Griffithine, a New Furanoquinolone Alkaloid from Haplophyllum griffithianum

Abstract

The new alkaloid griffithine (1) was isolated from total alkaloids from the aerial part of Haplophyllum griffithianum (Rutaceae). Spectral data established it as a furanoquinolin-4-one derivative with the structure N-methyl-7-O-(1c-dimethyl-2c,3c-dihydroxypropyl)-8-methoxyfuranoquinolin-4-one.The alkaloids dubamine, dubinine, dubinidine, dictamnine, skimmianine, N-methylhaplofoline, and gerphytine were isolated from the aerial part of Haplophyllum griffithianum Boiss. collected in Surkhandarya Province (Nilu village), Republic of Uzbekistan, during flowering [1,2]. Further separation of the total alkaloids produced a new alkaloid with mp 158-159°C that we called griffithine (1).Griffithine, C 18 H 21 NO 6 , was very soluble in MeOH and CHCl 3 , less soluble in alcohol, and insoluble in H 2 O, base, and benzine.The UV spectrum of 1 showed absorption bands at 201, 235, 259, 293, and 331 nm. The absorption maxima did not change after acidification or basicification. The IR spectrum of 1 contained absorption bands for hydroxyls (3362 cm -1 , broad), carbonyl (1623), and an aromatic ring (1591, 1538, 1518). A resonance in the 13 C NMR spectrum at 173.04 ppm corresponded to a ketone carbonyl.The structure of 1 was elucidated by analyzing PMR and 13 C NMR spectral data and results from DEPT (Table 1) and HETCOR experiments (Fig. 1).The strong-field region of the PMR spectrum showed resonances for two methyls at G 1.26 and 1.30 ppm. Resonances of CH 2 -OH and CH-OH protons geminal to hydroxyls were observed in the aliphatic region of the spectrum as three doublets of doublets at 4.31 (J = 9.8, 3.0 Hz, H-3c), 4.14 (J = 9.8, 7.4 Hz, H-3c), and 3.82 ppm (J = 7.4, 3.0 Hz, H-2c), respectively. The lack of other through-space couplings with resonances of aromatic protons indicated that a CH 2 (OH)-CH(OH) side chain was present.Resonances of aromatic H-2 and H-3 of the furan ring formed an AB-system at G 7.21 and 6.96 ppm and appeared as two doublets (J = 2.4 Hz), which were analogous to those of isofuranoquinoline alkaloids [3]. Resonances of aromatic H-5 and H-6 appeared as two doublets at 8.15 (J = 8.9 Hz) and 6.93 ppm (J = 8.9 Hz), respectively. Resonances for o-aromatic protons H-5 and H-6 indicated that the C-7 and C-8 positions were substituted.An analysis of the 13 C NMR and DEPT spectra of griffithine showed 18 resonances for C atoms as 8 quaternary, 5 methine, 1 methylene, and 4 methyl C atoms. Resonances of furan C atoms C-2 and C-3 appeared at 137.99 and 107.86 ppm; of quaternary C-2a, C-3a, C-4a, and C-8a, at 157.92, 106.04, 121.90, and 133.94 ppm, respectively. Resonances of C-5 and C-6 were observed at stronger field at 123.75 and 110.10 ppm, indicating that C-7 and C-8 were substituted. The C-4 carbonyl C atom resonated at the weakest field near 173.04 ppm. Resonances of methyl C atoms were found at 62.13 (8-OCH 3 ) and 35.77 ppm (N-CH 3 ), respectively ( Table 1). The C-8 methoxy group shifted the N-CH 3 resonance to weaker field by ~5 ppm [4].

The Genus Haplophyllum Juss.: Phytochemistry and Bioactivities—A Review

“…Alkaloids have been reported as the most representative compounds in the genus, and they are also of the utmost importance from a chemosystematic standpoint [ 114 ]. Skimmianine is the most reported compound of this class in the genus, followed by γ-fagarine [ 44 , 45 , 46 , 49 , 51 , 52 , 53 , 54 , 57 , 58 , 66 , 73 , 75 , 77 , 78 , 80 , 81 , 82 , 85 , 86 , 87 , 89 , 90 , 95 , 97 , 98 , 101 , 106 , 108 , 111 ]. Coumarins were also quite present in the Haplophyllum genus, in particular scopoletin [ 56 , 58 , 62 , 68 , 84 , 91 , 98 , 111 ].…”

Chemical Research and Biological Activity of Plants of the Genus Atraphaxis (A. Spinosa)

“…The resulting extract was concentrated under mild conditions (water bath temperature 40-45 ℃) after them, sample concentrate and analyzed on Agilent Technologies 7000 GS / MS system. Component identification carried out automatically by analogy with the known mass spectra of samples stored in the Wiley database [8][9][10][11][12][13][14][15][16][17][18].…”

Biologically Active Substances of Compositions Based on Plants of the Genus Haplophyllum

“…Useful trace elements such as calcium, phosphorus, zinc, and silicon were also found in it [6]. Bidens frondosa contains organic acids, essential oil, tannins, polysaccharides, coumarins (umbelliferon, skoletin), triterpenoids, vitamin C (up to 0.9%), carotenoids (0.05 %), carotenes, a large amount of vitamin C (up to 1000 mg%), manganese salts, polyacetylenes, and aromatic acids containing derivatives and thiophenes, flavonoids -(glycosides luteolin, Butin, sulfuretin, Auron) [7][8][9][10][11][12].…”