Naturally derived anti-HIV agents.

The urgent need for new anti-HIV/AIDS drugs is a global concern. In addition to obvious economical and commercial hurdles, HIV/AIDS patients are faced with multifarious difficulties associated with the currently approved anti-HIV drugs. Adverse effects, the emergence of drug resistance and the narrow spectrum of activity have limited the therapeutic usefulness of the various reverse transcriptase and protease inhibitors that are currently available on the market.

Sesquiterpenes from Warburgia ugandensis and their antimycobacterial activity.

The dichloromethane extract of the stem bark of Warburgia ugandensis afforded three new coloratane sesquiterpenes, namely: 6alpha,9alpha-dihydroxy-4(13),7-coloratadien-11,12-dial (1), 4(13),7-coloratadien-12,11-olide (2), and 7beta-hydroxy-4(13),8-coloratadien-11,12-olide (3), together with nine known sesquiterpenes, i.e., cinnamolide-3beta-acetate (4), muzigadial (5), muzigadiolide (6), 11alpha-hydroxymuzigadiolide (7), cinnamolide (8), 7alpha-hydroxy-8-drimen-11,12-olide (9), ugandensolide (10), mukaadial (11), ugandensidial (12), and linoleic acid (13).

Lessons from European population genetic databases: comparing the law in Estonia, Iceland, Sweden and the United Kingdom.

The advent of large-scale, population genetic databases (PGDs) in several countries around the world marks a significant development in human DNA banking and genetic research. The European countries that have led the way in the development of PGDs are Iceland, Sweden, Estonia and the U.K.

Isopimaric acid from Pinus nigra shows activity against multidrug-resistant and EMRSA strains of Staphylococcus aureus.

The diterpene isopimaric acid was extracted from the immature cones of Pinus nigra (Arnold) using bioassay-guided fractionation of a crude hexane extract. Isopimaric acid was assayed against multidrug-resistant (MDR) and methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentrations (MIC) were 32-64 microg/mL and compared with a commercially obtained resin acid, abietic acid, with MICs of 64 microg/mL.

Antimalarial compounds from Kniphofia foliosa roots.

During the course of screening Ethiopian medicinal plants for their antimalarial properties, it was found that the dichloromethane extract of the roots of Kniphofia foliosa Hochst. (Asphodelaceae), which have long been used in the traditional medicine of Ethiopia for the treatment of abdominal cramps and wound healing, displayed strong in vitro antiplasmodial activity against the chloroquine-sensitive 3D7 strain of Plasmodium falciparum with an ED50 value of 3.8 microg/mL and weak cytotoxic activity against KB cells with an ED50 value of 35.

Echinacea species (Echinacea angustifolia (DC.) Hell., Echinacea pallida (Nutt.) Nutt.,Echinacea purpurea (L.) Moench): a review of their chemistry, pharmacology and clinical properties.

This paper reviews the chemistry, pharmacology and clinical properties of Echinacea species used medicinally. The Echinacea species Echinacea angustifolia, Echinacea pallida and Echinacea purpurea have a long history of medicinal use for a variety of conditions, particularly infections, and today echinacea products are among the best-selling herbal preparations in several developed countries. Modern interest in echinacea is focused on its immunomodulatory effects, particularly in the prevention and treatment of upper respiratory tract infections.

In vitro 12(S)-HETE inhibitory activities of naphthoquinones isolated from the root bark of Euclea racemosa ssp. schimperi.

Platelet 12-lipoxygenase is believed to play a role in cancer and other pathological conditions, such as psoriasis, atherosclerosis and arthritis. The inhibition of 12-LOX is a potential therapeutic approach in the treatment of tumor metastasis. The extracts of Euclea racemosa Murr.

An anti-staphylococcal acylphloroglucinol from Hypericum foliosum.

An investigation into the antibacterial properties of Hypericum foliosum Aiton. (Guttiferae) has led to the isolation of a new bioactive acylphloroglucinol natural product which by NMR spectroscopy and mass spectrometry was characterised as 1,3,5-trihydroxy-6-[2''',3'''-epoxy-3'''-methyl-butyl]-2-[2''-methyl-butanoyl]-4-[3'-methyl-2''-butenyl]-benzene and is described here for the first time. This metabolite was evaluated against a panel of multidrug-resistant strains of Staphylococcus aureus and minimum inhibitory values ranged from 16 to 32 microg/ml.

Anti-inflammatory activity of extracts and a saponin isolated from Melilotus elegans.

The crude methanol extract of Melilotus elegans Ser. (Fabaceae), a plant widely used in Ethiopian traditional medicine for the treatment of asthma, haemorrhoid and lacerated wounds showed a significant anti-inflammatory activity against carrageenin-induced rat paw oedema. At a dose corresponding to 333.

Novel cyclopropyl beta-amino acid analogues of pregabalin and gabapentin that target the alpha2-delta protein.

As part of a program aimed at generating compounds with affinity for the alpha(2)-delta subunit of voltage-gated calcium channels, several novel beta-amino acids were prepared using an efficient nitroalkane-mediated cyclopropanation as a key step. Depending on the ester that was chosen, the target amino acids could be prepared in as few as three steps. The cyclopropyl amino acids derived from ketones proved to be potent binders of the alpha(2)-delta subunit of voltage-gated calcium channels, but did not interact with the large neutral amino acid system L (leucine) transporter.

The use of therapeutic drug monitoring in the management of protease inhibitor-related toxicity.

The aim of this project was to determine whether therapeutic drug monitoring (TDM) and subsequent dose modification is effective in the management of protease inhibitor (PI)-associated toxicity. A retrospective case-notes review of patients who had had TDM for suspected antiretroviral drug toxicity from November 2000 to March 2002 was carried out. This identified six symptomatic patients in whom high plasma drug levels of a PI had been found and subsequent dose modification was associated with improvement/resolution of symptoms.

Effect of mibefradil on sodium and calcium currents.

Interstitial cells of Cajal (ICC) generate the electrical slow wave. The ionic conductances that contribute to the slow wave appear to vary among species. In humans, a tetrodotoxin-resistant Na+ current (Na(V)1.

A furanocoumarin and polymethoxylated flavonoids from the Yucatec Mayan plant Casimiroa tetrameria.

As part of an ongoing study of the medicinal plants of the Yucatec Maya, Casimiroa tetrameria was investigated for its phytochemistry. From an ethyl acetate partition of an ethanol extract of the leaves, eight flavonoids and a furanocoumarin were isolated and characterised as 5,6,2',3',5',6'-hexamethoxyflavone, 5,6,2',3',6'-pentamethoxyflavone and 5-methoxy-8-(3''-hydroxymethyl-but-2''-enyloxy)-psoralen using a combination of 1H, 13C NMR and NOESY spectroscopy.

Anti-staphylococcal and cytotoxic compounds from Hyptis pectinata.

Bioassay-guided fractionation of a CHCl (3) extract prepared from the Mexican medicinal plant Hyptis pectinata led to the isolation of four pyrones, pectinolides A-C ( 1-3) and H ( 4). Activity was tracked using cultured KB cells. Multidrug-resistant strains of Staphylococcus aureus were sensitive to pectinolide H ( 4; KB > 20 microg/mL) in the concentration range of 32-64 microg/mL.

Bioactive constituents of Artemisia monosperma.

During a study on the chemistry and biological activity of Kuwaiti plants, new metabolites including 4,6-dihydroxy-3-[3'-methyl-2'-butenyl]-5-[4''-hydroxy-3''-methyl-2''-butenyl]-cinnamic acid (1), the 3R,8R stereoisomer of the C17 polyacetylene dehydrofalcarindiol (2) and a C10 polyacetylene glucoside (3) were characterised by spectroscopic means. Additionally, the previously characterised natural products 1,3R,8R-trihydroxydec-9-en-4,6-yne (4), spathulenol (5) and eriodyctiol-7-methyl ether (6) were also isolated. Compounds 2, 3, and 4 were evaluated for their ability to inhibit the enzyme 12-lipoxygenase and 3 and 4 showed moderate activity at 30 microg/ml.

Catechin gallates inhibit multidrug resistance (MDR) in Staphylococcus aureus.

Epicatechin gallate (1) and epigallocatechin gallate (2) were evaluated for their antibacterial and efflux inhibitory activity against a wild-type and three multidrug-resistant (MDR) strains of Staphylococcus aureus. Compound 2 was more active than 1 based on minimum inhibitory concentrations (MICs; 32-64 versus 64->512 microg/mL, respectively). When incorporated into the growth medium at 20 microg/mL, both compounds exhibited a four-fold potentiation of the activity of norfloxacin against a norfloxacin-resistant strain of S.

Antimycobacterial coumarins from the sardinian giant fennel (Ferula communis).

The structure of a new prenylated coumarin (E-omega-benzoyloxyferulenol, 1b) from the Sardinian giant fennel (Ferula communis) has been confirmed by synthesis. The parent compound ferulenol (1a) showed sub-micromolar antimycobacterial activity, which was partly retained in 1b and in the simplified synthetic analogue 3, but diminished in its omega-hydroxy and omega-acetoxy derivatives (1c and 1d, respectively). The outstanding activity of 1a, its low toxicity, and the evidence for definite structure-activity relationships make this prenylated 4-hydroxycoumarin an interesting antibacterial chemotype worth further investigation.

Spontaneous healing of a trophic ulcer of the metatarsal pad in a dog.

A two-year-old whippet cross presented with a large ulcer of the right metatarsal pad. Laceration of the plantar aspect of the metatarsal region involving the flexor tendons had occurred 10 days prior to ulcer formation. Pain sensation was absent distal to the wound, indicating tibial nerve damage.

Antibacterial and resistance modifying activity of Rosmarinus officinalis.

As part of a project to characterise plant-derived natural products that modulate bacterial multidrug resistance (MDR), bioassay-guided fractionation of a chloroform extract of the aerial parts of Rosmarinus officinalis led to the characterisation of the known abietane diterpenes carnosic acid (1), carnosol (2) and 12-methoxy-trans-carnosic acid. Additionally, a new diterpene, the cis A/B ring junction isomer of 12-methoxy-trans-carnosic acid, 12-methoxy-cis-carnosic acid (5), was isolated. The major components were assessed for their antibacterial activities against strains of Staphylococcus aureus possessing efflux mechanisms of resistance.

The antimycobacterial components of hops (Humulus lupulus) and their dereplication.

Bioassay-guided fractionation of a hexane extract of strobile hops (Humulus lupulus) was undertaken to isolate and characterize the antimycobacterial constituents using the fast-growing mycobacterial species Mycobacterium fortuitum. Activity was associated with a low polarity fraction and 1H NMR spectra indicated the presence of a fatty acid mixture with unsaturated components. GC-MS of the derivatives indicated the presence of palmitic, stearic and oleic acids with small quantities of lignoceric, arachidic, behenic and linoleic acids.

Iridoid glycosides from Eremostachys glabra.

Reversed-phase preparative HPLC of a methanol extract of the rhizomes of Eremostachys glabra yielded three new iridoid glycosides, namely, 6,9-epi-8-O-acetylshanziside methyl ester, 5,9-epi-penstemoside, and 5,9-epi-7,8-didehydropenstemoside. Their structures were elucidated on the basis of spectroscopic data interpretation. The free-radical scavenging activity of these compounds was assessed using the DPPH assay.

Carbon monoxide activates human intestinal smooth muscle L-type Ca2+ channels through a nitric oxide-dependent mechanism.

Carbon monoxide (CO) is increasingly recognized as a physiological messenger. CO is produced in the gastrointestinal tract with diverse functions, including regulation of gastrointestinal motility, interacting with nitric oxide (NO) to mediate neurotransmission. The aim of this study was to determine the effect of CO on the human intestinal L-type Ca(2+) channel expressed in HEK cells and in native cells using the patch-clamp technique.

Lopinavir/ritonavir combined with twice-daily 400 mg indinavir: pharmacokinetics and pharmacodynamics in blood, CSF and semen.

Objectives: To evaluate the steady-state blood plasma (BP), CSF and seminal plasma (SP) pharmacokinetics (PK) of twice-daily indinavir 400 mg and lopinavir/ritonavir.

Methods: Ten HIV-1-positive men on lopinavir/ritonavir participated in a PK study. PK sampling was performed before and 2 weeks after adding indinavir to lopinavir/ritonavir-containing regimens.

New constituents of Artemisia monosperma.

A new eudesmane sesquiterpene (1) and a C(10) diyne (2) were isolated from the aerial parts of Artemisia monosperma. The structures of these compounds were determined as rel-1beta,3alpha,6beta-trihydroxyeudesm-4-ene (1) and 1,3R,8R-trihydroxydec-9-en-4,6-yne (2) on the basis of spectral data interpretation. The absolute stereochemistry of 2 was determined using Mosher ester methodology in which the terminal primary hydroxyl group was first protected to simplify the stereochemical analysis.

Inhibitory activity of Juniperus communis on 12(S)-HETE production in human platelets.

Extracts of Juniperus communis L. (Cupressaceae) have been evaluated for their inhibitory activity on human platelet-type 12(S)-lipoxygenase [12(S)-LOX]. The methylene chloride extracts of Juniperi lignum, Juniperi pseudo-fructus and the ethyl acetate extract of Juniperi pseudo-fructus showed a significant inhibition on the production of 12(S)-HETE [12(S)-hydroxy-5,8,10,14-eicosatetraenoic acid] at 100 microg/mL (54.