Cephalotanes are a rare class of diterpenoids occurring exclusively in plants. The intriguing structures and promising biological activities for this unique compound class prompt us to investigate var. and , leading to the isolation of six undescribed cephalotane-type diterpenoids and/or norditerpenoids, ceforloids A–F (–). Their structures were elucidated by comprehensive analysis of spectroscopic data, including ECD and single-crystal X-ray diffraction studies, as well as quantum chemical calculations. Compound possesses an unprecedented norditerpenoid skeleton featuring an unusual acetophenone moiety, and originated putatively from a disparate biogenetic pathway. Compounds and incorporate a unique 12,13--hydroxybenzylidene acetal motif. Compound is a rare cephalotane-type diterpenoid glycoside. Immunosuppressive assays showed that compounds and exhibited mild suppressive activity against the activated T and B lymphocytes proliferation. These findings not only expanded the structural diversity of this small group of diterpenoids, but also explored their potential as novel structures for the development of immunosuppressive agents.

中文翻译：

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来自 Cephalotaxus Fortunei var. 的高度修饰的三尖杉烷型二萜类化合物。高山藻和中华锦藻

三尖杉烷是一类罕见的二萜类化合物，仅存在于植物中。这种独特的化合物类别的有趣结构和有前景的生物活性促使我们研究变种。和 ，导致分离出六种未描述的三尖杉烷型二萜类化合物和/或去甲二萜类化合物头孢类化合物 A–F (–)。通过对光谱数据的综合分析，包括 ECD 和单晶 X 射线衍射研究以及量子化学计算，阐明了它们的结构。该化合物拥有前所未有的去甲二萜骨架，具有不寻常的苯乙酮部分，并且推测起源于不同的生物遗传途径。化合物并包含独特的 12,13-羟基亚苄基缩醛基序。该化合物是一种罕见的三尖杉烷型二萜苷。免疫抑制测定表明，化合物对活化的T和B淋巴细胞增殖表现出轻度抑制活性。这些发现不仅扩大了这一小类二萜类化合物的结构多样性，而且还探索了它们作为开发免疫抑制剂的新结构的潜力。