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PubMed1990

[Effects of fungi and its liquid extract on seed germination of Dendrobium hancockii Rolf].

The experiment revealed that several species of fungi isolated from the protocorms of Orchidaceae notable promote the seed germination of Dendrobium hancockii. The seed germination rate amounts to over 20% when the seeds are incubated with fungi, but zero without incubation. Seed germination rate ranges from 40 to 70% when the incubation is affected in liquid extract of the cultural products of fungi, but the growth of protocorms and seedlings of Dendrobium hancockii is slower in liquid extract of fungi than on mycolia.

Fungi↗
PubMed2002

Evaluation of different promoters driving the GFP reporter gene and selected target tissues for particle bombardment of Dendrobium Sonia 17.

Three different morphological callus types, identified as type A, B and C, and tips of in vitro inflorescences were used as target tissues for genetic transformation. Five different DNA plasmids carrying a synthetic green fluorescent protein (gfp) gene driven by different promoters, CaMV 35S, HBT, and Ubi1 were tested for the genetic transformation of Dendrobium Sonia 17. 35S-sgfp-TYG-nos (p35S) with the CaMV 35S promoter showed the highest GFP transient expression rate, while the HBT and Ubi1 promoters showed a relatively lower expression rate in all of the target tissues tested. The highest number of GFP-expressing cells was observed on day 2 post-bombardment, and the number declined gradually over the course of the next 2 weeks. Type A and B callus were found to be the best potential target tissues for genetic transformation.

Culture Techniques↗
PubMed2006

High frequency early in vitro flowering of Dendrobium Madame Thong-In (Orchidaceae).

We have successfully developed a method to induce early in vitro flowering of the self-pollinated seedlings of a tropical orchid hybrid, Dendrobium Madame Thong-In. Transition of vegetative shoot apical meristem to inflorescence meristem was observed when young protocorms were cultured in modified KC liquid medium. In contrast, protocorms cultured on Gelrite-solidified medium only produced axillary shoots and roots. CW was required to trigger the transitional shoot apical meristem and BA enhanced inflorescence stalk initiation and flower bud formation. However, normal flower development was deformed in liquid medium but developed fully upon transferring to two-layered (liquid over Gelrite-solidified) medium. Under optimal condition, in vitro flowering was observed about 5 months after seed sowing. Segregation of flower colours was observed in these seedlings and seedpods formed upon artificial pollination of the in vitro flowers.

Benzyl Compounds↗
PubMed2006

Enhancement of growth and polysaccharide production in suspension cultures of protocorm-like bodies from Dendrobium huoshanense by the addition of putrescine.

Putrescine at 0.6 mM stimulated protocorm-like body growth and polysaccharide synthesis in suspension cultures of Dendrobium huoshanense. The specific growth rate of protocorm-like body increased from 0.047 to 0.056 day(-1), and the maximum dry weight and polysaccharide production reached 33.2 and 2.94 g l(-1), respectively, while they were 24.6 and 2.12 g l(-1), respectively, in the control. The administration of polyamine inhibitor, alpha-DL-difluoromethylarginine, at 1 mM, decreased protocorm-like body growth and polysaccharide production to 21.4 and 1.76 g l(-1), respectively.

Cell Culture Techniques↗
PubMed2006

A new phenanthrene with a spirolactone from Dendrobium chrysanthum and its anti-inflammatory activities.

Investigation of phenolic patterns from the stems of Dendrobium chrysanthum by HPLC-PDA-MS has led to the isolation of a new phenanthrene derivative with a spirolactone ring, dendrochrysanene (1), that proved to suppress the mRNA level of TNF-alpha, IL8, IL10, and iNOS in murine peritoneal macrophages. The structure of 1 was characterized on the basis of various NMR (1H, 13C, 1H-1H COSY, HMQC, and HMBC), mass spectrometry, and X-ray crystal diffraction data.

Animals↗
PubMed2004

Structural characterization of a 2-O-acetylglucomannan from Dendrobium officinale stem.

A heteropolysaccharide obtained from an aqueous extract of dried stem of Dendrobium officinale Kimura and Migo by anion-exchange chromatography and gel-permeation chromatography, was investigated by chemical techniques and NMR spectroscopy, and is demonstrated to be a 2-O-acetylglucomannan, composed of mannose, glucose, and arabinose in 40.2:8.4:1 molar ratios. It has a backbone of (1-->4)-linked beta-d-mannopyranosyl residues and beta-d-glucopyranosyl residues, with branches at O-6 consisting of terminal and (1-->3)-linked Manp, (1-->3)-linked Glcp, and a small proportion of arabinofuranosyl residues at the terminal position. The acetyl groups are substituted at O-2 of (1-->4)-linked Manp and Glcp. The main repeating unit of the polysaccharides is reported.

Carbohydrate Sequence↗
PubMed2005

Simultaneous determination of phenols (bibenzyl, phenanthrene, and fluorenone) in Dendrobium species by high-performance liquid chromatography with diode array detection.

A new method of analysis of 11 phenols, including five bibenzyls, three phenanthrenes, and three fluorenones, using high-performance liquid chromatography (HPLC)-diode array detection (DAD) was described. The separation of 11 phenols was effected by RP-HPLC (Beckman Coulter ODS column, 5 microm, 250 mm x 4.6 mm) using linear gradient elution systems of acetonitrile-1/1000 trifluoroacetic acid (TFA). Satisfactory separation of these compounds was obtained in less than 45 min. The method was validated for linearity, repeatability, limits of detection (LOD) and limits of quantification (LOQ). Good results were obtained with respect to repeatability (relative standard deviation (RSD)<3.5%) and recovery (85.77-104.92%). The developed method was applied to the simultaneous determination of 11 phenols from totally 31 Dendrobium species (mainly of medicinal plants) as well as other four samples from the similar genera as Pholidota, Flickingeria and Bulbophyllum. The range of the total amounts of bibenzyl, phenanthrene and fluorenone were found to from trace: 4.00, not detected (nd): 0.42 and nd: 0.24 microg mg(-1), respectively.

Calibration↗
PubMed2005

A method for isolating functional RNA from callus of Dendrobium candidum contented rich polysaccharides.

Isolation of high-quality RNA from Dendrobium candidum is particularly difficult. D. candidum contains considerable amounts of polysaccharides that coprecipitate with RNA, which render RNA unsuitable for either cDNA synthesis and/or PCR amplification. In this paper, a rapid and efficient method was described for functional RNA isolation from the callus of D. candidum. The procedure included: (i) an extraction with phenol and isopropyl alcohol, to remove proteins and polyphenols; (ii) purifications by lithium chloride, pre-cooled (-20 degrees C) ethanol successively to remove polysaccharides. The method resulted in high-quality RNA suitable for DDRT-PCR and cDNA library analysis finally.

DNA, Complementary↗
PubMed2005

Cloning and transcription analysis of an AGAMOUS- and SEEDSTICK ortholog in the orchid Dendrobium thyrsiflorum (Reichb. f.).

Studies have shown that several plant species possess AGAMOUS (AG) and SEEDSTICK (STK) orthologs. These genes are part of the so-called C- and D MADS-box gene lineages and play key roles in ovule development in Arabidopsis thaliana. We have cloned an AG- and STK ortholog in the orchid Dendrobium thyrsiflorum, named DthyrAG1 and DthyrAG2, respectively, and analyzed their expression patterns. Quantification by real-time RT-PCR analysis shows that both are transcribed in the mature flowers and during ovule development. Localization of the transcripts by in situ hybridization analysis in flowers reveals that both genes are transcribed in the rostellum, stigma, and stylar canal. Expression analysis during ovule development shows that DthyrAG1 is expressed only in the initial periods of placenta- and ovule development, whereas the DthyrAG2 is transcribed throughout ovule development. These results suggest that both C- and D lineage orthologs are involved in various aspects of flower development and that DthyrAG2 have a more prominent role than DthyrAG1 in late ovule development in D. thyrsiflorum.

Arabidopsis↗
PubMed2004

Thermoperiodic effect on flowering and endogenous hormonal status in Dendrobium (Orchidaceae).

Two year-old cloned plants of Dendrobium Second Love were submitted to 25 degrees C (light) and 10 degrees C (dark) under a 12h photoperiod (60 micromol m(-1)s(-1)) for 30 days. The endogenous levels of IAA, ABA, and the cytokinins Z, [9R]Z, iP, and [9R]iP were measured 15, 22, and 30 days after the start of the thermoperiodic treatment in lateral buds and leaves. The endogenous levels of IAA and cytokinins, especially the zeatin-derived forms, increased significantly in buds after 15 days of treatment. On the other hand, the amount of ABA decreased progressively and significantly throughout the treatment. The treatment conspicuously accelerated flower-bud development. The found correlation suggests that hormones are involved in the signal transduction pathway of thermoperiodic flowering control.

Dendrobium↗
PubMed2005

Micropropagation of Dendrobium nobile from shoot tip sections.

Successful shoot regeneration of Dendrobium nobile was achieved using thin shoot tip sections and triacontanol (TRIA) for the first time. Protocorm-like bodies (PLBs) or proliferating shoot buds were observed when thin shoot tip sections were cultured on the basal medium of Mitra et at. (Indian J. Exp. Biol. 14 (1976) 350) supplemented with 4.0 microg L(-1) TRIA. The highest percentage of explants (93%) produced PLBs or proliferating shoot buds (21) at 4.0 microg L(-1) TRIA-supplemented basal medium. All the newly formed PLBs or proliferating shoot buds survived and ultimately produced healthy shoots with 2-3 leaves. Shoots produced roots when cultured on basal medium supplemented with 2.0 microg L(-1) TRIA. The well-rooted shoots were transferred to pots containing charcoal chips, coconut husk and broken tiles (2:2:1), and a 92% survival rate was achieved. This work reveals that TRIA can be used as an effective growth regulator in the micropropagation and conservation of D. nobile.

Botany↗
PubMed2005

Bi-bicyclic and bi-tricyclic compounds from Dendrobium thyrsiflorum.

One bi-bicyclic and two bi-tricyclic derivatives of coumarin-benzofuran, phenanthrene-phenanthrene and phenanthrene-phenanthraquinone, along with seven known compounds, were isolated from stems of Dendrobium thyrsiflorum Rchb.f. (Orchidaceae). On the basis of chemical, NMR (1H, 13C, HMQC, HMBC and NOESY) and mass spectrometry data, their structures were elucidated as denthyrsin [3-(5',6'-dimethoxybenzofuran-2'-yl)-6,7-dimethoxy-2H-chromen-2-one; 1], denthyrsinol (4,5'-dimethoxy-[1,1']biphenanthrenyl-2,5,4',7'-tetraol; 2), and denthyrsinone (7,4',7'-trihydroxy-2,2',8'-trimethoxy-[5,1']biphenanthrenyl-1,4-dione; 3). Compounds 1-3 and denthyrsinin (1,5,7-trimethoxyphenanthrene-2,6-diol; 4) showed significant cytotoxic activities against Hela (13.5, 9.3, 9.9 and 2.7 microM, respectively), K-562 (0.45, 1.6, 6.0 and 2.3 microM, respectively) and MCF-7 (18.1, not tested, 3.5 and 4.8 microM, respectively) cell lines.

Animals↗
PubMed2002

Immunomodulatory sesquiterpene glycosides from Dendrobium nobile.

Four sesquiterpene glycosides with alloaromadendrane, emmotin, and picrotoxane type aglycones were isolated from the stems of Dendrobium nobile Lindl (Orchidaceae). Their structures were determined by spectroscopic methods and chemical reactions. Immunomodulatory activity of the isolates was evaluated in vitro.

Animals↗
PubMed2003

Copacamphane, picrotoxane, and alloaromadendrane sesquiterpene glycosides and phenolic glycosides from Dendrobium moniliforme.

Seven sesquiterpene glycosides with copacamphane, picrotoxane, and alloaromadendrane sesquiterpene aglyons along with three phenolic glycosides have been isolated from the stems of Dendrobium moniliforme. Among them, dendromonilisides A-D (1-4) were characterized as new compounds, and their structures were determined on the basis of spectral and chemical methods and by X-ray diffraction analysis. The six known compounds were identified as dendrosides A, C, and F, dendromoniliside E, vanilloloside, and acanthoside B. In a preliminary biological test procedure, compounds 1, 3, and vanilloloside were found to stimulate the proliferation of B cells and inhibit the proliferation of T cells in vitro.

Azulenes↗
PubMed2003

allo-aromadendrane- and picrotoxane-type sesquiterpenes from Dendrobium moniliforme.

Eight sesquiterpenes, four stilbene derivatives along with two lignans have been isolated from lipophilic fraction of stems of Dendrobium moniliforme (Orchidaceae). Among the eight sesquiterpenes, one allo-aromadendrane-type and four picrotoxane-type sesquiterpenes were identified to be new compounds, and alpha-dihydropicrotoxinin was isolated as a new natural product. Their structures were established on the basis of spectroscopic analysis.

Dendrobium↗
PubMed2004

A new VHR dual-specificity protein tyrosine phosphatase inhibitor from Dendrobium moniliforme.

Bioassay-guided fractionation of the EtOAc-soluble extract of Dendrobium moniliforme afforded a new phenanthraquinone-type metabolite, 7-hydroxy-5,6-dimethoxy-1,4-phenanthrenequinone ( 1), along with the previously reported 5-hydroxy-3,7-dimethoxy-1,4-phenanthrenequinone ( 2). The structures of the compounds were identified mainly on the basis of MS and NMR data. Compound 1 inhibited VHR dual-specificity protein tyrosine phosphatase (DS-PTPase) activity in a dose-dependent manner, displaying an IC (50) value of 3.0 +/- 0.2 microM.

Dendrobium↗
PubMed2004

Two new fluorenones from Dendrobium chrysotoxum.

Two new fluorenones have been isolated from the orchid Dendrobium chrysotoxum Lindl. and their structures established as 2,4,7-trihydroxy-5-methoxy-9-fluorenone and 2,4,7-trihydroxy-1,5-dimethoxy-9-fluorenone.

Dendrobium↗