Ola Bergendorff

Assays of the biological activities of guaiane sesquiterpenoids isolated from the fruit bodies of edible lactarius species

Three sesquiterpenoids that are found in the edible mushrooms Lactarius deliciosus, L. deterrimus and L. sanguifluus, have been assayed for biological activity. The compounds tested were a stearic acid ester of a sesquiterpene (I) and a sesquiterpene aldehyde (lactaroviolin, II) and alcohol (deterrol, III). The assays used were for mutagenic activity in the Ames Salmonella assay, for antimicrobial activity against bacterial fungi and algae, for cytotoxicity against Ehrlich ascitic tumour cells and L 1210 cells, and for phytotoxic activity against Lepidium sativum and Seteria italica. All three compounds showed weak mutagenic activity in the Ames assay. Two compounds (II and III) were found to have moderate cytotoxic activity and one (III) exhibited weak antibacterial activity. No compound revealed phytotoxic, algicidal or antifungal activity.

Furanocoumarins with affinity to brain benzodiazepine receptors in vitro.

Eight furanocoumarins were isolated from a methanol extract of dried roots of Angelica dahurica. One of these, phellopterin, strongly (IC50 = 0.36 microM) inhibits the binding of [3H]diazepam to central nervous system benzodiazepine receptors in vitro, while the others, despite their structural similarities with phellopterin, are considerably less active.

Inhibition of kainic acid binding to glutamate receptors by extracts of Gastrodia

S-(4-hydroxybenzyl)glutathione was isolated as the major principle responsible for the inhibition of the in vitro binding of kainic acid to brain glutamate receptors by water extracts of the plant Gastrodia elata. The affinity (IC50 value) of the compound is slightly lower compared to glutamate and glutathione.

Chemical changes in rubber allergens during vulcanization

Allergic contact dermatitis to rubber is caused by residues of chemicals used in manufacturing a rubber product. Several different additives are used to achieve a final product of the desired characteristics. Accelerators such as thiurams, dithiocarbamates, and mercaptobenzothiazoles are often among the additives responsible for allergic reactions recognized by dermatologists. The chemistry of the vulcanization process is complicated; as it occurs at an elevated temperature with a mixture of reactive chemicals, the compositions of the initial and final products differ. This paper investigates the changes in composition of common allergens during vulcanization, doing so by chemically analysing various rubber formulations at different stages of the process. Major changes were found in which added chemicals were consumed and new ones produced. An important observation is that thiuram disulfides rarely appear in the final rubber although they may have been used as additives. Instead, thiurams are often converted to dithiocarbamates or to products formed by addition to mercaptobenzothiazole structures, if these have been used together with thiurams as accelerators.

The sesquiterpenes of Lactarius deliciosus and Lactarius deterrimus

Abstract The sesquiterpenoid contents of the fruit-bodies of Lactarius deliciosus Fr. and L. deterrimus Grobger have been reinvestigated. Undamaged fruit-bodies of both species were found to contain only a single sesquiterpene, as two fatty acid esters. If the fruit-bodies are injured (e.g. by cutting), the esters are in minutes converted to five free sesquiterpenes. Three of these have previously been isolated from L. deliciosus while two are new, and the structures of the new compounds have been elucidated by spectral and chemical methods. The conversions of sesquiterpenes in the injured fruit-bodies appear to be enzymatic, and the possibility that they are part of a chemical defence system is discussed.

Occupational allergic contact dermatitis caused by sterile non-latex protective gloves: clinical investigation and chemical analyses.

Background An increased frequency of occupational contact hand dermatitis among surgical operating theatre personnel has been noticed.

Reaction profile in patch testing with allergens formed during vulcanization of rubber

Vulcanization of rubber changes its allergen pattern.

Isolation and identification from Salvia officinalis of two diterpenes which inhibit t-butylbicyclophosphoro[35S]thionate binding to chloride channel of rat cerebrocortical membranes in vitro

Ethanolic extracts from dried leaves of sage (Salvia officinalis) showed inhibition of [35S]tertiary-butylbicyclophosphorothionate ([35S]TBPS) binding to rat brain membranes in vitro. This ligand is considered to bind to the chloride channel of the GABA/benzodiazepine receptor complex in brain tissue. Substances having inhibitory activity were purified and their chemical structure identified as the diterpenes carnosic acid and carnosol (IC50 values of 33 +/- 3 microM and 57 +/- 4 microM, respectively). The two compounds did not affect binding of the ligands [3H]muscimol and [3H]diazepam to the GABA/benzodiazepine complex in vitro. Saturation experiments of [35S]TBPS binding indicated that carnosic acid decreases the binding affinity.

High-performance liquid chromatography analysis of rubber allergens in protective gloves used in health care.

A high‐performance liquid chromatography (HPLC) method developed for analysis of zinc dithiocarbamates was validated and used to perform a survey of disposable medical gloves used in southern Sweden. The gloves were extracted with acetone at room temperature for 10 min by shaking. The extracts were injected into a polyether ether ketone lined HPLC column, and peaks were analysed by a diode‐array detector. The survey shows that of 19 gloves analysed, 10 contained zinc diethyldithiocarbamate (0.070–3.5 mg/g), 3 contained zinc pentamethylenedithiocarbamate (1.0–4.3 mg/g), 4 contained zinc dibutyldithiocarbamate (0.9–1.1 mg/g), and 2 contained 2‐mercaptobenzothiazole (0.005–0.008 mg/g). None of them contained thiurams.

HPLC analysis of alkyl thioureas in an orthopaedic brace and patch testing with pure ethylbutylthiourea.

Ethylbutylthiourea (EBTU) is an accelerator used in the production of chloroprene (neoprene) rubber. EBTU occurs in a mixture with diethylthiourea (DETU) and dibutylthiourea (DBTU) in the accelerator. An analytical method originally developed for analysis of zinc dithiocarbamates in rubber has been used to analyse EBTU, DETU and DBTU in a knee brace responsible for an allergic contact dermatitis in a gardener suffering from arthrosis. EBTU was isolated and gave positive reactions when tested as a pure compound. The test reaction was accompanied by positive reactions to DETU and DBTU.