Sesquiterpenes from the leaves of Laurus nobilis L.
Ten sesquiterpenes, together with 12 known compounds were isolated from leaves of Laurus nobilis L. Based on spectroscopic analyses, the 10 compounds were determined to be eudesmane lactones and their corresponding methyl esters. Most of these compounds exhibited moderate-to-significant cytotoxicity towards K562 leukemia cells. One compound had a higher cytotoxicity than doxorubicin, while other compounds had moderate to no activity.
Syringin 4-O-beta-glucoside, a new phenylpropanoid glycoside, and costunolide, a nitric oxide synthase inhibitor, from the stem bark of Magnolia sieboldii.
Syringin 4-O-beta-glucoside (1), a new phenylpropanoid glycoside, and costunolide (2) were isolated from the stem bark of Magnolia sieboldii. The structures were determined by spectroscopic and chemical methods. Costunolide (2) exhibited strong nitric oxide synthase inhibitory activity in the endotoxin-activated murine macrophage, J774.1.
Urodiolenone from grapefruit juice, a urinary metabolite found in hypertensive subjects
Abstract Urodiolenone, a compound isolated from the urine of hypertensive subjects, is a 1:1 epimeric mixture of two dihydroxy derivatives of nookatone, a constituent of grapefruit. The structure of urodiolenone was suggested by NMR spectroscopy and confirmed by partial synthesis from nootkatone, a sesquiterpenoid ketone with a valencene skeleton. In addition, we show that urodiolenone itself is also present in the grapefruit in free form and possibly also as a glucuronide. The question whether urodiolenone is produced exogenously or endogenously is discussed.