title: Cytotoxic steroidal alkaloids from Kibatalia laurifolia.
abstract: Four new steroids, 3-epi-gitingensine (1), N-acetylgitingensine (6), kibalaurifoline (7) and kibalaurifenone (8), along with the known paravallarine (2), 7α-hydroxyparavallarine (3), gitingensine (4), and N-methylgitingensine (5) were isolated from the leaves of Kibatalia laurifolia. Their structures were determined primarily from mass spectrometry and 2D NMR analyses. On the basis of the known absolute configurations of 2 and 4, the absolute configurations of the new compounds were proposed. Due to the structural relationships of compounds 1-8, a biosynthetic pathway was suggested. Compound 2 was cytotoxic to KB cells (IC50 12.8 μM), followed by 1 with IC50 21.2 μM.
authors: Institute of Marine Biochemistry-VAST, 18 Hoang Quoc Viet Road, Cau Giay, Hanoi, Vietnam.
authors: Thi Dao
authors: TD
authors: Phi
authors: Van Cuong
authors: VC
authors: Pham
authors: Huong Doan
authors: HD
authors: Thi Mai
authors: Marc
authors: M
authors: Litaudon
authors: Françoise
authors: F
authors: Guéritte
authors: Van Hung
authors: VH
authors: Nguyen
authors: Van Minh
authors: VM
authors: Chau
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D029062:Apocynaceae / Q000737:chemistry*; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D007624:KB Cells; D019906:Nuclear Magnetic Resonance, Biomolecular; D018515:Plant Leaves / Q000737:chemistry; D013256:Steroids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D014744:Vietnam
chemical_list: D000470:Alkaloids; D000972:Antineoplastic Agents, Phytogenic; D013256:Steroids