Thirteen compounds were isolated from the aerial parts of Hypericum kelleri Bald., growing as an endemic on the island of Crete (Greece). These compounds comprise four previously unknown prenylated xanthones 1,2-dihydro-3,8-dihydroxy-6-methoxy-1,1,5-tri(3-methylbut-2-enyl)xanthen-2,9-dione (kellerine A), 1,2-dihydro-3,6,8-trihydroxy-1,1,5-tri(3-methylbut-2-enyl)xanthen-2,9-dione (kellerine B), 1,2-dihydro-3,8-dihydroxy-6-methoxy-1,1-bi(3-methylbut-2-enyl)xanthen-2,9-dione (6-methylpatulone), (R/S)-1,3,5-trihydroxy-2-(3-methyl-2-buten-1-yl)-4-[2-(3-methylbut-2-enyl)-3-methylbut-3-enyl]-6-methoxy-9H-xanthen-9-one ((2″R/S)-kellerine C) and the hitherto undescribed depsidone (R/S)-1,3,6-trihydroxy-5-methoxy-2-(3-methyl-2-buten-1-yl)-4-[2-(3-methylbut-2-enyl)-3-methylbut-3-enyl]-11Η-dibenzo[b,e] [1,4]dioxepin-9-one ((2″R/S)-creticine). As known compounds, brevipsidone D, 4-geranyl-2-(2'-isobutyryl)-phloroglucinol, 4-geranyl-2-(2'-methylbutyryl)-phloroglucinol, I3, II8-biapigenin, quercetin, avicularin, pseudohypericin and neochlorogenic acid have been isolated. The structures were elucidated on the basis of their 1D, 2D NMR, CD and MS data. The study confirms the typical occurrence of xanthones in Hypericum section Oligostema (Boiss.) Stef., and is also the first report on the simultaneous isolation of acylphloroglucinols in this section. Furthermore the first evidence of depsidones in the genus Hypericum L. is reported. Cytotoxicity was investigated in HeLa cells for prenylated xanthones and the depsidones. Both triprenylated 1,2-dihydroxanthones (kellerine A and B) showed significant in vitro cytotoxicity with IC50 values of 2.5 ± 0.1 (kellerine A) and 5.9 ± 0.9 (kellerine B) μM, whereas other compounds were less cytotoxic (IC50 > 20 μM).

中文翻译：

---

来自克里特岛（希腊）特有种金丝桃属植物的酚类代谢物

从作为克里特岛（希腊）特有种生长的金丝桃的地上部分分离出 13 种化合物。这些化合物包含四种以前未知的异戊二烯化氧杂蒽酮 1,2-dihydro-3,8-dihydroxy-6-methoxy-1,1,5-tri(3-methylbut-2-enyl)xanthen-2,9-dione (kellerine A ), 1,2-dihydro-3,6,8-trihydroxy-1,1,5-tri(3-methylbut-2-enyl)xanthen-2,9-dione (kellerine B), 1,2-dihydro- 3,8-二羟基-6-甲氧基-1,1-bi(3-methylbut-2-enyl)xanthen-2,9-dione (6-methylpatulone), (R/S)-1,3,5-trihydroxy -2-(3-甲基-2-丁烯-1-基)-4-[2-(3-甲基丁-2-烯基)-3-甲基丁-3-烯基]-6-甲氧基-9H-xanthen-9 -一种 ((2″R/S)-kellerine C) 和迄今为止未描述的地苯丙胺酮 (R/S)-1,3,6-trihydroxy-5-methoxy-2-(3-methyl-2-buten-1- yl)-4-[2-(3-methylbut-2-enyl)-3-methylbut-3-enyl]-11H-二苯并[b,e][1,4]dioxepin-9-one((2″R /S)-肌酸）。作为已知化合物，brevipsidone D、4-香叶基-2-(2'-异丁酰基)-间苯三酚、4-香叶基-2-(2'-甲基丁酰基)-间苯三酚、I3、II8-biapigenin、槲皮素、鸟苷、假金丝桃素和新绿原酸已被分离。根据其一维、二维 NMR、CD 和 MS 数据阐明了结构。该研究证实了金丝桃属植物Oligostema (Boiss.) Stef.中氧杂蒽酮的典型存在，也是该部分同时分离酰基间苯三酚的首次报道。此外，报道了金丝桃属植物中地昔酮的第一个证据。在 HeLa 细胞中研究了异戊二烯化氧杂蒽酮和地塞酮的细胞毒性。三异戊二烯化 1,2-二氢氧杂蒽酮（kellerine A 和 B）均显示出显着的体外细胞毒性，IC50 值为 2.5 ± 0.1（kellerine A）和 5.9 ± 0。