A new antiplasmodial coumarin from Toddalia asiatica roots

A new antiplasmodial coumarin, 5,7-dimethoxy-8-(3'-hydroxy-3'methyl-1'-butene)-coumarin (1), has been isolated from the roots of Toddalia asiatica. This finding supports the traditional use of this plant for the treatment of malaria.     

Morphinandienone alkaloids from Dehaasia longipedicellata

Five morphinoid alkaloids have been isolated from Dehaasia longipedicellata, namely (-) pallidine, a new alkaloid (+) pallidinine (1), (+)-milonine, (-) 8,14-dehydrosalutaridine and (-) sinoacutine.     

Antiulcer activity of Mikania cordata

The alkaloidal fraction obtained from an ethanolic extract of the leaves of Mikania cordata exhibited significant in vivo antiulcer activity in diclofenac sodium-induced gastric erosions in Long Evans rats.     

Antimicrobial activity of aqueous extracts and of berberine isolated from Berberis heterophylla

The antimicrobial activity of Berberis heterophylla leaves, stems and root aqueous extracts was studied in vitro on Gram-positive and Gram-negative bacteria and fungi. The in vitro antifungal activity of berberine isolated from the same source against different Candida species was also investigated.     

New phenantrene alkaloids from Cryptocarya crassinervia

The bark of Cryptocarya crassinervia provided two new phenantrene alkaloids, 2-hydroxyatherosperminine (1) and N-demethyl-2-methoxyatherosperminine (2).     

Cassine, an antimicrobial alkaloid from Senna racemosa

The leaves of Senna racemosa yielded the piperidine alkaloid cassine and an inositol methyl ether. Antimicrobial screening of the compounds revealed antibacterial activity of cassine with minimum inhibitory concentrations of 2.5 mg/ml for Staphylococcus aureus and Bacillus subtilis and 5.0 mg/ml for Candida albicans.     

Purification, characterization and evaluation of insecticidal activity of trypsin inhibitor from Albizia lebbeck seeds

A Bowman-Birk inhibitor with activity against gut proteases of Helicoverpa armigera was extracted in 0.1 M sodium phosphate buffer from defatted seed flour of Albizia lebbeck. It was purified to 29.62 folds with 51.43% recovery using ammonium sulfate precipitation, gel filtration chromatography on Sephadex G-100 column and ion exchange chromatography on DEAE-Sephadex A50. The purified protein had a molecular weight of 12,303 daltons as determined by SDS-PAGE. It was found to be heat stable up to 60°C and had two pH optima of 7.5 and 9.0. The inhibitor exhibited non-competitive pattern of inhibition with a low Ki value of 0.2 μM. The inhibitor was found to be susceptible to varying concentrations of reducing agents like DTT and 2-mercaptoethanol, thereby indicating the role of disulphide bridges in maintaining its three dimensional structure and stability. The purified inhibitor caused mortality and suppressed larval growth of Pieris brassicae larvae. It was also found to be effective against gut trypsin extracted from Spodoptera littoralis. The sequence of the genes encoding for such inhibitors can be determined and the genes expressing protease inhibitors can be used in vegetable crops to confer resistance against insect pests and other plant pathogens.     

Antimicrobial activity of some medicinal plants from India

The results of a preliminary antimicrobial screening of the methanol extracts of Zingiber officinale, Asteracantha longifolia, Citrus acida, Salacia microsperma and Tinospora cordifolia are reported.     

Two new amide alkaloids with anti-leukaemia activities from Aconitum taipeicum

Two new amide alkaloids, named 3-isopropyl-tetrahydropyrrolo [1,2-a] pyrimidine-2,4(1H,3H)-dione (1) and 1-acetyl-2,3,6-triisopropyl-tetrahydropyrimidin-4(1H)-one (2), were isolated from the roots of Aconitum taipeicum. Their chemical structures were characterized on the basis of MS, 1D- and 2D NMR. The anti-leukaemia activities of the compounds were also tested. The results indicated that the compounds exhibited more significant cell growth inhibitory activities against HL-60 cells than adriamycin, with the IC₅₀ of 1.1 ± 0.03 μg/mL and 1.6 ± 0.07 μg/mL respectively. In addition, two compounds showed anti-tumor activities against K562 cells as well.     

Antidiarrheal activity of dehydroleucodine isolated from Artemisia douglasiana

Dehydroleucodine (DhL), a sesquiterpene lactone obtained from Artemisia douglasiana, was screened for antidiarrheal effects. DhL inhibited castor oil-induced diarrhea in mice by judged by a decrease in the number of wet faeces in the DhL-treatment groups. DhL significantly reduced intestinal transit in mice. Yohimbine and phentolamine counteracted the inhibitory effect of DhL. It is suggested that alpha(2)-adrenergic receptors mediate the effect of DhL in intestinal motility. DhL reduced also intraluminal accumulation of fluid. Thus, the antidiarrheal activity of DhL is possibly related, at least in part, to its inhibitory action against gastrointestinal motility and the inhibition of enteropooling property.     

Two new cytotoxic isomeric indole alkaloids from the roots of Nauclea orientalis

A pair of new isomeric indole alkaloids, naucleaorals A (1) and B (2) were isolated from the roots of Nauclea orientalis. The structures of compounds 1 and 2 were fully characterized using spectroscopic data, and were tested for their cytotoxicity (HeLa and KB cells) and antimalarial activity. Compound 1 showed significant cytotoxicity to HeLa cells with an IC₅₀ value of 4.0 µg/mL, while compound 2 exhibited very modest cytotoxicity to both cell lines with IC₅₀ values of 7.8 and 9.5 µg/mL, respectively. Both compounds proved to be inactive in antimalarial assays (IC₅₀ > 10.00 µg/mL).     

Antimicrobial activity of coupled hydroxyanthracenones isolated from plants of the genus Karwinskia

The in vitro activity of some isolated hydroxyanthracenones belonging to the genus Karwinskia against four bacteria, six filamentous fungi and four yeast are reported. These hydroxyanthracenones were found to possess antimicrobial activity, particularly against Streptococcus pyogenes, Candida albicans, C. boidinii, C. glabrata and Cryptococcus neoformans; minimal inhibitory concentrations range between 16 and 2 microg/ml.     

Antimicrobial activity of flowers from Anthemis cotula

The flavonoid containing total extract of Anthemis cotula flowers, tested at the concentration of 200 μg/ml, showed interesting antimicrobial activity against both Gram-negative and Gram-positive microorganisms.     

Antifeedant activity of vicolides from Pentanema indicum

Vicolides A–D (0.2–2000 ppm) from Pentanema indicum showed antifeedant activity against Euproctes fraterna and Pericallia ricini V stage larvae.     

Leishmanicidal activity of Maytenus illicifolia roots

In vitro evaluation of leishmanicidal activity of aqueous and ethanolic extracts of Maytenus illicifolia against three species of Leishmania. The root extracts showed differential activity against parasites, whereas the aerial part of the extracts was inactive.     

Free radical scavenging activity of three Equisetum species from Fruska gora mountain

The scavenger activities of Equisetum arvense, Equisetum ramosissimum and Equisetum telmateia aboveground parts phosphate buffer (pH 7) extracts were evaluated using three different methods: DPPH assay, ESR and NO radical inhibition assay. Total reducing power was determined by FRAP assay. The E. telmateia extract demonstrated the most relevant scavenger and antioxidant properties. ESR signal of DMPO-OH radical adducts in the presence of E. telmateia phosphate buffer (pH 7) extract was reduced to 98.9% which indicated that E. telmateia could be a useful source of antioxidants with huge scavenger ability.     

Antibacterial activity of the essential oil from Ferula gummosa seed

Antibacterial activity of Ferula gummosa essential oil was studied against bacterial laboratory ATCC standards using the disk diffusion method. The results showed activity against Gram(+) bacteria and Escherichia coli. Little antibacterial activity was found against Pseudomonas aeruginosa.     

Antimicrobial activity of alkaloidal fraction from barks of Himatanthus lancifolius

The alkaloidal fraction from Himatanthus lancifolius barks demonstrated a broad-spectrum in vitro antimicrobial activity for most of the Gram (+) and Gram (-) tested microorganisms.     

New sphingolipids from the root of Isatis indigotica and their cytotoxic activity

Two new sphingolipids were isolated from the 95% EtOH extract of traditional Chinese medicinal plant Isatis indigotica. Their structures were elucidated as (2S,3R)-3-hydroxymethyl-N-(2'-hydroxynonacosanoyl)-trideca-9E-sphingenine(1) and 1-O-beta-D-glucopyranosyl-(2S,3R)-3-hydroxymethyl-N-(2'-hydroxynonacosanoyl)-trideca-9E-sphingenine(2) on the basis of spectroscopic data. Their cytotoxic effects were evaluated by using MTT method.     

Antimicrobial activity of Centaurea diffusa

The methanol soluble fraction of the aqueous extract obtained from the dry heads of Centaurea diffusa demonstrated antimicrobial activity in twelve evaluated microorganisms.