RESUMEN
Brazilian Red Propolis is a resinous material produced by Apis mellifera bees through the collection of the exudates of Dalbergia ecastaphyllum, rich in flavonoids, and Symphonia globulifera and Clusia species, which are rich in polyprenylated benzophenones. More than 200 compounds, including flavonoids and polyprenylated benzophenones have been found in Brazilian red propolis. The objective of the present study was to evaluate the chemical composition and antiviral activity of an ethanolic extract of red propolis from Alagoas, Brazil, against Herpes Simplex Virus (HSV-1). In the HPLC-PDA-ESI-MS/MS analysis were detected flavanones, isoflavones, chalcones, pterocarpans and polyprenylated benzophenones. The measurement of antiviral activity of red propolis extract was performed by DNA quantification through quantitative real-time PCR assay and negative staining Electron Microscopy. The pretreatment, post-treatment, and virucide assays using ethanolic extract of red propolis with concentration of 8, 12, 24, 48, or 96 µg/mL, indicated an inhibition of the viral binding and viral entry into cells as well as the replication of HSV-1. In the electron microscopy imaging was observed the disruption of the viral membrane in the HSV-1 treated with red propolis, when compared with HSV-1 that was treated with phosphate buffered saline alone, indicating that ethanolic extract from red propolis can act directly on the viral envelope, through lipid membrane degradation and/or directly blocking the enriched proteins on the viral surface.
RESUMEN
Three new caged polyprenylated benzophenone derivatives named burlemarxiones D-F (1-3) were isolated from the hexane extract of Clusia burle-marxii trunks. Burlemarxione D (1) contains the tetracyclo[8.3.1.03,11.05,10]tetradecane core skeleton also observed for burlemarxione A, its probable immediate precursor. However, two additional rings are formed to produce an unprecedented complex-caged core skeleton. These additional rings could be formed by a radical cyclization reaction of one prenyl group at C-5 with C-1 and C-33, followed by oxidative dehydrogenation (rearomatization) or by an intramolecular [4 + 2] radical cycloaddition (Diels-Alder reaction), followed by an enolization reaction (rearomatization). Burlemarxiones E and F were isolated after methylation with diazomethane that was necessary to avoid the interconversion of the pair of ß-diketones in tautomeric equilibrium. The proposed biosynthetic pathway for burlemarxiones D-F involves the condensation of either lavandulyl pyrophosphate or 2-(1-methylvinyl)-hexa-5-enyl pyrophosphate with the acylphloroglucinol derivative 6-benzoyl-5-hydroxy-5-cyclohexen-1,3-dione, followed by consecutive prenylation reactions. Therefore, Clusia burle-marxii reinforces the claim that the genus Clusia is an important source of sophisticated caged polyprenylated benzophenone derivatives.
Asunto(s)
Benzofenonas/química , Clusia/química , Benzofenonas/aislamiento & purificación , Brasil , Estructura Molecular , Fitoquímicos/química , Fitoquímicos/aislamiento & purificación , PrenilaciónRESUMEN
Three new polyprenylated benzophenone derivatives (1-3) were identified in the hexane extract of Clusia burle-marxii trunks, through the isolation and structural elucidation of their methyl derivatives, along with two known polyprenylated benzophenone derivatives sampsonine N (4) and obdeltifolione C (5). Burlemarxiones A (1) and B (2) show an unprecedent tetracyclo[8.3.1.03,11.05,10]tetradecane core skeleton. These compounds are a pair of ß-diketones in tautomeric equilibrium, whereas isonemorosonol (3) is the respective ß-diketone pair in tautomeric equilibrium with nemorosonol. Burlemarxione A methyl derivative (1a) and sampsonine N exhibited strong in vitro cytotoxic activity against GL-15 glioblastoma-derived human cell line.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Benzofenonas/farmacología , Clusia/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Benzofenonas/aislamiento & purificación , Brasil , Línea Celular Tumoral , Glioblastoma/tratamiento farmacológico , Humanos , Fitoquímicos/aislamiento & purificación , Fitoquímicos/farmacologíaRESUMEN
ABSTRACT Garcinia brasiliensis Mart., Clusiaceae, species became the target of studies for some years because it has several compounds including polyprenylated benzophenones, as 7-epiclusianone. This benzophenone has several properties, such as leishmanicidal, anti-inflammatory and antinociceptive effects, however still did not be studied anxiolytic activity. For this, the open field and elevated plus maze tests were used in order to evaluate the effect of administration of 7-epiclusianone (isolated from G. brasiliensis) on behavioral performance. Swiss male mice (n = 10 per group) were pre-treated with vegetable oil (10 ml/kg; i.p.) or 7-epiclusianone (1, 3 or 10 mg/kg, i.p.) or diazepam (0.2 mg/kg, i.p.). After 1 h, the animals were submitted to the open field and elevated plus maze tests. The administration of 7-epiclusianone exerted a possible anxiolytic effect in the open field, increased the number of central crossings and anti-tigmotactic effect. In pre-treated group with 7-epiclusianone (10 mg/kg) was also possible to determine a possible anxiolytic effect in the elevated plus maze due to increased permanence of animals in the open arms. The results suggest a possible anxiolytic-like effect presented by the 7-epiclusianone and suggest its potential for the treatment of anxiety.
RESUMEN
Lipophilic compounds of Brazilian Red Propolis (BRP) have received increasing attention due to some interesting findings regarding their biological activities. This study was first aimed at evaluating the chemical composition of BRP n-hexane extract (HEXred) by UPLC-MS-PDA. Chemical investigation mainly resulted in the identification of polyprenylated benzophenones (PPBs) in this extract, named oblongifolin A, guttiferone E, and/or xanthochymol. After that, an isocratic HPLC-UV method was validated for the determination of total content of PPBs (at 260 nm) expressed as garcinol, a commercially available guttiferone E diastereoisomer. The method showed to be specific, precise, accurate, and linear (0.1-10 µg/mL) for the determination of PPBs in HEXred, BRP-loaded nanoemulsions, as well as, in porcine skin and mucosa samples after permeation/retention studies. The matrix effect was determined for all complex matrices, demonstrating low effect during the analysis. The stability-indicating method was verified by submitting HEXred to acidic, alkaline, oxidative, and thermal stress conditions. No interference of degradation products was detected during analysis. Therefore, the proposed analytical and bioanalytical methods proved to be simple and reliable for the determination of PPBs in the presence of different matrices.