Four New Iridoid Metabolites Have Been Isolated from the Stems of Neonauclea reticulata (Havil.) Merr. with Anti-Inflammatory Activities on LPS-Induced RAW264.7 Cells.

One new iridoid, namely neonanin C (1) one monocyclic iridoid ring-opened derivative namely neonanin D (2), two new bis-iridoid derivatives namely reticunin A (3) and reticunin B (4) with sixteen known compounds (5-20) were isolated from the stems of Neonauclea reticulata (Havil.) Merr. These new structures were determined by the detailed analysis of spectroscopic data and comparison with the data of known analogues. Compounds 1-20 were evaluated for inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages cell line. The results showed that all compounds exhibited no obvious cytotoxicity compared to the control group and five compounds including isoboonein (7), syringaresinol (10), (+)-medioresinol (12), protocatechuic acid (14) and trans-caffeic acid (15) exhibited inhibitory activities with IC50 values at 86.27 ± 3.45; 9.18 ± 1.90; 76.18 ± 2.42; 72.91 ± 4.97 and 95.16 ± 1.20 µg/mL, respectively.

Three New Iridoid Derivatives Have Been Isolated from the Stems of Neonauclea reticulata (Havil.) Merr. with Cytotoxic Activity on Hepatocellular Carcinoma Cells.

Three new iridoids, namely neonanin A (1), neonanin B (2) and neoretinin A (3), as well as twelve known compounds, 6-hydroxy-7-methyl-1-oxo-4-carbomethoxyoctahydrocyclopenta[c]pyran (4), 4-epi-alyxialactone (5), loganetin (6), loganin (7), phenylcoumaran-α'-aldehyde (8), cleomiscosin A (9), ficusal (10), balanophonin (11), vanillic acid (12), p-coumaric acid (13), cis,trans-abscisic acid (14), and trans,trans-abscisic acid (15) were isolated from the stems of Neonauclea reticulata (Havil.) Merr. These new structures were determined by the detailed analysis of spectroscopic data and comparison with the data of known analogues. Compounds 1⁻13 were evaluated using an in-vitro MTT cytotoxic assay for hepatocellular carcinoma (HCC) cells, and the preliminary results showed that ficusal (10), balanophonin (11), and p-coumaric acid (13) exhibited moderate cytotoxic activity, with EC50 values of 85.36 ± 4.36, 92.63 ± 1.41, and 29.18 ± 3.48 µg/mL against Hep3B cells, respectively.

A New Bithiophene from the Root of Echinops grijsii.

A new bithiophene, 5-(4-hydroxy-3-methoxy-1-butyny)-2,2'-bithiophene (1), and sixteen known thiophenes: 2-(3,4-dihydroxybut-1-ynyl)-5-(penta-1,3-diynyl)thiophene (2), α-terthienyl (3), 5-(3,4-dihydroxybut-1-ynyl)-2,2'-bithiophene (4), 5-acetyl-2,2'-bithiophene (5), 5-formyl-2,2'-bithiophene (6), methyl 2,2'-bithiophene-5-carboxylate (7), 5-(but-3-en-1-ynyl)-2,2'-bithiophene (8), 5-(4-isovaleroyloxybut-1-ynyl)-2,2'-bithiophene (9), cardopatine (10), isocardopatine (11), 5-(3-hydroxy-4-isovaleroyloxybut-1-ynyl)-2,2'-bithiophene (12), 5-(3-hydroxymethyl-3-isovaleroyloxyprop-1-ynyl)-2,2'-bithiophene (13), 5-(4-hydroxy-1-butynyl)-2,2'-bithiophene (14), 5-(4-acetoxy-1-butynl)-2,2'-bithiophene (15), 2,2'-bithiophene-5-carboxylic acid (16) and 2-(4-hydroxybut-1-ynyl)-5-(penta-1,3-diynyl)thiophene (17) were isolated from the roots of Echinops grjisii Hance. Among them, compounds 6, 7 and 16 were isolated from a natural source for the first time. Compounds 2, 4 and 14 exhibited significant anti-inflammatory activity against nitrite of LPS-stimulated production in the RAW 264.7 cell line.