Foundations for the development of sound employer-employee relationships

Thesis (M.B.A.)--Boston Universit

Isolation and characterization of plant bioactive compounds and assessment of their use in veterinary science

The research activity of the PhD project in Veterinary Science was aimed at the isolation and structural characterization of secondary metabolites from medicinal plants and the evaluation of their use in veterinary science. The selected plants are species used in folk medicine or in the veterinary medicine, particularly plants used as antiparasitic and antimicrobial The chemical-biological investigation was carried out on the following plants: • Psiadia punctulata (DC.) Vatke of the Asteraceae family it is found in tropical arid areas from the grasslands and shrubs in arid pastures to the edge of the forest, South-Eastern Africa, and Middle East, some plants of this family are widely used as antimicrobial; • Hypoestes forskaolii (Vahl) Roem. & Schult, herbaceous plant belonging to the Acanthaceae family, widely distributed throughout the southern region of Saudi Arabia, some plants of this family are widely used as a natural anthelmintic; • Trichilia maynasiana C.DC belonging to the family of the Meliaceae is a tree widely distributed in tropical areas of South Africa used in folk medicine to treat various anti-inflammatory diseases; • Vernonia nigritiana Oliv. & Hiern. (Asteraceae) is an herbaceous plant or shrub widely distributed in West Africa, the leaves and other parts of the plant are traditionally used against skin inflammations, rheumatism, fever, headache and impairment. In veterinary medicine many plants of Vernonia genus are used for bacterial infections and intestinal worms. The isolation of secondary metabolites was achieved by chromatographic techniques such as column chromatography, thin layer chromatography, HPLC (High Pressure Liquid Chromatography). The structural characterization of all the isolates was performed by spectroscopic techniques, nuclear magnetic resonance experiments monodimensional (1H-NMR, 13C-NMR) and two-dimensional (COSY, HSQC, HMBC, ROESY), and mass spectrometry. The investigation of Psiadia punctulata led to the isolation of 30 compounds including diterpenes and flavones, of which 13 were new natural compounds. The antimicrobial activity of the dicloromethan extract was tested against Gram-positive bacteria (Staphylococcus aureus), Gram-negative (Pseudomonas aeruginosa) and dimorphic fungus Candida albicans. The results of this study highlighted that the dicloromethan extract showed antibacterial activity against S. aureus (MIC50 = 100 ug/mL), whereas no activity was detected against Gram-negative bacteria. Moreover, the extract showed antifungal activity against Candida albicans (MIC2 = 50 μg/mL and MIC0 = 130 μg/mL). The nine fractions A-I obtained after a silica gel column separation were tested for their antimicrobial activity at doses ranged from 20 to 100 μg/ml. The A,B and I fractions were found to be inactive on all species, instead six fractions (C-H) showed a remarkable activity. All the compounds isolated from active fractions were tested for their antimicrobial activity. Compound 3, 3',4',5,7-tetramethoxyflavone, at a concentration of 40 g/mL was able to inhibit by 50% the production of biofilm of the S. aureus and 90% for Candida albigans. The phytochemical investigation of H. forskaolii leaves led to the isolation of 13 compounds belonging to the class of diterpenes fusicoccane and isopimarane, among these 4 of fusicoccane diterpenes are new natural compounds. The n-hexane, chloroform, chloroform: methanol 9:1 and methanolic extracts of Hypoestes forskaolii were tested fot in vitro anthelmintic activity via Egg hacth Assay on different species of gastrointestinal netamathodes that naturally parasitize small ruminants. Polar extracts have not been able to show significant ovicidal activity (less than 50% of hatching), while the n-hexane extract at a concentration of 1 mg/ml showed moderate inhibition of 30% hatching. All the isolated compounds were also tested in vitro for the antiproliferative activity on HeLa and Jurkat U973 cell lines, all compounds did not significantly affect growth and cell viability. The phytochemical investigation of Trichilia maynasiana led to the isolation of nine compounds of which two are new natural compounds. These compounds belonging to the class of tirucallane and secoguaiane terpenes. The phytochemical study of V. nigritiana led to the isolation of seven secondary metabolites including two sesquiterpene lactones, never described before

Heavy metals in the muscle and hepatopancreas of red swamp crayfish (Procambarus clarkii) in campania (italy)

The aim of this study was to carry out a quali-quantitative analysis of the presence of non-essential and essential trace elements in freshwater crayfish (Procambarus clarkii) edible tissues to establish the healthiness of this product and to evaluate the pollution status of the sampling sites included in the present study. P. clarkii is one of the most common species of freshwater crustaceans in Italy, regularly consumed by local people. Moreover, the crayfish, due to its trophic position and diet, can be considered as an excellent bioindicator of the health status of the ecosystem. We collected sixty crayfish samples from two different sites in Campania (Italy): Villa Literno and Sessa Aurunca. Concentrations of trace elements were determined by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Our data showed low concentrations of Cd, Hg and Pb, with values below the European Commission MRL (Commission Regulation (EC) 1881/2006). We suggest that data obtained from this study showed that crayfish collected from Villa Literno and Sessa Aurunca were safe for human consumption. Furthermore, the results of this research indicated mild contamination of heavy metals of the sampling sites, indicating a good health status of the area’s aquatic ecosystem

Chemical Profiling of Astragalus membranaceus Roots (Fish.) Bunge Herbal Preparation and Evaluation of Its Bioactivity

Astragalus membranaceus (Fish.) Bunge is a perennial herb distributed in the northern part of China, and its roots, namely, Hang qi, are included as a natural ingredient in dietary supplement formulations commonly used to treat different disorders such as respiratory infections, diabetes, and heart failure. The availability of a simple method for the determination of the quality of Astragalus herbal preparations could be a challenging issue for commercial purposes. In this study, a liquid chromatography–mass spectrometry (LC–MS)/MS based approach was used to characterize specialized metabolite recovery of 3 commercial hydroalcoholic extracts of A. membranaceus (AMG1, AMG2, AMG3) in addition to a hydroalcoholic extract of A. membranaceus root (AST). The hypoglycemic effect, cholinesterase inhibition, and antioxidant activities were also evaluated. Thirty-one compounds, of which 19 polyphenols and 12 saponins, were identified. The extracts were also quantified by using a sensitive and selective Q-Trap system for their content in flavonoids and astragalosides, selecting astragaloside I and IV as chemical markers. From our results, AMG3 preparation (Axtragyl) was the most abundant in terms of both specialized classes of metabolites, showing a fingerprint similar to that of AST. Interestingly, tested enzyme inhibition ability of flavonoids, daidzein (11) and formononetin (19), reported a higher α-glucosidase inhibition in comparison with that of acarbose used as positive control. The in silico study clarified the interactions among the molecules and the importance of having a free hydroxy group. Moreover, Axtragyl was able to exert protective effects in Caco-2 cells treated with hydrogen peroxide, confirming its ability as a potential protective agent in intestinal injury

La ripresa degli scavi sull’acropoli di Butrinto. Considerazioni preliminari sullo scavo delle mura arcaiche

Il contributo nasce nell’ambito della missione italo-albanese dell’Università di Bologna e dell’Istituto di Archeologia di Tirana presso il sito archeologico di Butrinto (Albania meridionale) come presentazione preliminare dei risultati della campagna 2021. A seguito di un inquadramento storicotopografico dell’acropoli di Butrinto e di un riesame delle attività susseguitesi in quest’area del sito, lo studio analizza le evidenze emerse durante lo scavo nell’area della terrazza centrale della collina dell’acropoli. Si presentano i dati ottenuti dai saggi effettuati a ridosso delle mura arcaiche, lungo il margine meridionale dell’acropoli, e alcuni contesti significativi all’interno dell’emplekton delle mura, utili a definire la loro cronologia di costruzione grazie alla presenza di evidenze riferibili alle fasi di frequentazione di età arcaica. Lo studio dei materiali ceramici ha infatti permesso di confermare la datazione tra la fine del VII e l’inizio del VI secolo a.C. dei contesti rinvenuti. Inoltre, la loro analisi funzionale, unitamente all’interpretazione di un deposito di un gruppo di ghiande missili all’interno dell’emplekton, permette di avanzare alcune considerazioni circa la definizione dell’acropoli e il suo carattere sacro. I dati presentati, coerenti con il resto delle evidenze note, concorrono a delineare con maggior precisione la strutturazione dell’acropoli di Butrinto in età arcaica, le sue prime fasi di vita e le relazioni con la antistante isola di Corfù.The contribution is born within the activities of the Italian and Albanian archaeological mission of the University of Bologna and the Archaeological Institute of Tirana in the archaeological site of Butrint (Southern Albania) as a preliminary presentation of the results of the 2021 excavation campaign. Following the historical and topographic background of the acropolis of Butrint and a review of the activities carried out in this area of the site, the study analyses the findings coming from the excavation on the central terrace of the acropolis hill. We present data from trenches dug just behind the Archaic walls on the southern slope of the acropolis, along with some relevant contexts inside the walls emplekton, useful for defining the chronology of construction thanks to the presence of findings related to the attendance of the area during the Archaic age. The study of pottery findings confirmed the end of 7th century and the beginning of 6th century BC as chronology for these contexts. Furthermore, their functional analysis, together with the interpretation of a deposit of slingshots found inside the emplekton, allows to suggest some considerations on the definition of the acropolis and its sacred nature. These data, coherent with other known evidence, contribute to define the organization of the acropolis of Butrint during the Archaic age, its early stages of life and its relations with the island of Corfu

Alkaloids from Cissampelos tropaeolifolia d.c.

The phytochemical study of Cissampelos tropaeolifolia aerial parts led to the isolation and structural characterization by spectroscopic and spectrometric methods of two morfinan-7-one alkaolid named 2 O-methylflavinantine and Fissistigine D. The following known compounds were also identified: caffeic acid, caffeic acid methyl ester, caffeic acid ethyl ester, and p-coumaric acid. The structures of isolated compounds were elucidated by 1D- and 2D-NMR Spectroscopy (1H, 13C, 13C DEPT, DQF-COSY, HSQC, HMBC, ROESY ) and confirmed by mass spectrometry studies