Organic Synthesis and Process Chemistry Department, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 007, India; Department of Biotechnology, Acharya Nagarjuna University, Nagarjuna Nagar, Guntur 522 510, India.
Centre for Mass Spectrometry, Analytical & Structural Chemistry Department, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 007, India.
Bioorg Chem. 2021 Oct;115:105180. doi: 10.1016/j.bioorg.2021.105180. Epub 2021 Jul 17.
Marine microbes secrete exopolymeric substances (EPS), which surrounds the biofilm and inhibits the fungal growth. Elucidation of the structure and function of the extracellular exopolymeric substances is of vital relevance therapeutically. The active compound responsible for bioactivity was purified and characterized using TLC, LC/MS/MS, GC/MS and FT-IR. Bioactivity of the characterized cyclic peptides (CLPs) against azole resistant and susceptible Candida strains were examined for growth and biofilm formation using scanning electron microscopy, flow cytometry, confocal microscopy. In the present study we identified bioactive cyclic peptides from marine isolated Neobacillus drentensis that exhibited promising tensio-active properties and antifungal efficacy against azole resistant and susceptible Candida albicans. The cluster is composed of five CLP isoforms which were sequenced and identified as new peptides with compositional and structural variations in the amino acid sequence and fatty acid chain. In vitro cytotoxic activity of CLPs was tested in human fibroblast normal cells. We have observed that the CLPs repressed the Candida albicans growth and multiplication by inhibiting the biofilm formation and disruption of branching filamentous hyphae. CLPs have been found to arrest the C. albicans cell cycle by a block at G1-S transition followed by apoptotic cell death. The current studies suggest these natural marine derived CLPs function as potential anti-biofilm agents against azole C. albicans resistant strains.
海洋微生物分泌胞外多聚物（EPS），这些物质包围着生物膜并抑制真菌生长。阐明胞外多聚物的结构和功能在治疗上具有至关重要的意义。负责生物活性的活性化合物使用 TLC、LC/MS/MS、GC/MS 和 FT-IR 进行了纯化和表征。使用扫描电子显微镜、流式细胞术、共聚焦显微镜检查了表征的环状肽（CLP）对唑类耐药和敏感念珠菌菌株的生长和生物膜形成的生物活性。在本研究中，我们从海洋分离的新类芽孢杆菌中鉴定出具有生物活性的环状肽，它们表现出有前途的表面活性特性和抗唑类耐药和敏感白色念珠菌的功效。该簇由五个 CLP 同工型组成，对其进行测序并鉴定为具有组成和结构变化的新肽，在氨基酸序列和脂肪酸链中。在体外，用人成纤维细胞正常细胞测试了 CLP 的细胞毒性。我们观察到 CLP 通过抑制生物膜形成和破坏分枝丝状菌丝来抑制白色念珠菌的生长和繁殖。已经发现 CLP 通过在 G1-S 转换时阻断细胞周期并随后导致细胞凋亡来阻止白色念珠菌细胞的增殖。目前的研究表明，这些天然海洋衍生的 CLP 可作为抗唑类白色念珠菌耐药菌株的潜在抗生物膜剂。
