Polyphenolic content and pharmacological potential of french BFA propolis extracts

Propolis, or bee glue, is a natural resinous hive product collected by honeybees from buds and exudates of various trees and plants. Mixed with beewax and salivary enzymes, it is employed to fill cracks and embalm dead invaders in the hive. Propolis has been used in folk medecine since ancien times due to its pharmacological potential associated with antioxidant, antifungal, antibacterial as well as antitumoral properties. A batch of various French propolis extracts, supplied by “Ballot-Flurin Apiculteurs” (BFA), a company located in the South-West of France and specialized in apitherapy products, was fractionated and analysed by HPLC/MS. Its qualitative chemical composition highlights the presence of polyphenols such as hydroxycinnamic acid derivatives and flavonoids. Total polyphenol content and antioxidant activities were evaluated on six BFA propolis extracts, using respectively Folin-Ciocalteu, DPPH and ORAC assays. Preliminary antifungal (Candida albicans) and antibacterial (Staphylococcus aureus) evaluations will also be given

Normal phase HPLC profiling of the acetylcholinesterase activity in apolar plant extracts

Among nineteen evaluated Clusiaceous species, one stem bark CH2Cl2 crude extract was selected based on a significant inhibition of acetylcholinesterase (AChE) using the micro-dilution Ellman\u27s method [1]. A normal phase HPLC profiling with micro-fractionation of this extract provided discrete fractions every 20 seconds. In order to obtain a comprehensive profiling of AChE activity all microfractions were tested [2] in dilution assay (Ellman) as well as by bioautography (the Fast Blue B salt method). Furthermore the potency of inhibition was evaluated both by keeping the genuine concentration within the extract and after normalisation to a standard concentration level. From the active fractions five pure compounds were isolated and identified. The different methods of sample preparation and biological evaluation associated with normal-phase micro-fractionation of plant extracts are critically discussed

Delineating noncovalent interactions between the azinomycins and double-stranded DNA: Importance of the naphthalene substitution pattern on interstrand cross-linking efficiency

Using a series of synthetic azinomycin analogues, it is shown that the efficiency of in vitro DNA interstrand cross-linking is markedly reduced when either the C-5' methyl group or both the C-5' methyl and C-3' methoxy groups are deleted from the naphthalene ring.</p

Normal phase HPLC-based activity profiling of non-polar crude plant extracts – acetylcholinesterase inhibiting guttiferones from &lt;i&gt;Montrouziera cauliflora&lt;/i&gt; as a case study

The study describes bioactive compounds as inhibitors of acetylcholinesterase (AChE), from the stem bark extract of Montrouziera cauliflora, selected among 19 dichloromethane extracts from Clusiaceae species. Our work focused on the development of an original normal phase HPLC microfractionation strategy to rapidly assess highly active zones from this crude active non-polar plant extract. Two different microfraction collection methods were evaluated for the assessment of the AChE inhibition. Two guttiferones and a tocotrienol were directly isolated among five compounds identified off-line by NMR after upscaling the fractionation and their AChE inhibition was evaluated. The strengths and weaknesses of the two microfractionation collection methods for HPLC-AChE activity-based profiling are discussed