Meroterpenoids from Rhododendron nivale / 中国中药杂志

To elucidate the chemical material basis of Rhododendron nivale, this study comprehensively used various chromatographic techniques to isolate and obtain five new meroterpenoid enantiomers(1a/1b-5a/5b) from the ethyl acetate extract of R. nivale. A variety of spectral analytical methods, such as high-resolution mass spectrometry(HRMS), nuclear magnetic resonance spectroscopy(NMR), and infrared(IR) spectrum, were used to evaluate the structure, combined with the measurement and calculation of electronic circular dichroism(ECD). The new compounds 1a/1b-4a/4b were named as(±)-nivalones A-B(1a/1b-2a/2b) and(±)-nivalnoids C-D(3a/3b-4a/4b), along with one known enantiomer(±)-anthoponoid G(5a/5b). Human neuroblastoma cells(SH-SY5Y cells) induced by hydrogen peroxide(H_2O_2) were used as oxidative stress models to evaluate the protective activity of the isolated compounds against oxidative damage to nerve cells. It was found that compounds 2a and 3a had a certain protective effect on nerve cells against H_2O_2-induced oxidative damage at concentrations of 50 μmol·L~(-1), which increased the cell survival rate from 44.02%±2.30% to 67.82%±1.12% and 62.20%±1.87%, respectively. Other compounds did not show a significant ability to protect cells from oxidative damage. These findings enrich the chemical constituents of R. nivale and provide valuable information for identifying the structure of its meroterpenoids.

Mechanism of total flavonoids of Rhododendra simsii in alleviating ischemic brain injury / 中国中药杂志

This study explores the effect of total flavonoids of Rhododendra simsii(TFR) on middle cerebral artery occlusion(MCAO)-induced cerebral injury in rats and oxygen-glucose deprivation/reoxygenation(OGD/R) injury in PC12 cells and the underlying mechanism. The MCAO method was used to induce focal ischemic cerebral injury in rats. Male SD rats were randomized into sham group, model group, and TFR group. After MCAO, TFR(60 mg·kg~(-1)) was administered for 3 days. The content of tumor necrosis factor-α(TNF-α), interleukin-1(IL-1), and interleukin-6(IL-6) in serum was detected by enzyme-linked immunosorbent assay(ELISA). The pathological changes of brain tissue and cerebral infarction were observed based on hematoxylin and eosin(HE) staining and 2,3,5-triphenyltetrazolium chloride(TTC) staining. RT-qPCR and Western blot were used to detect the mRNA and protein levels of calcium release-activated calcium channel modulator 1(ORAI1), stromal interaction molecule 1(STIM1), stromal intera-ction molecule 2(STIM2), protein kinase B(PKB), and cysteinyl aspartate specific proteinase 3(caspase-3) in brain tissues. The OGD/R method was employed to induce injury in PC12 cells. Cells were randomized into the normal group, model group, gene silencing group, TFR(30 μg·mL~(-1)) group, and TFR(30 μg·mL~(-1))+gene overexpression plasmid group. Intracellular Ca~(2+) concentration and apoptosis rate of PC12 cells were measured by laser scanning confocal microscopy and flow cytometry. The effect of STIM-ORAI-regulated store-operated calcium entry(SOCE) pathway on TFR was explored based on gene silencing and gene overexpression techniques. The results showed that TFR significantly alleviated the histopathological damage of brains in MCAO rats after 3 days of admini-stration, reduced the contents of TNF-α, IL-1, and IL-6 in the serum, down-regulated the expression of ORAI1, STIM1, STIM2, and caspase-3 genes, and up-regulated the expression of PKB gene in brain tissues of MCAO rats. TFR significantly decreased OGD/R induced Ca~(2+) overload and apoptosis in PC12 cells. However, it induced TFR-like effect by ORAI1, STIM1 and STIM2 genes silencing. However, overexpression of these genes significantly blocked the effect of TFR in reducing Ca~(2+) overload and apoptosis in PC12 cells. In summary, in the early stage of focal cerebral ischemia-reperfusion injury and OGD/R-induced injury in PC12 cells TFR attenuates ischemic brain injury by inhibiting the STIM-ORAI-regulated SOCE pathway and reducing Ca~(2+) overload and inflammatory factor expression, and apoptosis.

A new lignan glucoside from stems and branches of Rhododendron ovatum / 中国中药杂志

Ten lignans were isolated from the ethanol extract of stems and branches of Rhododendron ovatum through column chromatography over silica gel, ODS, Sephadex LH-20, and MCI-gel resin and semi-preparative RP-HPLC. The structures of all compounds were elucidated by extensive spectroscopic data analysis(UV, IR, HR-ESI-MS, ECD and NMR) as(-)-4-epi-lyoniresinol-9'-O-α-L-rhamnopyranoside(1),(+)-lyoniresinol-3α-O-α-L-rhamnopyranoside(2),(+)-5'-methoxyisolariciresinol-9'-O-α-L-rhamnopyranoside(3),(-)-lyoniresinol-3α-O-β-D-glucopyranoside(4),(+)-lyoniresinol-3α-O-β-D-glucopyranoside(5),(-)-4-epi-lyoniresinol-9'-O-β-D-glucopyransoide(6), racemiside(7), neociwujiaphenol(8),(+)-syringaresinol(9), and homohesperitin(10). Among them, compound 1 was a new aryltetralin-type lignan. All the isolated lignans were tested for antioxidant activities in Fe~(2+)-cysteine induced rat liver microsomal lipid peroxidation in vitro, and compounds 8 and 9 showed antioxidant activities on the formation of malondiadehyde(MDA) in rat liver microsomes at 1×10~(-5) mol·L~(-1), with significant inhibitory rates of 75.20% and 91.12%, respectively.

Cloning and functional analysis of flavanone 3-hydroxylase gene in Rhododendron hybridum Hort / 生物工程学报

Flavanone 3-hydroxylase (F3H) is a key enzyme in the synthesis of phycocyanidins. In this experiment, the petals of red Rhododendron hybridum Hort. at different developmental stages were used as experimental materials. The R. hybridum flavanone 3-hydroxylase (RhF3H) gene was cloned using reverse transcription PCR (RT-PCR) and rapid-amplification of cDNA ends (RACE) techniques, and bioinformatics analyses were performed. Petal RhF3H gene expression at different developmental stages were analyzed by using quantitative real-time polymerase chain reaction (qRT-PCR). A pET-28a-RhF3H prokaryotic expression vector was constructed for the preparation and purification of RhF3H protein. A pCAMBIA1302-RhF3H overexpression vector was constructed for genetic transformation in Arabidopsis thaliana by Agrobacterium-mediated method. The results showed that the R. hybridum Hort. RhF3H gene is 1 245 bp long, with an open reading frame of 1 092 bp, encoding 363 amino acids. It contains a Fe2+ binding motif and a 2-ketoglutarate binding motif of the dioxygenase superfamily. Phylogenetic analysis showed that the R. hybridum RhF3H protein is most closely related to the Vaccinium corymbosum F3H protein. qRT-PCR analysis showed that the expression level of the red R. hybridum RhF3H gene tended to increase and then decrease in the petals at different developmental stages, with the highest expression at middle opening stage. The results of the prokaryotic expression showed that the size of the induced protein of the constructed prokaryotic expression vector pET-28a-RhF3H was about 40 kDa, which was similar to the theoretical value. Transgenic RhF3H Arabidopsis thaliana plants were successfully obtained, and PCR identification and β-glucuronidase (GUS) staining demonstrated that the RhF3H gene was integrated into the genome of A. thaliana plants. qRT-PCR, total flavonoid and anthocyanin contentanalysis showed that RhF3H was significantly higher expressed in the transgenic A. thaliana relative to that of the wild type, and its total flavonoid and anthocyanin content were significantly increased. This study provides a theoretical basis for investigating the function of RhF3H gene, as well as for studying the molecular mechanism of flower color in R. simsiib Planch.

Cloning and functional analysis of the phenylalaninammo-nialyase gene from Rhododendron fortunei / 生物工程学报

Phenylalaninammo-nialyase (PAL) is a key enzyme in the synthesis of methyl benzoate - a plant aroma compound. In order to understand the function of this enzyme in the formation of fragrance in the scented Rhododendron species-Rhododendron fortunei, we cloned a gene encoding this enzyme and subsequently examined the gene expression patterns and the profile of enzyme activity during development in various tissues. The full length of RhPAL gene was cloned by reverse transcription-PCR (RT-PCR) and rapid amplification of cDNA ends (RACE) techniques. The expression levels of RhPAL gene were measured by real-time quantitative reverse transcription PCR (qRT-PCR) and the amount of phenylalanine and cinnamic acid were assayed with LC-MS. The results showed that the ORF sequence of RhPAL gene amplified from the cDNA templates of flower buds had 2 145 bp, encoding 715 amino acids, and shared 90% homology to the PAL amino acid sequences from other species. qRT-PCR analysis showed that the expression of RhPAL in petals during flowering kept in rising even until the flowers wilted. The expression of RhPAL in pistil was much higher than that in stamen, while the expression in the younger leaves was higher than in old leaves. However, the expression level was relatively lower in petal and stamen compared to that in leaves. We also measured the PAL activity by Enzyme-linked immuno sorbent assay in the petals of flowers at different flowering stages. The results showed that PAL activity reached the highest at the bud stage and then decreased gradually to the lowest when the flowers wilted, which followed a similar trend in the emission of the flower fragrance. The phenylalanine and cinnamic acid contents measured by LC-MS were highly correlated to the expression level of RhPAL in various tissues and at different flowering stages, implying that RhPAL plays an important role in the formation of the flower fragrance. This work may facilitate the breeding and improvement of new fragrant Rhododendron cultivars.

Content determination of five flavonoids in Tibetan medicine Rhododendron anthopogonoides by quantitative analysis of multi-components by single marker (QAMS) / 中国中药杂志

To establish a quantitative analysis of multi-components by single marker(QAMS) method for five flavonoids in Rhododendron anthopogonoides and verify its feasibility and applicability in the medicinal materials of R. anthopogonoides. With hyperoside as the internal reference, relative correction factors(RCF) of rutin, quercetin, quercitrin and kaempferol were established by high-performance liquid chromatography(HPLC) analysis. RCFs were used to calculate the content of each component, system durability and relative retention time. Simultaneously, QAMS and external standard method(ESM) were used to determine the content of five flavonoids in 12 batches of R. anthopogonoides from different origins. The results were statistically analyzed to verify the accuracy and feasibility. The fingerprints and cluster analysis data of R. anthopogonoides analyzed and discussed differences among the batches. According to the results, the RCFs of rutin, quercetin, quercetin and kaempferol in R. anthopogonoides were 1.242 6, 0.990 5, 0.535 0, and 0.781 3, respectively. The RCFs represented a good reproducibility under different experimental conditions. Besides, there was no significant difference between QAMS and ESM. Besides, the fingerprint and cluster analysis data showed the consistency between the classification and with the origin distribution of the herbs. In conclusion, the QAMS method shows a good stability and accuracy in the quality control of R. anthopogonoides.

Rhododendron Molle (Ericaceae): phytochemistry, pharmacology, and toxicology / 中国天然药物

Rhododendron molle G. Don, belonging to the Ericaceae family, is a traditional Chinese medicinal plant with a wide spectrum of pharmacological effects. This paper aimed to review the phytochemistry, pharmacology and toxicology of R. molle, and to discuss the tendency of future investigations on this plant. A systematic review of literature about R. molle was carried out using resources including classic books about Chinese herbal medicine, and scientific data bases including CNKI, Pubmed, SciFinder, Scopus, and Web of Science. Over 67 compounds, including diterpenes, triterpenes, flavonoids, and lignans, had been extracted and identified from R. molle. The extracts/monomers isolated from the root, flower and fruits of this plant were used as effective agents for treating pains, inflammatory diseases, hypertension, and pest, etc. In addition, diterpenes, such as rhodojaponin III, were considered as the toxic agents associated with the toxicities of this plant. These findings will be significant for the discovery of new drugs from this plant and full utilization of R. molle.

Rhododendron Molle (Ericaceae): phytochemistry, pharmacology, and toxicology / 中国天然药物

Rhododendron molle G. Don, belonging to the Ericaceae family, is a traditional Chinese medicinal plant with a wide spectrum of pharmacological effects. This paper aimed to review the phytochemistry, pharmacology and toxicology of R. molle, and to discuss the tendency of future investigations on this plant. A systematic review of literature about R. molle was carried out using resources including classic books about Chinese herbal medicine, and scientific data bases including CNKI, Pubmed, SciFinder, Scopus, and Web of Science. Over 67 compounds, including diterpenes, triterpenes, flavonoids, and lignans, had been extracted and identified from R. molle. The extracts/monomers isolated from the root, flower and fruits of this plant were used as effective agents for treating pains, inflammatory diseases, hypertension, and pest, etc. In addition, diterpenes, such as rhodojaponin III, were considered as the toxic agents associated with the toxicities of this plant. These findings will be significant for the discovery of new drugs from this plant and full utilization of R. molle.

Rhododendrin inhibits toll-like receptor-7-mediated psoriasis-like skin inflammation in mice

Many active compounds present in Rhododendron brachycarpum have been used in traditional Oriental medicine for the treatment of various skin diseases. However, the precise mechanism of action of the compounds isolated from R. brachycarpum and their relevance as therapeutics for the treatment of psoriasis remain elusive. In this study, we report that rhododendrin isolated from R. brachycarpum strongly inhibits imiquimod (IMQ)-induced psoriasis-like skin inflammation in mice. We showed that topical treatment with rhododendrin reduces IMQ-induced skin hyperplasia, inflammatory mononuclear cell infiltration and the expression of pro-inflammatory mediators in mouse skin. In addition, we found that rhododendrin inhibits the activation of the TLR-7/NF-κB and mitogen-activated protein kinase pathways in both IMQ-induced psoriasis-like skin inflammation in mice and in normal human epidermal keratinocytes treated with IMQ. These results suggest that rhododendrin has an anti-inflammatory effect and can be used as a therapeutic to fight against psoriasis and other inflammatory skin diseases.

The effect of rhododendron honey on mice liver tissue / Efecto de la miel de rododendro en el tejido hepático de ratón

Rhododendron honey, made by bees from rhododendron pollen, contains a toxic substance called grayanotoxin. Depending on the dose, the poisonous honey can result in serious effects such as cardiac arrhythmia, fibrillation, and myocardial infarction. The purpose of this study is to investigate the effects of the poisonous RH of the Black Sea Region on the liver. Male mice were divided into five groups of twelve mice each, two being the control groups (distilled water) and the others being the rhododendron honey (RH) groups (25, 50, and 75 mg/kg) and 0.01 mg/kg grayanotoxin (GTx) groups. Liver tissues were collected 24 and 48 h later. The sections were stained with hematoxylin, eosin and PAS, then the histopathological score was performed. Significant statistical differences were observed between the RH and control groups in terms of congestion, steatosis, sinusoid dilatation, and inflammation. The control group demonstrated a normal liver structure in the light microscopy, while the GTx-applied 24 h group exhibited expansions in the sinusoids and congestion. Higher levels of congestion, steatosis, and inflammatory cells were seen in the GTx-applied 48 h group. In the same group, giant cells consisting of many nuclei were observed in the sinusoids. The results of the 25 mg RH-applied groups were similar in 24 and 48 h, histopathological score levels were increased slightly, congestion and steatosis were prominent in the 48 h group. Dense steatosis was seen in the hepatocytes around the vena centralis in 50 mg/kg RH-applied 48 h group. Congestion, steatosis and an increase in inflammatory cells were observed in the hepatocytes in the 75 mg/kg RH-applied 24- and 48 h groups. PAS (+) stained hepatocytes were decreased in the RH- and GTx-applied groups. The toxic effects of the rhododendron honey were observed in the mice liver tissue with respect to dose and time.

La miel de rododendro, elaborada por las abejas a partir del polen de rododendro, contiene una sustancia tóxica llamada grayanotoxina. Dependiendo de la dosis, la miel venenosa puede resultar en efectos graves, tales como arritmia cardiaca, fibrilación e infarto de miocardio. El propósito de este estudio fue investigar los efectos en el hígado de la miel venenosa de rododendro de la región del Mar Negro. Se distribuyeron ratones machos en cinco grupos de doce ratones cada uno, dos grupos control (agua destilada) y los otros grupos se trataron con la miel de rododendro (MR) (25, 50 y 75 mg/kg) y con 0,01 mg/kg grayanotoxina (GTX). Los tejidos hepáticos se recogieron 24 y 48 h más tarde. Las secciones fueron teñidas con hematoxilina-eosina y PAS. A continuación, se realizó la puntuación histopatológica. No se observaron diferencias estadísticamente significativas entre MR y los grupos de control en términos de congestión, esteatosis, dilatación sinusoidal e inflamación. El grupo control demostró una estructura normal del hígado en el microscopio de luz, mientras que el grupo de las 24 horas de aplicación de GTX exhibió expansiones en los sinusoides y congestión. Mayores niveles de congestión, esteatosis y células inflamatorias se observaron en el grupo de 48-horas de aplicación de GTX. En el mismo grupo, se observaron células gigantes que consistían en la presencia de muchos núcleos en los sinusoides. Los resultados de los grupos con aplicación de 25 mg de RH fueron similares en los resultados de 24 y 48 h, los niveles de puntuación histopatológica aumentaron ligeramente, la congestión y la esteatosis fueron prominentes en el grupo de 48 h. Se observó esteatosis densa en los hepatocitos en toda la vena central en el grupo de aplicación de 50 mg/kg de RH, 48 h. La congestión, la esteatosis y un aumento en las células inflamatorias se observaron en los hepatocitos en el grupo de 75 mg/kg de MR de 24 h y los grupos de 48 h. Hepatocitos teñidos con PAS (+) disminuyeron en los grupos de GTX y MR. Se observaron los efectos tóxicos de la miel de rododendro en el tejido hepático de ratones con respecto a la dosis y el tiempo.

Identification and characterization of three new flavonoids from Rhododendron dauricum / 中国天然药物

The present study was designed to determine the major chemical constituents of the leaves of Rhododendron dauricum L. Compounds were isolated and purified by various chromatographic methods, and their structures were elucidated by physicochemical properties and spectral data. The present study identified two new C-methyl flavanones, 5, 7, 3', 5'-tetrahydroxy-6, 8-di-C-methyl flavanone (1) and 5, 4'-dihydroxy-8-C-methylflavanone-7-O-β-D-glucopyranoside (2), and one new flavonoid glycoside, quercetin-3-O-β-D-(6"-O-cinnamoyl)-galactoside (3), along with seven known compounds, including syzalterin (4), poriolin (5), farrerol-7-O-β-D-glucopyranoside (6), myrciacetin (7), quercetin-3-O-β-D-(6-p-hydroxy-benzoyl)-galactoside (8), quercetin-3-O-β-D-(6-p-coumaroyl)-galactoside (9), and 5, 7, 3', 5'-tetrahydroxyl flavanone (10). Compounds 1-3 were determined to be new flavonoids; compounds 4-6 were isolated from this species for the first time; and compounds 7-10 were reported for the first time from this genus.

Type 2 myocardial infarction after ingestion of mad honey in a patient with normal coronary arteries

No abstract available.

Estimation of antioxidant, antimicrobial activity and brine shrimp toxicity of plants collected from Oymyakon region of the Republic of Sakha (Yakutia), Russia

BACKGROUND: Several plants are reported to be produced various biological active compounds. Lichens from the extreme environments such as high altitude, high UV, drought and cold are believed to be synthesized unique types of secondary metabolites than the other one. Several human pathogenic bacteria and fungi have been muted into drug resistant strains. Various synthetic antioxidant compounds have posed carcinogenic effects. This phenomenon needs further research for new effective drugs of natural origin. This manuscript aimed to screen new source of biological active compounds from plants of subarctic origin. RESULTS: A total of 114 plant species, including 80 species of higher plants, 19 species of lichens and 15 species of mosses, were collected from Oymyakon region of the Republic of Sakha (Yakutia), Russia (63˚20′N, 141˚42′E - 63˚15′N, 142˚27′E). Antimicrobial, DPPH free radical scavenging and brine shrimp (Artemia salina) toxicity of all crude extract were evaluated. The obtained result was analyzed and compared with commercial standards. A total of 28 species of higher plants showed very strong antioxidant activity (DPPH IC50, 0.45-5.0 µg/mL), 13 species showed strong activity (DPPH IC50, 5-10 µg/mL), 22 species showed moderate antioxidant activity (DPPH IC50,10-20 µg/mL) and 17 species showed weak antioxidant activity (DPPH IC50 more than 20 µg/mL). Similarly, 3 species of lichen showed strong antioxidant activity, one species showed moderate and 15 species showed weak DPPH reducing activity. In addition, 4 species of mosses showed moderate antioxidant activity and 11 species showed weak antioxidant activity. Similarly, extracts of 51 species of higher plants showed antimicrobial (AM) activity against Staphylococcus aureus and 2 species showed AM activity against Candida albicans. Similarly, 11 species of lichen showed AM activity against S. aureus and 3 species showed AM activity against Escherichia coli. One species of moss showed AM activity against S. aureus. And finally, one species of higher plant Rheum compactum and one species of lichen Flavocetraria cucullata showed the toxicity against Brine shrimp larvae in 100 µg/mL of concentration. CONCLUSION: The experimental results showed that subarctic plant species could be potential sources of various biologically active natural compounds.

Phenolic compounds from Rhododendron phaeochrysum var. agglutinatum / 中国中药杂志

Eight phenolic compounds were isolated from Rhododendron phaeochrysum var. agglutinatum and their sructures were identified as phaeochrysin (1), (2R)-4-(3',4'-dihydroxyphenyl) -2-butanol (2), (-) -rhododendrol (3), rhododendrin (4), (+) -isolariciresinol (5), (-) -lyoniresinol (6), lyoniresinol-9'-O-β-D-xylopyranoside (7), and dihydrodehydrodiconiferyl-3a-O-α-L-rhamnopyranoside (8). Compound 1 is new, and compounds 2, 5-8 were isolated from this plant for the first time.

Pharmacological evaluation of hyperin for antihyperglycemic activity and effect on lipid profile in diabetic rats.

Antihyperglycemic potential of hyperin at 25 and 50 mg/kg doses for 30 days to streptozotocin induced diabetic rats has been reported. In oral glucose tolerance test, hyperin treated rats showed a significant reduction in blood glucose level after 120 min. It was found that hyperin exhibited dose dependent and significant antihyperglycemic activity in streptozotocin induced diabetic rats which were nearly similar with standard drug glybenclamide. Activities of glucose-6-phosphatase, fructose-1,6-bisphosphatase, glycogen phosphorylase, glycosylated haemoglobin and level of serum urea and creatinine were significantly decreased in hyperin supplemented diabetic rats, dose dependently. Activities of hexokinase and glycogen synthase were increased with augmentation in liver glycogen, insulin and haemoglobin content in hyperin treated diabetic rats. General hematological parameters did not show any significant change in hyperin treated diabetic rats hence it is safe at these doses. Histopathological studies showed significant morphological changes in pancreatic β-cells of streptozotocin induced diabetic rats. A decreased number of secretory granules of β- cells were observed in diabetic rats and these pathological abnormalities were normalized after treatment with hyperin and standard drug glybenclamide. Further, hyperin decreases significant in serum total cholesterol, triglyceride, low density lipoprotein, very low density lipoprotein levels coupled with elevation of high density lipoprotein in diabetic rats. These results suggest that hyperin has a pivotal role in blood glucose level in streptozotocin induced hyperglycemia by improving the function of pancreatic islets and increasing glycolysis and decreasing gluconeogenesis.

Two new compounds from the flowers of Rhododendron molle / 中国天然药物

AIM@#To study the chemical constituents of the flowers of Rhododendron molle.@*METHODS@#Compounds were isolated by repeated chromatography over silica gel and Sephadex LH-20. Structures were elucidated based on spectral techniques, mainly 1D- and 2D-NMR and mass spectrometric analyses.@*RESULTS@#Two compounds (1 and 2) were isolated.@*CONCLUSIONS@#Compounds 1 and 2 were identified as two new compounds: 2α, 10α-epoxy-3β, 5β, 6β, 14β, 16α-hexahydroxy-grayanane and benzyl 2, 6-dihydroxybenzoate-6-O-α-L-rhamnopyranosyl-(1→3)-β-D-glucopyranoside, respectively.

Chemical constituents of Rhododendron seniavinii / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents of Rhododendron seniavinii.</p><p><b>METHOD</b>Compounds were isolated from the aqueous extract of the leaves of R. seniavinii by using Sephadex LH-20, ODS open column chromatography and other means. Their structures were elucidated according to spectral data and physiochemical properties.</p><p><b>RESULT</b>Thirteen compounds were isolated from R. seniavinii and identified as 5-methoxydehydroconiferyl alcohol (1), dehydroconiferyl alcohol (2), (-)-syringaresinol (3), (-)-lyoniresinol (4), (+)-lyoniresinol 3alpha-O-beta-D-glucopyranoside (5), (-)-lyoniresinol 3alpha-O-beta-D-glucopyranoside (6), 3,4,5-trimethoxyphenyl-1-O-beta-D-glucopyranoside (7), nikoenoside (8), 3,5,7-trihydroxychromone-3-0-alpha-L-rhamnopyranoside (9), 3,4,5-trimethoxyphenol (10), scopoletin (11), scopolin (12) and quercitrin (13).</p><p><b>CONCLUSION</b>Compounds 1-12 were obtained from this plant for the first time.</p>

Chemical constituents from leaves of Rhododendron rubiginosum var rubiginosum / 中国中药杂志

Thirteen compounds were isolated from the leaves of Rhododendron rubiginosum var. rubiginosum by various chromatographic techniques. On the basis of spectroscopic data, their structures were elucidated as 3,9-dihydroxy-megastigma-5-ene (1), 3 beta-hydroxy-5alpha ,6 alpha-epoxy-7-megastigmen-9-one (2), loliolide (3), ursolic acid(4), 2 alpha, 3 beta-dihydroxy-urs-12-en-28-oic acid (5), 2 alpha, 3 beta,23-trihydroxy-urs-12-en-28-oic acid (6), 7,9-dimethoxyrhododendrol (7), 7-methoxyrhododendrol (8), zingerone (9), isofraxidin (10), scopoletin (11), (+)-pinoresinol (12) and 3'-O-demethylepipinorisenol (13). All compounds were isolated from this plant for the first time, and compounds 1-3, 7-9, and 11-13 were isolated from the genus Rhododendron for the first time.

Chemical constituents of Rhododendron lepidotum / 中国中药杂志

An unusual natural product named 2,4,6-trihydroxacetophenone-3, 5-di-C-beta-D-glucoside (18) were isolated from aerial parts of Rhododendron lepidotum grows in Tibet, along with other 17 known compounds: hopenol-B (1), lupeol (2), ursolic acid (3), avicularin (4), quercetin (5), myricetin (6), hyperoside (7), myricetin-3'-O-beta-D-xyloside (8), (+)-taxifolin-3-O-alpha-L-arabinopyranoside (9), (+)-taxifolin-3-O-beta-D-glucopyranoside (10), lyoniside (11), confluentin (12), 2-(4-hydroxyphenyl)-ethyltriacontanoate (13), 2, 6-dimethoxy-4-hydroxyphenyl-1-O-beta-D-glucopyranoside (14), (-)-2-hydroxy-5-(2-hydroxyethyl) phenyl-O-beta-D-glucopyranoside (15), (-)-isola-riciresinol (16) and isofraxoside (17). All the compounds were firstly isolated from this plant as well as compounds 1, 13-18 were reported occurrence in R. spp. for the first time. The structures were identified based on analyses of spectroscopic data and physico-chemical evidences.

Grayanotoxin Poisoning from Honey: A Case Report

Honey is produced by bees from nectar collected from nearby flowers. Sometimes, honey produced from the Rhododendron species is contaminated by Grayanotoxin (GTX) in Nepal and other countries. There have been reports of GTX intoxication, also known as 'mad honey disease', from honey produced in countries other than Korea. The importation of wild honey has been prohibited by the Korean Food and Drug Administration since 2005, yet it is still distributed within Korea by the occasional tourist. We report a case of GTX intoxication from contaminated honey which included the symptoms of nausea, vomiting, general weakness, dizziness, blurred vision, hypotension and sinus bradycardia. By means of infusion with normal saline and atropine sulfate, the patient's condition fully recovered within 8 hours of hospital admission, and she was discharged without any complications.