Cytotoxic triterpenes from the aerial roots of Ficus microcarpa.

Curcuminoid analogs with potent activity against Trypanosoma and Leishmania species

Strained cyclophane natural products: Macrocyclization at its limits

Two new diarylheptanoids (1, 2) and seven new diarylheptanoid glucosides (3-9) were isolated from the rhizomes of Tacca chantrieri. Their structures were determined by spectroscopic analysis, including 2D NMR data, and the results of hydrolytic cleavage. The absolute configurations of the 3,5-dihydroxyheptane moieties of the new diarylheptanoids were determined to be 3R and 5R by the application of the CD exciton chirality method to the corresponding 3,5-bis-p-bromobenzoyl derivatives. The cytotoxic activities of the isolated compounds and some derivatives against HL-60 human promyelocytic leukemia cells, HSC-2 human oral squamous carcinoma cells, and normal human gingival fibroblasts (HGF) are reported.

New diarylheptanoids and diarylheptanoid glucosides from the rhizomes of Tacca chantrieri and their cytotoxic activity.

Constituents of the fruit of Amomum tsao-ko were investigated following a preliminary screening of the antioxidant activity of several extracts of the fruit of this plant that showed that the dichloromethane extract and the ethyl acetatesoluble and water-soluble fractions of the 70% aqueous acetone extract had higher activity than α-tocopherol and butylated hydroxytoluene (BHT). Eleven compounds were isolated from the ethyl acetate-soluble fraction, and their structures were elucidated as (+)-hannokinol (1), meso-hannokinol (2), (+)-epicatechin (3), (−)-catechin (4), β-sitosterol (5), β-sitosterol 3-O-glucoside (6), 2,6-dimethoxyphenol (7), protocatechualdehyde (8), protocatechuic acid (9), vanillic acid (10), and p-hydroxybenzoic acid (11) based on mass and various nuclear magnetic resonance (NMR) spectroscopic techniques. This is the first isolation of epicatechin and catechin from the genus Amomum. The radical scavenging activity of the isolated compounds was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and colorimetric and electron spin resonance (ESR) analyses. The antioxidant activity of the compounds was also determined based on the oxidative stability index (OSI). The catechins and catechol derivatives showed strong activities in both the DPPH radical scavenging activity and antioxidant activity assays.

http://lib3.dss.go.th/fulltext/journal/j.aocs/j.aocs/2000/no.6/jun2000vol77,no6,p667-673.pdf

Constituents of Amomum tsao-ko and their radical scavenging and antioxidant activities

Biarylheptanoids and other constituents from wood of Alnus japonica

Further investigation of the phenolic components of the wood of Alnus japonica Steud. show that bridged biarylheptanoids are accompanied by their open-chain counterparts, the supposed biogenetic precursors.

Further phenolic components from Alnus japonica Steud.

The wood of Alnus japonica Steud. has been found to contain three cyclized C9–C1–C9 phenols; alnusone (I), alnusonol (II), and alnusoxide (III).

Three new cyclized C9–C1–C9 compounds from Alnus japonica steud

Three new cyclized c9-c1-c9 compounds from alnus japonica steud.

Seven analogues of sclerin (1), which have different methyl substitution on the aropaatic ring were synthesized for the purpose of biological test. The compounds were mostly prepared by the application of the known methods used for the synthesis of (1), and also two new ones have been developed.The physical and chemical data of the sclerin analogues, thus prepared, are summarized (Table 2 and 3) and compared. Especially, their behaviors support, though qualitatively the reasoning for the unusual stability of the anhydride ring in sclerin, previously made by authors and this phenomenon represents a good example for steric population control, currently proposed by Milstein and Cohen.

Masayasu Nomura

Papers

Biarylheptanoids and other constituents from wood of Alnus japonica

Further phenolic components from Alnus japonica Steud.

Three new cyclized C9–C1–C9 compounds from Alnus japonica steud

Three new cyclized c9-c1-c9 compounds from alnus japonica steud.

Syntheses of sclerin analogues