Bioactive 6S-Styryllactone Constituents of Polyalthia parviflora

Abstract

Parvistones A-E (1-5), five new styryllactones possessing a rare α,β-lactone moiety and a 6S configuration, were isolated from a methanolic extract of Polyalthia parviflora leaves. The structures and the absolute configuration of the isolates were elucidated using NMR spectroscopy, specific rotation, circular dichroism, and X-ray single-crystal analysis. Compounds 8, 9, 11, and 12 were isolated for the first time. The results were supported by comparing the data measured to those of 6R-styryllactones. Moreover, a plausible biogenetic pathway of the isolated compounds was proposed. The structure-activity relationship of the compounds in an in vitro anti-inflammatory assay revealed the 6S-styryllactones to be more potent than the 6R derivatives. However, the effect was opposite regarding their cytotoxic activity. In addition, 6S-styrylpyrones isolated showed more potent anti-inflammatory and cytotoxic activity when compared to the 1S-phenylpyranopyrones obtained.

Lactones and Flavonoids isolated from the Leaves of Globimetula braunii

“…This is similar to the previously reported compounds 8-15 which have a mean sixmembered ring displacement of 0.178-0.179 Å and an average C6 displacement from the mean-plane at 0.301-0.325 Å[16][17][18][19][20][21][22]. The rotation angle of the hydroxyphenyl moiety and dihydropyran-2-one moiety around the butyl chain of compound 1 is 129.87(6)° which, compared to compounds 8-15, falls close to the range for these types of compounds at 14.20-120.25° suggesting that high degree of rotations are possible[16][17][18][19][20][21][22].…”

“…X-ray crystal structure of 1 (thermal displacement 50%). Solvent water molecules are omitted.This feature is shared with other literature examples containing a dihydropyran-2-one moiety such as 8-15 (Figure 4)[16][17][18][19][20][21][22]. The deviations of the six-membered ring O1-C6 from its least-squares plane are quite characteristic of these compounds.…”

Hydroxypropyl-β-Cyclodextrin Complexes of Styryllactones Enhance the Anti-Tumor Effect in SW1116 Cell Line

“…Styryllactones are a series of secondary metabolites isolated from the genus Goniothalamus, which generally contains 1 benzene ring and 1 unsaturated lactone ring (Bermejo et al, 1997;Bermejo et al, 1998;Cao et al, 1998;Bermejo et al, 1999;Hu et al, 1999;Mu et al, 1999a;Peris et al, 2000;Lan et al, 2005;Liou et al, 2014). In our previous work, styryllactone compounds were isolated from Goniothalamus griffithii (Annonaceae) and A B FIGURE 7 | Images from the differential scanning calorimetry (DSC) analysis.…”

“…Styryllactones represent a series of natural products, isolated exclusively from the genus Goniothalamus belonging to the Annonaceae family, which are mostly indigenous in southeast Asia. Styryllactones are classified based on different structural skeletons as follows (Bermejo et al, 1997;Bermejo et al, 1998;Cao et al, 1998;Bermejo et al, 1999;Hu et al, 1999;Mu et al, 1999a;Peris et al, 2000;Lan et al, 2005;Liou et al, 2014): styrene-pyrone ( Figure 1A), styrene-furanone ( Figure 1B), furan-pyrone ( Figure 1C), furan-furanone ( Figure 1D), pyran-pyrone ( Figure 1E), and heptyl esters ( Figure 1F).…”

Styryl Lactones from Roots and Barks Goniothalamus lanceolatus

“…The coupling constant between H-5 and H-6 is 5.4 Hz, indicating that the dihedral angle is close to 45º, thus establishing H-5 is in equatorial orientation, leading to Rconfiguration. Based on the presented spectral data (Table 1) [3], (-)-ent-goniothalamin oxide 12 [3,7], Parvistone D 13 [3,6], 1S,5S,7R,8S,3-exo,7-endo-(+)-8-epi-9deoxygoniopypyrone 14 [3,8] and parvistone E 15 [3].…”