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Marine organisms including bacteria, fungi, algae, sponges, echinoderms, mollusks, and cephalochordates produce a variety of products with antifungal activity including bacterial chitinases, lipopeptides, and lactones; fungal (-)-sclerotiorin and peptaibols, purpurides B and C, berkedrimane B and purpuride; algal gambieric acids A and B, phlorotannins; 3,5-dibromo-2-(3,5-dibromo-2-methoxyphenoxy)phenol, spongistatin 1, eurysterols A and B, nortetillapyrone, bromotyrosine alkaloids, bis-indole alkaloid, ageloxime B and (-)-ageloxime D, haliscosamine, hamigeran G, hippolachnin A from sponges; echinoderm triterpene glycosides and alkene sulfates; molluscan kahalalide F and a 1485-Da peptide with a sequence SRSELIVHQR; and cepalochordate chitotriosidase and a 5026.9-Da antifungal peptide. The antiviral compounds from marine organisms include bacterial polysaccharide and furan-2-yl acetate; fungal macrolide, purpurester A, purpurquinone B, isoindolone derivatives, alterporriol Q, tetrahydroaltersolanol C and asperterrestide A, algal diterpenes, xylogalactofucan, alginic acid, glycolipid sulfoquinovosyldiacylglycerol, sulfated polysaccharide p-KG03, meroditerpenoids, methyl ester derivative of vatomaric acid, lectins, polysaccharides, tannins, cnidarian zoanthoxanthin alkaloids, norditerpenoid and capilloquinol; crustacean antilipopolysaccharide factors, molluscan hemocyanin; echinoderm triterpenoid glycosides; tunicate didemnin B, tamandarins A and B and; tilapia hepcidin 1-5 (TH 1-5), seabream SauMx1, SauMx2, and SauMx3, and orange-spotted grouper β-defensin. Although the mechanisms of antifungal and antiviral activities of only some of the aforementioned compounds have been elucidated, the possibility to use those known to have distinctly different mechanisms, good bioavailability, and minimal toxicity in combination therapy remains to be investigated. It is also worthwhile to test the marine antimicrobials for possible synergism with existing drugs. The prospects of employing them in clinical practice are promising in view of the wealth of these compounds from marine organisms. The compounds may also be used in agriculture and the food industry., Competing Interests: None.

A monomeric 9.4-kDa peptide with antifungal activity was isolated from seeds of Phaseolus vulgaris cv Legumi secchi by using a protocol that involved affinity chromatography on Blue-Sepharose, ion exchange chromatography on Q-Sepharose, and gel filtration on Superdex 75. It was adsorbed on Blue-Sepharose and unadsorbed on Q-Sepharose. Its N-terminal sequence resembled those of other leguminous defensins. It impeded mycelial growth in the fungi Helminthosporium maydis, Rhizoctonia solani, Mycosphaerella arachidicola, and Fusarium oxysporum with an IC(50) value of 9.5, 3.5, 1, and 9.2 μM, respectively, but there was no effect on Valsa mali. SYTOX Green uptake by R. solani indicated that the antifungal peptide induced fungal membrane permeabilization. In contrast to the majority of previously reported defensins/defensin-like peptides, Legumi secchi antifungal peptide did not reduce the viability of MCF-7 breast cancer cells and HepG2 hepatoma cells or inhibit HIV-1 reverse transcriptase, indicating a dissociation between antifungal, antiproliferative and HIV-1 reverse transcriptase inhibitory activities.

Introduction: Invasive fungal infection (IFI) is a serious problem due to difficulties in early diagnosis and high mortality. Different approaches are adopted for the treatment and management of IFI, including prophylactic, empiric, preemptive and directed strategies., Areas Covered: This paper reviews the type of pharmacotherapy used for antifungal prophylaxis in infants with extremely low birth weights, pediatric patients with cardiac disease, preterm neonates, pediatric oncology patients, adult cancer patients with neutropenia, adult patients with hematologic malignancy, hematopoietic stem-cell transplantation recipients, organ transplant recipients, HIV-infected patients, immunosuppressed patients treated with moderate or high doses of corticosteroids, and patients with invasive fusariosis, candidemia, invasive candidiasis, systemic mycoses and immunocompromised patients., Expert Opinion: Azole drugs are the drugs most often used in cost-effective antifungal prophylaxis of patients with conditions such as immunodeficiency and cancer, which render them highly susceptible to IFI. Fluconazole is the most outstanding example. However, there are many azoles with different pharmacological characteristics that the physician can choose from. Echinocandins have favorable characteristics that make them useful for treating Candida infections. Antibodies, or their engineered derivatives directed against cell-wall polysaccharides and glycopeptides, and some protein epitopes of Candida albicans, appear to be a promising novel approach for prophylaxis against Candida infection and deserve further in-depth investigations.

A monomeric 5.5-kDa protein with hemolytic activity toward rabbit erythrocytes was isolated from seeds of Albizia lebbeck by using a protocol that involved ion-exchange chromatography on Q-Sepharose and SP-Sepharose, hydrophobic interaction chromatography on Phenyl-Sepharose, and gel filtration on Superdex 75. It was unadsorbed on both Q-Sepharose and SP-Sepharose, but adsorbed on Phenyl-Sepharose. Its hemolytic activity was fully preserved in the pH range 0-14 and in the temperature range 0-100 °C, and unaffected in the presence of a variety of metal ions and carbohydrates. The hemolysin reduced viability of murine splenocytes and inhibited proliferation of MCF-7 breast cancer cells and HepG2 hepatoma cells with an IC₅₀ of 0.21, 0.97, and 1.37 μM, respectively. It impeded mycelial growth in the fungi Rhizoctonia solani with an IC₅₀ of 39 μM but there was no effect on a variety of other filamentous fungi, including Fusarium oxysporum, Helminthosporium maydis, Valsa mali and Mycosphaerella arachidicola. Lebbeckalysin inhibited growth of Escherichia coli with an IC₅₀ of 0.52 μM., (Copyright © 2010 Elsevier GmbH. All rights reserved.)

A dimeric 34-kDa antifungal protein, designated as acafusin, was purified from Acacia confusa seeds using Q-Sepharose, DEAE-cellulose, Mono S and Superdex S75. It demonstrated antifungal activity toward Rhizoctonia solani with an IC(50) of 28 microM. Acafusin inhibited the activity of HIV-1 reverse transcriptase mildly with an IC(50) of 80 microM.

A 60 kDa antifungal amidase was purified from Peltophorum pterocarpum [corrected] seeds using an isolation procedure that entailed ion-exchange chromatography on Q-Sepharose, ion-exchange chromatography on DEAE-cellulose and FPLC-gel filtration on Superdex 75. Unlike most other antifungal proteins isolated previously, it was adsorbed on Q-Sepharose and DEAE-cellulose. The isolated protein, designated as peltopterin, exhibited an N-terminal amino acid sequence closely resembling those of amidases. It exhibited amidase activity and digested iodoacetamide with an optimum pH and temperature at pH 9 and 50 degrees C, respectively. It also hydrolyzed acrylamide and urea. It impeded mycelial growth in Rhizotonia solani with an IC(50) of 0.65 microm. Chitin deposition at hyphal tips in R. solani was observed by staining with Congo red after incubation with peltopterin. Its antifungal activity was stable throughout pH 0-14 and 25-100 degrees C. It potently inhibited HIV-1 reverse transcriptase with an IC(50) of 27 nm., (2009 John Wiley & Sons, Ltd.)

From the seeds of Acacia confusa, a chitinase-like antifungal protein designated as acaconin that demonstrated antifungal activity toward Rhizoctonia solani with an IC₅₀ of 30±4 µM was isolated. Acaconin demonstrated an N-terminal sequence with pronounced similarity to chitinases and a molecular mass of 32 kDa. It was isolated by chromatography on Q-Sepharose, SP-Sepharose and Superdex 75 and was not bound by either ion exchanger. Acaconin was devoid of chitinase activity. The antifungal activity against Rhizoctonia solani was completely preserved from pH 4 to 10 and from 0°C to 70°C. Congo Red staining at the tips of R. solani hyphae indicated inhibition of fungal growth. However, there was no antifungal activity toward Mycosphaerella arachidicola, Fusarium oxysporum, Helminthosporium maydis, and Valsa mali. Acaconin inhibited proliferation of breast cancer MCF-7 cells with an IC₅₀ of 128±9 µM but did not affect hepatoma HepG2 cells. Its IC₅₀ value toward HIV-1 reverse transcriptase was 10±2.3 µM. The unique features of acaconin include relatively high stability when exposed to changes in ambient pH and temperature, specific antifungal and antitumor actions, potent HIV-reverse transcriptase inhibitory activity, and lack of binding by strongly cationic and anionic exchangers.

A protein exhibiting an N-terminal amino acid sequence with some similarity to imidazoleglycerol phosphate synthase was purified from fresh Capparis spinosa melon seeds. The purification protocol entailed anion exchange chromatography on DEAE-cellulose, cation exchange chromatography on SP-Sepharose, and finally gel filtration by fast protein liquid chromatography on Superdex 75. The protein was adsorbed using 20 mM Tris-HCl buffer (pH 7.4) and desorbed using 1 M NaCl in the starting buffer from the DEAE-cellulose column and SP-Sepharose column. The protein demonstrated a molecular mass of 38 kDa in gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that it was monomeric. The protein inhibited proliferation of hepatoma HepG2 cells, colon cancer HT29 cells and breast cancer MCF-7 cells with an IC(50) of about 1, 40 and 60 microM, respectively. It inhibited HIV-1 reverse transcriptase with IC(50) of 0.23 microM. It inhibited mycelial growth in the fungus, Valsa mali. It did not exhibit hemagglutinating, ribonuclease, mitogenic or protease inhibitory activities.