On using an automatic scheme for obtaining the convex hull defining inequalities of a Weismantel 0–1 knapsack constraint

In this short note we obtain the full set of inequalities that define the convex hull of a 0–1 knapsack constraint presented in Weismantel (1997). For that purpose we use our O(n) procedures for identifying maximal cliques and non-dominated extensions of consecutive minimal covers and alternates, as well as our schemes for coefficient increase based tightening cover induced inequalities and coefficient reduction based tightening general 0–1 knapsack constraints.     

Greener Synthesis of Antiproliferative Furoxans via Multicomponent Reactions

Prostate and bladder cancers are commonly diagnosed malignancies in men. Several nitric oxide donor compounds with strong antitumor activity have been reported. Thus, continuing with our efforts to explore the chemical space around bioactive furoxan moiety, multicomponent reactions were employed for the rapid generation of molecular diversity and complexity. We herein report the use of Ugi and Groebke–Blackburn–Bienaymé multicomponent reactions under efficient, safe, and environmentally friendly conditions to synthesize a small collection of nitric-oxide-releasing molecules. The in vitro antiproliferative activity of the synthesized compounds was measured against two different human cancer cell lines, LNCaP (prostate) and T24 (bladder). Almost all compounds displayed antiproliferative activity against both cancer cell lines, providing lead compounds with nanomolar GI₅₀ values against the cancer bladder cell line with selectivity indices higher than 10.     

Synthesis of New 3′-Deoxyribonucleosides Employing the Acid-Catalyzed Fusion Method

Coupling of 4,6-dichloro-1H-imidazo[4,5-c]pyridine (2,6-dichloro-3-deaza-9H-purine) ( 1 ) with 1,2-O-di-acetyl-5-O-benzoyl-3-deoxy-β-D -ribofuranose ( 2 ), employing the acid-catalyzed fusion method, is reported (Scheme 1). The condensation reaction was regioselective and gave the three N¹-glycosylation products 3 – 5 , whereas no N³-nucleosides were detected. Treatment of 3 – 5 with methanolic ammonia afforded the corresponding deprotected nucleosides 6 – 8 . Compounds 6 and 7 were assigned the structure of the β-D - and α-D -anomeric N¹-(3′-deoxyribo)nucleosides, respectively. The third derivative 8 proved to be the α-D -anomer of a 3′-deoxyarabinonucleoside deriving from epimerization at C(2) of the sugar. The 2-chloro- and N⁶-substituted derivatives 9 , 11 , and 13 of 3′-deoxy-3-deazaadenosine ( 10 ) and of its α-D -anomer 12 can be obtained from these versatile synthons (Schemes 2 and 3).     

<Emphasis Type="Italic">k</Emphasis>–Pyramidal One–Factorizations

We consider one–factorizations of complete graphs which possess an automorphism group fixing k ≥ 0 vertices and acting regularly (i.e., sharply transitively) on the others. Since the cases k = 0 and k = 1 are well known in literature, we study the case k≥ 2 in some detail. We prove that both k and the order of the group are even and the group necessarily contains k − 1 involutions. Constructions for some classes of groups are given. In particular we extend the result of [7]: let G be an abelian group of even order and with k − 1 involutions, a one–factorization of a complete graph admitting G as an automorphism group fixing k vertices and acting regularly on the others can be constructed.     

Computational approaches to shed light on molecular mechanisms in biological processes

Computational approaches based on Molecular Dynamics simulations, Quantum Mechanical methods and 3D Quantitative Structure-Activity Relationships were employed by computational chemistry groups at the University of Milano-Bicocca to study biological processes at the molecular level. The paper reports the methodologies adopted and the results obtained on Aryl hydrocarbon Receptor and homologous PAS proteins mechanisms, the properties of prion protein peptides, the reaction pathway of hydrogenase and peroxidase enzymes and the defibrillogenic activity of tetracyclines.     

Yttrium Geothermometry Applied to Garnets from Different Metamorphic Grades Analysed by EPMA and µ-PIXE Techniques

We present a multi-analytical and multi-instrumental approach to a petrologic study of garnets from metapelites characterized by different metamorphic grades. The comparison between major, minor and trace element (Y) distribution in garnets crystallized at different temperatures was performed by electron microprobe (EDS and WDS) and the Proton Induced X-ray Emission microprobe (μ-PIXE). Two garnet samples were selected from metapelite rocks at different metamorphic grades from the tectonic unit of Stilo, Calabrian–Peloritanian Arc, Southern Italy. Quantitative spot analysis profiles and compositional X-ray maps of major elements and yttrium are reported. The major element zoning of garnets is mostly characterized by a smoothed and gradual concentric variation of all elements from core to rim. The Y concentration reveals a marked zoning with its distribution decreasing from about 7000 ppm to about 100 ppm from core to rim, respectively. The precise determination of the Y content by μ-PIXE technique allowed us to better define the rock thermal history, by applying the Y geothermometer. In particular, a common starting temperature of about 450 °C was calculated for the beginning of the garnet growth from all over the unit, but different temperatures in the range from 520 °C to 670 °C were estimated for the peak event in garnets from different areas, in agreement with the P–T values given by the main rock mineral assemblages, reflecting a different metamorphic grade.     

Asymmetric synthesis of (R)- and (S)-4-methyloctanoic acids. A new route to chiral fatty acids with remote stereocenters

The enantioselective synthesis of both enantiomers of 4-methyloctanoic acid, one major aggregation pheromone component of the rhinoceros beetles of the genus Oryctes and an important aroma compound, is described. The key step of the synthesis is based on a stereospecific alkylation with an alcohol-protected alkyl iodide using a pseudoephedrine derivative as a chiral auxiliary followed by subsequent removal of the auxiliary. Both enantiomers are obtained in excellent yields and enantioselectivities (93–94% ee). The strategy outlined allows preparation of a wide variety of enantiopure methyl-branched saturated and unsaturated fatty acids.     

Transformation of incidence structures and sharply multiply transitive permutation sets

In this note we generalize the transformation process introduced in [8]. This generalization allows to find the nonplanar nearfield discovered by H.Karzel and W.Kerby, [5], [6], and the affine Andrè planes.Dedicated to Prof. A.Barlotti and to Prof. L.A.Rosati on their 70th birthdayWork performed under the auspicies of G.N.S.A.G.A. and supported by 40% grants of M.U.R.S.T.