Nitric Oxide Inhibitory Activity of Xanthones from the Green Fruits of Cratoxylum formosum ssp. pruniflorum

Abstract

Three new xanthones, pruniflorone M-O (1-3), and a new xanthonolignoid, 3-methoxy-5 0 -demethoxycadensin G (4), were isolated from the green fruits of Cratoxylum formosum ssp. pruniflorum along with three known xanthones (5-7) and a known flavonoid (8). Their structures were elucidated by spectroscopic methods and the structure of 1 was also determined by X-ray crystallography. Compounds 2 and 7 showed potent nitric oxide inhibitory activity with IC 50 values of 4.4 and 4.3 mM, respectively. Moreover, 7 also showed strong antibacterial activity against both Gram-positive and Gramnegative bacteria with an MIC value of 4.67 mg mL À1 .

Bioactive prenylated xanthones from the stems ofCratoxylum cochinchinense

“…The 1 H and 13 C NMR data of 3 (Tables 1 and 2) were similar to those of 1,5-dihydroxy-6 0 -hydroxy-4 0 ,4 0 -dimethylpyran(2 0 ,3 0 :3,4) xanthone [7], except that a 1,2,3,4-tetrasubstituted benzene ring [d 7.63 (1H, br s, H-8) and 7.03 (1H, br s, H-7)] in 3 replaced a 1,2,3-trisubstituted benzene ring in the latter compound. Therefore, the structure of 3 was deduced as 1,5,6-trihydroxy-6 0 -hydroxy-4 0 ,4 0 -dimethyl-4 0 ,5 0 -dihydropyran(2 0 ,3 0 :3,4)xanthone, trivially named cochinchinone O.…”

“…Nine new compounds (1)(2)(3)(4)(5)(6)(7)(8)(9) were isolated from the 90% EtOH extract of the stems of C. cochinchinense by various column chromatographies (CCs). All of them gave characteristic UV absorption maxima in the range of 239 -287 and 312-380 nm, which were the typical absorptions of a xanthone chromophore [5].…”

Molecular and Crystal Structures of α,α,β-Trimethylfuranylxanthone from Cratoxylum formosum ssp. pruniflorum: A Partial Racemate

“…1), which known as formoxanthone C [6] [systematic name: 5,9,10-trihydroxy-1,1,2-trimethyl-4-(3-methylbut-2-enyl)-1H-furo [2,3-c]xanthen-6(2H)-one]. Our nitric oxide inhibitory activity study resulted that compound 1 exhibits potent nitric oxide inhibitory activity with IC 50 value of 4.3 μM [9] and also showed strong antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) ATCC43300, Enterococcus faecalis TISTR459, vancomycin-resistant Enterococcus faecalis (VRE) ATCC51299, Bacillus subtilis, and Salmonella typhi with an MIC value of 4.67 μg/mL −1 [9]. It is well documented that bioactivities are related to the structure of the compound thereby making the correct characterization and identification of compounds of paramount importance.…”

“…The importance of hydrogen bonds in natural products was well documented as it was known that the numbers and positions of hydrogen donors are important and related to their bioactivities. Compound 1 which is a natural product bearing a rich source of hydrogen bond donors (CH and OH) and acceptors (O) and possesses potent nitric oxide inhibitory activity and antibacterial activities [9]. Hydrogen bonds are essential to maintain the bioactive conformation and for recognition of the binding sites of the corresponding receptors [16].…”

Highly Cytotoxic Xanthones from Cratoxylum cochinchinense Collected in Myanmar

“…Eight known xanthones (1)(2)(3)(4)(5)(6)(7)(8), one anthraquinone (9), and four common triterpenoids were isolated from a MeOH extract of the bark. The structures of these compounds were established by ESI-MS, IR, X-ray analysis (for xanthones 5 and 7), 1D ( 1 H and 13 C) and 2D NMR spectral measurements.…”