Antibacterial activity of the phlorotannins dieckol and phlorofucofuroeckol-A from Ecklonia cava against Propionibacterium acnes

Abstract

Methanol extract of the marine brown alga Ecklonia cava has been shown to exhibit antimicrobial activity against Propionibacterium acnes. To identify the compounds conferring this antimicrobial activity, methanol extract was fractionated using silica-gel column chromatography by increasing solvent polarity, and the antimicrobial activities of each fraction were determined in terms of the minimum inhibitory concentration. Hexane, diethyl ether, acetone, ethyl acetate, acetonitrile, methanol, and water fractions were generated, with the acetone fraction exhibiting the greatest antibacterial activity (minimum inhibitory concentration = 156 μg/mL). The acetone fraction was further purifi ed by Sephadex LH-20 column chromatography and reverse-phase HPLC using an Alltima C18 column with an H 2 O-MeOH linear gradient from 30 to 100%. Two peaks were eluted at 18.1 (P1) and 23.8 (P2) min, both of which exhibited marked antibacterial activity (minimum inhibitory concentration = 39 μg/mL for both). The structures of these compounds were determined on the basis of 1 H and 13 C nuclear magnetic resonance data and, through comparison with published data, can be phloroglucinol derivatives dieckol (P1) and phlorofucofuroeckol-A (P2). These results suggest that phlorotannins derived from E. cava have antimicrobial activity against P. acnes, and so may be useful as natural additives in antiacne cosmetics and pharmaceutical products. Keywords: dieckol, minimum inhibitory concentration, natural additives, phlorofucofuroeckol-A, phlorotannins.Resumen: Se conoce que el extracto de metanol del alga parda marina Ecklonia cava presenta actividad antimicrobiana contra Propionibacterium acnes. Para identifi car los compuestos que confi eren esta actividad antimicrobiana se fraccionó el extracto de metanol, usando cromatografía en columna de sílica gel, mediante el aumento de la polaridad del disolvente. La actividad antimicrobiana de cada fracción se determinó en términos de la concentración mínima inhibitoria. Las fracciones de hexano, éter dietílico, acetona, acetato de etilo, acetonitrilo, metanol y agua fueron producidas. La fracción de acetona presentó la mayor actividad antibacteriana (concentración mínima inhibitoria = 156 μg/mL). Con base en este resultado, la fracción de acetona se purifi có por cromatografía en columna en LH-20 Sephadex y HPLC de fase inversa usando una columna Alltima C18 con un gradiente lineal de H 2 O-MeOH de 30 a 100%. Dos picos se eluyeron a 18.1 (P1) y 23.8 (P2) min, ambos tuvieron actividad antibacteriana marcada (concentración mínima inhibitoria = 39 μg/mL para ambos). La estructura de estos compuestos se determinó sobre la base de 1 H y 13 C de resonancia magnética nuclear y, mediante la comparación con valores publicados, éstos pueden ser derivados de fl oroglucinol diecol (P1) y fl orofucofuroecol-A (P2). Los resultados sugieren que fl orotaninos derivados de E. cava tienen actividad antimicrobiana frente a P. acnes, y por lo tanto, pueden ser útiles como aditivos naturales en los cosmético...

Virucidal and Synergistic Activity of Polyphenol-Rich Extracts of Seaweeds against Measles Virus

“… a Confirmed with Mass Spectroscopy (MS) fragmentation and European MassBank results; b Confirmed with Mass Spectroscopy (MS) fragmentation and Phenol-Explores 3.6 results; c Confirmed based on Choi et al [ 22 ]. …”

The Quest for Phenolic Compounds from Macroalgae: A Review of Extraction and Identification Methodologies

“…At last, size exclusion chromatography (SEC-CC) using Sephadex LH-20 has been repeatedly used in the fractionation of macroalgae polar extracts [60,76,77,88,115,151,156,157,174,175,[177][178][179][180][181][182]. The separation of compounds in Sephadex LH-20 is promoted by the metabolites' molecular size, but also by its solubility in the eluent.…”

“…Reversed-phase (RP) HPLC columns have been the most used in macroalgae phenolic rich extracts [32,39,62,73,157,159,169,173,180,182,[186][187][188][189]. Octadecyl ("C18" or "ODS") has been the most used stationary phase, with a particle size of 5 µm.…”

“…Purification of dieckol with purity > 95% from SEC-CC fraction[157,182]. Purification of dieckol and phlorofucofuroeckol A from SEC-CC fraction[180].Ecklonia kuromeSeparation of dieckol, 974-B, 974-A, phlorofucofuroeckol B and phlorofucofuroeckol A from RP-CC fraction[159].…”

Pharmaceutical properties of marine polyphenols: an overview

“…Thereby, phlorotannins-β-lactam antibiotics combinations exert a synergistic effect against MRSA, indicating the promising treatment of MRSA infections. In addition, it has shown that phlorofucofuroeckol-A from E. cava and E. bicyclis exhibited effective inhibition against Propionibacterium acnes, which may be useful as natural additives in anti-acne cosmetic products 86,87 . Although the relationship between the structure and anti-bacterial activity of the phlorotannins is limited, their inhibitory activity may be suggested to depend on the degree of polymerization of phlorotannin derivatives.…”