The long-standing history of Corynebacterium parvum, immunity, and viruses.

We report a review of all the experimental and clinical studies performed in the last 60 years on the antiviral activity of inactivated Corynebacterium parvum (Cutibacterium acnes). This bacterium has been originally investigated and used for its oncolytic properties linked to immunomodulating activity, but the interest to successfully prevent and treat bacterial, fungal, and viral infections and lethality, uprising the innate immunity barriers produced many experimental models and very few clinical studies. The dramatic defenseless situation due to impending CoViD-19 pandemic claims to exhume and highlight this aspecific strategy in preventive and therapeutic settings; as a matter of fact, no new or mutated virus can potentially escape to this strong innate immune surveillance strengthened by adequate C. parvum protocols.

Synthesis of α/ß dipeptides containing linear or cyclic α-dehydro-ß-amino acids as scaffolds for bioactive compounds.

The synthesis of α/ß dipeptides containing linear or cyclic α-dehydro-ß-amino acids has been performed starting from alkylidene acetacetamides, which were obtained from α-amino esters via Ir-catalyzed allylic amination. Differently hindered carbonates were synthesized via a protocol involving chemoselective Luche's reduction, acylation, and allylic amination. Depending on the nature of the selected α-amino acid, we observed strong influence on the product regiochemistry due to the carbonate size and the amino-acid side chain. In particular, complete regioselectivity was observed in the aminic allylation of carbonates deriving from amino acids possessing a methylene unit in ß-position. On the contrary, methyl carbonates deriving from ß-branched amino acid afforded different results depending on the hindrance of the carbonate. Moreover, spontaneous cyclization was observed for carbamate-containing intermediates, allowing to obtain peptidomimetic polyfunctionalized dihydropyrimidine-2,4-dione. Finally, by inverting the order of reduction/acylation steps on the starting alkylidene acetoacetamides, the formation of polyfunctionalized 1,3-oxazinane-2,4-dione was obtained demonstrating the wide applications of these substrates for the preparation of bioactive peptidomimetics.

Synthesis and conformational analysis of cyclotetrapeptide mimetic beta-turn templates and validation as 3D scaffolds.

The conformations of all stereoisomers of PMRI cyclotetrapeptide mimetics 1-8 are essentially determined by the predisposition of the diamine to stabilize beta-turns. The peptide mimetics can be regarded as 3D scaffolds for designing molecules with a predictable display of the pharmacophores. We used the models for testing novel RGD analogues as alpha(v)beta(3)-integrin receptor antagonists.

Primary tuberculosis of submandibular gland.

Salivary gland tuberculosis is a rare pathology and does not always have the diagnostic guidelines led by previous tubercular localizations. Tubercular bacillus can reach the salivary gland in different ways, but the condition that most frequently causes a tubercular infection is the decay of the human organism defensive capacity toward the germ.A 15-year-old Romanian boy presented with a swelling in the left submandibular region. Normal extraoral, intraoral examination, and routine diagnostic examinations were performed. In order to make a final diagnosis, we performed a surgical left submandibular gland sialo-adenectomy operation to enable a histologic examination of the withdrawn tissue. Microscopic examination of the gland and lymph nodes showed a chronic necrotizing phlogosis of tubercular type. Previous routine examinations have been important only after final diagnosis to confirm that the submandibular tubercular localization was a primary infection. Diagnosis of this kind of disease is extremely difficult and is made with certainty only with the histologic examination, as happened in our case.

A practical synthetic route to functionalized THBCs and oxygenated analogues via intramolecular Friedel-Crafts reactions.

A practical catalytic approach to the synthesis of 4-substituted 1,2,3,4-tetrahydro-beta-carbolines (THBCs, 1) and 1,2,3,9-tetrahydropyrano[3,4-b]indoles (2) via InBr3-catalyzed intramolecular Friedel-Crafts (F-C) cyclization is described. The use of cross-metathesis reaction represents a direct route to the cyclization precursors and the use of InBr3 (5 mol%) allowed polycyclic indole compounds to be isolated in high yields under mild reaction conditions (rt, DCM, minutes). Finally, efforts toward the development of a stereocontrolled version of the present cyclization are presented, highlighting [salenAlCl] and bimetallic [(salenAlCl)2-InBr3] system as promising chiral Lewis acids (ee up to 60%).

Catalytic enantioselective addition of indoles to arylnitroalkenes: an effective route to enantiomerically enriched tryptamine precursors.

A new valuable catalytic protocol for the preparation of synthetically useful beta-indolyl nitro compounds bearing benzhydryl stereocenters is presented. The combined use of catalytic amounts of a commercially available chiral [SalenAlCl] complex and pyridine allowed, for the Friedel-Crafts alkylation reaction of indoles with aromatic nitro-olefins to be carried out in good yields and enantioselectivity (up to 63% ee).

Development of new calcium receptors based on oxazolidin-2-ones containing pseudopeptides.

With the aim of designing a new calcium receptor, the synthesis and the conformational analysis of a small library of dipeptides having the general formula Ac-Oxx-L-Xaa-OBn [Oxx = L-Oxd, (4S,5R)-4-methyl-5-carboxyoxazolidin-2-one; D-Oxd, (4R,5S)-4-methyl-5-carboxyoxazolidin-2-one; or D-Oxac (4R)-(2-oxo-1,3-oxazolidin-4-yl)-acetic acid] is reported. Ac-L-Oxd-L-Ala-OBn was identified as the most promising compound by MS-ESI analysis and this outcome was confirmed by photoluminescence spectroscopy.

Development and conformational analysis of a pseudoproline-containing turn mimic.

The liquid-phase synthesis and the conformational analysis of a small library of fully protected tetramers containing L-pyroglutamic acid (L-pGlu), (4S,5R)-4-methyl-5-carboxybenzyloxazolidin-2-one (L-Oxd), or (4R,5S)-4-methyl-5-carboxybenzyloxazolidin-2-one (D-Oxd) as residue i + 1 are reported to test the tendency of these oligomers to assume a -hairpin conformation. The most promising molecule is Boc-L-Val-D-Oxd-Gly-L-Ala-OBn, which assumes a preferential -turn conformation in CDCl3, as shown by IR and 1H NMR analysis. These findings have been confirmed by DFT calculations, which provide an interpretation for the available experimental data and agree with the reported observations.