SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
A new neolignan glucoside denchyside B along with three known lignans have been isolated from the herbs of Dendrobium chrysanthum Wall. (Orchidaceae). The structures were elucidated on the basis of spectroscopic methods.
A new sesquiterpene glycoside with a picrotoxane-type aglycone has been isolated from the stems of Dendrobium nobile Lindl. Its structure was elucidated as 7,12-dihydroxy-5-hydroxymethyl-11-isopropyl-6-methyl-9-oxatricyclo[6.2.1.0(2,6)]undecan-10-one-15-O-beta-D-glucopyranoside on the basis of spectroscopic data and chemical methods.
Three new bibenzyl derivatives have been isolated from the stems of Dendrobium nobile Lindl. (Orchidaceae). Their structures were established as 4,5-dihydroxy-3,3',alpha-trimethoxybibenzyl (1), 4,4'-dihydroxy-3,3',5,alpha-tetramethoxybibenzyl (2) and 4-hydroxy-3,3',4',5,alpha-pentamethoxybibenzyl (3) on the basis of spectroscopic analysis.
Two new fluorenone derivatives denchrysans A (1) and B (2) and one new phenanthrenediglycoside denchryside A (3) were isolated from the herbs of Dendrobium chrysanthum (Orchidaceae). Their structures were established on the basis of spectral evidence.
Orchids are members of Orchidaceae, one of the largest families in the flowering plants. Among the angiosperms, orchids are unique in their floral patterning, particularly in floral structures and organ identity. The ABCDE model was proposed as a general model to explain flower development in diverse plant groups, however the extent to which this model is applicable to orchids is still unknown. To investigate the regulatory mechanisms underlying orchid flower development, we isolated candidates for A, B, C, D and E function genes from Dendrobium crumenatum. These include AP2-, PI/GLO-, AP3/DEF-, AG- and SEP-like genes. The expression profiles of these genes exhibited different patterns from their Arabidopsis orthologs in floral patterning. Functional studies showed that DcOPI and DcOAG1 could replace the functions of PI and AG in Arabidopsis, respectively. By using chimeric repressor silencing technology, DcOAP3A was found to be another putative B function gene. Yeast two-hybrid analysis demonstrated that DcOAP3A/B and DcOPI could form heterodimers. These heterodimers could further interact with DcOSEP to form higher protein complexes, similar to their orthologs in eudicots. Our findings suggested that there is partial conservation in the B and C function genes between Arabidopsis and orchid. However, gene duplication might have led to the divergence in gene expression and regulation, possibly followed by functional divergence, resulting in the unique floral ontogeny in orchids.
Intersimple sequence repeats (ISSR) molecular fingerprinting markers have been employed to authenticate eight populations of Dendrobium officinale using 10 primers selected from 76 ISSR primers. A total of 127 DNA fragments were amplified, of which 115 were polymorphic (90.5% of all bands). Sixteen specific authentication markers have been found. To enhance the efficiency of authentication, ISSR fingerprinting codes have been constructed using six polymorphic bands for authenticating D. officinale populations. Eight wild populations of D. officinale have been authenticated accurately using ISSR.
Isoamoenylin (6), a dihydrostilbene from Dendrobium amoenum, was synthesised from 3,4,5-trimethoxybenzaldehyde (1) in four steps with an overall yield of 60%. The spectral data for synthetic 6 are in good agreement with those of the natural product. Isoamoenylin showed moderate antioxidative and weak antibacterial activities.
This article reported the contents of total alkaloid from Dendrobium nobile Lindel, in different growing conditions. The result showed that the total alkaloid contents from plants taming on sawdust media were higher than from growing on trees at wild. The experiment also found total alkaloid contents of leaves were higher than that of stems.
OBJECTIVE: To isolate the mycorrhizal fungi from the roots of wild Dendribium candidum and D. nobile collected from Yunnan and Sichuan provinces and determine their biological activities. METHOD: The isolation was completed using solidified potato dextrose agar (PDA, Difco) of plates and the biological activities were tested by means of symbiotic germination of fungus-seedlings. RESULTS: 25 Species of mycorrhizal fungi were obtained and most of them belong to Basidiomycotina and Deuteromycotina. The preliminary biological activity test has shown that of these fungi 5 species help promote the seed germination of D. candidun, 7 species can establish the symbiotical relationship with seedlings of D. candium and D. nobile, and 3 species can stimulate the growth of seedlings of the two medicinal plants. CONCLUSION: Isolation and screening of fungi helpful to the growth and development of Dendrobium is important in the production of the herb.
OBJECTIVE: To set up a system for the culture of Dendrobium chrysotoxum in vitro. METHOD: Tissue culture, fire fly luminescence and phenol-H2SO4 method. RESULT: The embryo could germinate with or without light, the MS, 1/2MS, B5, N6 mediums are suitable to the growth and the differentiation of sprout with light, 0.5 mg.L-1 NAA and 1 mg.L-1 6-BA, and ATP have regular changes, the content of polysaccharide was 2.833% in plant and 7.254% in sprout. CONCLUSION: The light has no effects on the embryo germination, but the phytohormone, nitrogen source and organized elements are important to the growth and differentiation of the sprout which should be transferred to the MS, 1/2MS, B5, N6 mediums in time supplemented with NAA [symbol: see text] 6-BA, ATP may be served as the dynamic indication of nourishment demand in the plant. The content of polysaccharide in the sprout is higher and can be utilized.
OBJECTIVE: To study rDNA ITS sequence differences between F type and that of H type of Dendrobium officinale in main habitat of China. METHOD: The population differences of the rDNA ITS region (including ITS1, ITS2, 5.8S) sequences of D. officinale were studied by the method of DNA sequences analysis. RESULT: There were two different sites between the rDNA ITS sequence of F type and that of H type. One was in ITS1 region, and the other was in 5.8S region. It was proved that there was some relativity between the character of rDNA ITS region and the life type of the populations. The phenomenon of single nucleotide polymorphism (SNP) existed in 5.8S region of rDNA ITS region between F type and H type. The sequences of rDNA ITS region of D. officinale were reported for the first time, and the sequences of ITS region ranged 634 bp (ITS1 231 bp, ITS2 240 bp, 5.8S 163 bp). CONCLUSION: The analysis of rDNA ITS of D. officinale deeply reveal the population differences of D. officinale of F type and H type.
OBJECTIVE: To analyse the 1H-NMR finger-print of the stem of Dendrobium loddigesii. METHOD: Silica gel column chromatography was used to separate the chemical constituents of SCE A of the stem of D. loddigesii. The characteristic signals of the H-NMR finger-print were analysed after determining the structures of the compounds isolated from SCE A. RESULT: 1H-NMR finger-prints of the samples of D. loddigesii collected from different regions showed highly characteristic features and reproducibility. Four compounds predominant in SCE A were isolated and their structures were determined by spectral analysis as 1, 2, 3 and 4, respectively. CONCLUSION: Compound 3 and 4 were isolated from D. loddigesii for the first time. The 1H-NMR finger-print of CGE A of the stem of D. loddigesii showed mainly the characteristic signals of the above four compounds and might be utilized for the original authentication of this plant.
With LiCor-6400 Portable Photosynthesis System, carbon dioxide exchange pattern for leaves of Dendrobium nobile during 24 hours were studied in sunny day and rainy day, and the variation of CO2 exchange rate to light intensity was analysed. The results showed that in sunny day D. nobile absorbed CO2 in all day except at midday, at noon photorespiration took place. The CO2 exchange pattern was similar to Crassulacean Acid Metabolism(CAM). In rainy day CO2 uptake was in all day, at night CO2 uptake was monitored at 21:00, then CO2 released from 23:00 to dawn. Light saturation point was 1000 mumol/m2s. Over light saturation point photosynthesis, photoinhibition of photosynthesis will be induced by high-light. Exposed to high-light, the light saturation point and the CO2 uptake velocity would be decreased. With variation of environmental factors, photosynthetic pathway in D. nobile could change from CAM to C3 photosynthetic metabolism. It may be one of main reasons for D. nobile to adapt to the shade-requiring environment, the slow growth and rareness in nature.
OBJECTIVE: To examine effects of fungus AR-18 (Epulorhiza sp.) on the growth of Dendrobium candidum and D. nobile in vitro culture. METHODS: Effects of fungus AR-18 on fresh weight and dry weight of D. candidum and D. nobile were studied in vitro culture, when agar was used as rest, and effects of fungus AR-18 and nutrients on fresh weight and dry weight of D. candidum and D. nobile were studied in vitro culture, when vermiculite was used as rest. RESULTS: In agar medium, effects of fungus AR-18 on fresh weight and dry weight of D. candidum and D. nobile were not significant (P > 0.05). However, in vermiculite medium, the effect of fungus AR-18 on fresh weight of D. nobile was significant (P < 0.05). Fresh weight of D. nobile inoculated with fungus AR-18 was increased by 16% compared with the non-inoculated ones (control). The effect of fungus AR-18 on dry weight of D. nobile was very significant (P < 0.01). Dry weight of D. nobile inoculated with fungus AR-18 was increased by 21% compared with the control. In vermiculite medium, the effect of combination treatment (Fungus AR-18 + Distilled H2O) on fresh weight of D. nobile was very significant (P < 0.01). Fresh weight of D. nobile inoculated with fungus AR-18 was increased by 47% compared with the control, while the effect of combination treatment (Fungus AR-18 + Nutrients) on fresh weight of D. nobile was not significant (P > 0.05). In addition, the effect of combinations treatment (Fungus AR-18 + Nutrients) and (Fungus AR-18 + Distilled H2O) on dry weight of D. nobile was not significant (P > 0.05). So the combination treatment (Fungus AR-18 + Distilled H2O) was the best for the growth of D. nobile. In vermiculite medium, effects of fungus AR-18 and nutrients on fresh weight and dry weight of D. candidum were not significant (P > 0.05). CONCLUSION: It is important in vitro culture to select a proper rest for the control of the growth of fungus to establish a beneficial symbiotic relationship between plants and fungi. If the fungus AR-18 is utilized as biological manure in got-up planting of D. nobile, a good result may be obtained.
OBJECTIVE: To study the effects of hyphae and their metabolites of Mycena anoectochila, M. dendrobii and M. orchidicola on promoting the protocorns multiplication of D. candidum and platelet growth of A.roxburghii. METHODS: Add 20% (V/V) ground hypha or 10 mg/L ethyl acetate extracts of fermentation liquid respectively to the plant culture media. RESULTS: The ground hypha of 3 Mycena and ethyl acetate extracts of M. orchidicola could promote the protocorn multiplication rate of D. candidum. The ground hypha of M. dendrobii could increase the numbers of bud and improve the platelet growth of A.roxburghii. The ethyl acetate extracts of fermentation liquid of M. anoectochila increased the numbers of bud and M. orchidicola significantly improved the platelet growth of A. roxburghii. CONCLUSION: The effects of 3 Mycena Endophytic fungi on promoting growth of Dendrobium candidum and Anoectochilus roxburghii are related with their metabolites in and out of hypha.
Effects of additives on tissue culture and rapid propagation of Dendrobium canducum Walla. ex Lindal. by 1/2 MS added activated charcoal, plant growth regulators, banana juice, apple juice and potato juice were studied. The result showed that the medium 1/2 MS + 0.1 mg/L NAA + 0.5% activated charcoal was suitable for propagation of protocorm-like body (PLB), the medium 1/2 MS + 0.5 mg/L 6-BA + 0.5% activated charcoal was suitable for differentiation of PLB, and 0.5% activated charcoal, banana juice and apple juice could promote root formation and growth.
The diseases on the Dendrobium plants and their occurrence and damage as well as control methods have been investigated and studied. 11 kinds of fungi, 4 kinds of bacteria, 3 kinds of virus and one root-knot nematode were recorded. To control them effectively, cultural methods such as selecting cultivable field, keeping the field sanitation, enhancing cultural operations are mostly recommended. The application of chemical germicides is also stressed.
OBJECTIVE: To investigate the characteristics of growth, and water-soluble polysaccharide and total alkaloid accumulation in protocom-like bodies (PLBs) of Dendrobium huoshanenese in liquid culture system. METHOD: PLBs were suspended in liquid medium and growth kinetics was analyzed. Water-soluble polysaccharide and total alkaloid content in PLBs were determined by colorimetry. RESULT: PLBs were induced from stem explants of D. huoshanenese regenerants cultured on MS medium supplemented with NAA or NAA and KT at different concentrations. Basal MS medium was suitable for propagation of PLBs. When PLBs were suspended in liquid medium, mumax was 0.044.d-1, t(d) was 15.8 d and the optimum growth time was 4 weeks. Water-soluble polysaccharide and total alkaloid contents in PLBs were 3.75% and 0.0261%, respectively. CONCLUSION: PLBs in liquid culture system show a potential for rapid growth and high metabolite synthesis, which provides possibility for exploiting resources of D. huoshanenese by large scale culture of PLBs.