Huang Jiwu, Li Chuangjun, Ma Jie, Xu Kailing, Chen Xinyi, Jiang Jiandong, Zhang Dongming
State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.
Phytochemistry. 2021 Jun;186:112746. doi: 10.1016/j.phytochem.2021.112746. Epub 2021 Mar 31.
Seven undescribed compounds, namely (+)-psiflavanone A, (-)-psiflavanone A, (+)-psiflavanone B, (-)-psiflavanone B, (+)-psiketide, (-)-psiketide, and psidinone, were isolated and chirally separated from the 95%-ethanol extract of Psidium guajava leaves. (+)/(-)-Psiflavanone A and (+)/(-)-psiflavanone B are two pairs of rare enantiomeric C-benzoylated flavanones isolated from the title plant for the first time. (+)/(-)-Psiketide are a pair of enantiomeric aromatic polyketides, and psidinone is the first example of a C phenanthrenediquinone with an angle-type 6/6/6 tricyclic skeleton. Their structures were identified by extensive analysis of HRESIMS, UV, IR, NMR, and calculated electronic circular dichroism (ECD) data. Particularly, the structures of (+)-psiflavanone A, (-)-psiflavanone A, (+)-psiflavanone B, and psidinone were further confirmed by X-ray diffraction. Psidinone exhibited antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, and Mycobacterium Smegmatis mc 155, with minimum inhibitory concentrations (MICs) of 16, 8, and 0.5 μM, respectively. These results not only highlight the chemical diversity and biological activity of P. guajava but are also expected to pave way for its further expansion to other applications in future.
从番石榴叶的95%乙醇提取物中分离并手性拆分得到了7种未描述的化合物，即(+)-番石榴黄酮A、(-)-番石榴黄酮A、(+)-番石榴黄酮B、(-)-番石榴黄酮B、(+)-番石榴酮、(-)-番石榴酮和番石榴二酮。(+)/(-)-番石榴黄酮A和(+)/(-)-番石榴黄酮B是首次从该植物中分离得到的两对罕见的对映体C-苯甲酰化黄烷酮。(+)/(-)-番石榴酮是一对对映体芳香族聚酮化合物，番石榴二酮是具有角型6/6/6三环骨架的C-菲醌的首个实例。通过对高分辨电喷雾电离质谱（HRESIMS）、紫外光谱（UV）、红外光谱（IR）、核磁共振（NMR）以及计算得到的电子圆二色光谱（ECD）数据进行广泛分析，确定了它们的结构。特别地，(+)-番石榴黄酮A、(-)-番石榴黄酮A、(+)-番石榴黄酮B和番石榴二酮的结构通过X射线衍射进一步得到证实。番石榴二酮对金黄色葡萄球菌、表皮葡萄球菌和耻垢分枝杆菌mc155具有抗菌活性，其最低抑菌浓度（MIC）分别为16、8和0.5 μM。这些结果不仅突出了番石榴的化学多样性和生物活性，也有望为其未来在其他应用方面的进一步拓展铺平道路。
