Perception and multimeaning analysis of graphic symbols for Thai picture-based communication system.

Graphic symbols are a vital part of most augmentative and alternative communication systems. Communication fluency of graphic symbol user depends on how well the relationship between symbols and its referents are learnt. The first aim of this study is to survey the perception of the selected graphic symbols across seven age groups of participants with different educational background.

Prenylflavonoids: a new class of non-steroidal phytoestrogen (Part 1). Isolation of 8-isopentenylnaringenin and an initial study on its structure-activity relationship.

Bioassay-guided fractionation of a methanolic extract of a Thai crude drug, derived from heartwood of Anaxagorea luzonensis A. Gray (Annonaceae), resulted in the isolation of 8-isopentenylnaringenin (1) as an estrogen agonist with a activity of about an order of magnitude greater than genistein. Various flavonoids possessing isopentenyl side chains in the A-ring have been prepared and evaluated for their ability to bind estrogen receptor.

Retrodihydrochalcones and homoisoflavones isolated from Thai medicinal plant Dracaena loureiri and their estrogen agonist activity.

Biological evaluation of the extract prepared from the stem wood of Dracaena loureiri, a Thai folkloric medicine called "Chan-daeng", revealed a significant capacity to inhibit [3H]-estradiol binding to the estrogen receptor. During the course of separation, two novel (1 and 2) and two known retrodihydrochalcones (3 and 4), in addition to three known homoisoflavones (5, 6, and 7), were isolated. The structures of compounds 1 and 2 were established by NMR and MS studies by correlating their spectroscopic properties with those of 3 and 4.