Biomedical subjects

Dedy Darnaedi

Publications and source records attributed to Dedy Darnaedi.

14 recordsLinked to original sources

PubMed2006

Resveratrol oligomers and their O-glucosides from Cotylelobium lanceolatum.

Three new resveratrol oligomers, cotylelophenol C (1) (resveratrol tetramer) and cotylelosides A (2) and B (3) (O-glucosides of resveratrol trimer), together with four known glucosides of resveratrol oligomers (vaticasides A, B, C, D) and piceid, were isolated from an acetone soluble part of stem of Cotylelobium lanceolatum (Dipterocarpaceae). The structures of new compounds were determined by spectral data analysis. The characteristic properties observed in the NMR spectra of 1 were also discussed.

Ericales↗

PubMed2005

Two novel trimeric resveratrol derivatives from Cotylelobium lanceolatum.

Two new resveratrol (= 5-[(E)-2-(4-hydroxyphenyl)ethenyl]benzene-1,3-diol) trimers, cotylelophenols A (1) and B (2), were isolated from the stem of Cotylelobium lanceolatum (Dipterocarpaceae), together with ten known resveratrol oligomers (3-12). The structures of the isolates were established on the basis of spectroscopic analyses, including a detailed NMR spectroscopic investigation of 1 under different conditions. Compound 1 is the first resveratrol trimer with a rearranged 4-hydroxyphenyl group. Four possible biogenetic pathways towards resveratrol oligomers are proposed (Scheme).

Ericales↗

PubMed2005

New resveratrol tetramers from the stem bark of Upuna borneensis.

Five new resveratrol (=5-[(E)-2-(4-hydroxyphenyl)ethenyl]benzene-1,3-diol) tetramers, upunaphenols H-J (1-3) and trans-(4) and cis-upunaphenol K (5), were isolated from the stem of Upuna borneensis (Dipterocarpaceae). Their structures were elucidated on the basis of 1D- and 2D-NMR as well as FAB-MS data. Compounds 1-3 bear a rare biphenyl bond in their frameworks. Compounds 1 and 2 have an unprecedented nonacyclic fused ring system, and compounds 2 and 3 have symmetrical structures.

Ericales↗

PubMed2005

Resveratrol derivatives from Upuna borneensis.

Four new resveratrol derivatives, upunaphenols B (1), C (4), D (5) (resveratrol tetramer) and E (6, resveratrol dimer with a C6-C1 unit), together with nine known resveratrol oligomers and resveratrol were isolated from an acetone soluble part of stem of Upuna borneensis (Dipterocarpaceae). The structures of new compounds were determined by spectral analysis including 1D and 2D NMR experiments.

Chromatography, Thin Layer↗

PubMed2004

Six new constituents from the roots of Erythrina variegata.

Three new isoflavonoids, eryvarins M-O (1-3), two new 2-arylbenzofurans, eryvarins P and Q (4 and 5), and a new 3-aryl-2,3-dihydrobenzofuran, eryvarin R (6), together with three known compounds, were isolated from the roots of Erythrina variegata. The structures of these compounds were established by spectroscopic analysis. Eryvarin R (6) is an unusual 3-aryl-2,3-dihydrobenzofuran derivative with a formyl (CHO) group. Eryvarin Q (5) showed potent antibacterial activity against methicillin-resistant Staphylococcus aureus.

Erythrina↗

PubMed2004

Acetophenone C-glucosides and stilbene O-glucosides in Upuna borneensis.

Three acetophenone C-glycosides; 2,4,6-trihydroxyacetophenone 3-C-beta-(2'-O-p-hydroxybenzoyl)-glucopyranoside, 2,4,6-trihydroxyacetophenone 3-C-beta-(2'-O-E-coumaroyl)-glucopyranoside, 2,4,6-trihydroxyacetophenone 3-C-beta-(2'-O-E-cinnamoyl)-glucopyranoside, and two resveratrol O-glycosides; piceid 2'-O-p-hydroxybenzoate and, piceid 2'-O-E-ferulate, together with three known compounds were isolated from the acetone soluble part of stem of Upuna borneensis (Dipterocarpaceae). The structures of isolates were determined by spectral analysis including extensive 2D-NMR spectral analyses.

Acetophenones↗

PubMed2004

Three new resveratrol oligomers from the stem bark of Vatica pauciflora.

Three new stilbene oligomers (1-3) were isolated from the stem bark of Vatica pauciflora. The structures of a resveratrol heptamer (pauciflorol D) (1), a resveratrol dimer (pauciflorol E) (2), and an indanone derivative (pauciflorol F) (3) were elucidated by means of spectroscopic data interpretation, especially HMBC and NOESY NMR experiments.

Ericales↗

PubMed2003

Eryvarins F and G, two 3-phenoxychromones from the roots of Erythrina variegata.

Two 3-phenoxychromones, eryvarins F and G, were isolated from the roots of Erythrina variegata. Their structures were established to be 3-(2,4-dihydroxyphenoxy)-7-hydroxy-6,8-di(3,3-dimethylallyl)chromen-4-one and 3-(2,4-dihydroxyphenoxy)-8-(3,3-dimethylallyl)-2,2-dimethylpyrano[5,6:6,7]chromen-4-one on the basis of spectroscopic and chemical evidence. Eryvarins F and G are unusual 3-phenoxychromone derivatives with two isoprenoid groups.

Chromatography, Gel↗

PubMed2003

Stilbene derivatives from Gnetum gnemon Linn.

Four stilbene derivatives, gnemonols K and L (resveratrol trimers), M (isorhapontigenin dimer), and gnemonoside K (glucoside of resveratrol trimer) together with eleven known stilbenoids and a lignan were isolated from the acetone, methanol and 70% methanol soluble parts of the root of Gnetum gnemon (Gnetaceae). The structures of the isolates were determined by spectral analysis. The antioxidant activity of the stilbenoids on lipid peroxide inhibition and super oxide scavenging activity were also investigated.

Antioxidants↗

PubMed2003

Phenolic constituents of Gnetum klossii.

Four new phenolic derivatives, gnetofurans A-C (1-3) and dihydropinosylvindiol (4), were isolated from a methanol-soluble extract of the stems of Gnetum klossii, together with nine known compounds [gnetifolin F (5), isorhapontigenin, gnetulin, gnetins E and C, latifolol, gnetol, (-)-epsilon-viniferin, and trans-resveratrol]. The structures of the new compounds were determined by spectral data analysis.

Benzofurans↗

PubMed2003

Three new trimeric stilbenes from Gnetum gnemon.

Three stilbene trimers (gnemonols D, E, F) were isolated from the root of Gnetum gnemon. The structures were determined by spectroscopic analysis. In addition, the antioxidant activity of the compounds on lipid peroxide inhibition and super oxide scavenging activity were also investigated.

Gnetum↗

PubMed2002

Allozyme analysis of cryptic species in the Asplenium niduscomplex from West Java, Indonesia.

In various fern species, a large amount of rbcL sequence variation has been reported, and it is possible that these species contain several reproductively isolated cryptic species. In our previous study on Asplenium nidus L., it was suggested that the plants growing in Mt. Halimun National Park, West Java, Indonesia, consist of several cryptic species based on the results of crossing experiments among rbcL sequence types. In this study, we examined allozyme polymorphisms of five rbcL sequence types found in West Java in order to test the hypothesis that the assemblages of A. nidus delimited based on the rbcL sequences are separate Mendelian populations and gene flow is disrupted by reproductive isolation from one another. The calculated fixation indices suggested that the individuals in each rbcL type are randomly crossing at least in the investigated localities. Nevertheless, these rbcL-based assemblages were genetically differentiated in allozymes that are encoded in their nuclear genomes, and it is also suggested that gene flow is disrupted even between sympatrically distributed pairs of rbcL sequence types. Therefore, our findings support the view that the five rbcL sequence types in West Java are potential cryptic species.

Journal Article↗

PubMed2002

Stilbenoids from the stem of Gnetum latifolium (Gnetaceae).

An acetone extract of the stem of Gnetum latifolium Blume afforded the stilbene trimer (latifolol) together with five known stilbenoids (gnetin E, gnetin D, gnetin C, (-)epsilon -viniferin and resveratrol). Their structures were elucidated on the basis of spectral evidence, in particular by using 2D NMR methods.

Gnetum↗

PubMed2002

Stilbene derivatives from two species of Gnetaceae.

Five new stilbene oligomers (gnemonols A, B and C, gnemonoside E and gnetal) were isolated together with 2b-hydroxyampelopsin F and gnetin E from Gnetum gnemon and G. gnemonoides. The structures of the compounds were elucidated on the basis of spectral evidence.

Benzofurans↗