Limonoids from Azadirachta excelsa.
Activity-directed fractionation of a stem extract of Azadirachta excelsa using KB (human oral epidermoid carcinoma) cells led to the isolation of four meliacin-type limonoids. Two of these constituents were novel, namely, 2,3-dihydronimbolide and 3-deoxymethylnimbidate, and these were purified along with the known compounds, nimbolide and 28-deoxonimbolide. The structures of the new compounds were determined by spectroscopic methods. Nimbolide and 28-deoxonimbolide were broadly cytotoxic when evaluated against a panel of human cancer cell lines, while the two novel compounds were inactive in this regard. The defection of nimbolide and 28-deoxonimbolide as cytotoxic constituents was facilitated by an electrospray LC/MS dereplication procedure.
Cui
B
B
Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago 60612, USA.
Chai
H
H
Constant
H L
HL
Santisuk
T
T
Reutrakul
V
V
Beecher
C W
CW
Farnsworth
N R
NR
Cordell
G A
GA
Pezzuto
J M
JM
Kinghorn
A D
AD
D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002770:Cholenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D007783:Lactones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D036701:Limonins; D010946:Plants, Medicinal / Q000737:chemistry*; D012632:Secosteroids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D013057:Spectrum Analysis; D014407:Tumor Cells, Cultured
C112676:2,3-dihydronimbolide; C112677:3-deoxymethylnimbidate; D000972:Antineoplastic Agents, Phytogenic; D002770:Cholenes; D004224:Diterpenes; D007783:Lactones; D036701:Limonins; D012632:Secosteroids; C062897:28-deoxonimbolide; C042198:nimbolide