Barros Elcio Daniel Sousa, Monção Evaldo Dos Santos, Chaves Mariana Helena, Lopes Cícero Alves, Vieira Gerardo Magela
Laboratory of Natural Products, Department of Chemistry, Federal University of Piauí (UFPI), Teresina, PI, Brazil.
Department of Teaching, Research and Extension, Federal Institute of Maranhão (IFMA), Coelho Neto, MA, Brazil.
J Venom Anim Toxins Incl Trop Dis. 2025 May 16;31:e20240064. doi: 10.1590/1678-9199-JVATITD-2024-0064. eCollection 2025.
Bufadienolides are the main secondary metabolites found in the paratoid gland secretions (PGS) of toads of the Bufonidae family. These compounds are considered the main bioactive components of PGS. The aim of this study was to develop and validate the first method for the quantification of total bufadienolides (free and esterified) in samples of paratoid secretions from toads, using the UV-Vis absorption spectrophotometry technique.
The proposed method was based on the bathochromic shift induced by the reaction of the α-pyrone group of bufadienolides (296 nm) with a 5% (w:v) aqueous solution of sodium hydroxide and detection at 356 nm, after 60 min (time defined based on the evaluation of kinetic assays).
The proposed method showed wide linearity (r = 0.9999), low LOD (1.3 × 10 µg/mL) and LOQ (3.9 × 10 µg/mL), recovery (84%-99%), repeatability (%RSD ≤ 5), reproducibility and robustness (p > 0.05). The total bufadienolide content in PGS extracts from 12 samples of ranged from 478 to 801 mg of EqMB/g of extract, while the sample presented 661 mg of EqMB/g of extract.
The new developed method is innovative, simple, fast, accurate, robust, low cost, and can contribute to future research focused on the quantification of total bufadienolides in samples of toad glandular secretions. In addition to serving as a strategic tool in the selection of work matrices, optimizing time, and minimizing costs.
蟾蜍二烯羟酸内酯是蟾蜍科蟾蜍腮腺分泌物（PGS）中发现的主要次生代谢产物。这些化合物被认为是PGS的主要生物活性成分。本研究的目的是开发并验证第一种使用紫外-可见吸收分光光度法技术对蟾蜍腮腺分泌物样品中总蟾蜍二烯羟酸内酯（游离和酯化形式）进行定量的方法。
所提出的方法基于蟾蜍二烯羟酸内酯的α-吡喃酮基团（296 nm）与5%（w:v）氢氧化钠水溶液反应引起的红移，并在60分钟后（根据动力学分析评估确定的时间）在356 nm处进行检测。
所提出的方法显示出宽线性范围（r = 0.9999）、低检测限（1.3×10 µg/mL）和定量限（3.9×10 µg/mL）、回收率（84%-99%）、重复性（%RSD≤5）、重现性和稳健性（p>0.05）。来自12个样品的PGS提取物中总蟾蜍二烯羟酸内酯含量范围为478至801 mg EqMB/g提取物，而 样品的提取物中含量为661 mg EqMB/g。
新开发的方法具有创新性、简单、快速、准确、稳健、低成本，可有助于未来专注于蟾蜍腺分泌物样品中总蟾蜍二烯羟酸内酯定量的研究。此外，还可作为选择工作基质、优化时间和最小化成本的战略工具。
