10.1021/acs.orglett.7b02445.s002 Yu-Xi Yuan Yu-Xi Yuan Yu Zhang Yu Zhang Ling-Li Guo Ling-Li Guo Yue-Hu Wang Yue-Hu Wang Masuo Goto Masuo Goto Susan L. Morris-Natschke Susan L. Morris-Natschke Kuo-Hsiung Lee Kuo-Hsiung Lee Xiao-Jiang Hao Xiao-Jiang Hao Tabercorymines A and B, Two Vobasinyl–Ibogan-Type Bisindole Alkaloids from Tabernaemontana corymbosa American Chemical Society 2017 novel bisindole alkaloid cancer cell lines skeleton Vobasinyl Compound 1 alkaloids spectroscopic data combination chemical transformation Alkaloids 1 vincristine-resistant KB ECD calculation Tabernaemontana corymbosa Tabercorymines antiproliferative activity Bisindole Tabernaemontana corymbosa vobasinyl unit bond heteropentacyclic ring system single-crystal X-ray diffraction 2017-09-06 14:51:15 Dataset https://acs.figshare.com/articles/dataset/Tabercorymines_A_and_B_Two_Vobasinyl_Ibogan-Type_Bisindole_Alkaloids_from_Tabernaemontana_corymbosa/5379673 Tabercorymines A (<b>1</b>) and B (<b>2</b>), two new vobasinyl–ibogan-type bisindole alkaloids with an unprecedented skeleton, were isolated from Tabernaemontana corymbosa. Their structures were established by a combination of spectroscopic data, chemical transformation, single-crystal X-ray diffraction, and ECD calculation. Compound <b>1</b> represents a novel bisindole alkaloid, characterized by a caged heteropentacyclic ring system incorporating an unprecedented C-7/C-20 bond in the vobasinyl unit. Alkaloids <b>1</b> and <b>2</b> showed potent antiproliferative activity against several human cancer cell lines, including vincristine-resistant KB.