Thawatchai Santisuk

Phenolic, iridoid and ionyl glycosides from Homalium ceylanicum

Abstract Salireposide, salirepin and two related novel phenolic glycosides named homaloside B [1-(2-methoxybenzoyloxy)methyl-5-hydroxyphenyl-β- d - glucopyranoside] and homaloside C (1-furoyloxymethyl-5-hydroxyphenyl-β- d -glucopyranoside) were isolated from the n-butanol-soluble fraction of Homalium ceylanicum. Two other new glucosides, 6- O -(3″,4″-dimethoxycinnamoyl)catapol and 3-hydroxy-β-inoyl-β- d -glucopyranoside were also isolated from this fraction. The structures were solved by chemical and NMR spectroscopic (COLOC, FLOCK, selective INEPT) methods.

NOVEL CYTOTOXIC RING-A SECO-CYCLOARTANE TRITERPENES FROM GARDENIA CORONARIA AND G. SOOTEPENSIS

Abstract Coronalolide methyl ester (1), coronalolide (2), and coronalolic acid (3) were isolated from the leaves and/or stems of Gardenia coronaria. A further compound, methyl coronalolate acetate (4), was purified from the stems after methylation. The novel compounds 1–4 have the rare ring-A seco-cycloartane carbon skeleton and their structures were assigned on the basis of spectral data and molecular modeling, as well as X-ray crystallography performed on 1. Compounds 1 and 2 were also isolated from the leaves of Gardenia sootepensis and showed broad cytotoxic activity when evaluated against a panel of human cancer cell lines.

Bioactive butenolides from Melodorum fruticosum

Abstract From leaves and branches of Melodorum fruticosum , five butenolides have been isolated: (4 Z )-6-acetoxy-7-benzoyloxy-2,4-heptadien-4-olide, (4 E )-6-acetoxy-7-benzoyloxy-2,4-heptadien-4-olide, (4 Z )-7-benzoyloxy-6-hydroxy-2,4-heptadien-4-olide, (4 E )-7-benzoyloxy-6-hydroxy-2,4-heptadien-4-olide and (4 Z )-6-benzoyloxy-7-hydroxy-2,4-heptadien-4-olide. In addition, two known flavonoids (chrysin, pinocembrin) and benzoic acid were isolated. All butenolides showed cytotoxic activities in several tumour cell lines. The structures of the isolated compounds were elucidated by spectroscopic methods.

Pimarane diterpenes from Kaempferia pulchra

Abstract Two novel pimarane diterpenes, 2α-acetoxysandaracopimaradien-1α-ol and sandaracopimaradien-1α,2α-diol, have been isolated from the hexane extract of the rhizomes of Kaempferia pulchra. Ethyl 4-methoxy-trans-cinnamate is also reported from the same source. The structures were assigned by spectroscopic methods. A single-crystal X-ray diffraction analysis confirmed the structure of 2α-acetoxysandaracopimaradien-1α-ol.