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

Abstract

The title xanthone known as Formoxanthone C (1) was isolated from the green fruits of Cratoxylum formosum ssp. pruniflorum. Compound 1 crystallized out in P2 1 /c space group, indicating that 1 exists both enantiomers. The unit cell parameters are a = 13.8038(2), b = 14.6712(2), c = 9.4686(1) Å, β = 95.358(1) • , V = 1909.19(4) Å 3 , and Z = 4. The α,α,β-trimethyldihydrofuran ring was in an envelope conformation and disordered over two sites with 0.628(1) and 0.372(1) occupancies for the major and minor components, respectively, which corresponded to the less furan ring strain and the steric hindrance between the two methyl substituents (at positions 1 and 2 ) on the furan ring of the major component than that of the minor component. The crystal structure is stabilized by intermolecular O−H···O hydrogen bonds and weak C−H···O interactions.

Chemopreventive Effect of Cratoxylum formosum (Jack) ssp. pruniflorum on Initial Stage Hepatocarcinogenesis in Rats

“…Dulcisxanthone B from the root displayed anti-inflammation activity in a lipopolysaccharide-activated RAW264.7 cell line by inhibiting nitric oxide production [ 35 ], whereas cochinchinone C inhibits cancer phenotypes by downregulating NF-κB in multidrug-resistant A549 lung cancer cell line [ 36 ]. The green fruit of CP contains formoxanthone C, pruniflorone M-O, xanthonolignoid, and flavonoid derivative [ 37 , 38 , 39 ]. Pruniflorone demonstrated potent in vitro nitric oxide inhibitory activity suggesting a potential anti-inflammation property [ 39 ], while formoxanthone C induced A549 lung cancer cell death via apoptosis by downregulating histone deacetylase 4 [ 40 ].…”

Formoxanthone C Inhibits Malignant Tumor Phenotypes of Human A549 Multidrug Resistant-cancer Cells through Signal Transducer and Activator of Transcription 1-Histone Deacetylase 4 Signaling

“…A voucher specimen (No. 0012677) has been deposited at the Prince of Songkla University Herbarium [21].…”

“…One of them is formoxanthone C (XanX), a xanthone from the green fruit of Cratoxylum formosum ssp. pruniflorum [21]. This xanthone has exhibited cytotoxic activities against the NCI-H187 and human small-cell lung cancer cell lines [22,23].…”