Microbial Screening Technologies, Smithfield, NSW, 2164, Australia.
School of Natural Sciences, Macquarie University, Macquarie Park, NSW, 2109, Australia.
J Antibiot (Tokyo). 2024 Mar;77(3):147-155. doi: 10.1038/s41429-023-00688-x. Epub 2023 Dec 18.
Talcarpones A (1) and B (2) are rare bisnaphthazarin derivatives produced by Talaromyces johnpittii (ex-type strain MST-FP2594), a newly discovered Australian fungus, which is formally described and named herein. The talcarpones were isolated along with the previously reported monomeric naphthoquinone, aureoquinone (3), suggesting a biosynthetic link between these metabolites. Talcarpone A is a lower homologue of hybocarpone (4), which was first isolated from a mycobiont of the lichen Lecanora hybocarpa. The structures of 1 and 2 were elucidated by detailed spectroscopic analysis, molecular modelling and comparison with literature data. Talcarpones 1 and 2 exhibited moderate antifungal activity (MIC 0.78-3.1 µg ml) and weak activity against Gram-positive bacteria (MIC 13-25 µg ml). The talcarpones also demonstrated noteworthy chemical reactivities, with 2 converting rapidly to 1, which in turn converted slowly to the highly coloured 3. These post-biosynthetic reactions point to a potential ecological role for the talcarpones in providing ongoing (slow-release) physicochemical protection for T. johnpittii against solar irradiation.
塔卡尔酮 A（1）和 B（2）是由澳大利亚新发现的真菌帚状青霉（ex-type 菌株 MST-FP2594）产生的罕见双萘嵌苯醌衍生物，本文对其进行了正式描述和命名。这两种塔卡尔酮与先前报道的单体萘醌化合物金壳菌素（3）一起被分离出来，这表明这些代谢产物之间存在生物合成联系。塔卡尔酮 A 是 hybocarpone（4）的低同系物，后者最初是从地衣 Lecanora hybocarpa 的真菌共生体中分离出来的。通过详细的光谱分析、分子建模和与文献数据的比较，阐明了 1 和 2 的结构。塔卡尔酮 1 和 2 表现出中等的抗真菌活性（MIC 0.78-3.1μg/ml）和较弱的抗革兰氏阳性菌活性（MIC 13-25μg/ml）。这些塔卡尔酮还表现出显著的化学反应性，2 迅速转化为 1，1 又缓慢转化为颜色很深的 3。这些生物合成后反应表明，塔卡尔酮可能在为帚状青霉提供持续（缓慢释放）物理化学保护方面发挥了潜在的生态作用，使其免受太阳辐射的影响。
