เคจพอลิพรีลินเลทเตทแซนโทนจากยางและเปลือกของ Garcinia scortechinii

Thesis (M.Sc., Organic Chemistry)--Prince of Songkla University, 200

Pigmentosins from Gibellula sp. As antibiofilm agents and a new glycosylated asperfuran from Cordyceps javanica

n the course of our exploration of the Thai invertebrate-pathogenic fungi for biologically active metabolites, pigmentosin A (1) and a new bis(naphtho-α-pyrone) derivative, pigmentosin B (2), were isolated from the spider-associated fungus Gibellula sp. Furthermore, a new glycosylated asperfuran 3, together with one new (6) and two known (4 and 5) cyclodepsipeptides, was isolated from Cordyceps javanica. The pigmentosins 1 and 2 showed to be active against biofilm formation of Staphylococcus aureus DSM1104. The lack of toxicity toward the studied microorganism and cell lines of pigmentosin B (2), as well as the antimicrobial effect of pigmentosin A (1), made them good candidates for further development for use in combination therapy of infections involving biofilm-forming S. aureus. The structure elucidation and determination of the absolute configuration were accomplished using a combination of spectroscopy, including 1D and 2D NMR, HRMS, Mosher ester analysis, and comparison of calculated/experimental ECD spectra. A chemotaxonomic investigation of the secondary metabolite profiles using analytical HPLC coupled with diode array detection and mass spectrometry (HPLC–DAD–MS) revealed that the production of pigmentosin B (2) was apparently specific for Gibellula sp., while the glycoasperfuran 3 was specific for C. javanica

Lovastatin Analogues from the Soil-Derived Fungus <i>Aspergillus sclerotiorum</i> PSU-RSPG178

Three new lovastatin analogues (<b>1</b>, <b>4</b>, and <b>5</b>) together with four known lovastatin derivatives, namely, lovastatin (<b>2</b>), α,β-dehydrolovastatin (<b>3</b>), α,β-dehydrodihydromonacolin K (<b>6</b>), and α,β-dehydro-4a,5-dihydromonacolin L (<b>7</b>), were isolated from the soil-derived fungus <i>Aspergillus sclerotiorum</i> PSU-RSPG178. Their structures were established using spectroscopic evidence. Compound <b>5</b> exhibited the most potent activity against HMG-CoA reductase, with an IC₅₀ value of 387 μM. In addition, the present study indicated the direct interaction of compound <b>5</b> with HMG-CoA reductase. Compound <b>5</b> was considered to be noncytotoxic against noncancerous Vero cells, with an IC₅₀ value of 40.0 μM, whereas compound <b>2</b> displayed much stronger activity, with an IC₅₀ value of 2.2 μM