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A phytochemical investigation of methanol extract from leaves of Pachyrhizus erosus (L.) Urban, a leguminous shrub distributed in Vietnam and other tropical and subtropical countries led to the isolation of a new prenylated chalcone, erosusone (1) and a new megastigmane glycoside epimer, 3-episedumoside F1 (9), together with thirteen known compounds including flavonoids (2-6), a 3-benzoxepine lactone (7), a pyridine-4,5-diol derivative (8), megastigmanes and megastigmane glycosides (10-15). Their structures were elucidated by means of high resolution-electrospray ionization (HR-ESI)-MS, one dimensional (1D) and two-dimensional NMR (2D-NMR) spectroscopy as well as comparison with the data reported in the literature. The cytotoxic effects on LU-1 (lung carcinoma), HepG2 (hepatocellular carcinoma), and MCF7 (breast carcinoma) cell lines were assessed. Prenylated chalcones 1-2 and isoflavone 3 exhibited cytotoxicity against all tested cell lines with IC50 values ranging from 22.04 to 45.03 µM.

Four new alkaloid glycosides, zanthonitisides A–D (1-4), together with five known compounds (5–9) were isolated from the aqueous fraction of stems and twigs of Zanthoxylum nitidum (Roxb.) DC. Their structures were determined on the basis of extensive spectroscopic methods, including 1D-, 2D-NMR, MS, and CD data. All isolated compounds were evaluated for their cytotoxic activity against three human cancer cell lines, CT-26, MCF-7, and MKN-45. As results, compound 4 showed significant cytotoxic activity on MKN-45 cancer cell line with IC50 value of 7.4 ± 1.0 μM. Compound 9 exhibited moderate cytotoxic activity on all tested cancer cell lines with an IC50 values ranging from 34.7 to 44.7 μM.

Various Elaeocarpus species including Elaeocarpus tonkinensis have been important medicinal plants that used in traditional medication system and mainly used to cure nervous system-related disorders. However, their antiviral potential has not been reported yet. During the screening of medicinal plant extracts with the antiviral activity against influenza viruses, we found that E. tonkinensis extract has strong antiviral activity. Through organic solvent partition and repeated column chromatography using SiO 2, C-18 and Sephadex LH-20, a total of nine compounds were purified from the methanol extract of E. tonkinensis. Their chemical structures were determined by NMR and MS spectral data to be trolliamide (1), gallic acid (2), urolithin M-5 (3), hydroquinone (4), 2,4-dihydroxybenzoic acid (5), 3,5-dihydroxy-4-methoxybenzoic acid (6), corilagin (7), chebulagic acid (8), and shikimic acid (9). Their antiviral activity against influenza virus strains A/Puerto Rico/8/34 (H1N1; PR8), A/Hong Kong/8/68 (H3N2; HK) and B/Lee/40 (Lee) was examined on the basis of cytopathic effect (CPE) assay. Among them, compounds 2, 3, 4, 7, and 8 significantly inhibited viral replication in a dose-dependent manner with EC 50 values ranging from 7.8 to 59.6 μg/mL against influenza A and/or B viruses with selectivity indices above 5.0. This study suggests that the botanical materials of E. tonkinensis could be promising inhibitors of influenza A andB viruses and applied to the development of a novel herbal medicine.

Two new oleanane-type saponins, 1α-hydroxy-olean-12-en-3-O-β-D-xylopyranoside (1) and 1α-hydroxy-olean-12-en-3-O-α-L-arabinopyranoside (2), along with six known compounds (3-8), were isolated from the leaves and twigs of Elaeocarpus hainanensis Oliv. Their structures were determined based on chemical and spectroscopic analyses. This is the first report on oleanane-type triterpenoids in the genus Elaeocarpus.

Panax bipinnatifidus Seem. (Araliaceae), 1 of 11 kinds of ginseng (Panax spp.), has been used in traditional medicine but there are very few publications regarding its chemical constituents. This f...

A new chromone, 5,7-dihydroxy-6,8-dimethoxy-2-methyl-4H-chromen-4-one (1), together with seven known compounds, 5,7-dihydroxy-6-methoxy-2-methyl-4H-chromen-4-one (pisonin B) (2), 5,7-dihydroxy-2-methyl-4H-chromen-4-one (noreugenin) (3), 5-hydroxy-7-methoxy-2-methyl-4H-chromen-4-one (eugenin) (4), (2S)-7,4'-dihydroxyflavan (5), 3',7-dihydroxy-4'-methoxy-8-methylflavan (6), 3',7-dihydroxy-4'-methoxyflavan (7) and 6,8-dimethyl-5,7,4'-trihydroxyflavanone (( - )-farrerol) (8), were isolated from Hymenocallis littoralis Salisb. (Amaryllidaceae) growing in Vietnam. Their structures were determined based on spectroscopic and physicochemical analyses.

In a continuing search for anti-HIV compounds from plants of Vietnam, 19 compounds, including a new triterpene, were isolated from an extract of the leaves and stem of Vatica cinerea. The new triterpene was determined to be a cycloartane triterpenoid with 29 skeletal carbons and was assigned the name vaticinone (1). The known triterpenes included three cycloartanes, a lanostane, two dammaranes, three lupanes, an ursane, and an oleanane. A chlorophyll isolate was identified as pheophorbide a (13). The majority of the triterpenes, the sesquiterpene, 1-hydroxycyclocolorenone, and pheophorbide a showed anti-HIV activity, with the chlorophyll being the most active, demonstrating an IC(50) value of 1.5 microgram/mL (2.5 microM), while being completely devoid of toxicity up to a concentration of 20 microgram/mL (33.8 microM). Vaticinone (1) was found to inhibit the replication of HIV-1, with an IC(50) value of 6.5 microgram/mL (15.3 microM; selective index = 1.4). The structures of these isolates were determined by spectral data including 1D and 2D NMR spectra.

The eudesmane sesquiterpenoid, verticillatol (1), as well as the lignan, (+)-5'-demethoxyepiexcelsin (2), and a known lignan, (+)-epiexcelsin (3), were isolated from Litsea verticillata Hance. Lignan 2 showed moderate anti-HIV activity with an IC(50) value of 16.4 microg/ml (42.7 microM), while the known lignan 3 was inactive up to a concentration of 20 microg/ml (48.3 microM). Compound 1 demonstrated weak activity with an IC(50) value of 34.5 microg/ml (144.7 microM) while being devoid of cytotoxicity at 20 microg/ml. The structures were elucidated by 1D and 2D NMR spectroscopy, and the absolute configuration of the new sesquiterpenoid was determined by the generation of Mosher esters.

We report herein the first isolation of a novel structural type sesquiterpene designated as ‘litseane’ from the twigs and leaves of Litsea verticillata Hance (Lauraceae). The isolate (litseaverticillol A, 1 ) was obtained as a racemate through bioassay-guided fractionation and found to inhibit the replication of human immunodeficiency virus (HIV) type 1 with an IC 50 value of 5.0 μg/mL (21.4 μM) and a selectivity index of 2.6. Spectroscopic data and a potential biosynthetic pathway are given.

We report herein the first isolation of a novel structural type sesquiterpene designated as ‘litseane’ from the twigs and leaves of Litsea verticillata Hance (Lauraceae). The isolate (litseaverticillol A, 1 ) was obtained as a racemate through bioassay-guided fractionation and found to inhibit the replication of human immunodeficiency virus (HIV) type 1 with an IC 50 value of 5.0 μg/mL (21.4 μM) and a selectivity index of 2.6. Spectroscopic data and a potential biosynthetic pathway are given.

Bioassay directed-fractionation led to the identification of litseaverticillols A–H ( 1 – 8 ) from the leaves and twigs of Litsea verticillata Hance. These new sesquiterpenes possess a unique skeleton that was recently designated as ‘litseane’. The structures of these compounds were determined by spectroscopic means including 1D and 2D NMR data. Structural configurations were determined by ROESY experiments. Mosher ester reactions and optical rotation measurements established the sesquiterpenes 1 – 8 as racemates. Isolates 1 – 8 inhibited HIV-1 replication in HOG.R5 cells with IC 50 values ranging from 2 to 15 μg/ml (8–58 μM) while affecting the growth of HOG.R5 at concentrations 2–3-fold higher. Based on this data, structure–activity relationships can be discerned, suggesting compounds of this class are good candidates for analog production.

Bioassay-directed fractionation led to the isolation of 14 compounds, six of which possess antimalarial activity, from the dried leaves and stems of Rhaphidophora decursiva. Polysyphorin (1) and rhaphidecurperoxin (6) showed strong activities against Plasmodium falciparum. Rhaphidecursinol A (2), rhaphidecursinol B (3), grandisin (4), and epigrandisin (5) were less active against the same organism. Among the isolates, rhaphidecursinol A (2) and rhaphidecursinol B (3) were determined to be new neolignans, and rhaphidecurperoxin (6) is a new benzoperoxide. Known compounds isolated include polysyphorin (1), grandisin (4), epigrandisin (5), (+)-medioresinol, (-)-pinoresinol, (-)-syringaresinol, (+)-glaberide I, (+)-dehydrovomifoliol, (-)-liliolide, (-)-hydroxydihydrobovolide, and N-butylbenzamide, of which compound 1 appears worthy of further evaluation as an antimalarial agent. Structure elucidation and identification were accomplished by spectroscopic means including 1D and 2D NMR analyses.