Nmr Studies of Colchicine and its Photoisomers, β- and λ-Lumicolchicines

Meksuriyen, Duangdeun; Li, Lin; Cordell, Geoffrey A.; Mukhopadhyay, Sibabrata; Banerjee, Sukdeb

doi:10.1021/np50055a012

Cited by 32 publications

(18 citation statements)

References 21 publications

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“…Additional NMR studies were conducted by Mweksuriyen et al . 7 to complete the 13 C NMR assignment of the carbons in light of discrepancies in the earlier reports 8, 9 despite a large literature regarding the structural aspects of colchicine 10–15 . The discrepancies associated with earlier studies can be ascribed due to the overlapping signals in the NMR spectrum as well as the lack of advanced pulse programs for detailed NMR analysis that are now available.…”

Section: Introductionmentioning

confidence: 93%

NMR and DFT investigations of structure of colchicine in various solvents including density functional theory calculations

Pierens

Venkatachalam

Reutens

2017

Sci Rep

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A detailed NMR investigation of the chemical shifts of hydrogen and carbon atoms associated with the structure of the naturally occurring alkaloid colchicine was conducted using high field NMR. Initially, the experimental chemical shifts for colchicine in chloroform and DMSO were compared to the values calculated using density functional theory (DFT). There were significant deviations observed for the chloroform solvent, but these were only slight in the DMSO solution. Dilution of the chloroform solution changed the experimental chemical shifts and improved agreement with the DFT calculations, suggesting self-aggregation at higher concentrations. A dimeric model was proposed for which agreement with the DFT calculated chemical shifts was better than for corresponding monomeric structures. Three further solvents were studied to evaluate changes in chemical shift values at different dilutions. Chloroform, benzene and water showed significant chemical shift changes implying self-aggregation, whereas DMSO and acetone did not show significant change upon dilution.

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Section: Introductionmentioning

confidence: 93%

NMR and DFT investigations of structure of colchicine in various solvents including density functional theory calculations

Pierens

Venkatachalam

Reutens

2017

Sci Rep

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“…The spectral data we obtained for those known compounds were in full agreement with those reported in the literature. The identified compounds can be categorized into three classes: (-)-colchicine-type: (-)-colchicine (1) (264 mg, 0.03% w/w, plant dry weight) [11], (-)-2demethylcolchicine (2) (2 mg, 0.0002% w/w, plant dry weight) [15], (-)-3-demethylcolchicine (3) (12.5 mg, 0.0013% w/w, plant dry weight) [11], (-)demecolcine (4) (4.7 mg, 0.0005% w/w, plant dry weight) [11], (-)-N-methyldemecolcine (5) (61 mg. 0.007% w/w, plant dry weight) [15], and (-)-3demethyl-N-methyldemecolcine (6) (34 mg, 0.004% w/w, plant dry weight); lumiderivatives: βlumicolchicine (7) (13.5 mg, 0.0014% w/w, plant dry weight) and 3-demethyl-β-lumicolchicine (8) (3.8 mg, 0.0004% w/w, plant dry weight) [11,16]; and flavones: apigenin (9) (5 mg, 0.0005% w/w, plant dry weight) [17] (Figure 1). 8.12 (H-8), an AB pattern at δ H 7.23 and 6.79 (d, J = 10.5 Hz; H-12 and H-11, respectively), and an upfield-shifted ketone carbonyl at δ C 180.3 (C-9) were characteristic for a tropolone C-ring, whose presence was confirmed by corresponding HMBC data (Table 1).…”

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confidence: 99%

A New Colchicinoid from Colchicum tauri, an Unexplored Meadow Saffron Native to Jordan

Alali

Ma'aya'h

Alkofahi

et al. 2006

Natural Product Communications

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This study reports the isolation, characterization, and biological evaluation of constituents of Colchicum tauri Siehe ex Stef. (Colchicaceae), an unexplored Colchicum species native to Jordan. Methanolic extraction, crude alkaloid fractionation, and separation using several different chromatographic techniques (open columns, preparative TLC, and semi-preparative HPLC), as directed by the brine shrimp lethality test (BST), resulted in the isolation and identification of nine compounds: (-)-colchicine (1), (-)-2-demethylcolchicine (2), (-)-3-demethylcolchicine (3), (-)-demecolcine (4), (-)- N-methyldemecolcine (5), (-)-3-demethyl- N-methyldemecolcine (6), β-lumicolchicine (7), 3-demethyl-β-lumicolchicine (8), and apigenin (9). Compounds 1–5 and 7–8 were isolated for the first time from this species, while compound (6) represents a new colchicinoid. The structure elucidations were achieved using a series of spectroscopic and spectrometric techniques, principally 1D-NMR (1H, and 13C), 2D-NMR (COSY, ROESY, HMBC, and HSQC), and low resolution EI-MS. All compounds were tested for general toxicity using the BST, and compounds 1 and 4 were found to be the most potent, with LC50 values of 2.5 and 8.1 μg/mL, respectively.

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“…The only differences are the lack of signals in the 1 H NMR spectrum at G 6.52 (s) and in the 13 C NMR spectrum at G 107.3 (d) together with the occurence of the signal in the 13 C NMR spectrum at G 146.5 (s). The structure was also confirmed by the HMBC correlations for C-4 with the protons H-5D and H-5E [11,12]. The 1 H and 13 C NMR data and HMBC correlations of 4-hydroxycolchicine (6) are given in Table 1 in comparison with colchicine (1).…”

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confidence: 61%

Colchicinoids from the Seeds of Colchicum umbrosum

2015

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A new colchicinoid from the seeds of Colchicum umbrosum (Colchicaceae) has been isolated and identified as 4-hydroxycolchicine (6) together with seven known colchicinoids as colchicine (1), N-deacetyl-Nformylcolchicine (2), colchifoline (3), colchicilline (4), 3-demethylcolchicine (5), demecolcine (7), and colchicoside (8).The medicinal importance of the genus Colchicum is attributed to the presence of tropolonic alkaloids, colchicinoids, mainly colchicine [1]. Colchicine has been found to possess antitumoral and anti-inflammatory properties and has still kept its importance in the treatment of gout and many other diseases, such as familial Mediterranean fever (FMF), Behcetcs syndrome, chirosis, and psoriasis [2]. Unfortunately, due to its low therapeutic index, this alkaloid cannot be used as an antineoplastic agent. It is also used in biological and breeding studies to produce polyploids and in the tubulin binding assay as a positive control because of its affinity for tubulin [3]. Demecolcine has lower toxicity than colchicine and has been succefully used in the treatment, especially, of myeloid leukemia and Hodgkincs syndrome [2].The genus Colchicum (Colchicaceae) is represented by 45 species in Turkey. Turkey is a major center for diversity and speciation for Colchicum species when the endemism rate (35%) is considered [4,5].In continuation of our investigations on Turkish Colchicum species for their alkaloid content [6-9], we now study alkaloids from the seeds of Colchicum umbrosum. This is the first detailed investigation of the seeds of Colchicum umbrosum for their colchicinoids. In a previous work, it has been reported that the corms of this plant contain colchicine, 3-demethylcolchicine, N-formyl-N-deacetylcolchicine, colchifoline, and colchicoside as colchicinoids [10].We now report the presence of a new colchicinoid, 4-hydroxycolchicine, isolated fort he first time from a natural source (6), together with the known colchicinoids colchicine (1), N-deacetyl-N-formylcolchicine (2), colchifoline (3), colchicilline (4), 3-demethylcolchicine (5), demecolcine (7), and colchicoside (8) in the seeds of Colchicum umbrosum.

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Nmr Studies of Colchicine and its Photoisomers, β- and λ-Lumicolchicines

Cited by 32 publications

References 21 publications

NMR and DFT investigations of structure of colchicine in various solvents including density functional theory calculations

NMR and DFT investigations of structure of colchicine in various solvents including density functional theory calculations

A New Colchicinoid from Colchicum tauri, an Unexplored Meadow Saffron Native to Jordan

Colchicinoids from the Seeds of Colchicum umbrosum

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