利用超高效能液相層析串聯高解析質譜法建立茄科植物中固醇類生物鹼的分析平台

Abstract

固醇類生物鹼為存在於茄科植物中的次級代謝物，具備防禦病原入侵的功能。此類化合物雖具有一定毒性與苦味，但在低劑量或可接受攝取範圍內，可能對人體健康產生正面效益。本研究利用超高效能液相層析串聯高解析質譜法，建立固醇類生物鹼的分析平台，結合精確分子量、同位素分佈與二級碎裂圖譜，成功鑑別出42種固醇類生物鹼，包括32種Spirosolane型與10種Solanidane型結構，涵蓋12對異構物。研究結果顯示，固醇類生物鹼在番茄（Solanum lycopersicum）、龍葵（Solanum nigrum）、與馬鈴薯（Solanum tuberosum）間，以及不同品種與植株部位間，皆呈現顯著差異。番茄所含之固醇類生物鹼與其他樣品皆不同，而龍葵、茄子與馬鈴薯則共同含有α-solasonine與α-solamargine兩種主要成分。番茄以Esculeoside A為主要成分，集中於果實，蒂頭則以α-tomatine與β1-tomatine為主。龍葵中，以未成熟果實含量最高，且在不同部位及成熟階段皆以α-solasonine與α-solamargine為主，占比超過70%。馬鈴薯則以α-solanine與α-chaconine為主要成分，二者占總量的90%以上，集中於表皮，且發芽樣本含量顯著高於未發芽者。在加工處理方面，殺菁雖不改變總量，但可能導致結構轉換，其中龍葵果實中羧基化生物鹼的比例由30%大幅提升至97%。而熱風乾燥的熱處理也會導致番茄中Esculeoside A含量大幅下降並進一步轉化為其他構型。本研究所建構之分析平台能有效鑑別並量化茄科植物中固醇類生物鹼的成分與變化，為探討其生理功能、健康效益及潛在風險提供分析依據，亦可作為未來品質評估與產品開發的重要工具。

Steroidal alkaloids are secondary metabolites found in Solanaceous plants and play a defensive role against pathogen invasion. Although these compounds possess inherent toxicity and bitterness, they may offer potential health benefits to humans when consumed at low doses or within acceptable intake levels. In this study, a steroidal alkaloid profiling platform was established using ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS/MS). By confirming precise molecular weight, isotopic distribution, and MS/MS fragmentation patterns, the platform successfully identified 42 steroidal alkaloids, including 32 spirosolane-type and 10 solanidane-type structures, encompassing 12 pairs of isomers. The results revealed significant variations in the composition and distribution of steroidal alkaloids among tomato (Solanum lycopersicum), black nightshade (Solanum nigrum), and potato (Solanum tuberosum), as well as across different cultivars and plant tissues. The steroidal alkaloid profile of tomato was distinct from the others, while black nightshade, eggplant, and potato all shared the presence of α-solasonine and α-solamargine. In tomato, Esculeoside A was the predominant compound in the fruit, whereas α-tomatine and β1-tomatine were more abundant in the calyxes. In black nightshade, immature fruits showed the highest levels of alkaloids, with α-solasonine and α-solamargine accounting for over 70% of the total content across different tissues and developmental stages. In potato, α-solanine and α-chaconine were the main components, making up more than 90% of the total alkaloid content, primarily concentrated in the skin, and their levels were significantly higher in sprouted tubers than in unsprouted ones. With respect to post-harvest processing, blanching did not alter the total alkaloid content but induced structural transformations, such as an increase in the proportion of carboxylated alkaloids in black nightshade fruit from 30% to 97%. Heat drying also led to a substantial decrease in the Esculeoside A content in tomato and promoted its conversion into other structural forms. This analytical platform provides a sensitive and reliable tool for identifying and quantifying the composition and variation of steroidal alkaloids in Solanaceous plants. It offers a valuable basis for exploring their physiological roles, potential health effects, and associated risks, and serves as a critical resource for quality evaluation, standardization, and the development of related products.