Ethnopharmacological relevanceDendrobium officinale Kimura & Migo (DO) is a valuable Traditional Chinese Medicine to nourish stomach, in which polysaccharides are identified as active ingredients. However, limited scientific evidences have been reported on the gastroprotective efficacy of DO. The aim of the current study was to investigate the protective effects and underlying mechanism of polysaccharides from DO(DOP) on gastric mucosal injury.Material and methodsFor in vitro study, HFE145 cells were pretreated with DOP before induction of cell apoptosis by H2O2. Cell apoptosis and related proteins expression were detected. In the in vivo study, absolute ethanol was administered orally to induce gastric mucosal injury in rat. The gastric mucosal injury area and histological examination were used to evaluate the effects of DOP treatment on the recovery of the gastric mucosal injury.ResultsH2O2 treatment for 6 h significantly induced cell apoptosis in HFE145 cells. However, the destructive effects of H2O2 on HFE 145 cells could be reversed by the pretreatment with DOP. The increased ROS level induced by H2O2 for 4 h was reduced after DOP pretreatment. The number of apoptotic cells in both early and late apoptosis stages decreased significantly and the nuclei morphology changes were improved with DOP pretreatment. Furthermore, DOP inhibited caspase 3 activation and PARP cleavage, downregulated Bax expression and upregulated Bcl2 expression in cell model. Further study revealed that pretreatment of DOP inhibited p -NF-κBp65/NF-κBp65 level, indicating DOP inhibited H2O2-mediated apoptosis via suppression of NF-κB activation. In addition, DOP treatment could ameliorate gastric mucosal injury and inhibit mucin loss induced by ethanol in animal model. DOP treatment also interfered with ethanol-induced apoptosis process by downregulating Bax/Bcl2 ratio in gastric mucosa.ConclusionsThe present study was the first one to demonstrate the gastroprotective effect of DOP through inhibiting oxidative stress-induced apoptosis. This study provided a solid evidence for the potential use of DO as a therapy or health supplement for gastric mucosal diseasesDownload high-res image (137KB)Download full-size image

A new bibenzyl derivative, dendrocandin V (1) and a new sesquiterpene amino ether, wardianumine A (2), together with eleven known compounds, including phenanthrenes (denbinobin (3), 9,10-dihydro-denbinobin (4), mostatin (5), loddigesiinols A (6)), bibenzyls (moscatilin (7), 5-hydroxy-3,4′-dimethoxybibenzyl (8), 3,4-dihydroxy-5,4′-dimethoxy bibenzyl (9), dendrocandin A (10), gigantol (11), dendrocandin U (12)) and an alkaloids (dihydroshihunine, 13) were isolated from the EtOH extraction of stems of Dendrobium wardianum Warner. Isolation of the new compound 2 indicated that N,N-dimethylethanolamine as the key adduction in the synthesis of dendroxine and its analogs in Dendrobium species. The hypothetical biosynthetic pathway of 2 was then postulated. Inspired by literature and traditional usage of the herbal medicine, some compounds were sent for cytotoxic activity and the results indicated that compounds 1, 3, 4, 5 showed cytotoxic activities against five human cancer cell lines (HL-60, A-549, SMMC-7721, MCF-7, and SW-480) with IC50 from 2.33–38.48 μM. Among those compounds, 3 and 4 showed cell line selectivity with strong activity comparable to DDP.Download high-res image (176KB)Download full-size image

Three new triterpenoids, patrinolides B-D (1–3), and two new iridoids, patriscabioins K–L (9–10), together with five known compounds (4–8) were isolated from the extract of the whole plants of Patrinia scabiosaefolia. Compounds 1, 9, and 10 contained the unique substituents in Valerianaceae family, such as isovalery and 3-methylcrotonyl. Compound 2 was a 24-nor-ursane triterpenoid. Their structures were established on the basis of extensive spectroscopic analysis (UV, IR, MS, 1D and 2D NMR). The inhibitory activities against nitric oxide synthase (NOS) of all triterpenoids were tested. The results showed that compound 4 had moderate inhibitory activity with IC50 of 10.1 μM. Furthermore, it also showed strongest inhibitory activities on AChE with IC50 values of 10.0 μM.Download high-res image (220KB)Download full-size image

•Valeriana stenoptera analysis gave 21 iridoids and sesquiterpenoids, 10 being previously unknown.•The sesquiterpenoids mainly belong to the patchoulane-type.•Seven of the tested compounds showed NGF-promoting activity in PC12 cells.Twenty-one compounds (nine iridoids and twelve sesquiterpenoids), including ten previously unknown (five iridoids and five sesquiterpenoids) were isolated from whole dried material of Valeriana stenoptera. Structures were established on the basis of extensive spectroscopic analysis and the relative stereochemistry of 13-hydroxypatchoulol A was further confirmed by X-ray crystallographic data. All isolates were evaluated for their effects on nerve growth factor (NGF)-mediated neurite outgrowth in pheochromocytoma (PC12) cells and seven compounds showed potent promoting effects.Graphical abstractPhytochemical research of Valeriana stenoptera resulted in isolation of many iridoids and sesquiterpenoids. Seven of these compounds showed promoting effects on NGF-induced neurite outgrowth in PC12 cells at a concentration of 10 μM.

A series of novel 4β-triazole-podophyllotoxin glycosides were synthesized by utilizing the Click reaction. Evaluation of cytotoxicity against a panel of five human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7, SW480) using MTT assay shows that most of these compounds show weak cytotoxicity. It was observed that compound 16 shows the highest activity with IC50 values ranging from 2.85 to 7.28 μM, which is more potent than the control drugs etoposide and cisplatin against four of five cancer cell lines tested. Compound 16 is characterized with an α-d-galactosyl residue directly linked to the triazole ring and a 4′-OH group on the E ring of the podophyllotoxin scaffold. HPLC investigation of representative compound indicates that incorporation of a sugar moiety seems to improve the chemical stability of the podophyllotoxin scaffold.

The bioassay-guided chemical investigation of the stems of Dendrobium fimbriatum Hook led to the isolation of seven first reported bibenzyl dimers with a linkage of a methylene moiety, fimbriadimerbibenzyls A–G (1–7), together with a new dihydrophenanthrene derivative (S)-2,4,5,9-tetrahydroxy-9,10-dihydrophenanthrene (8) and thirteen known compounds (9–21). The structure of the new compound was established by spectroscopic analysis. Biological evaluation of bibenzyl derivatives against five human cell lines indicated that seven of those compounds exhibited broad-spectrum and cytotoxic activities with IC50 values ranging from 2.2 to 21.2 μM. Those rare bibenzyl dimers exhibited cytotoxic activities in vitro and the cytotoxicity decreased as the number of oxygen-containing groups in the structure decreases.

The stems and leaves of Passiflora edulis Sims, are used as a folk medicine for treating both anxiety and nervousness in American countries. Phytochemical investigation of the n-butanol (n-BuOH) fraction of this plant led to the isolation of four new 2,6-dideoxyhexose-C-glycosyl flavones, including luteolin-8-C-β-digitoxopyranosyl-4′-O-β-d-glucopyranoside (1), apigenin-8-C-β-digitoxopyranoside (2), apigenin-8-C-β-boivinopyranoside (3) and luteolin-8-C-β-boivinopyranoside (4), together with five known compounds (5–9). The structures of these compounds were elucidated by extensive spectroscopic methods. All compounds were evaluated for their neurite outgrowth enhancing activities and the results indicated that luteolin (7) enhanced NGF-induced neurite outgrowth in PC12 cells at 50.0 μM.Highlights► We identified uncommon C-deoxyhexosyl derivatives of luteolin and apigenin from Passiflora edulis. ► A 2,6-dideoxy-sugar moiety was present in flavones from Passiflora species. ► P. edulis Sims exhibited neurite outgrowth enhancing activities.

Nardokanshone A (1), a new type of sesquieterpenoid–chalcone hybird, with a 2,3-dihydrofuran ring fusing an aristolane-type sesquiterpenoid and a chalcone, along with its possible bioprecursor, kanshone C (2), together with four known flavones were isolated from Nardostachys chinensis. Their structures were elucidated by spectroscopic methods, and the absolute configuration of 1 was determined by quantum chemical DFT calculations. The possible biosynthetic pathway of 1 was also proposed.

•A neutral heteropolysaccharide was purified from dried stem Dendrobium officinale.•The structure of DOP-1-1 was partially elucidated.•The antioxidant and immune activities of DOP-1-1 was evaluated.•DOP-1-1 exhibited significant immune-modulating effect and the immune mechanism of DOP-1-1 was through upregulating NF-кB and ERK1/2.A neutral heteropolysaccharide (DOP-1-1) consisted by mannose and glucose (5.9:1) with an average molecular weight at about 1.78 × 105 Da was purified from Dendrobium officinale. Based on Fourier transform infrared spectrum (FT-IR) and nuclear magnetic resonance (NMR) spectra, it suggested that partial structure of DOP-1-1 is an O-acetylated glucomannan with β-d configuration in pyranose sugar forms. The immunomodulatory activity of DOP-1-1 was evaluated by secretion level of cytokine (interleukin (IL)-1β and IL-10) and tumor necrosis factor (TNF)-α in vitro. Our results suggested that DOP-1-1 could stimulate cytokine production (TNF-α, IL-1β) in cells. These findings demonstrated that the purified polysaccharide from D. officinale presented significant immune-modulating activities. Furthermore, by Western-blot we can found that the signaling pathways of DOP-1-1 induced immune activities involving ERK1/2 and NF-кB. As to antioxidant activity, DOP-1-1 hadn’t showed remarkable scavenging capacity of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) in contrast with other studies of polysaccharides from D. officinale.