Antialgal Activity of Several Cyanobacterial Exometabolites

Abstract

The isolation of norharmalane (3,4-dihydro-9H-pyrido(3,4-b)indole) from culture media of the cyanobacterium Nodularia harveyana is described. The minimum toxic quantities against selected cyanobacteria of this compound, of the two known cyanobacterial exometabolites 4,4 -dihydroxybiphenyl and norharmane (9H-pyrido(3,4-b)indole) and in addition of harmane (1-methyl-9H-pyrido(3,4-b)indole) were determined using a special TLC plate assay. The three β-carbolines harmane, norharmane and norharmalane were tested both as bases and as hydrochlorides. All four test compounds were found to be cytotoxic against the cyanobacterial test organisms in low quantities (0.5 to 18.0 μg). For the β-carbolines the following structure-response relationships were revealed: the double bond in position 3-4 and possibly the 1-methyl-group increased the cytotoxic effect of these indole alkaloids. Minimum toxic quantities detected for β-carboline bases were in general lower than those of equimolar amounts of the corresponding hydrochlorides. The possible applicability of both β-carbolines and biphenyls as agents in antifouling systems is discussed.

Cyanobacterial Natural Products for the Inhibition of Biofilm Formation and Biofouling

“…[37] This compound was later shown in athin layer chromatography assay to have a' minimum toxic quantity' ranging from 1-4 µ ga gainst Arthrospira laxissima, Chroococcus minutus, Nostoc carneum, Nostoc insulare , Synechocystis aquatilis and Synechococcus sp. [38] These values complemented earlier studies by Kodani et al,w hich showed inhibition at 30 µ g/disk against ap anel of algae. [39] In µ Ma gainst ap anel of five cyanobacteria after twod ays of incubation.…”

Allelopathic activity of the norharmane-producing cyanobacterium Synechocystis aquatilis against cyanobacteria and microalgae

“…high EC50 values). These results partially correspond with earlier studies demonstrating that harmane and norharmane inhibited the growth of cyanobacteria rather than green algae (Kodani et al 2002, Volk 2006. However, our study showed that green algae can be affected by norharmane particularly at the high concentration used in the experiment (10 µg ml -1 ).…”

“…Among substances produced by some strains of cyanobacteria and exhibiting the growth inhibition towards phytoplankton organisms are harmane and norharmane (Kodani et al 2002;Volk 2005Volk , 2006Volk, Furkert 2006;Volk, Mundt 2007), and nostocarboline (Blom et al 2006). Due to their natural origin, most allelopathic compounds will not only be biodegradable but also less polluting than traditional synthetic chemicals (Macías et al 2008;Park et al 2006a,b), which means that most allelochemicals have short half lives compared to synthetic pesticides.…”

Controlling of Microbial Growth by Using Cystoseira barbata Extract

“…Many compounds of marine algae show anti-bacterial activities as polysaccharide (Laurienzo, 2010), lyengaroside (Ali et al, 2002), polyhydroxy lated fucophlorethol (Sandsdalen et al, 2003), bromophenols (Oh et al, 2008), guaiane sesquiterpene (Chakraborty & Lipton, 2010), lactone malyngolide (Cardelina et al, 1979) cycloeudesmol (Sims et al, 1975), polyphenolic compound (Devi, 2008), halogenated compound (Vairappan, 2003) and quinone metabolite (Horie et al, 2008). Flavonoids comprise a large group of naturally compounds widely distributed in the algae and some of these compounds have been reported to contain various and potent biological activities including anti oxidative tissue protective and tumoristatic effects as well as the inhibition of hepatic cholesterol biosynthesis (Krant et al, 2005;Kim et al, 2007;Matanjun et al, 2008 andVolk, 2009). Indeed, marine algae contain polyphenols, carotenoids and flavonoids as antioxidants, protect the body's tissues against oxidative stress and associated pathologies such as cancer and inflammation (Tapiero et al, 2002).…”