The presence, yield and composition of secondary metabolites in plants, viz. the volatile components and those occurring in essential oils, can be affected in a number of ways, from their formation in the plant to their final isolation. Several of the factors of influence have been studied, in particular for commercially important crops, to optimize the cultivation conditions and time of harvest and to obtain higher yields of high-quality essential oils that fit market requirements. In addition to the commercial importance of the variability in yield and composition, the possible changes are also important when the essential oils and volatiles are used as chemotaxonomic tools. Knowledge of the factors that determine the chemical variability and yield for each species are thus very important. These include: (a) physiological variations; (b) environmental conditions; (c) geographic variations; (d) genetic factors and evolution; (e) political/social conditions; and also (f) amount of plant material/space and manual labour needs. Copyright © 2008 John Wiley & Sons, Ltd.

Factors affecting secondary metabolite production in plants: volatile components and essential oils

Essential oils as antimicrobials in food systems – A review

Lignans neolignans, and related compounds

Phthalides, and their corresponding dihydro and tetrahydro analogues, are components of several genera of the plant family Apiaceae. These taxa have been reported as exhibiting a wide range of bioactivities against experimental models of several illnesses and physiological conditions, including microbial and viral infections, stroke, tuberculosis, and vasoconstriction. Many of these genera are purported to possess medicinal values, and of these several are considered to be traditional herbal medicines. This review provides an overview of the methods of investigation, the structural diversity, and the bioactivity of phthalides, dihydrophthalides, tetrahydrophthalides, and dimers from plants in the Apiaceae.

The structural diversity of phthalides from the Apiaceae.

This paper reviews the toxicokinetics of amphetamines. The designer drugs MDA (methylenedioxy-amphetamine, R,S-1-(3;,4;-methylenedioxyphenyl)2-propanamine), MDMA (R,S-methylenedioxymethamphetamine), and MDE (R,S-methylenedioxyethylamphetamine), as well as BDB (benzodioxolylbutanamine; R,S-1-(1;,3;-benzodioxol-5;-yl)-2-butanamine or R,S-1-(3;,4;-methylenedioxyphenyl)-2-butanamine) and MBDB (R,S-N-methyl-benzodioxolylbutanamine), were taken into consideration, as were the following N-alkylated amphetamine derivatives: amphetaminil, benzphetamine, clobenzorex, dimethylamphetamine, ethylamphetamine, famprofazone, fencamine, fenethylline, fenproporex, furfenorex, mefenorex, mesocarb, methamphetamine, prenylamine, and selegiline. English-language publications from 1995 to 2000 were reviewed. Papers describing identification of metabolites or cytochrome P450 isoenzyme-dependent metabolism and papers containing pharmacokinetic/toxicokinetic data were considered and summarized. The implications of toxicokinetics for toxicologic assessment or for interpretation in forensic cases are discussed.

Toxicokinetics of amphetamines: metabolism and toxicokinetic data of designer drugs, amphetamine, methamphetamine, and their N-alkyl derivatives.

Commercial Australian sandalwood oil produced from Santalum spicatum (R. Br.) A. DC. roots was analyzed using GC and GC/MS. Seventy constituents were identified: four monoterpenes, 64 sesquiterpenes and two others. Four compounds (Z)-β-curcumen-12-ol, (Z)-12-hydroxysesquicineole,6,10-epoxybisabol-2-en-12-olandnor-helifolen-12-al were found to our knowledge for die first time in nature and were characterized using 1H-, 13C-N M R, GC/FTIR and GC/MS analyses.

Western Australian sandalwood oil - - new constituents of Santalum spicatum (R. Br.) A. DC. (Santalaceae)

Characterization of oxalic acid derivatives as new metabolites of metamizol (dipyrone) in incubated hen's egg and human.

Using GC and GC/MS, 40 compounds were identified in the essential oils of various organs of ACHILLEA PTARMICA. Three ponticaepoxides and (+)-(4 S,6' R)-beta-sesquiphellandrene could be isolated from the root.

Essential Oils of Achillea ptarmica.

Famprofazone (1) metabolites were studied in human urine after medication by 50 mg oral dose. The human urine was collected over 48 h from six volunteers at time intervals of 6, 12, 24 and 48 h. The amount of famprofazone metabolites were recovered from the urine samples by application of Extrelut extraction method. The resultant extracts were derivatized using N-methyl-N-trimethylsilytrifluoroacetamide (MSTFA) for trimethylsilylation followed by N-methyl-bis-trifluoroacetamide (MBTFA) for trifluoroacetylation. Methamphetamine (2) and 3-hydroxymethyl-propyphenazone (3), excreted in human urine, were identified as famprofazone metabolites by gas chromatography-mass spectrometry (GC-MS). The quantitative results revealed that the average amounts of 2 and 3, excreted in human urine were equal to 2.6 and 4 mg, respectively, through 48 h. However, 3 was analysed after enzymatic hydrolysis of the urine samples using beta-glucuronidase/arylsulphatase. The excreted methamphetamine enantiomers could be separated by application of indirect GC-technique using S-(-)-N-trifluoroacetylprolyl chloride (TPC) as a chiral derivatizing agent. The average amount of (-)-methamphetamine isomer excreted in the urine was found to be three fold those of the (+)-isomer.

Michael Neugebauer

Papers

Western Australian sandalwood oil - - new constituents of Santalum spicatum (R. Br.) A. DC. (Santalaceae)

Characterization of oxalic acid derivatives as new metabolites of metamizol (dipyrone) in incubated hen's egg and human.

Essential Oils of Achillea ptarmica.

Stereoselective metabolic study of famprofazone.

Bisepoxylignan glycosides from Stauntonia hexaphylla