Chemical constituents of Arisaema franchetianum tubers.

A novel pyrrolidine alkaloid, (2R*,3S*,5S*)-N,2-dimethyl-3-hydroxy-5-(10-phenyldecyl)pyrrolidine (1), and 17 known compounds were isolated from Arisaema franchetianum Engl. (Araceae) tubers. The 17 compounds were bergenin (2), emodin (3), caffeic acid (4), nobiletin (5), 3-O-ß-d-galactopyranosyl-hederagenin 28-O-ß-d-xylopyranosyl(1 â†’ 6)-ß-d-galactopyranosyl ester (6), coniferin (7), qingyangshengenin (8), methylconiferin (9), syringaresinol 4'-O-ß-d-glucopyranoside (10), gagaminine (11), perlolyrine (12), (S)-1-(1'-hydroxyethyl)-ß-carboline (13), 1-(ß-carboline-1-yl)-3,4,5-trihydroxy-1-pentanone (14), 1-methoxycarbonyl-ß-carboline (15), indolo[2,3-α]carbazole (16), 4-hydroxycinnamic acid methyl ester (17), and methyl 4-[2-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-1-(hydroxymethyl)ethyl] ferulate (18). The inhibitory activities of compound 1 and its N-methyl derivative (1a) against porcine respiratory and reproductive syndrome virus (PRRSV), human leukemic K562 cells, and human breast cancer MCF-7 cells were evaluated. Compounds 1 [50% inhibited concentration (IC(50)) = 12.5 ± 0.6 µM] and 1a (IC(50) = 15.7 ± 0.9 µM) were cytotoxic against K562 cells. Compound 1a also had a weak effect on PRRSV with an IC(50) value of 31.9 ± 6.0 µM [selectivity index (SI) = 18.7].

Identification of porcine reproductive and respiratory syndrome virus inhibitors through an oriented screening on natural products.

Porcine reproductive and respiratory syndrome(PRRS) caused by porcine reproductive and respiratory syndrome virus(PRRSV) is one of the most infectious diseases in the swine industry worldwide, causing big economic losses. Vaccines are major weapons against PRRSV, however, current available vaccines have several limitations. Developing chemical drugs as alternatives is required. On the basis of traditional medical knowledge, we purposely selected 15 natural products originated from Chinese herbs with anti-infectious effects. Their antiviral activities were evaluated by PRRSV-induced cytopathic effect(CPE) on MARC-145 cells and reverse transcription polymerase chain reaction(RT-PCR) assay. Compounds ethoxysanguinarine(EOSG) and atractylodinol were found to be the hits which could significantly reduce PRRSV-associated CPE with 50% inhibited concentration(IC50) values of 7.9 and 39.4 µmol/L, respectively. Meanwhile, compounds ethoxysanguinarine and atractylodinol significantly decreased mRNA expression of ORF7 gene in a dose-dependent manner. Study results suggest that compounds ethoxysanguinarine and atractylodinol may be useful anti-PRRSV drugs for swine industry or the hits for further lead optimization.

Bioactive isoquinoline alkaloids from Corydalis saxicola.

Twelve isoquinoline alkaloids including two new nitro-containing tetrahydroprotoberberines, (-)-2,9-dihydroxyl-3,11-dimethoxy-1,10-dinitrotetrahydroprotoberberine (1) and (+)-4-nitroisoapocavidine (2), were isolated from the whole plant of Corydalis saxicola Bunting. The structures of the new compounds were established by spectroscopic analysis and chemical evidence. The inhibitory activity of these isolates against cholinesterase and canine parvovirus were evaluated. Compounds 1 and 1A, (+)-1-nitroapocavidine (5), berberine (8), palmatine (9), dehydrocavidine (10), and sanguinarine (11) showed potent inhibitory activity against acetylcholinesterase with IC(50) values of less than 10 µM, while only compound 1 possessed weak activity against canine parvovirus. Structure-activity studies demonstrated that the nitro substituents at ring A in the tetrahydroprotoberberines led to an increase in the anti-acetylcholinesterase activity.

Anti-inflammatory flavonolignans from Hydnocarpus anthelminthica seeds.

A new flavonolignan, anthelminthicol A (1), together with four known compounds, was isolated from the EtOAc extracts of the seeds of Hydnocarpus anthelminthica. Their structures were elucidated using extensive spectroscopic techniques. Bioassay showed that compounds 3-5 could inhibit nitric oxide production in LPS-stimulated RAW 264.7 macrophage cell lines, with IC(50) values of 7.81, 9.38, and 10.55 µM, respectively.

[Expression and detection of recombinant directing toxin SL120 in Pichia pastoris].

Anti-HIV-1 gp120 single chain antibody(scFv) gene and staphylococcus extoxin A(SEA) gene were inserted into vector pPIC9K. The recombinant plasmid was integrated into Pichia pastoris by electroporation. High level expression was performed by determining the Muts phenotype and screening muti-copy integrants. The recombinant protein was about 57kD and the production was 50.1 mg/L. It was shown that the two kinds of protein affected the conformation of each other by antibody affinity assay, but the recombinant targeting toxins could highly mediate CTLs to kill HIV-1 target cells.