*4.8. Antifungal E*ff*ects*

The antifungal effects of macroalgae were also assessed by many studies. Species such as *E. cava* were found to have potential as a novel antifungal agen<sup>t</sup> against *T. rubrum* at an MIC of dieckol of 200 μM [168], while *Halimeda tuna* methanolic extracts were very effective against *Aspergillus niger*, *Aspergillus flavus*, *Aspergillus alternaria*, *Candida albicans*, and *Epidermophyton floccosum* [7]. Studies of Ertürk et al. [169] evaluated the antifungal activity of *Enteromorpha linza* and *Padina pavonica*, and it was found to be stronger than the standard antifungal activity (100 units of nystatin) against *Aspergillus niger* and *Candida albicans*. Instead, the acetone extract of *T. conoides* exerted a mild antifungal capability against *Aspergillus niger*, with an inhibition zone diameter close to 3 mm [170]. In a study performed on 45 chronic asthmatic patients with acute respiratory distress, Mickymaray et al. [171] observed the highest antifungal activity against *C. albicans* in the case of *L. paniculata*, followed by *U. prolifera*, *Cladophoropsis* sp., *A. specifera*, and *Tydemania* sp. ethanolic fraction extracts. The minimum fungicidal concentration and MIC values of the above algal ethanolic fractions ranged between 125 and 1000 μg/mL and 125 and 500 μg/mL, respectively [171].

Like most bioactivities of algae, the antifungal activity of seaweed extracts can be related to the presence of phenolic compounds, polyunsaturated fatty acids, and various terpenoids [172,173]. For example, bromophenols were successfully isolated from the red alga *Odonthalia corymbifera*, and others obtained by chemical transformation of bis(hydroxyphenyl)methanes with bromine were tested for antimicrobial and antifungal activities by Oh et al. [174]. Among the natural bromophenols, 2,2,3,3-tetrabromo-4,4,5,5-tetrahydroxydiphenylmethane isolated from *Odonthalia corymbifera* showed good antifungal activity against *C. albicans*, *A. fumigatus*, *T. rubrum*, and *T. mentagrophytes* while

two of the synthesized compounds exhibited e ffective antibacterial activity against *S. aureus*, *B. subtilis*, *M. luteus*, *P. vulgaris*, and *S. typhimurium* [174].
