Anti-Newcastle Disease Virus activity of 3ß and 3α Friedelanol Triterpenoids from the leaves of Synadenium glaucescens Pax.

Newcastle Disease (ND) is a highly pathogenic disease of avian species which is caused by Newcastle Disease Virus (NDV). It is one of the major causes of mortality and morbidity to poultry industry in the third world countries. Currently, there is no treatment measures against ND; the only existing measure is vaccination, though it is incapable to offer 100% immunity. In Tanzania, the leaves of Synadenium glaucescens Pax. are traditionally used for treatment of various ailments including ND. Previously, its leaves extract has been scientifically confirmed to exhibit anti-NDV activity though bioactive compound(s) responsible for this activity is/are unknown. Therefore, this study was aimed to evaluate anti-NDV activity of 3ß-Friedelanol (1) and 3α-friedelanol (2) isolated from its leaves extract. Isolation of these compounds was achieved by column chromatography method whereas, their chemical structures were determined by Nuclear Magnetic Resonance (NMR) data and by comparing with the available literature NMR data. Anti-NDV activity study was done in embryonated chicken eggs (ECEs). Treatment of NDV inoculated ECEs with 3ß-Friedelanol (1) reduced the viral load to zero and maintained the survival of embryos, this was revealed by continuous organs formation and increase in embryo weights with no significant different (p > 0.05) from un-inoculated ECE. These effects suggest that, 3ß-Friedelanol (1) possesses anti-NDV activity. Therefore, existence of 3ß-Friedelanol (1) in the leaves of S. glaucescens may justify its earlier described anti-NDV activity and traditional use in the treatment of ND. Hence, its leaves extract may be considered for development of anti-NDV herbal formulation while 3ß-Friedelanol could either serve as a drug or lead compound for synthesis of anti-NDV drugs.

Differentiation of tannin-containing herbal drugs by HPLC fingerprints.

A new HPLC system coupled with multiple detectors - Diode array detector (DAD), fluorescence detector (FLD), electrochemical amperometric detector (ADC) and mass spectrometry detector (MSD) was developed for the characterization and differentiation of tannin-containing herbal drugs included in The European Pharmacopoeia. The HPLC separation system consisted of an Agilent ZORBAX Eclipse XDB C18 column and a gradient water and methanol as the mobile phase which was kept at a flow rate of 0.3 mL x min(-1). Four kinds of detectors were connected by a micro-splitter valve and simultaneously recorded the response of each analytical sample. Thirty-one samples from eight kinds of tannin-containing drugs were measured using this HPLC system and their signals from all detectors were comprehensively processed via principal component analysis (PCA). The statistic result demonstrates that thirty-one batches from different herbal drugs can be reasonably identified and systematically classified by their chemical fingerprints. The proposed multi-detector HPLC method aided by chemometrics not only offers a new pattern for the study of tannin-containing herbs, but also provides a useful foundation for quality control of herbal medicines.

Antiprotozoal properties of 16,17-dihydrobrachycalyxolide from Vernonia brachycalyx.

Extracts of the leaves from Vernonia brachycalyx showed in vitro activity against Plasmodium falciparum and promastigotes of Leishmania major. The germacrane dilactone 16,17-dihydrobrachycalyxolide (1) which was previously isolated from the aerial parts of the plant was shown to be the major antiplasmodial principle. An X-ray crystallographic analysis established the absolute configuration and some signals in the NMR spectra were reassigned. 16,17-Dihydrobrachycalyxolide (1) elicited a strong antiplasmodial and antileishmanial activity but also a high toxicity against human lymphocytes.

Imbalances of trace elements related to oxidative damage in Alzheimer's disease brain.

Four elements that have been implicated in free-radical-induced oxidative stress in Alzheimer's disease (AD) were measured by instrumental neutron activation analysis (INAA) in seven brain regions from 58 AD patients and 21 control subjects. A statistically significant elevation of iron and zinc was observed in multiple regions of AD brain, compared with controls. Mercury was elevated in AD in most regions studied, but the high variability of mercury levels in both AD and control subjects prevented the AD-control difference from reaching significance. Selenium, a protective agent against mercury toxicity, was significantly elevated only in AD amygdala. The elevation of iron and zinc in AD brain has the potential of augmenting neuron degeneration through free radical processes.

Two new antiprotozoal 5-methylcoumarins from Vernonia brachycalyx.

Two new isomeric 5-methylcoumarins, 2'-epicycloisobrachycoumarinone epoxide (1) and cycloisobrachycoumarinone epoxide (2), have been isolated from the roots of Vernonia brachycalyx by means of bioactivity-guided fractionation. The structures were elucidated by MS and NMR spectroscopic methods. Compounds 1 and 2 showed in vitro activity against Leishmania major promastigotes and against Plasmodium falciparum schizonts and demonstrated an inhibition on the proliferation of human lymphocytes, which was significantly weaker than the antiparasitic effects.

Triterpenoid saponins from Phytolacca rivinoides and Phytolacca bogotensis.

Investigation of the ethanolic extracts from Phytolacca rivinoides and P. bogotensis has resulted in the isolation of five new triterpenoid glycosides of serjanic acid. Their structures have been established mainly by spectroscopic methods (FAB-MS, 1H, 13C NMR, COSY, NOESY, TOCSY, HETCOR and J-resolved 1H NMR) as 3-O-(O-beta-D-galactopyranosyl-(1-->3)-O-beta-D-glucopyranosyl)serjan ic acid 28-O-beta-D-glucopyranosyl ester, 3-O-(O-beta-D-glucopyranosyl-(1-->3)-O-[beta-D-galactopyranosyl-(1-->4)] -O- beta-D-glucopyranosyl)serjanic acid 28-O-beta-D-glucopyranosyl ester, 3-O-(O-alpha-L-rhamnopyranosyl-(1-->2)-O-beta-D-glucopyranosyl-(1-->2)- O-beta-glucopyranosyl)serjanic acid 28-O-beta-D-glucopyranosyl ester, 3-O-(O-beta-D-glucopyranosyl-(1-->3)-O-beta-D-galactopyranosyl-(1-->4)- O-beta-D-glucopyranosyl)serjanic acid 28-O-beta-D-glucopyranosyl ester and 3-O-(O-beta-D-galactopyranosyl-(1-->4)-O-[beta-D-glucopyranosyl-(1-->3)] - O-beta-D-glucopyranosyl)serjanic acid.

An antileishmanial chalcone from Chinese licorice roots.

A bioassay guided fractionation of an extract of Chinese licorice roots led to the isolation of (E)-1-[2,4-dihydroxy-3-(3-methyl-2-butenyl)phenyl]-3-[4- hydroxy-3-(3-methyl-2-butenyl]phenyl-2-propen-1-one, which in vitro showed potent antileishmanial activity. In addition, the novel chalcone (E)-1-[2,4-dihydroxy-3-(3-methyl-2- butenyl)phenyl]-3-(2,2-dimethyl-8-hydroxy-2H-benzopyran-6-yl)-2-prope n-1-one was isolated from the roots. The latter compound only showed antileishmanial activity at high concentrations.

Novel cyclopentenoid cyanohydrin rhamnoglucosides from flacourtiaceae1.

Two novel cyclopentenoid cyanohydrin glycosides, (1 S,4 R)-and (1 R,4 S)-1-[6- O-(alpha- L-rhamnopyranosyl)-beta- D-glucopyranosyloxy]-4-hydroxy-2-cyclopentene-1-carbonitrile, were isolated from seeds of the Indian medicinal plant HYDNOCARPUS PENTANDRA (F. Ham.) Oken (Flacourtiaceae) and characterized by optical rotations as well as (1)H-and (13)C-NMR spectra. The structural assignment is founded on these data and on degradation with alpha- L-rhamnosidase to the corresponding beta- D-glucopyranosides, epivolkenin and taraktophyllin, also present in the seeds in small amounts. Earlier reports of cyclopentenoid rhamnoglucosides from Passifloraceae are rejected.