Two novel aporphine-derived alkaloids from the stems of Fissistigma glaucescens

Three new indole alkaloid derivatives from Fissistigma oldhamii Levl. and their anti-inflammatory effects

Three new indole alkaloid derivatives, fissindoalkas A-C (1-3) together with one known biogenetically related polysubstituted indole alkaloid (4) were isolated from the roots of Fissistigma oldhamii (Hemsl.) Merr. The structures of compounds 1-4 were elucidated using comprehensive spectroscopic methods. The inhibitory activities of compounds 1-4 against nitric oxide (NO) production induced by lipopolysaccharide (LPS) were evaluated in vitro using mouse macrophage RAW264.7 cells. Compounds 2 and 3 showed potent inhibitory activities on NO production with IC50 values of 2.52 ± 0.18 and 2.33 ± 0.16 μM. These results indicate that the discovery of indole alkaloid derivatives, from the roots of F. oldhamii, which show significant anti-inflammatory properties, could be of great importance to the research and for the development of novel natural anti-inflammatory agents.

Alkaloids from the stems of Fissistigma maclurei Merr. inhibit the proliferation of synoviocytes

Two new aporphine-derived alkaloids, aporaloids C and D (1 and 2), along with eight known biogenetically related alkaloids (3-10) were isolated from the stems of Fissistigma maclurei Merr. Their structures were elucidated by detailed analysis of NMR, HRESIMS, MS, IR, UV and Optical rotations data. Compounds 1 and 2 represent a rare example of N-methylol aporphine-derived alkaloids from natural sources. The inhibitory effect of all compounds on the proliferation of primary synovial cells was evaluated. Compound 3 showed potent inhibitory effect on the proliferation of synoviocytes with an IC50 value of 4.8 μM. Compounds 1, 2, 6-9 and 10 exhibited moderate inhibitory activity on synoviocytes, with IC50 values of 36.8, 37.1, 31.2 μM, 32.5, 36.3, 36.8 and 18.2 μM, respectively.

Unlocking the hidden potential: Enhancing the utilization of stems and leaves through metabolite analysis and toxicity assessment of various parts of Aconitum carmichaelii

ETHNOPHARMACOLOGICAL RELEVANCE

Aconitum carmichaelii is widely used in traditional Chinese medicine clinics as a bulk medicinal material. It has been used in China for more than two thousand years. Nevertheless, the stems and leaves of this plant are usually discarded as non-medicinal parts, even though they have a large biomass and exhibit therapeutic properties. Thus, it is crucial to investigate metabolites of different parts of Aconitum carmichaelii and explore the relationship between metabolites and toxicity to unleash the utilization potential of the stems and leaves.

AIM OF THE STUDY

Using plant metabolomics, we aim to correlate different metabolites in various parts of Aconitum carmichaelii with toxicity, thereby screening for toxicity markers. This endeavor seeks to offer valuable insights for the development of Aconitum carmichaelii stem and leaf-based applications.

MATERIALS AND METHODS

UHPLC-Q-Orbitrap MS/MS-based plant metabolomics was employed to analyze metabolites of the different parts of Aconitum carmichaelii. The cardiotoxicity and hepatotoxicity of the extracts from different parts of Aconitum carmichaelii were also investigated using zebrafish as animal model. Toxicity markers were subsequently identified by correlating toxicity with metabolites.

RESULTS

A total of 113 alkaloids were identified from the extracts of various parts of Aconitum carmichaelii, with 64 different metabolites in stems and leaves compared to daughter root (Fuzi), and 21 different metabolites in stems and leaves compared to mother root (Wutou). The content of aporphine alkaloids in the stems and leaves of Aconitum carmichaelii is higher than that in the medicinal parts, while the content of the diester-diterpenoid alkaloids is lower. Additionally, the medicinal parts of Aconitum carmichaelii exhibited cardiotoxicity and hepatotoxicity, while the stems and leaves have no obvious toxicity. Finally, through correlation analysis and animal experimental verification, mesaconitine, deoxyaconitine, and hypaconitine were used as toxicity markers.

CONCLUSION

Given the low toxicity of the stems and leaves and the potential efficacy of aporphine alkaloids, the stems and leaves of Aconitum carmichaelii hold promise as a valuable medicinal resource warranting further development.

Biologically active isoquinoline alkaloids covering 2019-2022

Isoquinoline alkaloids are an important class of natural products that are abundant in the plant kingdom and exhibit a wide range of structural diversity and biological activities. With the deepening of research in recent years, more and more isoquinoline alkaloids have been isolated and identified and proved to contain a variety of biological activities and pharmacological effects. In this review, we introduce the research progress of isoquinoline alkaloids from 2019 to 2022, mainly in the part of biological activities, including antitumor, antimicrobial, antidiabetic, antiviral, anti-inflammatory, antioxidant, neuroprotective, hepatoprotective, analgesic, and other activities. This study provides a clear direction for the rational development and utilization of isoquinoline alkaloids, suggesting that these alkaloids have great potential in the field of drug research.

Bioactive 5/5/5/6 Four-Ring System Iridoids from Plumeria alba L

Two rare 5/5/5/6 four-ring system iridoids, allamancins A and B (1 and 2) together with one known biogenetically related iridoid derivative, 3-O-methyallamancin (3) were isolated from the flowers of Plumeria alba L. The structures of these iridoid derivatives were determined by comprehensive spectroscopic analyses. The absolute configuration of 1 was confirmed by X-ray crystallographic analysis. The inhibitory activities of compounds 1-3 against nitric oxide (NO) production induced and three cancer cell lines were evaluated in vitro. Compounds 1 and 3 showed inhibitory activities on NO production with IC50 values of 18.3±0.12 and 22.1±0.14 μM, respectively. Compounds 1-3 showed moderate inhibitory activities against cancer cell lines of A549, Hela and MCF-7.