Molecular Networking-Guided Isolation of Cycloartane-type Triterpenoids from Curculigo orchioides and Their Inhibitory Effect on Nitric Oxide Production

The MolNetEnhancer workflow was applied to molecular
networking
analysis of the CH2Cl2-soluble fraction of the
rhizomes of Curculigo orchioides, which
showed a potent inhibitory effect on the lipopolysaccharide (LPS)-induced
nitric oxide production. Among the molecular network, clusters of
cycloartane-type triterpenoids were classified using the ClassyFire
module of MolNetEnhancer, and their structures were predicted by the
in silico fragment analysis tool, Network Annotation Propagation (NAP).
Using mass spectrometry (MS)-guided isolation methods, six cycloartane-type
triterpenoids (1–6) were isolated,
and their structures were elucidated based on the interpretation of
NMR, HRESIMS, and single-crystal X-ray diffraction. Among the isolates,
compounds 1 and 4, which have an α,β-unsaturated
carbonyl moiety on the A-ring, exhibited significant inhibitory effects
on LPS-induced nitric oxide production in RAW264.7 cells with IC50 values of 12.4 and 11.8 μM, respectively.

本研究将MolNetEnhancer分析流程应用于仙茅（Curculigo orchioides）根茎二氯甲烷（CH₂Cl₂）可溶性组分的分子网络分析，该组分对脂多糖（LPS）诱导的一氧化氮生成具有显著抑制活性。在该分子网络中，研究人员借助MolNetEnhancer的ClassyFire模块对环阿尔廷型三萜类化合物簇进行了分类，并通过计算机模拟片段分析工具网络注释传播（Network Annotation Propagation, NAP）预测了其结构。采用质谱（MS）引导的分离方法，研究人员共分离得到6个环阿尔廷型三萜类化合物（1~6），并通过核磁共振（NMR）、高分辨质谱（HRESIMS）及单晶X射线衍射的谱图解析阐明了其化学结构。在所分离得到的化合物中，A环上带有α,β-不饱和羰基结构的化合物1和4，在RAW264.7细胞中对LPS诱导的一氧化氮生成表现出显著抑制活性，其半最大效应浓度（IC50）分别为12.4 μM和11.8 μM。