Banca de DEFESA: VINICIUS ANTONIO BARBOSA GONCALVES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : VINICIUS ANTONIO BARBOSA GONCALVES
DATE: 27/02/2026
TIME: 14:00
LOCAL: Auditório do departamento de química-UFRPE
TITLE:

Chemical study and Biological potential of Pollens Collected by Stingless Bees from the Caatinga: Melipona subnitida (Jandaíra), Scaptotrigona Aff. depilis (Canudo), Partamona cupira (Cupira), and Melipona mandacaia (Mandaçaia)

KEY WORDS:

Stingless bees; Caatinga; Pollen; Phenolic compounds; Molecular docking; Bioprospecting.

PAGES: 104
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Inspeção de Produtos de Origem Animal
SUMMARY:

Stingless bees (Meliponini) play an essential role in maintaining biodiversity through pollination. The present study aimed to analyze the chemical profile and biological potential of pollens collected by stingless bees from the Caatinga biome: Melipona subnitida (jandaíra), Scaptotrigona aff. depilis (canudo), Partamona cupira (cupira), and Melipona mandacaia (mandaçaia). Eleven pollen samples were subjected to palynological analysis, extraction and chemical analyses, antiradical activity, and activity against Mycobacterium tuberculosis. All samples underwent solid-phase extraction (SPE-C18) using water, methanol (MeOH), and ethyl acetate:dichloromethane (AcOEt:CH₂Cl₂, 1:1). The two resulting fractions were submitted to chemical analyses (MeOH fractions analyzed by UPLC-DAD-qTOF-MS/MS and AcOEt:CH₂Cl₂ fractions by GC-MS), antiradical activity using DPPH and ABTS assays, flavonoid and total phenolic content determination, and testing against Mycobacterium tuberculosis. The pollen samples were also extracted with water and submitted to sugar quantification by HPLC-IR. UPLC-DAD-qTOF-MS/MS analyses allowed the identification of three major classes of compounds in the pollen extracts from the four species: spermidine derivatives, lipids, and flavonoids. The four main flavonoids (quercetin, kaempferol, luteolin, and naringenin) present in most samples were studied by molecular docking, with quercetin and luteolin showing affinity for DprE1, while kaempferol and naringenin interacted with KasA, essential proteins of Mycobacterium tuberculosis. GC-MS confirmed a predominantly lipophilic profile, with fatty acid esters, hydrocarbons, aliphatic alcohols, sterols, and triterpenes. The AcOEt:CH₂Cl₂ fractions showed low antibacterial activity (MIC > 200 µg/mL), and only the MeOH fraction of Partamona cupira exhibited moderate activity (MIC 100–200 µg/mL). Phenolic and flavonoid contents were higher in the MeOH fractions of pollens from S. aff. depilis (94.65 ± 2.22 mg GAE/g and 61.80 ± 1.89 mg QE/g, respectively) and P. cupira (59.19 ± 2.52 mg GAE/g and 31.38 ± 3.60 mg QE/g, respectively), which also showed greater activity against DPPH and ABTS radicals. Sugar analysis revealed that all pollens contained the sugar mannitol, with meliponic pollen from S. aff. depilis showing the highest concentrations of mannitol, followed by fructose and glucose among the species studied.

COMMITTEE MEMBERS:
Externo à Instituição - KRISTERSON REINALDO DE LUNA FREIRE - UFPB
Externo ao Programa - 2534469 - RONALDO NASCIMENTO DE OLIVEIRA - nullPresidente - TANIA MARIA SARMENTO DA SILVA