Structure elucidation and biosynthetic investigations of marine cyanobacterial secondary metabolites

This thesis details my investigations of marine cyanobacterial natural products that resulted in the discovery of thirteen new secondary metabolites, the isolation of over fifteen previously reported metabolites and the biosynthetic investigation of two additional cyanobacterial compounds. Two novel lipopeptides were identified from a Lyngbya majuscula and Schizothrix sp. assemblage collected in the Fiji Islands. Somamide A is a depsipeptide consisting of a hexanoate moiety extended by seven amino acids, including two nonstandard units characteristic of cyanobacterial peptides. In contrast, somocystinamide A is a unique linear disulfide dimer displaying potent cytotoxicity against a mammalian neuroblastoma cell line. The organic extract from a Puerto Rican L. majuscula proved remarkably rich in chemistry, producing twelve known compounds as well as four new secondary metabolites. Among these new isolates were the novel sodium channel blocker antillatoxin B, a new chlorinated quinoline derivative and the new α-pyrone malyngamide T. A collection of L. majuscula from Antany Mora, Madagascar, led to the isolation of the previously reported antineoplastic agent dolastatin 16 and the discovery of a new series of lipopeptides, the antanapeptins. These new molecules are characterized by the presence of the unique β-hydroxy acid 3-hydroxy-2-methyloctynoate, or its reduced double- or single-bond equivalent. Wewakazole is a novel cyclic dodecapeptide isolated from a Papua New Guinea collection of L. majuscula. This large molecule contains both a methyloxazole and two oxazoles, residues rarely observed in marine cyanobacterial metabolites. Extensive utilization of 1D and 2D NMR techniques were required to elucidate the structure of this distinctive peptide. Biosynthetic investigations of two halogenated cytotoxins were also conducted on a cultured L. majuscula strain originally isolated from Hector Bay, Jamaica. Stable isotope feeding experiments demonstrated that both jamaicamide A and hectochlorin derive from mixed PKS and NRPS biosynthetic origins but are comprised of primary precursors unique to each molecule

Faculty Brass Quintet

Kemp Recital Hall Tuesday Evening October 27, 1998 8:00p.m

Illinois State University Faculty Brass Quintet

Apollo Theater Friday Afternoon January 30, 1998 12:30 p.m

Faculty Recital:Faculty Brass Quintet

Kemp Recital Hall Tuesday Evening April 7, 1998 8:00p.m

New Peptides Isolated from Lyngbya Species: A Review

Cyanobacteria of the genus Lyngbya have proven to be prodigious producers of secondary metabolites. Many of these compounds are bioactive and show potential for therapeutic use. This review covers peptides and hybrid polyketide-non-ribosomal peptides isolated from Lyngbya species. The structures and bioactivities of 50 Lyngbya peptides which were reported since 2007 are presented

Antitumor Peptides from Marine Organisms

The biodiversity of the marine environment and the associated chemical diversity constitute a practically unlimited resource of new antitumor agents in the field of the development of marine bioactive substances. In this review, the progress on studies of antitumor peptides from marine sources is provided. The biological properties and mechanisms of action of different marine peptides are described; information about their molecular diversity is also presented. Novel peptides that induce apoptosis signal pathway, affect the tubulin-microtubule equilibrium and inhibit angiogenesis are presented in association with their pharmacological properties. It is intended to provide useful information for further research in the fields of marine antitumor peptides

Marine Cyanobacteria Compounds with Anticancer Properties: Implication of Apoptosis

Marine cyanobacteria have been proved to be an important source of potential anticancer drugs. Although several compounds were found to be cytotoxic to cancer cells in culture, the pathways by which cells are affected are still poorly elucidated. For some compounds, cancer cell death was attributed to an implication of apoptosis through morphological apoptotic features, implication of caspases and proteins of the Bcl-2 family, and other mechanisms such as interference with microtubules dynamics, cell cycle arrest and inhibition of proteases other than caspases

The Discover In-Hospital Cardiac Arrest (Discover IHCA) Study: An Investigation of Hospital Practices After In-Hospital Cardiac Arrest

IMPORTANCE: In-hospital cardiac arrest (IHCA) is a significant public health burden. Rates of return of spontaneous circulation (ROSC) have been improving, but the best way to care for patients after the initial resuscitation remains poorly understood, and improvements in survival to discharge are stagnant. Existing North American cardiac arrest databases lack comprehensive data on the post-resuscitation period, and we do not know current post-IHCA practice patterns. To address this gap, we developed the Discover In-Hospital Cardiac Arrest (Discover IHCA) study, which will thoroughly evaluate current post-IHCA care practices across a diverse cohort. OBJECTIVES: Our study collects granular data on post-IHCA treatment practices, focusing on temperature control and prognostication, with the objective of describing variation in current post-IHCA practice. DESIGN, SETTING, AND PARTICIPANTS: This is a multicenter, prospectively collected, observational cohort study of patients who have suffered IHCA and have been successfully resuscitated (achieved ROSC). There are 24 enrolling hospital systems (23 in the United States) with 69 individual enrolling hospitals (39 in the United States). We developed a standardized data dictionary, and data collection began in October 2023, with a projected 1000 total enrollments. Discover IHCA is endorsed by the Society of Critical Care Medicine. INTERVENTIONS, OUTCOMES, AND ANALYSIS: The study collects data on patient characteristics including pre-arrest frailty, arrest characteristics, and detailed information on post-arrest practices and outcomes. Data collection on post-IHCA practice was structured around current American Heart Association and European Resuscitation Council guidelines. Among other data elements, the study captures post-arrest temperature control interventions and post-arrest prognostication methods. Analysis will evaluate variations in practice and their association with mortality and neurologic function. CONCLUSIONS: We expect this study, Discover IHCA, to identify variability in practice and outcomes following IHCA, and be a vital resource for future investigations into best-practice for managing patients after IHCA

Guest Recital:Tara Nogle, Trumpet

St. Luke Union Church Thursday Afternoon April 23, 1998 4:30p.m