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Varying concentrations of cyclopropane-1,1-dicarboxylic acid (CDA), an inhibitor of 1-aminocyclopropane-1-carboxylic acid oxidase, added to the solid culture medium of tomato nodal shoot segments resulted in a reduction in the level of endogenous ethylene according to the concentration of inhibitor applied. Following treatment with inhibitor, plants were homogenised and the concentrations of CDA and of 1-aminocyclopropane-1-carboxylic acid (ACC) were measured simultaneously in the resulting juice using an HPLC-ESI/MS-MS method. The levels of CDA and ACC measured in the plant tissues were associated with the concentration of inhibitor added to the solid medium. The HPLC-ESI/MS-MS method described produced limits of detection of 0.8 pmol for ACC and of 4 pmol for CDA.

Liquid chromatography coupled to ion spray tandem mass spectrometry was developed as a method for the simultaneous analysis of the amino acid 1-aminocyclopropane-1-carboxylic acid (ACC) and its structural analogue, cyclopropane-1,1-dicarboxylic acid (CDA). ACC and CDA fragmentation as well as optimization of MS parameters were investigated in positive ion mode. In selective reaction monitoring mode the protonated molecule [M+H]+ was selected as parent ion for both ACC and CDA, while the immonium ion from ACC and the [M+H-H2O]+ ion from CDA were selected, respectively, as product ions. In spite of the high selectivity of MS/MS among the 20 protein amino acids potentially present with ACC and CDA in the plant material analyzed, Glu and Thr can interfere with the signal of ACC. As a result, their chromatographic separation is necessary. This was achieved in less than 4 min by ion-pair reversed-phase chromatography with nonafluoropentanoic acid as ion-pair reagent. A linear response within a concentration range of 1-5 mg l(-1) was observed for this LC method and the detection limit was found to be 20 pmol for ACC and 150 pmol for CDA (using a 20-microl loop). This methodology was successfully applied to the detection of ACC in apple tissue.

The oil from Moringa oleifera variety Mbololo seeds from Kenya was extracted using three different procedures including cold press (CP), extraction with n-hexane (H), and extraction with a mixture of chloroform/methanol (50:50) (CM). The oil concentration ranged from 25.8% (CP) to 31.2% (CM). The density, refractive index, color, smoke point, viscosity, acidity, saponification value, iodine value, fatty acid methyl esters, sterols, tocopherols (by HPLC), peroxide value, and at 232 and 270 nm and the susceptibility to oxidation measured with the Rancimat method were determined. The oil was found to contain high levels of unsaturated fatty acids, especially oleic (up to 75.39%). The dominant saturated acids were behenic (up to 6. 73%) and palmitic (up to 6.04%). The oil was also found to contain high levels of beta-sitosterol (up to 50.07%), stigmasterol (up to 17.27%), and campesterol (up to 15.13%). alpha-, gamma-, and delta-tocopherols were detected up to levels of 105.0, 39.54, and 77. 60 mg/kg of oil, respectively. The induction period (at 120 degrees C) of M. oleifera seed oil was reduced from 44.6 to 64.3% after degumming. The M. oleifera seed oil showed high stability to oxidative rancidity. The results of all the above determinations were compared with those of a commercial virgin olive oil.

Ethylene production is inhibited by several new structural analogues of amino cyclopropane carboxylic acid (ACC), without an amine function in the C1 position. The Substituted Cyclopropane Carboxylic Acids (SCCA) require a minimal cyclopropane ring but no amine function to exhibit inhibition. Ethylene inhibition was essayed on tomato discs, and on partially purified ACC oxidase from apple fruits. These new inhibitors possess a cyclopropane ring and a substituant (R2) in the C2 position. First results showed that the amount of ethylene inhibition is strongly correlated to the chemical structure of (R2, R5) and to the presence or not of a carboxylic function in the C1 position of the cyclopropane ring. To evaluate the nature of inhibition, kinetic studies were made using partially purified ACC oxidase from apple fruits. From all the inhibitors tested the best results were obtained using trans — phenyl cyclopropane carboxylic acid and cyclopropane 1,1 dicarboxylic acid.

In this work, the effect of a modified atmosphere with carbon dioxide (CO 2 ) on the biochemical pathways, responsible for the production of the secondary metabolites; such as aroma, anthocyanins, flavonoids etc…; was studied. The results of the effect of CO 2 treatment can be correlated with biochemical events such as the expression of the enzymes, responsible for the aroma development; the levels of the endogenous hormones, (e.g. IAA, ethylene), resulted to the further maturation of fruits. The commercial applications of this type of experiments are extensive and are correlated with the production of fruit juices and wines, as well as with the conservation of fresh fruits.

A general strategy was developed to synthesize ω-methylthioalkyl glucosinolates through a coupling reaction between 1-thio-β-D-glucopyranose and a hydroximoyl halide obtained from the corresponding nitroalkyl methylsulfide precursor.

The existence of myrosinase activity in both the endocarp and the seeds of Cucumis melo fruit is reported. This activity increases during the ripening of the fruit.

Starting from a free hemiacetalic hydroxyl group, the glycosylation is performed by means of the DMF-COCl 2 Vilsmeier-Haack reagent and silver tosylate. The nature of the reactive species is discussed.

The glycosylation reaction based upon anomeric free hydroxyl group activation by its transformation into an alkcxyiminium salt by the action of the N,N-dimethylformamide/phosgene complex has been extended to the pentofuranose series. The mechanism of this glycosylation is discussed. Nine glycosides have been prepared.