Diterpenoid Alkaloids from Delphinium ajacis and Their Anti-inflammatory Activity.

Three novel diterpenoid alkaloids, comprising two C19 -diterpenoid alkaloids (1 and 2) and one C20 -diterpenoid alkaloid (3), were isolated from Delphinium ajacis, alongside the six known compounds (4-9). Their structures were elucidated by spectroscopic methods (MS, UV, IR, 1D and 2D NMR) and chemical properties. Simultaneously, the anti-inflammatory properties of all compounds (1-9) was conducted, focusing on nitric oxide (NO) production in LPS-induced BV-2 cells. The results indicated compounds 1-3, 7, and 8 have potential anti-inflammatory activity.

Lysidrhodosides A-I, acylphloroglucinol glucosides with anti-inflammatory activities from the leaves of Lysidice rhodostegia.

Lysidrhodosides A-I (1-9), nine acylphloroglucinol glucoside derivatives along with three known analogues (10-12) were isolated from the leaves of Lysidice rhodostegia. Their structures and absolute configuration were elucidated by spectroscopic data analysis (NMR, UV, IR, HR-ESI-MS), single-crystal X-ray diffraction, and acid hydrolysis with HPLC analysis. Notably, compounds 7-9 represent the first examples of 3-methylbutyryl phloroglucinol glucoside dimers isolated from this plant. Additionally, compounds 1-12 were assessed for their inhibitory effects on nitric oxide (NO) in the LPS-induced BV-2 cells. The results showed that compounds 6 and 12 significantly inhibited the production of the inflammatory mediator NO, with an inhibitory rate of 95.96 and 91.13% at a concentration of 50 µM, respectively.

Two new clerodane diterpenoids and a new pyran-2-one derivative with anti-neuroinflammatory activities from Croton crassifolius.

Two new clerodane diterpenoids (1 and 2), a new pyran-2-one derivative (3), along with five known compounds (4‒8), were isolated from Croton crassifolius. Notably, crassifolin X (1) is a novel clerodane diterpenoid, characterized with a peculiar δ-lactone core being formed between C-1 and C-4. Their structures, including absolute configurations, were established on the basis of spectroscopic methods (UV, IR, HRESIMS and NMR), and circular dichroism experiments. In addition, all compounds were evaluated for their anti-neuroinflammatory activities based on the expression of TNF-α and IL-6 levels on LPS-induced BV2 cells, and compounds 1‒3 and 5 showed potential anti-neuroinflammatory activity.