Prenylated Benzoylphloroglucinols and Xanthones from the Leaves of Garcinia oblongifolia with Antienteroviral Activity

Abstract

An acetone extract of the leaves of Garcinia oblongifolia showed antiviral activity against enterovirus 71 (EV71) using a cytopathic effect inhibition assay. Bioassay-guided fractionation yielded 12 new prenylated benzoylphloroglucinols, oblongifolins J-U (1-12), and five known compounds. The structures of 1-12 were elucidated by spectroscopic analysis including 1D- and 2D-NMR and mass spectrometry methods. The absolute configurations were determined by a combination of a Mosher ester procedure carried out in NMR tubes and ECD calculations. Compared to ribavirin (IC50 253.1 μM), compounds 1, 4, and 13 exhibited significant anti-EV71 activity in vitro, with IC50 values of 31.1, 16.1, and 12.2 μM, respectively. In addition, the selectivity indices of these compounds were 1.5, 2.4, and 3.0 in African green monkey kidney (Vero) cells, respectively.

Antiviral Activity of Fridericia formosa (Bureau) L. G. Lohmann (Bignoniaceae) Extracts and Constituents

“…Additionally, the xanthones norbellidifolin, 1,5,8-trihydroxy-3-methoxyxanthone, and 2- C-β-D -glucopyranosyl-1,3,7-trihydroxyxanthone showed remarkable activity with EC 50 values of 0.77, > 0.98, and 0.21 mM for hepatitis B surface antigen (HBsAg) and <0.62, 0.35, and 0.04 mM for hepatitis B antigen (HBeAg), respectively [32]. Besides, euxanthone, from Garcinia oblongifolia (Clusiaceae) leaves extract, disclosed significant activity in vitro against Enterovirus 71, with EC 50 value of 12.2  μ M [33]. In addition, the selectivity index of this compound was 3.0 in relation to the cytotoxicity to Vero cells (CC 50 36.6  μ M) [33].…”

Pyrrolidine dithiocarbamate inhibits enterovirus 71 replication by down-regulating ubiquitin–proteasome system

“…Compounds extracted from Chinese herbs have showed promising antiviral effect against EV71 infection (Chiang et al, 2005;Lin et al, 2009;Song et al, 2014;Zhang et al, 2014). The application of these compounds resulted in reduced viral replication, inhibited apoptosis of the infected cells, or decreased mortality of the infected mice.…”

(±)-Melicolones A and B, Rearranged Prenylated Acetophenone Stereoisomers with an Unusual 9-Oxatricyclo[3.2.1.13,8]nonane Core from the Leaves of Melicope ptelefolia

“…In the HMBC spectrum (Figure 2), the correlations from CH 3 -18 (19) to C-16 and C-17, from H 2 -15 to C-3, C-4, and C-17 and from 16-OH to C-15, C-16, and C-17, as well as a weak but distinctive four-bond correlation from CH 3 -19 to C-3 allowed the elaboration of the ring A in 1 to be a 2,2-dimethyl-3-hydroxypyran moiety. 10 The multiple HMBC correlations of H 2 -10/C-4, C-5, and C-12; H-11/C-1, C-4, C-5, C-10, and C-12; CH 3 -13 (14)/C-11, C-12, and C-1; and 1-OH/C-5 established a cyclohexane moiety consisting of C-1, C-5, C-4, and C-10 to C-12, which was divided to rings B and C by a C-5−O−C-11 oxygen bridge. A carbomethoxy was attached to C-5 based on the HMBC correlations of 6-OCH 3 /C-6 and H-11/C-6 together with the oxygenated nature of C-5 (δ C 102.1).…”