Banca de DEFESA: SARAH POLLYANA DIAS DOS SANTOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : SARAH POLLYANA DIAS DOS SANTOS
DATE: 30/10/2024
TIME: 09:00
LOCAL: videoconferência
TITLE:

Aspidosperma nitidum Benth and Aspidosperma pyrifolium Mart. (Apocynaceae): Phytochemical study, evaluation of biological activity and review of NMR data on b-carboline alkaloids.

KEY WORDS:

Aspidosperma nitidum; Aspidosperma pyrifolium; indole alkaloids; b-carbolines; Anti-inflammatory

PAGES: 362
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SPECIALTY: Química dos Produtos Naturais
SUMMARY:

The genus Aspidosperma (Apocynaceae) stands out for the presence of indolic alkaloids, characterised by a diversity of structures and interesting biological activities. The species Aspidosperma nitidum Benth and Aspidosperma pyrifolium Mart. are known as carapanauba and pereiro, respectively. Native to the Amazon region and the caatinga, they are used in folk medicine mainly for their anti-inflammatory, antimalarial and antimicrobial properties. The aim of this work is to study the phytochemistry of the A. nitidum and A. pyrifolium species, as well as to investigate the safety of using the extract and the anti-inflammatory and healing properties of the hydroethanolic extract of the stem bark of Aspidosperma nitidum Benth (ANCCE). In addition to a literature review of indolic alkaloids of the b-carboline type. However, this work is divided into chapters: In Chapter I: We present a brief introduction, the theoretical background on the species studied and the objectives of this work. Chapter II: The study of the dereplication of the A. nitidum and A. pyrifolium species, using the CLUE-Q-TOF-EM and CG-EM techniques. However, only the A. pyrifolium species used both methods, as well as the proposed fragmentation of the indolic alkaloids annotated in both techniques. This study enabled the annotation of 22 (twenty-two) indolic alkaloids, as well as the verification of fragmentation patterns in the majority of these alkaloids. In Chapter II: The study of the dereplication of the A. nitidum and A. pyrifolium species, using the CLUE-Q-TOF-MS and GC-MS techniques. However, only the A. pyrifolium species used both methods, as well as the proposed fragmentation of the indolic alkaloids annotated in both techniques. This study enabled the annotation of 22 (twenty-two) indolic alkaloids, as well as the verification of fragmentation patterns in the majority of these alkaloids. Chapter III: Phytochemical study and evaluation of the anti-inflammatory and healing activity of the hydroethanolic extract of the bark of the species Aspidosperma nitidum Benth. This project, carried out in partnership with the Pharmaceutical Technology and Biotechnology Laboratory - TECBIOFAR and the Federal University of Ceara - UFC, enabled the isolation of an isocoumarin and the sucrose glycoside, known in the literature, but isolated for the first time in the species of A. nitidum and the proposal of a new compound glycosylated 1-benzazepine derivative, identified for the first time in the literature. In the assessment of biological activity, the MTT and hemolytic assays were carried out, and at all the concentrations assessed the extract proved not to be cytotoxic. The acute toxicity model also showed no signs of toxicity or significant changes in behaviour or biochemical and hematological parameters after using the extract. In the hematogenic model, the A. nitidum extract significantly reduced the percentage of oedema, as well as the levels of MPO and pro-inflammatory cytokines. Likewise, it proved to be effective in reducing leukocyte migration (mainly polymorphonuclear), total proteins, MPO and cytokine concentrations in the zymosam-induced air pouch test. In addition, the extract revealed a healing effect, reducing the area of the skin wound. Chapter IV: We present a review of NMR data on alkaloids of the type b-carboline, isolated from natural origin, with biological activities or not, reported in the literature from 1992 to 2023, available in the Scifinder and ScienceDirect databases. This work made it possible to catalog 300 indolic alkaloids of the b-carboline type, along with their 1D NMR data. These alkaloids were subdivided into 4 main classes and up to 13 subclasses, in line with their structural diversity. Among these alkaloids, there are 82 bioactive ones, reporting their occurrence in 92 species and 50 families. This work will help in de-replication studies, as well as in determining the structures of these alkaloids. All the work presented highlights the importance of Aspidosperma species in popular use, as well as the structural diversity of the indolic alkaloids found in the genus, as future research for potential drugs.

COMMITTEE MEMBERS:
Externo à Instituição - HECTOR HENRIQUE FERREIRA KOOLEN - UEA
Externo à Instituição - CAROLINE DA ROS MONTES D'OCA - UFPR
Interno - 1803692 - FABRICIO GAVA MENEZES
Externa à Instituição - JOYCE KELLY DO ROSÁRIO DA SILVA - UFPA
Presidente - 1569526 - RENATA MENDONÇA ARAUJO