C19 Benzylisoquinoline Alkaloid with Unprecedented Architecture from Hypecoum erectum

1H NMR guided isolation of 3-arylisoquinoline alkaloids from Hypecoum erectum L. and their anti-inflammation activity

Nine 3-arylisoquinoline alkaloids including five undescribed ones, hypectumines A-E (1-5), were isolated from the whole herb of Hypecoum erectum L. with the guidance of 1H-NMR. Their structures were established by a combination of 1D, 2D NMR, and HRESIMS spectrometry. Among them, hypectumines A and B possessed rare urea moieties while hypectumines C and D were characterized by 3-(methylamino)propanoic acid scaffolds. Biological assay demonstrated that alkaloids hypectumine B and 2,3-dimethoxy-N-formylcorydamine had anti-inflammatory effects by inhibiting NO production on LPS-induced RAW264.7 cells with IC50 values of 24.4 and 44.2 μM, respectively. Furthermore, hypectumine B could reduce the expression of pro-inflammatory cytokines TNF-α and IL-6, suggesting it might be a potential candidate for treating inflammatory disease.

New trends in the practical use of isoquinoline alkaloids as potential drugs applicated in infectious and non-infectious diseases

In the last years, traditional natural products have been the center of attention for the scientific community and exploration of their therapeutic abilities is proceeding permanently. Isoquinoline alkaloids have always attracted scientific interest due to either their positive or negative effects on human organism. The present review describes research on isoquinoline alkaloids isolated from different plant species. Alkaloids are one of the most important classes of plant derived compounds among these isoquinoline alkaloids possess varied biological activities such as anticancer, antineurodegenerative diseases, antidiabetic, antiinflammatory, antimicrobial, and many others. The use of plants against different disorders is entrenched in traditional medicine around the globe. Recent progress in modern therapeutics has stimulated the use of natural products worldwide for various ailments and diseases. The review provides a collection of information on the capabilities of some isoquinoline alkaloids, its potential for the treatment of various diseases and is designed to be a guide for future research on different biologically active isoquinoline alkaloids and plant species containing them. The authors are aware that they were not able to cover the whole area of the topic related to biological activity of isoquinoline alkaloids. This review is intended to suggest directions for further research and can also help other researchers in future studies.

Dimeric benzylisoquinoline alkaloids from Thalictrum delavayi and their biological activities

A phytochemical investigation of the whole plants of T. delavayi led to the isolation of five new dimeric benzylisoquinoline alkaloids, thalidelavines A-E (1-5), together with six known congeners (6-11). The structures and absolute configurations of new compounds were established based on analyses of spectroscopic data, ECD calculations, and single crystal X-ray crystallography. Thalidelavines A-E (1-5) were structurally complex bisbenzylisoquinoline alkaloids with various configurations. These isolated alkaloids were evaluated for their cytotoxic and immunosuppressive effects. Among them, both 9 and 10 displayed significant cytotoxicities against T98G cell lines with an IC₅₀ value of 2.1 μM, compared with the positive CPT-11 (IC₅₀ = 3.0 μM). In addition, 5-7 showed remarkable immunosuppressive effects. These findings not only enrich the structural diversity of bisbenzylisoquinoline alkaloids, but also provide potential candidates for the further development of the antitumor and immunosuppressive agents.

Hypeisoxazole A, a Racemic Pair of Tetrahydroisoxazole-Fused Benzylisoquinoline Alkaloids from Hypecoum erectum and Structural Revision of Hypecoleptopine

(±)-Hypeisoxazole A (1), a racemic pair of rearranged benzylisoquinoline alkaloids possessing an unprecedented diindeno[2,1-c:2',1'-d] isoxazole scaffold, was isolated from the medicinal herb Hypecoum erectum, along with hypecoleptopine (2), whose structure is now revised as a novel spiro-benzylisoquinoline alkaloid with a 6/6/5/6/6 skeleton. Their structures were determined by comprehensive spectroscopic and spectrometric analyses, X-ray diffraction, and computational studies. Racemic mixture of 2 and its pure enantiomers modulated neuronal excitability activity.