Anti-HIV-1 Activities and Chemical Constituents from Leaves and Twigs of Santisukia pagetii (Bignoniaceae)

The first phytochemical investigation of the leaves and twigs of Santisukia pagetii (Bignoniaceae) using a bioassay-guided fractionation led to the isolation and identification of seventeen known compounds, including four triterpenoids, 3- O-acetylpomolic acid (1), ursolic acid (2), 3- O-acetylursolic acid (3) and siaresinolic acid (4), three iridoid glycosides, specioside (5), verminoside (6) and ambiguuside (7), three flavonoid glycosides, luteolin-7- O-neohesperidoside (8), apigenin-7- O-neohesperidoside (9) and isoquercitrin (10), two phenolic compounds, p-coumaric acid (11) and caffeic acid (12), one monoterpenoid, ( 6S)-menthiafolic acid (13), together with α-D-glucose (14), β-D-maltose (15), β-sitosterol 3- O-β-D-glucopyranoside (16), a mixture of β-sitosterol (17A) and stigmasterol (17B). Compounds 1–13 were isolated from Santisukia genus for the first time. In addition, compounds 1–7, 9 and 10 were found to be active against HIV-1 in anti-syncytium assay, while only compounds 1 and 3 were found to be active (84.4% and 87.2% inhibition at 200 μg/mL, with IC50 values of 290.96 and 210.34 μM, respectively) against HIV-1 reverse transcriptase. Moreover, anti-HIV-1 activities of compounds 1, 3–8, and 13 were reported for the first time.

Triterpenoid saponins from the stem bark of Catunaregam spinosa

Four new triterpenoid saponins, Catunaroside E (1; 3-O-{β-D-glucopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→3)]-β-D-glucopyranosyl}-siaresinolic acid), Catunaroside F (2; 3-O-{α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→3)]-β-D-glucopyranosyl}-28-O-(β-D-glucopyranosyl)-oleanolic acid), Catunaroside G (3; 3-O-[α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl]- 28-O-(β-D-glucopyranosyl)-siaresinolic acid), and Catunaroside H (4; 3-O-{β-D-glucopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→3)]-β-D-glucopyranosyl}-28-O-(β-D-glucopyranosyl)-siaresinolic acid), and the known triterpenoid saponin Mussaendoside J (5), were isolated from the stem bark of Catunaregam spinosa . Their structures were elucidated on the basis of their spectral data and chemical evidence.