C20-diterpenoid alkaloids from Delphinium trifoliolatum

Crystal structure of 14-O-acetyldelcosine, C26H41NO8

C26H41NO8, orthorhombic, P212121 (no. 19), a = 8.24370(10) Å, b = 13.1867(2) Å, c = 22.8490(4) Å, V = 2483.85(6) Å3, Z = 4, Rgt (F) = 0.0357, wRref (F 2) = 0.0975, T = 169.99(10) K.

The diterpenoid alkaloids

The diterpenoid alkaloids are a family of extremely important natural products that have long been a research hotspot due to their myriad of intricate structures and diverse biological properties. This chapter systematically summarizes the past 11 years (2009-2019) of studies on the diterpenoid alkaloids, including the "so-called" atypical ones, covering the classification and biogenetic relationships, phytochemistry together with 444 new alkaloids covering 32 novel skeletons and the corrected structures, chemical reactions including conversion toward toxoids, synthetic studies, as well as biological activities. It should be noted that the synthetic studies, especially the total syntheses of various diterpenoid alkaloids, are for the first time reviewed in this treatise. This chapter, in combination with our four previous reviews in volumes 42, 59, 67, and 69, will present to the readers a more completed and updated profile of the diterpenoid alkaloids.

Antifungal Activity of New Diterpenoid Alkaloids Isolated by Different Chromatographic Methods from Delphinium peregrinum L. var. eriocarpum Boiss

This paper aimed to investigate the potential antifungal influences of new alkaloids from Delphinium peregrinum L. var. eriocarpum Boiss. New Diterpenoid alkaloids Delcarpum (1), Hydrodavisine (4) and known alkaloids Peregrine (2), Delphitisine (3) were isolated by different chromatographic methods from the aerial parts of D. Peregrinum eriocarpum Boiss, which grows in Syria. The structures of alkaloids were proposed based on 1D NMR spectroscopy 1H-NMR, 13C-NMR, DEPT-135, DEPT-90, 2D NMR spectroscopy DQF-COSY, HMQC, EI-Ms mass spectrum, and IR spectroscopic measurements. The antifungal activity of the isolated alkaloids was evaluated against different dermatophyte fungal isolates compared with fluconazole. In the case of Peregrine (2) the minimum inhibitory concentrations(MICs) recorded 128-256, 32-64, and 32 for Epidermophyton floccosum, Microsporum canis, and Trichophyton rubrum, respectively, compared to 32-64, 16, and 32 μg/mL in the case of fluconazole, respectively. The MICs recorded on application of the four alkaloids mixture were 64, 32, and 16 in the case of E. floccosum, M. canis, and T. rubrum, respectively, which were significantly lower than that measured for each of the individual alkaloid and were compatible for fluconazole. In conclusion, MICs of the tested alkaloids showed a variable potential effect on the investigated fungal isolates. Peregrine (2) was the most effective alkaloid, however, the application of the mixture of alkaloids induced significant synergistic activity that was more pronounced than the application of individual ones.

Diterpenoid alkaloids from Aconitum anthoroideum that offer protection against MPP+-Induced apoptosis of SH-SY5Y cells and acetylcholinesterase inhibitory activity

Nine unprecedented diterpenoid alkaloid, including a diterpenoid alkaloid featuring a diterpenoid moiety, anthoroidine A; one bisditerpenoid alkaloid joined with a carbon-carbon single bond, anthoroidine B; three racemulosine-type C₂₀-diterpenoid alkaloids, anthoroidines C-E; one hetidine-type C₂₀-diterpenoid alkaloid, anthoroidine F; and three hetisine-type C₂₀-diterpenoid alkaloids, anthoroidines G-I, together with ten known diterpenoid alkaloids were isolated from Aconitum anthoroideum DC. Their structures were established via detailed spectroscopic analyses. Most of the isolated compounds along with five known diterpenoid alkaloids obtained in a previous study were screened for neuroprotective activities and acetylcholinesterase inhibitory effects. Nominine showed potent protective activity against MPP⁺-induced apoptosis in SH-SY5Y cells, with a rescue rate of 34.4% (50 μM). Rotundifosine F showed a significant inhibitory activity against AChE (IC₅₀ = 0.3 μM). The structure-activity relationship of these alkaloids is also briefly discussed.

Four new C20-diterpenoid alkaloids from Aconitum rotundifolium

Four new C₂₀-diterpenoid alkaloids, rotundifosines D-G (1-4), along with eight known ones (5-12) were isolated from the whole plant of Aconitum rotundifolium Kar. & Kir. The structures of the compounds were elucidated on the basis of spectroscopic analyses, including HR-ESI-MS and 1D, 2D NMR. Rotundifosine F (3) is a rare C₂₀-diterpenoid alkaloid with quaternary ammonium salt. Alkaloids 1-4, 5, 6, 9, and 12 were evaluated for cytotoxicity against MCF-7, HCT-116 and HepG2 human cancer cell lines.

Crystal structure of ajacisine D monohydrate, C30H44N2O9

C30H44N2O9, monoclinic, P21 (no. 4), a = 7.9827(3) Å, b = 12.6787(6) Å, c = 14.0183(9) Å, β = 90.903(5)°, V = 1418.62(13) Å3, Z = 2, R gt(F) = 0.0607, wR ref(F 2) = 0.1298, T = 298(2) K.

Grandiflodines A and B, two novel diterpenoid alkaloids from Delphinium grandiflorum

Two novel diterpenoid alkaloids, grandiflodines A and B (1 and 2), were isolated from Delphinium grandiflorum.

A new C20-diterpenoid alkaloid from the lateral roots of Aconitum carmichaeli

A new C₂₀-diterpenoid alkaloid carmichaedine (1) and six known alkaloids (2-7) were isolated from the lateral roots of Aconitum carmichaeli. Their structures were established on the basis of extensive spectroscopic analyses. Compound 1 exhibited potent antibacterial activity against Bacillus subtilis with minimum inhibitory concentration of 8 μg/mL.

Diterpenoid alkaloids

The lasting attention that researchers have devoted to diterpenoid alkaloids is due to their various bioactivities and toxicities, structural complexity, and intriguing chemistry. From 1998 to the end of 2008, more than 300 new diterpenoid alkaloids were isolated from Nature. This review focuses on their structural relationships, and investigations into their chemical reactions, synthesis, and biological activities. A table that lists the names, plant sources, and structural types is given along with 363 references.

New C(19)- and C(18)-diterpenoid alkaloids from Delphinium anthriscifolium var. savatieri

Three new C(19)-diterpenoid alkaloids, anthriscifoldines A-C (1-3), and two new C(18)-diterpenoid alkaloids, anthriscifolcines F and G (5, 6), were obtained from the whole herbs of Delphinium anthriscifolium var. savatieri during our further investigation on a larger scale of recollected plants. Their structures were elucidated based on the interpretation of NMR and high-resolution ESI-MS data, and chemical transformation. In addition, five known C(19)-diterpenoid alkaloids were also isolated and identified as nudicaulamine (4), delbruninol (7), blacknine (8), winkleriline (9), and deltaline (10).

Diterpenoid Alkaloids from Delphinium majus

From the whole herbs of Delphinium majus, three new C(19)-diterpenoid alkaloids, majusines A-C (1-3), and six new C(20)-diterpenoid alkaloids, majusimines A-D (4-7) and majusidine A and B (8 and 9), have been isolated, together with 15 known compounds. The structures of compounds 1-9 were elucidated by spectroscopic data interpretation.

New C18-diterpenoid alkaloids from Delphinium anthriscifolium var. savatieri

Five new C18-diterpenoid alkaloids, anthriscifolcines A (1), B (2), C (3), D (4), and E (5), together with a known C19-diterpenoid alkaloid delcorine (6), were isolated from the whole herb of Delphinium anthriscifolium var. savatieri. The structures of these new alkaloids were established on the basis of spectral data (1D- and 2D-NMR, HR-ESI-MS).