Institut für Pharmazeutische Biologie und Biotechnologie, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, Geb. 26.23, 40225 Düsseldorf, Germany.
J Nat Prod. 2013 Jun 28;76(6):1099-104. doi: 10.1021/np4001366. Epub 2013 May 28.
The endophytic fungus Penicillium citrinum was isolated from a fresh stem of the Moroccan plant Ceratonia siliqua. Extracts of P. citrinum grown on rice and white bean media yielded five new compounds, namely, citriquinochroman (1), tanzawaic acids G and H (2 and 3), 6-methylcurvulinic acid (4), 8-methoxy-3,5-dimethylisoquinolin-6-ol (5), and one new natural product, 1,2,3,11b-tetrahydroquinolactacide (6), which had previously been described as a synthetic compound. In addition, 13 known compounds including seven alkaloids and six polyketides were isolated. The structures of the new compounds were unambiguously determined on the basis of one- and two-dimensional NMR spectroscopy as well as by high-resolution mass spectrometry. Citriquinochroman (1) features a new skeleton, consisting of quinolactacide and (3S)-6-hydroxy-8-methoxy-3,5-dimethylisochroman linked by a C-C bond. 1,2,3,11b-Tetrahydroquinolactacide (6) may be a biogenetic precursor of quinolactacide. Citriquinochroman (1) showed cytotoxicity against the murine lymphoma L5178Y cell line with an IC50 value of 6.1 μM, while the other compounds were inactive (IC50 >10 μM) in this assay.
从摩洛哥植物刺槐的新鲜茎中分离出内生真菌青霉。从大米和白豆培养基中生长的青霉提取物中得到了五个新化合物，分别为桔青霉素（1）、坦扎瓦酸 G 和 H（2 和 3）、6-甲基弯曲酸（4）、8-甲氧基-3,5-二甲基异喹啉-6-醇（5）和一种新的天然产物 1,2,3,11b-四氢喹诺拉酸（6），以前曾被描述为一种合成化合物。此外，还分离出了 13 种已知化合物，包括 7 种生物碱和 6 种聚酮化合物。新化合物的结构根据一维和二维 NMR 光谱以及高分辨率质谱法得到了明确的确定。桔青霉素（1）具有一个新的骨架，由喹诺拉酸和（3S）-6-羟基-8-甲氧基-3,5-二甲基异吲哚通过 C-C 键连接而成。1,2,3,11b-四氢喹诺拉酸（6）可能是喹诺拉酸的生物合成前体。桔青霉素（1）对 L5178Y 鼠淋巴瘤细胞系表现出细胞毒性，IC50 值为 6.1 μM，而其他化合物在该测定中均无活性（IC50>10 μM）。
