Two New Sesquiterpenes fromAcorus calamus

Abstract

A novel cadinane sesquiterpene with a propan-2-ylidene, named (1R,4R,6S,10R)-1-hydroxy-7(11)-cadinen-5,8-dione (1), and a new sesquiterpene, named (2R,6R,7S,9S)-1(10),4-cadinadiene-2,9-diol (2), were isolated from the ethanol extract of the rhizome of Acorus calamus L. Their structures were elucidated on the basis of spectroscopic data including NMR spectroscopy and X-ray crystallography. The absolute configurations of compounds 1 and 2 were confirmed by comparison of their experimental optical rotations with those obtained from theoretical calculations at the B3LYP/6-311+G (d) level of theory.

Bioactive Sesquiterpenoids from the Rhizomes of Acorus calamus

“…A comparison of the 1 H and 13 C NMR data indicated that 7 possesses the same gross structure as the reported compound, (1 R ,4 R ,6 S ,10 R )-1-hydroxy-7(11)-cadinen-5,8-dione, which was also isolated from A . calamus . The 2D NMR data ( 1 H– 1 H COSY, HSQC, and HMBC) confirmed the above conclusion.…”

“…A comparison of the 1 H and 13 C NMR data indicated that 7 possesses the same gross structure as the reported compound, (1R,4R,6S,10R)-1-hydroxy-7(11)-cadinen-5,8-dione, which was also isolated from A. calamus. 20 The 2D NMR data ( 1 H− 1 H COSY, HSQC, and HMBC) confirmed the above conclusion. The NOESY correlations between Me-15 and H-6/H-3b, H-3a, and Me-14 indicated that H-6 and Me-15 are β-oriented and Me-14 is α-oriented.…”

A Novel Tropoloisoquinoline Alkaloid, Neotatarine, from Acorus calamus L.

“…Previous phytochemical studies on A . calamus revealed the presence of sesquiterpenes, flavones, phenylpropanoids, alkaloids, etc . Bioactivity studies showed that the crude extract of A .…”

New Acorane-Type Sesquiterpene from Acorus calamus L.

“…So far, many sesquiterpenes from A. calamus mainly consist of acorane, guaiane, cadinane, and elemane-type sesquiterpenes [ 9 , 10 , 11 ]. Compounds 1 and 2 are nonisoprenoid sesquiterpenoids, and may derive from the acorane skeleton with new biogenetic pathways.…”