Eighteen 22-O-ester derivatives of jorunnamycin A (2) were prepared via 2, and their cytotoxicity against human non-small-cell lung cancer (NSCLC) cells was evaluated. Preliminary study of the structure-cytotoxicity relationship revealed that the ester part containing a nitrogen-heterocyclic ring elevated the cytotoxicity of the 22-O-ester derivatives. Among them, 22-O-(4-pyridinecarbonyl) ester 6a is the most potent compound (IC50 1.
View Article and Find Full Text PDFBackground: Glioblastoma is the most aggressive form of brain tumors showing resistance to treatment with various chemotherapeutic agents. The most effective way to eradicate glioblastoma requires the concurrent inhibition of multiple signaling pathways and target molecules involved in the progression of glioblastoma. Recently, we obtained a series of 1,2,3,4-tetrahydroisoquinoline alkaloids with potent anti-cancer activities, including ecteinascidin-770 (ET-770; the compound 1a) and renieramycin M (RM; the compound 2a) from Thai marine invertebrates, together with a 2'-N-4"-pyridinecarbonyl derivative of ET-770 (the compound 3).
View Article and Find Full Text PDFRenieramycin M and jorunnamycin C, two isoquinolinequinone compounds differing only at the C-22 ester side chain, were evaluated for their cytotoxic effects on human colon (HCT116) and breast (MDA-MB-435) cancer cell lines. These two compounds displayed potent cancer cell growth inhibition, their IC(50) values reaching nanomolar order. To examine their effects on transcription, we carried out oligonucleotide microarray analysis with focus on the similarities and differences between the two compounds in terms of transcriptional profiles.
View Article and Find Full Text PDFTwenty-four ester analogues of renieramycin M (1m) were prepared from jorunnamycin A (3a), which was easily transformed from marine natural 1m in three steps. These analogues, along with 1m itself, cyanojorumycin (2b), and jorunnamycins A (3a) and C (3b), were evaluated in vitro for cytotoxicity by measuring IC(50) values through the 3-(4,5-dimethyltriazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay using human HCT116 colon carcinoma and MDA-MB-435 breast carcinoma cell lines. Nitrogen-containing heterocyclic ester derivatives 9a-f showed similar in vitro cytotoxicity to 1m, whereas the other derivatives were slightly less cytotoxic than 1m.
View Article and Find Full Text PDFJorunnamycins A-C (1a-c), three stabilized renieramycin-type bistetrahydroisoquinolines, were isolated from the mantles, the visceral organs, and the egg ribbons of the Thai nudibranch Jorunna funebris that was pretreated with potassium cyanide (KCN), along with five known compounds, renieramycins M (2m), N (2n), O (2o), and Q (2q) and mimosamycin (3). The structures of 1a-c were elucidated from spectroscopic data and by chemical conversion of renieramycin M (2m) into 1c via 1a. The chemical stability and the oxidative degradation generating simple isoquinoline alkaloids of a carbinolamine analog 1d, which was easily prepared by reacting 1c with silver nitrate in aqueous acetonitrile, are discussed.
View Article and Find Full Text PDFEcteinascidins 770 (1b) and 786 (3b) were isolated from the pretreated Thai tunicate Ecteinascidia thurstoni with potassium cyanide in buffer solution (pH 7). These structures were fully elucidated by extensive 2D NMR analysis.
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