Cytotoxic and antibacterial naphthoquinones from an endophytic fungus, Cladosporium sp. (2016)

• Record Type: Journal Article
• Authors: Khan, Md. Imdadul Huque; Sohrab, Md. Hossain; Rony, Satyajit Roy; Tareq, Fakir Shahidullah; Hasan, Choudhury Mahmood; Mazid, Md. Abdul
• Is Part Of: Toxicology reports. Volume 3(2016)
• Page Start: 861
• Page End: 865
• Publication Date: 2016
• Subjects: Anhydrofusarubin (PubChem CID: 157509) -- Methyl ether of fusarubin (PubChem CID: 14050831) -- Triton X-100 (PubChem CID: 5590) -- Hydrogen Peroxide (PubChem CID: 784); Endophytic fungi -- Cladosporium species -- Fusarubin -- Cytoxicity -- Antibacterial activity; Toxicology -- Periodicals; Clinical toxicology -- Periodicals; Drug-Related Side Effects and Adverse Reactions; Hazardous Substances; Poisoning; Toxicology; Electronic journals; Periodicals; Periodicals; 571.9505
• DOI: 10.1016/j.toxrep.2016.10.005
• Languages: English
• ISSNs: 2214-7500

Abstract

Abstract: Objective: Endophytes have the potential to synthesize various bioactive secondary metabolites. The aim of the study was to find new cytotoxic and antibacterial metabolites from endophytic fungus, Cladosporium sp. isolated from the leaves of Rauwolfia serpentina (L.) Benth. ex Kurz. (Fam: Apocyanaceae). Materials and methods: The endophytic fungus was grown on potato dextrose agar medium and extracted using ethyl acetate. Secondary metabolites were isolated by chromatographic separation and re-crystallization, and structures were confirmed by 1 H NMR, 13 C NMR and mass spectroscopic data. The cytotoxicity was determined by WST-1 assay and brine shrimp lethality bioassay, while antibacterial activity was assessed by disc diffusion method. Results: Two naphthoquinones, namely anhydrofusarubin (1 ) and methyl ether of fusarubin (2), were isolated from Cladosporium sp. The isolated compounds1 and2, by WST-1 assay against human leukemia cells (K-562) showed potential cytotoxicity with IC50 values of 3.97 μg/mL and 3.58 μg/mL, respectively. Initial screening of crude ethyl acetate extract and column fractions F-8 and F-10 exhibited noticeable cytotoxicity to brine shimp nauplii with LC50 values of 42.8, 1.2 and 2.1 μg/mL, respectively. Moreover, the isolated compound 2 (40 μg/disc) showed prominent activities against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus megaterium with an average zone of inhibition of 27 mm, 25 mm, 24 mm and 22 mm, respectively and the activities were compared with kanamycin (30 μg/disc). Conclusion: Our findings indicate that anhydrofusarubin (1 ) and methyl ether of fusarubin (2 ) might be useful lead compounds to develop potential cytotoxic and antimicrobial drugs.