Seven New and Two Known Lipopeptides as well as Five Known Polyketides: The Activated Production of Silent Metabolites in a Marine-Derived Fungus by Chemical Mutagenesis Strategy Using Diethyl Sulphate
作者:Chang-Jing Wu、Chang-Wei Li、Cheng-Bin Cui
DOI:10.3390/md12041815
日期:——
AD-2-1 is an antitumor fungal mutant obtained by diethyl sulfate mutagenesis of a marine-derived Penicillium purpurogenum G59. The G59 strain originally did not produce any metabolites with antitumor activities in MTT assays using K562 cells. Tracing newly produced metabolites under guidance of MTT assay and TLC analysis by direct comparison with control G59 extract, seven new (1–7) and two known (8–9) lipopeptides were isolated together with five known polyketides 10–14 from the extract of mutant AD-2-1. Structures of the seven new compounds including their absolute configurations were determined by spectroscopic and chemical evidences and named as penicimutalides A–G (1–7). Seven known compounds were identified as fellutamide B (8), fellutamide C (9), 1′-O-methylaverantin (10), averantin (11), averufin (12), nidurufin (13), and sterigmatocystin (14). In the MTT assay, 1–14 inhibited several human cancer cell lines to varying extents. All the bioassays and HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses demonstrated that the production of 1–14 in the mutant AD-2-1 was caused by the activated production of silent metabolites in the original G59 fungal strain. Present results provided additional examples for effectiveness of the chemical mutagenesis strategy using diethyl sulphate mutagenesis to discover new compounds by activating silent metabolites in fungal isolates.
AD-2-1 是一种抗肿瘤真菌突变体,它是通过硫酸二乙酯诱变海洋源青霉菌 G59 获得的。在使用 K562 细胞进行的 MTT 试验中,G59 菌株原本不产生任何具有抗肿瘤活性的代谢物。在 MTT 试验和 TLC 分析的指导下,通过与对照 G59 提取物的直接比较,对新产生的代谢物进行了追踪,从突变体 AD-2-1 的提取物中分离出了七种新的(1-7)和两种已知的(8-9)脂肽,以及五种已知的多酮类化合物 10-14。通过光谱和化学证据确定了七种新化合物的结构及其绝对构型,并将其命名为青霉酰胺 A-G(1-7)。七个已知化合物被鉴定为fellutamide B (8)、fellutamide C (9)、1′-O-methylaverantin (10)、averantin (11)、averufin (12)、nidurufin (13) 和 sterigmatocystin (14)。在 MTT 试验中,1-14 对几种人类癌细胞株有不同程度的抑制作用。所有生物测定和高效液相色谱-光电二极管阵列检测器(PDAD)-紫外和高效液相色谱-电子喷雾电离(ESI)-质谱分析表明,突变体 AD-2-1 中 1-14 的产生是由原始 G59 真菌菌株中沉默代谢物的活化产生引起的。本研究结果为利用硫酸二乙酯诱变的化学诱变策略通过激活真菌分离物中的沉默代谢物来发现新化合物的有效性提供了更多实例。