Modern interpretation of the traditional application of Shihu - A comprehensive review on phytochemistry and pharmacology progress of Dendrobium officinale.

ETHNOPHARMACOLOGICAL RELEVANCE: The traditional Chinese medicine (TCM) "Shihu" has a long history of medicinal use in China from some species of Dendrobium. D. officinale is a major source of "Shihu" and is widely cultivated in south of China and listed separately as "Tiepi Shihu" by the Chinese Pharmacopoeia in now time. Traditionally, D. officinale has been widely used in daily health care and the treatment of diabetes and gastrointestinal diseases. AIM OF THIS REVIEW: In order to better develop and utilize D. officinale, we conducted this systematic review of previous studies, showed clear structure of all isolates from D. officinale together with pharmacological progress, hoping to provide references for further research and utilization. In addition, specific display of the chemical components and the research progress of related activities can help to better understand the traditional records and modern pharmaceutical applications of the plant medicine. MATERIALS AND METHODS: Information on phytochemistry and pharmacological studies of D. officinale was collected from various scientific databases including Web of Science, SciFinder, ACS, Springer, Scopus, PubMed, ScienceDirect, Google Scholar and CNKI. RESULTS: More than 180 compounds isolated from D. officinale, including bibenzyls, phenols, phenylpropanoids, lignans, flavonoids and polysaccharides are listed in this review. Furthermore, modern pharmacological researches such as hypoglycemia, immune regulation, antioxidant, cardiovascular regulation and gastrointestinal protection are summarized. CONCLUSION: Based on the summary of the research work of D. officinale, we systematically show the chemical composition of the plant, and concluded the relationship of those composition with plant habitat together with the relationship between the structure of chemical components and pharmacological activity. Moreover, we suggest that some of small molecule compounds could also be quality control of D. officinale besides polysaccharides.

Purification, structural characterization and immunomodulatory activities of a polysaccharide from the fruiting body of Morchella sextelata.

A novel polysaccharide (MSP-1) was isolated from the fruiting body of Morchella sextelata and purified using DEAE-52 and Sephadex G-75. The molecular weight of MSP-1 was 1.17 × 104 Da, as detected by HPLC analysis. The monosaccharide composition of MSP-1 was mannose and glucose at a ratio of 1.00: 1.25. Methylation and NMR results revealed that the backbone of MSP-1 was composed of →4)-ß-D-Manp-(1→, →4)-ß-D-Glcp-(1→, →4)-α-D-Glcp-(1→, and →4, 6)-α-D-Glcp-(1→. SEM images of MSP-1 presented a dense network structure with porous characterizations. The immunomodulatory activities of MSP-1 were evaluated using RAW264.7 cells, and the results showed that MSP-1 promoted proliferative and phagocytic activity and increased the production of NO, TNF-α and IL-6. These results indicated that MSP-1 exhibited significant immunomodulatory activities.

Total Synthesis of Gastrodinol via Photocatalytic 6π Electrocyclization.

The first total synthesis of gastrodinol, an unprecedented poly-p-cresol-substituted natural product with a rearranged and reconstructed C ring moiety, is reported. Our synthesis features a convergent fragment approach. The Sonogashira coupling reaction forges the two segments together to furnish the conjugated ene-yne. Photocatalytic 6π electrocyclization followed by spontaneous aromatization is used to construct the tetrasubstituted B ring at the late stage. Further study shows that gastrodinol exhibits significant cytotoxic activity against five human cancer cell lines in vitro (IC50 2.5-3.8 µM).

Structural characterization and hypoglycemic effect via stimulating glucagon-like peptide-1 secretion of two polysaccharides from Dendrobium officinale.

Two polysaccharides, named DOP-1 and DOP-2, with molecular weights of 6.8 kDa and 14.3 kDa, respectively, were isolated and purified from the stems of Dendrobium officinale. Monosaccharide composition, Fourier-transform infrared spectroscopy, methylation, and nuclear magnetic resonance analyses indicated that DOP-1 and DOP-2 may have a backbone consisted of →4)-ß-d-Glcp-(1→, →4)-ß-d-Manp-(1→, →4)-2-O-acetyl-ß-d-Manp-(1→ and →4)-3-O-acetyl-ß-d-Manp-(1→. In vivo assays showed that D. officinale polysaccharides (DOPs) exerted significant hypoglycemic effects accompanying increased serum insulin and glucagon-like peptide-1 (GLP-1) levels in streptozotocin-induced diabetic rats. Further in vitro experiments showed that DOP-induced GLP-1 secretion was inhibited by an intracellular calcium chelator, a Ca2+/calmodulin-dependent protein kinase (CaMK) II inhibitor, a specific calcium-sensing receptor antagonist, and a p38-mitogen-activated protein kinases (MAPK) inhibitor. These results indicated that DOPs may decrease fasting blood sugar levels by stimulating GLP-1 secretion and that intracellular DOP-induced GLP-1 secretion involved the Ca2+/calmodulin/CaMKII and MAPK pathways.

Poly p-hydroxybenzyl substituted bibenzyls and phenanthrenes from Bletilla ochracea Schltr with anti-inflammatory and cytotoxic activity.

Ten previously undescribed stilbenoids, including six bibenzyls (bleochrins A-F, 1-6), three phenanthrenes derivatives (bleochrins G-J, 7-10) along with eleven known compounds were isolated from the rhizomes of Bletilla ochracea Schltr. The structural characterizations of 1-21 were accomplished by spectroscopic data, while the absolute stereostructure of 6 was confirmed by electronic circular dichroism (ECD) data analyses. All isolated metabolites except 7 were evaluated for cytotoxic activity against five human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7 and SW480). Four isolates exhibited significant inhibitory ability against HL-60, SMMC-7721, and MCF-7 cell lines, with IC50 values ranging from 0.79 to 6.57 µM. The isolates were tested further for inhibitory effects on the NO production of the liposaccharide (LPS)-induced RAW264.7 macrophages and showed activity with IC50 values at 15.29-24.02 µM.

Stilbenes with anti-inflammatory and cytotoxic activity from the rhizomes of Bletilla ochracea Schltr.

Four new dihydrophenanthrenofuran, bleochranols A-D (1-4), along with 21 known compounds including phenanthrenes (5-14) and bibenzyls (15-25) were isolated and elucidated from the rhizomes of Bletilla ochracea. Combination of 1D/2D NMR techniques and the Electronic Circular Dichroism (ECD) spectroscopy based on the empirical helicity rules, chemical structure of those isolates were determined. All the compounds were evaluated for cytotoxicity against HL-60, SMMC-7721, A-549, MCF-7 and SW480 human cancer cell lines by MTS assay and anti-inflammatory activity by nitric oxide (NO) production in LPS-stimulated RAW 264.7 macrophages. Among the 25 tested compounds, bleochranol A (1) showed remarkable cytotoxic activity against HL-60, A-549, and MCF-7 with IC50 values of 0.24 ±â€¯0.03, 3.51 ±â€¯0.09 and 3.30 ±â€¯0.99 µM respectively. The anti-inflammatory assay showed that compound 12 exhibited most potential activity against NO production in RAW 264.7 macrophages with IC50 2.86 ±â€¯0.17 µM. The results indicated that the main chemical constituents of B. ochracea were phenanthrene and bibenzyl and similar to that of B. striata.