Screening of Antifungal Antibiotics According to Activities Inducing Morphological Abnormalities

Gunji, Shigemichi; Arima, Kei; Beppu, Teruhiko

doi:10.1080/00021369.1983.10865911

Cited by 39 publications

(35 citation statements)

References 4 publications

(4 reference statements)

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“…The zone of growth inhibition was measured using a hand-held digital calipers. The MIC was determined by the microbroth dilution method [11]. The MIC was defined as the lowest concentration of antimicrobial agent that completely inhibited visible growth of the organism.…”

Section: Extraction and Isolationmentioning

confidence: 99%

A New 24-membered Lactone and a New Polyene δ-Lactone from the Marine Bacterium Bacillus marinus

Xue

Tian

et al. 2008

J Antibiot

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A new 24-membered macrolide macrolactin T (1), and a new polyene d-lactone macrolactin U (2), along with macrolactins A, B, D, O, and S, were isolated from the cultured broth of the bacterium Bacillus marinus, which was isolated from Suaeda salsa collected in the coastline of Bohai Sea of China. The structures of 1 and 2 were elucidated on the basis of extensive spectroscopic data analyses. The inhibitory activity of macrolactins T, B and D against fungi Pyricularia oryzae and Alternaria solani, and bacteria Staphylococcus aureus is reported.

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Section: Extraction and Isolationmentioning

confidence: 99%

A New 24-membered Lactone and a New Polyene δ-Lactone from the Marine Bacterium Bacillus marinus

Xue

Tian

et al. 2008

J Antibiot

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“…This method is useful to detect agents whose mode of action is associated with inhibition of the fungal cell wall (Fukuda et al, 1991). In addition, since fungal cells shows changes in morphological features after treatment with drugs that interfere with the biosynthesis of fungal wall (Gunji et al, 1983;Fukushima et al, 1993), the microscopical appearance of fungal hypha treated with extracts of L. pacari is also described. The stem bark was dried at 40 ºC for three days to constant weight (520 g) and later triturated.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the antifungal activity and mode of action of Lafoensia pacari A. St.-Hil., Lythraceae, stem-bark extracts, fractions and ellagic acid

Junior¹,

Raimondi²,

Zacchino³

et al. 2010

Rev. bras. farmacogn.

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RESUMO: "Avaliação da atividade antifúngica e modo de ação dos extratos da entrecasca, frações e ácido elágico de Lafoensia pacari A. St.-Hil., Lythraceae,". Os extratos, frações e ácido elágico, isolados da entrecasca de Lafoensia pacari A. St.-Hil., Lythraceae, foram testados in vitro para atividade antifúngica, frente a um painel de leveduras, hialo-hifomicetos e dermatófitos, utilizando o método de microdiluição. O extrato EtOH, frações e ácido elágico exibiram atividade contra Candida spp. e Saccharomyces cerevisiae com valores de CIM entre 250-1000 μg/mL, porém não mostraram ação contra fungos filamentosos e dermatófitos (CIM>1000 μg/mL). Os extratos ativos foram avaliados nos ensaios de inibição do crescimento das hifas de Neurospora crassa, no teste do sorbitol, e pelo estudo do efeito do ergosterol na CIM do ácido elágico. Os extratos ativos, frações e ácido elágico mostraram zonas manchadas ao redor dos discos de papel e induziram malformações nas hifas. Além disso, a CIM do ácido elágico contra Saccharomyces cerevisiae passou de 62 para 250 µg/mL na presença do sorbitol 0,8 M, sugerindo que o ácido elágico provavelmente poderia exercer ação na parede celular fúngica. Esses resultados indicam que o ácido elágico pode ser o principal composto antifúngico de Lafoensia pacari, sugerindo que o modo de ação antifúngico desses extratos e ácido elágico poderia estar associado à inibição da parede celular fúngica.Unitermos: Lafoensia pacari, mangava-brava, atividade antifúngica, extratos e frações, inibição da parede celular, ácido elágico.ABSTRACT: Stem-bark extracts, fractions and the isolated constituent, ellagic acid of Lafoensia pacari St. Hil. (Lythraceae) were in vitro assayed for antifungal activity against a panel of yeasts, hialohyphomycetes as well as dermatophytes with the microbroth dilution method. The EtOH extract and its fractions and ellagic acid exhibited activity against Candida spp and Saccharomyces cerevisiae with MIC values between 250-1000 μg/mL, but they showed no action against filamentous fungi and dermatophytes (MIC>1000 μg/mL). Active extracts were evaluated in Neurospora crassa hyphal growth inhibition and sorbitol assays and then the effect of ergosterol on the MIC of ellagic acid was studied. The active extracts and its fractions and ellagic acid showed a blotchy zone around the paper disk and induced malformations of the hypha. Besides, MIC of the ellagic acid against the Saccharomyces cerevisiae was raised from 62 to 250 µg/mL in the presence of sorbitol 0.8 M, suggesting that the ellagic acid would probably exert its action on fungal cell wall. These results indicate that ellagic acid might be the main active antifungal compound of Lafoensia pacari and further suggest that the mode of antifungal action of these extracts and ellagic acid could be associated with the inhibition of fungal cell wall.

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“…Therefore, there is a great need for novel antifungal drugs with new mechanisms of action. Morphological deformation of fungal hyphae is often induced by antifungal drugs [3]. As this phenomenon is specific to fungi, it could be used to screen for selective antifungal antibiotics [4].…”

mentioning

confidence: 99%

Identification of Phoslactomycin E as a Metabolite Inducing Hyphal Morphological Abnormalities in Aspergillus fumigatus IFO 5840

et al. 2007

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In our survey for antifungal compounds, a fermentation broth of Streptomyces sp. HA81-2 was found to inhibit the in vitro growth of Aspergillus fumigatus IFO 5840 accompanied by hyphal morphological abnormalities. One of the isolated antibiotics was identified as phoslactomycin E based on LC-MS and NMR spectral data. In a preliminary assay using the membrane fractions of A. fumigatus, phoslactomycin E was found to inhibit the activity of 1,3-b glucan synthase.Keywords antifungal activity, phoslactomycin E, Aspergillus fumigatus, hyphal morphological abnormalities, 1,3-b glucan synthase Opportunistic fungal infections are a major cause of serious morbidity and mortality in immunocompromised patients. However, there are few drugs for antifungal chemotherapy of deep-seated mycosis. As both human and fungal cells are eukaryotes, it is difficult to develop antifungal drugs without side effects in human hosts. Current targets are limited to ergosterol, cell wall components, biosynthetic pathways of cell wall and cytosine deaminase [1,2]. Therefore, there is a great need for novel antifungal drugs with new mechanisms of action. Morphological deformation of fungal hyphae is often induced by antifungal drugs [3]. As this phenomenon is specific to fungi, it could be used to screen for selective antifungal antibiotics [4]. In addition, this hyphal deformation is expected to reflect the disruption of cell wall biosynthesis, which is a specific target of antifungal agents. Moreover, investigating the mechanism of antifungal-induced hyphal morphological abnormalities is potentially useful for understanding the morphogenesis of fungal hyphae.In the course of our search for antifungal antibiotics, we found that a fermentation broth of Streptomyces sp. HA81-2 exhibited antifungal activity against Aspergillus fumigatus IFO 5840 accompanied by hyphal abnormalities. The isolated active fraction was identified as phoslactomycin E (PLME) [5] based on LC-MS and NMR spectral data. We herein report the isolation procedures for PLME, its molecular characteristics, and its induction of morphological changes in fungal cells.Active principles were isolated as follows; fermentation broth was filtered, the filtrate was applied on Diaion HP-20 column, and then eluted using an increasing gradient of aq MeOH (10ϳ100%). The 80ϳ90% MeOH fractions were concentrated in vacuo to afford crude extract, which was partitioned between water and CHCl 3 . Purification of

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Screening of Antifungal Antibiotics According to Activities Inducing Morphological Abnormalities

Cited by 39 publications

References 4 publications

A New 24-membered Lactone and a New Polyene δ-Lactone from the Marine Bacterium Bacillus marinus

A New 24-membered Lactone and a New Polyene δ-Lactone from the Marine Bacterium Bacillus marinus

Evaluation of the antifungal activity and mode of action of Lafoensia pacari A. St.-Hil., Lythraceae, stem-bark extracts, fractions and ellagic acid

Identification of Phoslactomycin E as a Metabolite Inducing Hyphal Morphological Abnormalities in Aspergillus fumigatus IFO 5840

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