Camptothecin (CPT) and its derivatives have attracted worldwide attention because of their notable anticancer activity. However, the growing demand for CPT in the global pharmaceutical industry has caused a severe shortage of CPT-producing plant resources. In this study, phytochemical analysis of Nothapodytes tomentosa results in the isolation and identification of CPT (13) and 16 analogues (1 – 12, 14 – 17), including a new (1) and five known (9, 10, 12, 15, and 17) CPT analogues with an open E-ring. In view of the potential anticancer activity of CPT analogues with an open E-ring, the fragmentation pathways and mass spectra profiles of these six CPT analogues (1, 9, 10, 12, 15, and 17) are investigated, providing a reference for the rapid detection of these compounds in other plants. Furthermore, based on the fragmentation patterns of CPT (13) and known analogues (2 – 8, 11, 14, 16, 18 – 26), the distribution and content of these compounds in different tissues of N. tomentosa, N. nimmoniana, Camptotheca acuminata, and Ophiorrhiza japonica are further studied. Our findings not only provide an alternative plant resource for further expanding the development and utilization of CPT and its analogues, but also lay a foundation for improving the utilization of known CPT-producing plant resources.

喜树碱（CPT）及其衍生物因其显着的抗癌活性而引起了全世界的关注。然而，全球制药行业对喜树碱的需求不断增长，导致喜树碱生产植物资源严重短缺。在本研究中，对Nothapodytes tomentosa进行植物化学分析，分离和鉴定了 CPT ( 13 ) 和 16 个类似物 ( 1  –  12, 14  –  17 )，其中包括一个新的 ( 1 ) 和五个已知的 ( 9, 10, 12, 15)和17 ) 具有开放 E 形环的 CPT 类似物。鉴于具有开放E环的CPT类似物的潜在抗癌活性，对这6种CPT类似物（1、9、10、12、15和17）的碎裂途径和质谱图进行了研究，为后续研究提供参考。快速检测其他植物中的这些化合物。此外，根据喜树碱 ( 13 ) 和已知类似物 ( 2  –  8, 11, 14, 16, 18  –  26 ) 的碎片模式，这些化合物在毛白猪笼草、尼莫尼亚猪笼草不同组织中的分布和含量，对喜树、蛇根进行了进一步的研究。我们的研究结果不仅为进一步扩大喜树碱及其类似物的开发利用提供了替代植物资源，而且为提高已知产喜树碱植物资源的利用率奠定了基础。