Chromatographic refining of the EtOAc extract of a solid rice culture of the hypersaline lake-derived fungus Penicillium simplicissimum strain WSH17 afforded a new linear antibacterial peptide quinoisobutyride A (1) along with three known metabolites (2-4). The chemical structure of 1 was unambiguously determined based on extensive 1D and 2D NMR spectroscopic analyses together with HRESIMS. In addition, Marfey’s derivatization method along with biogenetic considerations were used to determine the absolute configuration of its amino acids’ entities. Interestingly, in this study we distinguished a new unusual heterocyclic amino acid which is comprised as a unit of compound 1. Among the isolated compounds, only 1 revealed a promising antibacterial activity against Staphylococcus aureus (ATCC700699) with a MIC value of 2.72 μM (2.0 μg/mL). Moreover, citrinamide A (3) was the only isolated compound that showed a cytotoxic activity against human epithelial colorectal adenocarcinoma (Caco-2) cell line with an IC₅₀ value of 12.76 μM (5.5 μg/mL).

所述超坚实稻培养的EtOAc萃取物的色谱精制淀衍生真菌简青霉菌株WSH17得到一个新的线性抗菌肽quinoisobutyride A（1）配有三个已知的代谢物（沿2 - 4）。的化学结构1被明确地确定基于广泛的一维和二维NMR光谱与HRESIMS一起分析。此外，使用Marfey的衍生化方法以及生物遗传因素来确定其氨基酸实体的绝对构型。有趣的是，在这项研究中，我们区分了一个新的不寻常的杂环氨基酸，它是化合物1的一个单元。在分离出的化合物中，只有1种显示出对金黄色葡萄球菌（ATCC700699）的有希望的抗菌活性，MIC值为2.72μM（2.0μg/ mL）。此外，柠檬酰胺A（3）是唯一显示出对人上皮结肠直肠腺癌（Caco-2）细胞具有细胞毒活性且IC ₅₀值为12.76μM（5.5μg / mL）的化合物。