organic chemistry

Acetylcholinesterase inhibitory activity of pyrrolizidine alkaloids from Echium confusum Coincy

Four pyrrolizidine alkaloids, namely 7-O-angeloyllycopsamine N-oxide 1, echimidine N-oxide 2, echimidine 3 and 7-O-angeloylretronecine 4, were isolated for the first time from the whole plant ethanolic extract of Echium confusum Coincy, through bioassay-guided approach. Their structures were determined by spectroscopic means. All the isolates compounds showed moderate activities in inhibiting AChE, with IC50 0.276–0.769.

Fatty acid content profile and main constituents of Corylus avellana kernel in wild type and cultivars growing in Italy

The kernel composition (moisture, ash, protein, carbohydrate, calories, fat, monounsaturated and polyunsaturated fatty acids) of two hazelnut (Corylus avellana L.) cultivars (‘Tonda Gentile Trilobata’ and ‘Tonda Gentile Romana’) and of two wild types growing in different climatic conditions (north-west and central Italy) was evaluated. The main kernel component was fatty acid (65.9 ± 1.8%, mean value), and the most abundant fatty acid in hazelnut was oleic acid (C18:1) (83.5 ± 1.0%, mean value).

Efficient synthesis and first regioselective C-6 direct arylation of imidazo[2,1-c][1,2,4]triazine scaffold and their evaluation in H2O2-induced oxidative stress

Oxidative stress and apoptosis are both associated with various acute and chronic disorders. Thus, the aim of the present study is to synthesize imidazo[2,1-c][1,2,4]triazines derivatives and to evaluate their effects in H2O2-induced oxidative stress in human neuroblastoma cell line (SH-SY5Y cells). The effects of the compounds on cell viability were measured by MTT assay and the changes in stress and apoptosis-related proteins were investigated by PathScan® Stress and Apoptosis Signaling Antibody Array kit and Western Blot technique.

From pyrrolidinyl-benzodioxane to pyrrolidinyl-pyridodioxanes, or from unselective antagonism to selective partial agonism at ?4?2 nicotinic acetylcholine receptor

Each of the four aromatic eCH¼ of (S,R)-2-pyrrolidinyl-1,4-benzodioxane [(S,R)-6] and of its epimer at the dioxane stereocenter (S,S)-6, previously reported as a4b2 nAChR ligands, was replaced with nitrogen. The resulting four diastereoisomeric pairs of pyrrolidinyl-pyridodioxanes were studied for the nicotinic affinity and activity at a4b2, a3b4 and a7 nAChR subtypes and compared to their common carbaisostere.

Chemical and antimicrobial analyses of Sideritis romana L. subsp. purpurea (Tal. ex Benth.) Heywood, an endemic of the Western Balkan

A comprehensive study on essential oil and different solvent extracts of Sideritis romana L. subsp. purpurea (Tal. ex Benth.) Heywood (Lamiaceae) from Montenegro is reported. The gas chromatography-mass spectrometry analysis of the essential oil revealed a total of 43 components with bicyclogermacrene (23.8%), germacrene D (8%), (E)-caryophyllene (7.9%) and spathulenol (5.5%) as the major ones. Sesquiterpenoid group was found to be the most dominant one (64.8%), with 19.9% of the oxygenated forms.

Sideritis romana L. subsp. purpurea (Tal. ex Benth.) Heywood, a new chemotype from Montenegro

A study on essential oil fractions of the Western Balkan endemic Sideritis romana L. subsp. purpurea (Tal. ex Benth.) Heywood collected in Montenegro is reported. The 24-h systematic steam distillation extraction procedure was performed. The gas chromatographic/mass spectrometric (GC/MS) analysis of the fractions showed ?-elemene and spathulenol as two main constituents, revealing a new chemotype of this plant species.

Essential oil extraction, chemical analysis and anti-candida activity of calamintha nepeta (L.) Savi subsp. glandulosa (Req.) ball-new approaches

A comprehensive study on essential oils (EOs) extracted from different Calamintha nepeta
(L.) Savi subsp. glandulosa (Req.) Ball (CG) samples from Tarquinia (Italy) is reported. In this study,
the 24-hour steam distillation procedure for EO preparation, in terms of different harvesting and
extraction times, was applied. The GC/MS analysis showed that CG essential oils from Tarquinia
(TEOCG) belong to pulegone-rich chemotype. The analysis of 44 samples revealed that along

Esential oils extraction: a 24-hour steam distillation systematic methodology

Steam distillation is known to be the most prevalent method of essential oil extraction. Despite many studies on extraction methods, there is no report about the impact of distillation process duration on the yield and oil quality. A new 24-h steam distillation process for extraction of plant essential oils is presented. For improving the total yield, prolonged and continued isolation was used. A selection of plant species from Lamiaceae and Apiaceae families was subjected to direct steam distillation and essential oils were collected at different times (1, 2, 3, 6, 12 and 24 h).

The influence of pH on the scleroglucan and scleroglucan/borax systems

The effects that an increase of environmental pH has on the triple helix of scleroglucan (Sclg)
and on the Sclg/borax hydrogel are reported. Rheological experiments show that the hydrogel is less
sensitive to pH increase than Sclg alone, while at pH = 14 a dramatic viscosity decrease takes place for
both systems. This effect is evidenced also by the reduced water uptake and anisotropic elongation
detected, at pH = 14, by the swelling behaviour of tablets prepared with the Sclg/borax system.

Future perspectives in high efficient and ultrafast chiral liquid chromatography through zwitterionic teicoplanin-based 2-µm superficially porous particles

With the aim of pushing forward the limits of high efficient and ultrafast chiral liquid chromatography, a new Chiral Stationary Phase (CSP) has been prepared by covalently bonding the teicoplanin selector on 2.0 ?m Superficially Porous Particles (SPPs). An already validated bonding protocol, which permits to achieve teicoplanin-based CSPs exhibiting zwitterionic behaviour, has been employed to prepare not only the 2.0 ?m version of the CSP but also two other analogous CSPs based, respectively, on 2.7 ?m SPPs and 1.9 ?m Fully Porous Particles (FPPs).

© Università degli Studi di Roma "La Sapienza" - Piazzale Aldo Moro 5, 00185 Roma