Oleanane triterpene saponins with cardioprotective activity from Clinopodium polycephalum

Two New Oleanane-Triterpenoid Saponins from Clinopodium gracile

Two new oleanane-triterpenoid saponins, clinograsaponins A (1) and B (2), together with twelve known ones (3-14), were isolated from the whole herb of Clinopodium gracile (Bentham) Matsumura. Their structures were determined by spectroscopic analysis and chemical method. All the isolated compounds were evaluated for their activities against ATP-citrate lyase (ACLY) and nuclear factor kappa B (NF-κB).

Isolation of chemical constituents with anti-inflammatory activity from Reineckia carnea herbs

Three new saponins (1-3), a new natural product (4) and six other known compounds (5-10) were isolated from the whole Reineckia carnea plant. Their structures were established by comparison of their NMR spectra and MS data with literature data. In addition, all the isolated compounds were evaluated in vitro for anti-inflammatory activities against LPS-stimulated nitric oxide (NO) production in RAW 264.7 macrophages. Compounds 1-4 exhibited anti-inflammatory activities with IC₅₀ values of 37.5 µM, 31.4 µM, 34.6 µM, and 56.1 µM, respectively. Furthermore, compounds 5-10 showed anti-inflammatory activities with IC₅₀ values ranging from 20.3 to 42.9 µM.

Transcriptome analysis of Clinopodium gracile (Benth.) Matsum and identification of genes related to Triterpenoid Saponin biosynthesis

BACKGROUND

Clinopodium gracile (Benth.) Matsum (C. gracile) is an annual herb with pharmacological properties effective in the treatment of various diseases, including hepatic carcinoma. Triterpenoid saponins are crucial bioactive compounds in C. gracile. However, the molecular understanding of the triterpenoid saponin biosynthesis pathway remains unclear.

RESULTS

In this study, we performed RNA sequencing (RNA-Seq) analysis of the flowers, leaves, roots, and stems of C. gracile plants using the BGISEQ-500 platform. The assembly of transcripts from all four types of tissues generated 128,856 unigenes, of which 99,020 were mapped to several public databases for functional annotation. Differentially expressed genes (DEGs) were identified via the comparison of gene expression levels between leaves and other tissues (flowers, roots, and stems). Multiple genes encoding pivotal enzymes, such as squalene synthase (SS), or transcription factors (TFs) related to triterpenoid saponin biosynthesis were identified and further analyzed. The expression levels of unigenes encoding important enzymes were verified by quantitative real-time PCR (qRT-PCR). Different chemical constituents of triterpenoid saponins were identified by Ultra-Performance Liquid Chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS).

CONCLUSIONS

Our results greatly extend the public transcriptome dataset of C. gracile and provide valuable information for the identification of candidate genes involved in the biosynthesis of triterpenoid saponins and other important secondary metabolites.

Diterpenoid and triterpenoid glycosides from Clinopodium chinense

Two new compounds, including a diterpenoid glycoside (1) and a triterpenoid glycoside (6), along with six known compounds were isolated from Clinopodium chinense. The structures of the new compounds were determined on basis of extensive spectral analysis and chemical method. Compounds 1-8 were evaluated for their insulin resistance effect and cytotoxic activity against the A549 and HepG2 cancer cell lines. None of the compounds were cytotoxic (IC₅₀ > 100 μM), while compounds 1-3 and 5 showed the activity of ameliorating insulin resistance in HepG2.