Single Crystal X-ray Diffraction, Spectroscopic and Mass Spectrometric Studies of Furanocoumarin Peucedanin

Abstract

The structure of peucedanin, isolated from Peucedanum tauricum Bieb. (Apiaceae), has been established using single crystal X-ray diffraction. This furanocoumarin isolated from the light petroleum extract of P. tauricum fruits was characterized by high resolution EI-MS, sATR-FTIR and 2D NMR spectroscopic techniques. The EI-MS showed the typical fragmentation pattern of methoxyfuranocoumarins. Extensive 1D (1 H and 13 C) as well as 2D NMR data enabled complete assignment of the carbon atoms in the peucedanin molecule. The FTIR data confirms intermolecular hydrogen bonding between peucedanin molecules in polar solvents. Peucedanin crystallises in the R-3 space group from the trigonal system with one molecule in the asymmetric part of the unit cell. The crystal lattice of peucedanin consists of the molecules arranged in separate columns. They are related by two fold screw axes and centres of symmetry. Interestingly, peucedanin columns form two channels per unit cell with a diameter of 7.5Å going through the crystal lattice in the Z-direction. These channels are filled with disordered water molecules, which are surrounded by hydrophobic methyl groups and are located exactly at the centres of the channels. The peucedanin molecules are stacked in a single column with the opposite orientation of the neighbouring molecules. These results could be interesting in further application of this molecule, for example in biological tests of its activity.

Efficient Separation of the Methoxyfuranocoumarins Peucedanin, 8-Methoxypeucedanin, and Bergapten by Centrifugal Partition Chromatography (CPC)

“…The identity of the isolated methoxyfuranocoumarins was confirmed additionally by ESI-MS ( Table 2 ). The obtained results were consistent with the literature data [ 45 , 49 , 63 , 64 ]. Semipreparative isolation of the 5MOP afforded c.a.…”

“…Baker). External standards: bergapten (≥98%, Sigma, St. Louis, MO, USA), 8-methoxypeucedanin, and peucedanin (≥99%, isolated in our laboratory by use of LC/prep TLC and assayed by HPLC-DAD-ESI-MS) [ 43 , 45 ] were used in the quantitative analysis.…”

“…This species has been found to be an interesting source of secondary metabolites such as new guaiene-type sesquiterpenoids [ 39 , 40 ] and methoxyfuranocoumarins [ 39 , 41 , 42 , 43 ], such as 8-methoxypeucedanin (8MP), peucedanin (P), and bergapten (5MOP) (see the chemical formula in Figure 1 ). All of them have been previously isolated from this plant matrix, and although the ultimately developed isolation procedures made it possible to obtain compounds with high purity, in each case, however, they were time-consuming and involved multiple stages [ 39 , 40 , 41 , 42 , 44 , 45 ]. The estimation of the content of secondary metabolites (such as essential oil components, flavonoids, phenolic acids, and coumarins) in extracts of different parts of P. tauricum has been carried out in different ontogenetic stages (flowers, mature and immature fruits, and each time simultaneously in leaves).…”

“…Recently, the influence of this natural substance on apoptosis induction by intrinsic and extrinsic pathways and suppression of cell growth of SK-N-AS neuroblastoma and SW620 metastatic colon cancer cells has been discovered [ 33 ]. The rare furanocoumarins P and 8MP have recently gained some attention [ 45 , 47 ]; however, only a few reports concerning their biological activity have appeared to date. Peucedanin, studied previously, was found to be active against Ehrlich’s tumors and human hepatic carcinoma HepG2 cells [ 48 ].…”

“…In addition, the activity of this compound as a blocker of Ca 2+ canals has been confirmed [ 25 ] and also activation of the early stages of apoptosis (in an Annexin V-Cy3 test) with no necrosis effect, the decrease of heat-shock proteins Hsp 27 and 72 levels, and morphological changes in the tested HeLa cells, as has previously been reported [ 28 , 39 ]. Some interesting interaction between P and biological membranes (lipid monolayers) has been preliminary studied [ 47 ], and an interesting structural organization of crystals of this furanocoumarin in polar solvents was found [ 45 ]. In recent studies, P and 8MP have been found to be moderate activators of apoptosis, blocking the G1 phase of the cell cycle and showing anti-proliferative activity in promyelocytic HeLa cells [ 29 ].…”