Cyclic Sesquiterpene–Flavanone [4+2] Hybrids, Syzygioblanes A–C, Found in an Indonesian Traditional Medicine, “Jampu Salo” (Syzygium oblanceolatum)

• DOI: 10.1021/acs.orglett.4c01248
• Publication Date: 2024-05-10T15:23:58Z
• Authors: Nona Koga; Yohei Saito; Katsunori Miyake; Saidanxia Amuti; Shuichi Fukuyoshi; Satoshi Yoshida; Sota Sato; Yusuke Yamada; Akihito Ikeda; Naruhiko Adachi; Masato Kawasaki; Akira Takasu; Shinji Aramaki; Toshiya Senda; Abdul Rahim; Ahmad Najib; Gemini Alam; Nobuyuki Tanaka; Kyoko Nakagawa-Goto
• Keywords: Flavanone

A plant used in an Indonesian traditional herbal medicine as a diabetes treatment and known locally "Jampu Salo" was collected on Sulawesi Island, Indonesia. It identified Syzygium oblanceolatum (C. B. Rob.) Merr. (Myrtaceae) found for the first time Sulawesi; it previously reported only eastern Philippines Borneo. phytochemical study of S. led to isolation three unprecedented meroterpenoids, syzygioblanes A–C (1–3, respectively). These compounds might be biosynthesized through [4+2] cycloaddition various germacrane-based cyclic sesquiterpenoids with flavone desmethoxymatteucinol form spiro skeleton. The unique complex structures were elucidated by microcrystal electron diffraction analysis addition general analytical techniques such high-resolution mass spectrometry, nuclear magnetic resonance methods, infrared spectroscopy. Synchrotron X-ray calculations electronic circular dichroism spectra helped determine absolute configurations. newly isolated exhibited collateral sensitivity more strongly inhibit growth multidrug resistant tumor cell line compared chemosensitive line.