1,2,3,4-Tetrahydronorharman-1-one

J Asian Nat Prod Res. 2017 May;19(5):504-509.

Ingenine E, a new cytotoxic β-carboline alkaloid from the Indonesian sponge Acanthostrongylophora ingens.[Pubmed: 27588456 ]

A new β-carboline alkaloid ingenine E (4), along with three known metabolites annomontine (1), acanthomine A (2), and 1,2,3,4-Tetrahydronorharman-1-one (3) were isolated from the Indonesian marine sponge Acanthostrongylophora ingens.
METHODS AND RESULTS:
Their structure characterization was unequivocally carried out using one- and two-dimensional NMR spectroscopy, as well as high-resolution mass spectrometry. The cytotoxic activity of the isolated compounds was evaluated toward MCF7, A549, HCT116, PC12, and Hela cancer cell lines. Ingenine E (4) exhibited cytotoxic activity against MCF7, HCT116, and A549 cell lines with IC50 values of 3.5, 0.67, and 2.15 μg/ml.

J Nat Prod. 2003 Jun;66(6):823-8.

New manzamine alkaloids with activity against infectious and tropical parasitic diseases from an Indonesian sponge.[Pubmed: 12828469]

Eleven manzamine type alkaloids, two beta-carbolines, and five nucleosides have been isolated from an Indonesian sponge. Among these are the previously characterized 12,34-oxamanzamine A, 12,34-oxamanzamine E, manzamine A (1), 8-hydroxymanzamine A, 6-deoxymanzamine X, manzamine E (2), manzamine X, manzamine F (4), norharman, thymine, 2',3'-didehydro-2',3'-dideoxyuridine, uracil, thymidine, and 2'-deoxyuridine.
METHODS AND RESULTS:
The structures for the five new compounds have been assigned as 32,33-dihydro-31-hydroxymanzamine A (3), 32,33-dihydro-6-hydroxymanzamine A-35-one (5), des-N-methylxestomanzamine A (6), 32,33-dihydro-6,31-dihydroxymanzamine A (7), and 1,2,3,4-Tetrahydronorharman-1-one (8), on the basis of NMR and X-ray data. The bioactivity and SAR of the manzamines against malaria, TB, and leishmania are also presented. The structural revision of two previously reported pyrazoles as uracil and thymine is also discussed.