Study of inhibition of germination of potato by ethylene.

In Canada, the potato () is by far the most cultivated vegetable and plays a major nutritional role. However, during storage, the potato can easily undergo germination. In this study we have shown the inhibition potential of ethylene as an anti-germinative agent acting especially on phenols.

Plants of the 'Libellus de Medicinalibus Indorum Herbis' from Mexico, 1552. Zephyranthes fosteri (Amaryllidaceae) Alkaloids.

The Libellus de Medicinalibus Indorum Herbis (Booklet of Indian Medicinal Plants) is the first book of medicinal plants written in the American continent. It was first published in 1939 as 'An Aztec Herbal'. One of the depicted plants is Huetzcanixochitl (laughing flower) interpreted as Zephyranthes fosteri (Amaryllidaceae).

Factors Affecting the Formation of 2:1 Host:Guest Inclusion Complexes of 2-[(R-Phenyl)amine]-1,4-naphthalenediones (PAN) in β- and γ-Cyclodextrins.

The molecular hosts cyclodextrins form inclusion complexes with a wide variety of guests, resulting in complexes with various host:guest stoichiometries. In the case of a series of 19 1,4-naphthoquinolines as guests with either β- or γ-cyclodextrin studied using electrospray mass spectroscopy, in most cases only 1:1 complexes were observed, with 2:1 host:guest complexes observed in just 6 out of 38 host:guest combinations. It is shown that these higher-order complexes were observed only in the case of small (or no) electronically withdrawing substituents, and were much less likely in the case of the larger γ-cyclodextrin host.

On the synthesis of cyclodextrin-peptide conjugates by the Huisgen reaction.

A,D-substituted cyclodextrin (CDX) substituted on their primary rim side are ideal scaffolds for the macromolecular assembly and formation of templated structures. Their substitution can be achieved through various reactions. However, the use of the well-known Huisgen reaction in this context is under-reported.

XAS examination of glutathione-cobalt complexes in solution.

In the present work, we have investigated the coordination modes of cobalt with glutathione (γ-l-glutamyl-l-cysteinyl-glycine, GSH). A systematic study of cobalt-GSH complexes at basic and neutral pH has been undertaken with a multi-spectroscopic approach combined with quantum chemistry calculations. XAS (x-ray absorption spectroscopy) has been performed at the cobalt K edge in order to shed light into the cation coordination sphere and formal oxidation states.

Acetylcholinesterase-inhibiting alkaloids from Zephyranthes concolor.

The bulbs and aerial parts of Zephyranthes concolor (Lindl.) Benth. & Hook.

Development of normal phase-high performance liquid chromatography-atmospherical pressure chemical ionization-mass spectrometry method for the study of 6,6'-bis-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-benzo[1,2,4]-triazin-3-yl)-[2,2']-bipyridine hydrolytic degradation.

In the field of nuclear waste management, the 6,6'-bis-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-benzo[1,2,4]-triazin-3-yl)-[2,2']-bipyridine (CyMe(4)BTBP) is a polycyclic N-based molecule eligible to remove actinides from spent nuclear fuel by liquid-liquid extraction processes. In such processes, the organic phase containing the extracting molecules will undergo hydrolysis and radiolysis, involving degradation products. The purpose of this work was to develop a normal phase chromatography (NP-HPLC) coupled to atmospherical pressure chemical ionisation-mass spectrometry (APCI-MS) method to separate and identify degradation products of CyMe(4)BTBP dissolved in octanol, submitted to HNO(3) hydrolysis.

A new approach for the purification and characterisation of PA49.5, the main prebiotic of Lactococcus lactis subsp. cremoris.

The main autolysin PA49.5, an enzyme that hydrolyzes or destroys the components of a biological endogenous cell or a tissue, was purified 3045 times from the homogenate of a whole cell extract of Lactococcus lactis subsp. cremoris ATCC 9596 (Mc5), with a recovery yield of 52%.

A structural study of model peptides derived from HIV-1 integrase central domain.

The HIV-1 integrase (IN) catalyzes the integration of viral DNA in the human genome. In vitro the enzyme displays an equilibrium of monomers, dimers, tetramers and larger oligomers. However, its functional oligomeric form in vivo is not known.

Cytotoxic effects of mammea type coumarins from Calophyllum brasiliense.

Calophyllum brasiliense (Clusiaceae) is a big tree from the Tropical Rain Forests of the American continent. The organic extracts from the leaves yielded coumarins of the mammea type: mammea A/BA, A/BB, B/BA, B/BB, C/OA, C/OB, B/BA cyclo F, B/BB cyclo F, and isomammeigin. The triterpenoids friedelin and canophyllol, as well as the biflavonoid amentoflavone, protocatechuic and shikimic acids, were also obtained.