Kurt Leander

Quantitation of Δ1‐tetrahydrocannabinol in plasma from cannabis smokers

A method to identify and accurately measure non‐labelled Δ1‐tetrahydrocannabinol (Δ1‐THC) in blood of cannabis smokers has been developed. It consists of the following steps: To a 5 ml plasma sample is added deuterated Δ1‐THC (Δ1‐THC‐d2) as internal standard. After extraction with light petroleum and evaporation, the Δ1‐THC containing fraction is separated by chromatography on Sephadex LH‐20 (1 times 40 cm) using light petroleum‐chloroform‐ethanol (10:10:1) as eluant. A fraction containing Δ1‐THC is collected and subjected to mass fragmentography (LKB 9000; 3% OV‐17/Gas‐Chrom Q; 230°). The mass spectrometer was adjusted to record the intensities of m/e 299 and 314 of Δ1‐THC and m/e 301 and 316 of Δ1‐THC‐d2. The standard curve was made by plotting peak height m/e 299/m/e 301. Peak levels of 19–26 ng ml−1 were reached within 10 min after smoking a cigarette containing 10 mg Δ1‐THC.

Identification of monohydroxylated metabolites of cannabidiol formed by rat liver.

Cannabidiol (CBD) was metabolized in vitro by rat liver enzymes. Unchanged CBD and eight monohydroxylated metabolites were isolated and positively identified. As previously reported, 7‐hydroxy‐CBD was the major metabolite. The second most abundant metabolite was 6α‐hydroxy‐CBD; whereas only a trace amount of 6β‐hydroxy‐CBD was found. In addition hydroxylation occurred in all positions of the pentyl side chain, 4″‐hydroxy‐CBD being most abundant. 3″‐Hydroxy‐CBD was formed in half of the yield of 4″‐hydroxy‐CBD, while 1″‐, 2″‐, and 5″‐hydroxy‐CBD were each formed in approximately one fourth of the yield of 4″‐hydroxy‐CBD.

Amotin and amoenin, two sesquiterpenes of the picrotoxane group from Dendrobium amoenum

Abstract Two new sesquiterpenes, amotin and amoenin, of the picrotoxane group were isolated from Dendrobium amoenum . The constitution of amoenin was evident from spectral investigations and by its conversion into α-dihydro-picrotoxinin on oxidation with oxygen in the presence of platinum. The constitution of amotin was shown by its spectral properties and the conversion of aduncin into amotin by hydrogenolysis of its epoxide ring. That the configuration at C-4 in aduncin and amotin is R was supported by circular dichroism measurements on some derivatives of picrotoxinin and aduncin.

A new triterpene glucoside from Cymbidium giganteum

Abstract A new triterpene glucoside, cymbidoside, has been isolated from Cymbidium giganteum . Its structure is shown to be 4ξ-(β- d -glucopyranosyloxymethyl)-14α-methyl-22ξ, 24ξ, 25,28-tetrahydroxy-9,19-cyclo-5α,9β-ergostan-3-one.