Two New Phenolic Glycosides from the Aerial Part of Dryopteris erythrosora.

BACKGROUND: Dryopteris erythrosora (D.C. Eaton) Kuntze is a species of fern in the family of Dryopteridaceae, which is distributed throughout East Asia. The genus Dryopteris has been used as traditional medicine, especially to treat hepatitis and protect liver. However, only few studies of chemical constituents of D. erythrosora have been conducted so far. OBJECTIVE: In this study, we investigated the phytochemical constituents of D. erythrosora. MATERIALS AND METHODS: The 80% methanol extract of the aerial part of D. erythrosora was used for the isolation of phenolic compounds. The isolated compounds were elucidated by various spectroscopic methods including nuclear magnetic resonance and mass spectrometry. RESULTS: The present phytochemical investigation on the aerial part of D. erythrosora led to the isolation of two new phenolic glycosides, 1 and 2, as well as nine known flavonoids including two flavones (3 and 4) and seven flavonols (5-11). CONCLUSION: In this study, two new phenolic glycosides together with nine known flavonoids were isolated from the aerial part of D. erythrosora. Among them, compounds 4, 8, and 11 were isolated for the first time in Dryopteridaceae family from the present investigation. These results helped us to enrich our understanding of the chemical constituents of D. erythrosora and to identify compounds 1 and 2 which could be potential chemotaxonomic markers for the species. SUMMARY: The genus Dryopteris has been used as traditional medicine, especially to treat hepatitis and protect liverTwo new phenolic glycosides were isolated from D. erythrosoraNine known flavonoids (3-11) were isolated from D. erythrosoraCompounds 4, 8, and 11 were isolated for the first time in Dryopteridaceae family. Abbreviations used: HPLC: High-performance liquid chromatography; Q-TOF LC/MS: Quadrupole-time-of-flight liquid chromatography/mass spectrometry; NMR: Nuclear magnetic resonance; TMS: Tetramethylsilane.

Cytotoxic and antioxidant activities of diterpenes and sterols from the Vietnamese soft coral Lobophytum compactum.

Two new diterpenes, lobocompactols A (1) and B (2), and five known compounds (3-7) were isolated from the methanol extract of the soft coral Lobophytum compactum using combined chromatographic methods and identified based on NMR and MS data. Each compound was evaluated for cytotoxic activity against A549 (lung) and HL-60 (acute promyelocytic leukemia) human cancer cell lines. Among them, compound 5 exhibited strong cytotoxic activity against the A549 cell line with an IC(50) of 4.97 ± 0.06 µM. Compounds 3, 4, and 7 showed moderate activity with IC(50) values of 23.03 ± 0.76, 31.13 ± 0.08, and 36.45 ± 0.01 µM, respectively. The cytotoxicity of 5 on the A549 cells was comparable to that of the positive control, mitoxantrone (MX). All compounds exhibited moderate cytotoxicity against the HL-60 cell line, with IC(50) values ranging from 17.80 ± 1.43 to 59.06 ± 2.31 µM. Their antioxidant activity was also measured using oxygen radical absorbance capacity method, compounds 1 and 2 exhibiting moderate peroxyl radical scavenging activity of 1.4 and 1.3 µM Trolox equivalents, respectively, at a concentration of 5 µM.

Antioxidant activity of a new C-glycosylflavone from the leaves of Ficus microcarpa.

By bioactive-guided fractionation of methanol extract of the Ficus microcarpa leaves, one new C-glucosylflavone, ficuflavoside (1), one new megastigmane glycoside, ficumegasoside (8), and twelve known compounds including flavonoids (2-6), phenylpropanoids (7), megastigmanes (9-11) and sterol derivatives (12-14) were isolated. Their chemical structures were elucidated by mass, 1D, and 2D NMR spectroscopies. The antioxidant activities of these compounds were measured using the oxygen radical absorbance capacity methods. Compounds 1-6 exhibited potent antioxidant activities of 6.6-9.5µM Trolox equivalents at the concentration of 2.0µM. The results indicated 2, 3, and 5 having meaningful reducing capacity of copper (I) ions concentration of 6.1-8.4µM.

A new monoterpenoid glycoside from Myrica esculenta and the inhibition of angiotensin I-converting enzyme.

One new monoterpenoid glycoside, myresculoside (1), and eleven known compounds, were isolated from methanol extract of Myrica esculenta leaves by repeated column chromatography. The effects of these compounds on angiotensin I-converting enzyme (ACE) inhibition were investigated. Compounds 3 and 4 showed the most potent ACE inhibition with rates of 29.97% and 25.63% at concentration of 100 µM, respectively. Compounds 5, 6, and 11 showed weak activity with inhibitory rates of 0.07-1.41% at concentration of 100 µM.

Chemical components from the Vietnamese soft coral Lobophytum sp.

Chromatographic separation resulted in the identification of one new squalene derivative, named lobophytene (1), three cembranoid diterpenes (2-4), and two sterols (5 and 6) from the Vietnamese marine soft coral Lobophytum sp. Their structures were identified on the basis of extensive spectroscopic data and comparison of those with reported data. Compounds 1 and 2 showed significant cytotoxic activities against lung (A549) and colon (HT-29) cell lines with IC(50) values of 8.2 and 5.6 microM for 1; 5.1 and 1.8 microM for 2, respectively.

Cucurbitane-type triterpene glycosides from the fruits of Momordica charantia.

The chemical study of Momordica charantia fruits led to the isolation of three new cucurbitane triterpene glycosides, momordicosides U, V, and W (1-3). The structures of these compounds were determined to be (19R, 23R)-5beta, 19-epoxy-19-methoxycucurbita-6,24-diene-3beta, 23-diol 3-O-beta-D-allopyranoside (1), (23R)-5beta, 19-epoxycucurbita-6,24-diene-3beta, 23-diol 3-O-beta-D-allopyranoside (2), and (19R)-5beta, 19-epoxy-19,25-dihydroxycucurbita-6,23(E)-diene-3beta-ol 3-O-beta-D-glucopyranoside (3), by chemical and spectroscopic methods.

Two new C-glucosyl benzoic acids and flavonoids from Mallotus nanus and their antioxidant activity.

Two new 2-C-beta-D-glucopyranosyl benzoic acid derivatives named mallonanosides A (1) and B (2) were isolated from the methanolic extract of the leaves of Mallotus nanus along with five known flavonoids, kaempferin (3), juglanin (4), quercitrin (5), myricitrin (6), and rhoifolin (7). Their structures were established on the basis of spectral and chemical evidence. Their antioxidant activities were shown to depend on the number of hydroxyl groups, and the location and species of sugar moiety.

Lupane-type triterpene glycosides from the leaves of Acanthopanax koreanum and their in vitro cytotoxicity.

Three new lupane triterpene glycosides, acankoreosides J-L ( 1- 3), were isolated from the leaves of Acanthopanax koreanum. Based on the spectroscopic data, the chemical structures were determined as 3 alpha-hydroxy-20-oxo-30-norlupane-23,28-dioic 28- O- alpha- L-rhamnopyranosyl-(1 --> 4)- beta- D-glucopyranosyl-(1 --> 6)- beta- D-glucopyranosyl ester ( 1); 3 alpha,20,29-trihydroxylupane-23,28-dioic 28- O- alpha- L-rhamnopyranosyl-(1 --> 4)- beta- D-glucopyranosyl-(1 --> 6)- beta- D-glucopyranosyl ester ( 2); and (20S)-3 alpha-hydroxy-29,29-dimethoxylupane-23,28-dioic 28- O- alpha- L-rhamnopyranosyl-(1 --> 4)- beta- D-glucopyranosyl-(1 --> 6)- beta- D-glucopyranosyl ester ( 3). Compounds 1- 3 were evaluated for their cytotoxicity and showed moderate activity against four cell lines, A549 (lung), HL-60 (leukemia), MCF-7 (breast), and U937 (leukemia), with IC (50) values of 23.4, 36.5, 22.6, and 18.5 microM for 1; 6.8, 18.6, 23.1, and > 100 microM for 2; and 28.9, 21.8, 11.0, and 27.5 microM for 3, respectively.

C29 sterols with a cyclopropane ring at C-25 and 26 from the Vietnamese marine sponge Ianthella sp. and their anticancer properties.

Two new C(29) sterols with a cyclopropane ring at C-25 and C-26, petrosterol-3,6-dione (1) and 5alpha,6alpha-epoxy-petrosterol (2), along with petrosterol (3), were isolated from the Vietnamese marine sponge Ianthella sp. The structures of the new compounds were elucidated by comprehensive spectroscopic analyses. Compounds 1-3 showed cytotoxic activities on A549, HL-60, MCF-7, SK-OV-3, and U937 cancer cell lines with IC(50) in the range of 8.4-22.6 microM, whereas compounds 1-3 exhibited only weak cytotoxic activities on HT-29 cell. After HL-60 cells were treated with the compounds, several apoptosis events like chromatin condensation and the increase of the population of sub-G1 hypodiploid cells were observed. These data supported that the compounds might have potential for leukemia treatment.