, the in vitro antioxidant and anti-inflammatory activities of terpenoid-rich extract were evaluated. The results showed with 95% ethanol/5% water, a material-liquid extraction yield of 1:30 g/ml, and extraction 72 hr for three extractions, the highest terpenoids content in H. itama propolis of 46.44 ± 0.07%. The H. itama propolis terpenoid-rich extract showed relative low antioxidant effect but inhibited inflammatory response by decreasing the inflammatory mediators iNOS, IL-1β, IL-10, and increasing the antioxidant mediators HO-1. This study provided experimental parameters for the terpenoids optimal extraction from H. itama propolis and revealed their strong anti-inflammatory activity. PRACTICAL APPLICATIONS: H. itama stingless propolis is a newly founded stingless bee propolis type recently. H. itama stingless propolis has abundant terpenoids, however, scant information were provided regarding its extraction optimization. In this study, we investigated and obtained the optimal extract parameters of terpenoids in H. itama propolis，and demonstrated their strong anti-inflammatory activities; however, their antioxidant activities are relatively low. This study provided theoretical basis for the usage of H. itama stingless propolis in industry.

Cardanols detected in non-polar propolis extracts from Scaptotrigona aff. postica (Hymenoptera, Apidae, Meliponini)

Abstract The propolis produced by stingless bees of the tribe Meliponini is a viscous product that contains the resin collected from buds, leaves and plant exudates, mixed with salivary secretions, wax and soil. The species Scaptotrigona aff. postica (Latreille, 1807), (Hymenoptera, Apidae, Meliponinae) popularly known as “tubi” in Maranhão State, Brazil, does not mix soil to produce its propolis. The propolis from S. postica harvested in Barra do Corda, Maranhão State, is popularly used in the treatment of wounds and respiratory illnesses. The hydroalcoholic extract of this propolis, rich in flavone-6,8-di-C-glycosides (vicenin-2 and schaftoside), pyrrolizidine alkaloids derived from retronecine, catechin and caffeoylquinic acid derivatives exhibited antiviral activity against the herpes simplex and rubella viruses. The aim of this study was to increase knowledge about the chemical composition of the S. postica propolis by analyzing non-polar extracts obtained using hexane and chloroform as the solvents, by GC-EI-MS. A total of 15 constituents were identified comparing their respective mass spectral data with those available in the NIST data bases and those reported in the literature. The main constituents detected were the phenolic lipids, known as cardanols, 3-(4,7-heptadecadienyl) phenol (5), 3-(10-heptadecenyl) phenol (7), 3-heptadecylphenol (9) and 3-pentadecyl phenol or hydrocardanol (13), which predominated in the hexane extract, while the predominant constituents in the chloroform extract were 3-pentadecyl phenol or hydrocardanol (13) and 3-(8-pentadecenyl) phenol (12). The antioxidant, antitumoral, antifeedant, cytotoxic, anticarcinogenic, antiproliferative, antimicrobial, antileishmanial and larvicidal activities of the cardanols have been demonstrated in many studies.