Non-covalent interactions in organotin(IV) derivatives of 5,7-ditertbutyl- and 5,7-diphenyl-1,2,4-triazolo[1,5-a]pyrimidine as recognition motifs in crystalline self- assembly and their in vitro antistaphylococcal activity

Non-covalent interactions are known to play a key role in biological compounds due to their stabilization of the tertiary and quaternary structure of proteins [1]. Ligands similar to purine rings, such as triazolo pyrimidine ones, are very versatile in their interactions with metals and can act as model systems for natural bio-inorganic compounds [2]. A considerable series (twelve novel compounds are reported) of 5,7-ditertbutyl-1,2,4-triazolo[1,5-a]pyrimidine (dbtp) and 5,7-diphenyl- 1,2,4-triazolo[1,5-a]pyrimidine (dptp) were synthesized and investigated by FT-IR and 119Sn M\uf6ssbauer in the solid state and by 1H and 13C NMR spectroscopy, in solution [3]. The X-ray crystal and molecular structures of Et2SnCl2(dbtp)2 and Ph2SnCl2(EtOH)2(dptp)2 were described, in this latter pyrimidine molecules are not directly bound to the metal center but strictly H-bonded, through N(3), to the -OH group of the ethanol moieties. The network of hydrogen bonding and aromatic interactions involving pyrimidine and phenyl rings in both complexes drives their self-assembly. Noncovalent interactions involving aromatic rings are key processes in both chemical and biological recognition, contributing to overall complex stability and forming recognition motifs. It is noteworthy that in Ph2SnCl2(EtOH)2(dptp)2 \u3c0\u2013\u3c0 stacking interactions between pairs of antiparallel triazolopyrimidine rings mimick basepair interactions physiologically occurring in DNA (Fig.1). M\uf6ssbauer spectra suggest for Et2SnCl2(dbtp)2 a distorted octahedral structure, with C-Sn-C bond angles lower than 180\ub0. The estimated angle for Et2SnCl2(dbtp)2 is virtually identical to that determined by X-ray diffraction. Ph2SnCl2(EtOH)2(dptp)2 is characterized by an essentially linear C-Sn-C fragment according to the X-ray all-trans structure. The compounds were screened for their in vitro antibacterial activity on a group of reference staphylococcal strains susceptible or resistant to methicillin and against two reference Gramnegative pathogens [4] . We tested the biological activity of all the specimen against a group of staphylococcal reference strains (S. aureus ATCC 25923, S. aureus ATCC 29213, methicillin resistant S. aureus 43866 and S. epidermidis RP62A) along with Gram-negative pathogens (P. aeruginosa ATCC9027 and E. coli ATCC25922). Ph2SnCl2(EtOH)2(dptp)2 showed good antibacterial activity with a MIC value of 5 \u3bcg mL-1 against S. aureus ATCC29213 and also resulted active against methicillin resistant S. epidermidis RP62A

MC 2019 Berlin Microscopy Conference - Abstracts

Das Dokument enthält die Kurzfassungen der Beiträge aller Teilnehmer an der Mikroskopiekonferenz "MC 2019", die vom 01. bis 05.09.2019, in Berlin stattfand

Annual Report of the University, 2001-2002, Volumes 1-4

VITAL ACADEMIC CLIMATE* by Brian Foster, Provost/Vice President of Academic Affairs A great university engages students and faculty fully in important ideas and issues ... not just to learn about them, but to take them apart and put them back together, to debate, deconstruct, resist, reconstruct and build upon them. Engagement of this sort takes concentration and commitment, and it produces the kind of discipline and passion that leads to student and faculty success and satisfaction in their studies, research, performance, artistic activity and service. It is also the kind of activity that creates a solid, nurturing spirit of community. This is what we mean when we talk about a vital academic climate. We are striving for an environment that will enrich the social, cultural and intellectual lives of all who come in contact with the University. Many things interconnect to make this happen: curriculum, co-curricular activities, conferences, symposia, cultural events, community service, research and social activity. Our goal is to create the highest possible level of academic commitment and excitement at UNM. This is what characterizes a truly great university. *Strategic Direction 2 New Mexico native Andres C. Salazar, a Ph.D. in electrical engineering from Michigan State University, has been named the PNM Chair in Microsystems, Commercialization and Technology. Carrying the title of professor, the PNM Chair is a joint appointment between the School of Engineering and the Anderson Schools of Management. Spring 2002 graduate John Probasco was selected a 2002 Rhodes Scholar, the second UNM student to be so honored in the past four years. The biochemistry major from Alamogordo previously had been awarded the Goldwater Scholarship and the Truman Scholarship. Andres c. Salazar Biology student Sophie Peterson of Albuquerque was one of 30 students nationwide to receive a 2002-2003 Award of Excellence from Phi Kappa Phi, the oldest and largest national honor society. Regents\\u27 Professor of Communication and Journalism Everett M. Rogers was selected the University\\u27s 4 71h Annual Research Lecturer, the highest honor UNM bestows upon members of its faculty. John Probasco honored by Student Activities Director Debbie Morris. New Mexico resident, author and poet Simon}. Ortiz received an Honorary Doctorate of Letters at Spring Commencement ceremonies. Child advocate Angela Angie Vachio, founder and executive director of Peanut Butter and Jelly Family Services, Inc., was awarded an Honorary Doctorate of Humane Letters. American Studies Assistant Professor Amanda}. Cobb won the 22 d annual American Book Award for listening to Our Grandmothers\\u27 Stories: The Bloomfield Academy for Chickasaw Females, 1852-1949