benzyloxycarbonylleucyl-leucyl-leucine-aldehyde and enmein

Thirty-two enmein-type ent-kaurane diterpenoids, including 13 new compounds, were isolated from the aerial parts of Isodon phyllostachys. Compounds 1 and 2 are the first examples of 3,20:6,20-diepoxyenmein-type ent-kauranoids, and the structures of these new compounds were established mainly by analyzing NMR and HREIMS data. The absolute configurations of 1 and 8 and the relative configuration of 9 were determined using single-crystal X-ray diffraction. Compounds 11, 15, 20, and 21 were active against five human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7, and SW-480), with IC50 values ranging from 1.2 to 5.0 μM. Compounds 3, 11, 15, 17, 20, 21, 25, and 29 strongly inhibited NO production in LPS-stimulated RAW264.7 cells, with IC50 values ranging from 0.74 to 4.93 μM.

Topics: Animals; Antineoplastic Agents, Phytogenic; Crystallography, X-Ray; Diterpenes; Diterpenes, Kaurane; Drug Screening Assays, Antitumor; Drugs, Chinese Herbal; HL-60 Cells; Humans; Inhibitory Concentration 50; Isodon; Lipopolysaccharides; Mice; Molecular Conformation; Molecular Structure; Nitric Oxide; Plant Components, Aerial

Fourteen enmein-type 6,7-seco-ent-kaurane diterpenoids, seven new ones (sculponins M-S, 1-7) and seven known compounds (8-14), were isolated from the aerial parts of Isodon sculponeatus . Compound 1 is the first example of an ent-kauranoid, possessing a 11,12-epoxy group, and compounds 6 and 7 have a rare 3,6-epoxy group. The structures were established primarily by NMR and MS methods, and the absolute configurations of 1, 3, and 6 were determined by single-crystal X-ray diffraction. Compound 14 showed significant cytotoxic activity against five human tumor lines, with IC50 values ranging from 1.0 to 3.5 μM, and it also inhibited NO production in LPS-stimulated RAW264.7 cells, with an IC50 value of 2.2 μM.

Topics: Antineoplastic Agents, Phytogenic; Crystallography, X-Ray; Diterpenes; Diterpenes, Kaurane; Drug Screening Assays, Antitumor; Humans; Inhibitory Concentration 50; Isodon; Lipopolysaccharides; Molecular Conformation; Molecular Structure; Nitric Oxide; Nuclear Magnetic Resonance, Biomolecular