Glucosyloxybenzyl 2-Isobutylmalates from the tubers of Gymnadenia conopsea

An integrated strategy for quality control of Pseudobulbus Cremastrae seu Pleiones based on Q-marker

Pseudobulbus Cremastrae seu Pleiones (PCsP), a traditional Chinese medicine known as ‶Shan-Ci-Gu″, possesses properties for clearing heat, counteracting toxicity, dissipating phlegm, and resolving masses. As a TCM with multiple bases, the dried pseudobulbs of Pleione bulbocodioides (PB), Pleione yunnanensis (PY) and Cremastra appendiculata (CA) are considered to be the official sources of PCsP. Additionally, several unofficial substitutes are also available in the market. To enhance the quality control of PCsP, an integrated strategy based on Q-marker was proposed. Initially, a study of integrating plant metabolomics, target isolation, structure identification, and activity testing afforded five Q-markers, including three new compounds. Furthermore, a quality evaluation method using a single standard to determine multi-components (SSDMC) based on Q-marker was established, which could effectively distinguish PB from CA and the counterfeit herbs. Finally, the transitivity of Q-markers was explored through a representative Chinese compound prescription containing PCsP. The results indicated that the identified Q-markers together with the established analysis methods could be effectively applied for quality control of PCsP and its preparations.

Separation and purification of benzylester glucosides and derivatives from tubers of Gymnadenia conopsea (L.) R. Br. by linear gradient counter-current chromatography combined with elution-extrusion mode

Tubers of Gymnadenia conopsea (L.) R. Br. (Orchidaceae), a traditional medicine and food homologous plant, has a broad application and development prospect in the food and drug industries. Benzylester glucosides, the main effective active components in this plant, are difficult to separate due to their similar structures and high polarity. In this study, linear gradient counter-current chromatography was used to separate benzylester glucosides and derivatives, combined with elution-extrusion mode. The main separation parameters were optimized, including the ratio of mobile phase and sample loading. Finally, seven compounds were successfully separated, including 4-hydroxybenzyl alcohol (1), 4-hydroxybenzaldehyde (2), dactylorhin B (3), loroglossin (4), dactylorhin A (5), 4-(ethoxymethyl) phenol (6), and militarine (7). The structures were analyzed by mass spectrometry and nuclear magnetic resonance spectrometry. According to our findings, the established method was an efficient approach to separate benzylester glucosides and derivatives from tubers of G. conopsea. The established strategy could be applied to purify other similar high-polarity compounds from complex natural products.

New Phenolic Glycosides from Coelogyne fuscescens Lindl. var. brunnea and Their Cytotoxicity against Human Breast Cancer Cells

The phytochemical investigation of the whole plants of Coelogyne fuscescens Lindl. var. brunnea led to the discovery of three new phenolic glycosides, i.e., coelofusides A-C (1-3) and 12 known compounds (4-15). For the first time, we reported the nuclear magnetic resonance (NMR) data of 4-O-(6'-O-glucosyl-4″-hydroxybenzoyl)-4-hydroxybenzyl alcohol (4) in this study. The identification of the structures of newly discovered compounds was done through the analysis of their spectroscopic data [NMR, mass spectrometry, ultraviolet, Fourier transform infrared, optical rotation, and circular dichroism (CD)]. In comparison to anticancer drugs (i.e., etoposide and carboplatin), we evaluated anticancer potential of the isolated compounds on two different breast cancer cell lines, namely, T47D and MDA-MB-231. Human fibroblast HaCaT cells were used as the control cells. After a 48 h incubation, flavidin (8), coelonin (10), 3,4-dihydroxybenzaldehyde (11), and oxoflavidin (12) showed significant cytotoxic effects against breast cancer cells. Among them, oxoflavidin (12) exhibited the most potent cytotoxicity on MDA-MB-231 with an IC50 value of 26.26 ± 4.33 μM. In the nuclear staining assay, oxoflavidin induced apoptosis after 48 h in both T47D and MDA-MB-231 cells in a dose-dependent manner. Furthermore, oxoflavidin upregulated the expression of apoptotic genes, such as p53, Bax, poly(ADP-ribose) polymerase, caspase-3, and caspase-9 genes while significantly decreasing antiapoptotic protein (Bcl-2) expression levels.

Gymnadenia conopsea (L.) R. Br.: Comprehensive review of propagation and breeding, traditional uses, chemical composition, pharmacology, quality control, and processing

ETHNOPHARMACOLOGICAL RELEVANCE

Gymnadenia conopsea, a perennial herbaceous flowering plant that belongs to the family of Orchidaceae, sporadic distributed in the altitudes of 200-4700 m across northern Europe and, temperate and subtropical Asia region. The dried tubers of G. conopsea have been used to treat cough, asthma, and their syndromes, and also as a tonic in China and surrounding countries for a long history. G. conopsea is often processed deeply processed before use to enhance its efficacy. In recent years, because of its remarkable pharmacological activity and health care function, G. conopsea has been used more and more widely. Due to its extensive application and bad growth environment, the wild distribution of G. conopsea is decreasing and it has been listed as an endangered plant.

AIM OF THE REVIEW

This review aims to summarize the propagation and breeding, traditional uses, chemical composition, pharmacology, quality control, and processing of G. conopsea. Moreover, it also provides suggestions for the future high-value utilization of G. conopsea.

MATERIALS AND METHODS

A literature search on Gymnadenia genus and G. conopsea was performed using scientific databases including SciFinder, ACS, Web of Science, Springer, ScienceDirect, PubMed, and CNKI. Information was also collected from classic books of Chinese herbal medicine, official websites, Ph.D. and M.Sc. Dissertations, and so on. Structures of chemical compounds were drawn by ChemDraw software.

RESULTS

As of submission date of this manuscript, total 170 natural compounds have been isolated and characterized from G. conopsea, and all of the compounds were isolated from the tubers. The isolated compounds including benzylester glucosides, dihydrostilbenes, phenanthrenes, phenolic compounds, alkaloids, polysaccharide, lignans, flavones, triterpenoids, steroids, and other compounds. Some of these compounds and active extracts exhibited a wide range of pharmacological activities, in which, the tonifying, anti-fatigue, anti-oxidant, anti-viral, sedative and hypnotic activities are consistent with the traditional uses for the treatment of diseases. In addition, a variety of new pharmacological activities, such as preventing and treating gastric ulcers, immunoregulatory, anti-hyperlipidemia, anti-anaphylaxis, anti-silicosis, anti-cancer and neuroprotective activities have also been reported. However, the bioactive compounds responsible for most of the above pharmacological effects have not been well summarised till now. In this manuscript, analysis, speculation and summary of compounds that responsible for pharmacological effects were conducted.

CONCLUSIONS

The chemical constituents and pharmacological activities studies of G. conopsea extract have been summarised in this context, the isolated compounds responsible for the pharmacological activities were also analyzed and deduced according to the publications, all above led to suggestions for the future high-value utilization of G. conopsea.

Arundinosides I-IX and graminifolosides A-B: 2R-benzylmalate and 2R-isobutylmalates derivatives from Arundina graminifolia (D.Don) Hochr. with antioxidant, cytocompatibility and cytoprotective properties

Phytochemical investigation of the underground parts of Arundina graminifolia D.Don Hochr was conducted leading to the isolation of nine new glucosyloxybenzyl 2R-benzylmalate and two new glucosyloxybenzyl 2R-isobutylmalate derivatives. The compounds were purified using chromatographic techniques and their structures were deduced based on spectroscopic techniques including nuclear magnetic resonance and high-resolution mass spectrometry as well as comparing with previous literature. The antioxidant activities of the isolated compounds were also evaluated. The compounds showed potent antioxidant activities in the ABTS radical scavenging, DPPH radical scavenging and FRAP activities. Furthermore, the isolated compounds were observed to exert minimal cytotoxic effects against RAW 264.7 cell, suggesting biocompatibility as well as cytoprotective effects against hydrogen peroxide induced cell toxicity.

Lung protective effects of dietary malate esters derivatives from Bletilla striata against SiO2 nanoparticles through activation of Nrf2 pathway

Objective

To study the protective activities of the dietary malate esters derivatives of Bletilla striata against SiO₂ nanoparticles-induced A549 cell lines and its mechanism action.

Methods

The components were isolated and elucidated by spectroscopic methods such as 1D NMR and 2D NMR. And MTT assays was used to tested these components on the A549 cell survival rates and ROS or proteins levels were detected by Western blotting.

Results

A new glucosyloxybenzyl 2-isobutylmalate (a malate ester derivative), along with 31 known compounds were isolated and identified from n-BuOH extract of EtOH extract of B. striata. Among them, compounds 3, 4, 11, 12 and 13 possessed noteworthy proliferative effects for damaged cells, with ED₅₀ of 14.0, 13.1, 3.7, 11.6 and 11.5 µmol/L, respectively, compared to positive control resveratrol (ED₅₀, 14.7 µmol/L). Militarine (8) prominently inhibited the intracellular ROS level, and increased the expression of Nrf2 and its downstream genes (HO-1 and γ-GCSc). Furthermore, Nrf2 activation mediates the interventional effects of compound 8 against SiO₂ nanoparticles (nm SiO₂)-induced lung injury. Moreover, treatment with compound 8 significantly reduced lung inflammation and oxidative stress in nm SiO₂-instilled mice. Molecular docking experiment suggested that 8 bound stably to the HO-1 protein by hydrogen bond interactions.

Conclusion

The dietary malate esters derivatives of B. striata could significantly increase the viability of nm SiO₂-induced A549 cells and decrease the finer particles-induced cell damages. Militarine is especially promising compound for chemoprevention of lung cancer induced by nm SiO₂ through activation of Nrf2 pathway.

Glucosyloxybenzyl 2-isobutylmalates and phenolic glycosides from the flowers of Bletilla striata

Four previously undescribed compounds, including three glucosyloxybenzyl 2-isobutylmalates (1-3), one phenolic glycoside (4), along with ten known compounds were isolated from the flowers of Bletilla striata. The structures and absolute configurations of the undescribed compounds were elucidated on the basis of HR-ESIMS, NMR spectroscopy, optical rotation value, and acid hydrolysis experiment. Cytotoxicity of the isolated compounds against A549, HCT-116, and SW1990 cells and protective effects of t-BHP-induced L02 cytotoxic were assayed. The antioxidant activities of the isolated compounds were also evaluated.

Discovery of glucosyloxybenzyl 2-hydroxy-2-isobutylsuccinates with anti-inflammatory activities from Pleione grandiflora

Six new glucosyloxybenzyl 2-hydroxy-2-isobutylsuccinates, pleionesides A-F (1-6), along with two known compounds (7, 8) were obtained from the pseudobulbs of Pleione grandiflora (Rolfe) Rolfe. The structures and absolute configurations of new compounds were established by HRESIMS and NMR data, along with acidic hydrolysis and alkaline hydrolysis experiments. Compounds 1-6 were tested for their anti-inflammatory activities on LPS-induced BV2 microglial cells. Amoung them, 2, 4 and 5 showed moderate activities with IC₅₀ values of 73.4, 32.8 and 57.1 μM, respectively, compared with the positive control quercetin with an IC₅₀ value of 28.3 μM.

Hepatoprotective Glucosyloxybenzyl 2-Hydroxy-2-isobutylsuccinates from Pleione yunnanensis

Nine new glucosyloxybenzyl 2-hydroxy-2-isobutylsuccinates, pleionosides M-U (1-9), and 12 known compounds (10-21) were isolated from the pseudobulbs of Pleione yunnanensis. Their structures and absolute configurations were established through a combination of HRESIMS and NMR data and supported by physical and chemical methods. Compounds 5, 6, 10, and 15 showed significant in vitro hepatoprotective activity against d-galactosamine (d-GalN)-induced toxicity in HL-7702 cells with increasing cell viability by 27%, 22%, 19%, and 31% compared to the model group (cf. bicyclol, 14%) at 10 μM, respectively. Compounds 4, 9, and 11 exhibited moderate hepatoprotective activity against N-acetyl-p-aminophenol (APAP)-induced toxicity in HepG2 cells with increasing cell viability by 9%, 16%, and 12% compared to the model group (cf. bicyclol, 9%) at 10 μM, respectively.

Chemical characterization of a PD-1/PD-L1 inhibitory activity fraction of the ethanol extract from Gymnadenia conopsea

Searching for PD-1/PD-L1 inhibitor from medicinal plants has become a potential method to discover small molecular cancer immunotherapy drugs. Using PD-1/PD-L1 inhibitory activity assay in vitro, a bioactive fraction was obtained from the ethanol extract of Gymnadenia conopsea. A sensitive UPLC-HRMS/MS method was established for the rapid screening and identification of compositions from bioactive fraction. Based on the characteristic fragmentation patterns of standards analysis and extracted ion chromatogram (EIC) method, 46 compounds were rapidly screened and identified (including 35 succinic acid ester glycosides and 11 other compounds), among which 17 compounds were tentatively identified as new compounds.

Rapid Characterizaiton of Chemical Constituents of the Tubers of Gymnadenia conopsea by UPLC-Orbitrap-MS/MS Analysis

Gymnadenia conopsea R. Br. is a traditional Tibetan medicinal plant that grows at altitudes above 3000 m, which is used to treat neurasthenia, asthma, coughs, and chronic hepatitis. However, a comprehensive configuration of the chemical profile of this plant has not been reported because of the complexity of its chemical constituents. In this study, a rapid and precise method based on ultra-high performance liquid chromatography (UPLC) combined with an Orbitrap mass spectrometer (UPLC–Orbitrap–MS/MS) was established in both positive- and negative-ion modes to rapidly identify various chemical components in the tubers of G. conopsea for the first time. Finally, a total of 91 compounds, including 17 succinic acid ester glycosides, 9 stilbenes, 6 phenanthrenes, 19 alkaloids, 11 terpenoids and steroids, 20 phenolic acid derivatives, and 9 others, were identified in the tubers of G. conopsea based on the accurate mass within 3 ppm error. Furthermore, many alkaloids, phenolic acid derivates, and terpenes were reported from G. conopsea for the first time. This rapid method provides an important scientific basis for further study on the cultivation, clinical application, and functional food of G. conopsea.

Chemical constituents of Bletilla striata

A new triphenanthrene compound named 2,2',2'',7,7',7''-hexahydroxy-4,4',4''-trimethoxy-[9,9',9'',10,10',10'']-hexahydro-1,8,1',6''-triphenanthrene (1), together with eleven known compounds (2－12), were isolated from tubers of Bletilla striata. Their structures were determined by analysis of spectroscopic data.

HPLC-ESI-MSn Identification and NMR Characterization of Glucosyloxybenzyl 2R-Benzylmalate Deriva-Tives from Arundina Graminifolia and Their Anti-Liver Fibrotic Effects In Vitro

Four new glucosyloxybenzyl 2R-benzylmalate derivatives, named Arundinoside H (2), I (5), J (6), K (8) as well as four known compounds Arundinoside D (1), G (3), F (4), E (7) were isolated and characterized by a combination of chemical and spectroscopic methods, including HR-ESI-MS, 1D and 2D NMR experiments. Besides, 24 unreported compounds were inferred from ESI-MSⁿ data. The anti-liver fibrotic activities of the isolates were determined as proliferation inhibition of lipopolysaccharide (LPS)-induced activation of rat hepatic stellate cells (HSC-T6). The result suggested Arundinosides D, H, F, I and K showed moderate inhibitory effects in vitro.

Hepatoprotective activity of glucosyloxybenzyl succinate derivatives from the pseudobulbs of Pleione bulbocodioides

Ten previously undescribed glucosyloxybenzyl succinate derivatives, pleionosides A-J, and fifteen known compounds were isolated from the pseudobulbs of Pleione bulbocodioides (Franch.) Rolfe. Their structures were elucidated by a combination of MS and NMR data, physical and chemical methods and a comparison with known compounds. Furthermore, three compounds exhibited potent hepatoprotective activity against N-acetyl-p-aminophenol (APAP)-induced HepG2 cell damage in in vitro assays, with cell survival rates of 31.89%, 31.52% and 31.97% at 10 μM. Four compounds exhibited moderate antioxidant activity with increasing viability at 10 μM of 36.1%, 45.0%, 25.5% and 20.7%.

Arundinosides A-G, new glucosyloxybenzyl 2R-benzylmalate derivatives from the aerial parts of Arundina graminifolia

Seven new glucosyloxybenzyl 2R-benzylmalate derivatives, arundinosides A-G (1-7) were isolated from the aerial parts of the bamboo orchid Arundina graminifolia. This is the first occurrence of this class of compounds in the genus Arundina. Their planar structures and absolute configuration were determined by extensive NMR spectroscopic data as well as chemical conversion. Their neuroprotective properties were also evaluated on their potential ability to reduce the beta amyloid damage on PC12 cell model.

Phenolic compounds from Bletilla striata

Two new malic acid derivatives, namely eucomic acid 1-methyl ester (2) and 6'''-acetylmilitaline (7), together with ten known compounds (1, 3-6, 8-12), were isolated from the dry tubers of Bletilla striata (Thunb.) Reichb. F., a perennial traditional Chinese medicinal herb, which was used for the treatment of pneumonophthisis, pneumonorrhagia, tuberculosis, and hemorrhage of the stomach or lung. Their structures were elucidated by spectroscopic analyses, including 1D-, 2D-NMR, and HR-ESI-MS.

A New Strategy for Deleting Animal drugs from Traditional Chinese Medicines based on Modified Yimusake Formula

Traditional Chinese medicine (TCM), such as Uyghur Medicine (UM) has been used in clinical treatment for many years. TCM is featured as multiple targets and complex mechanisms of action, which is normally a combination of medicinal herbs and sometimes even contains certain rare animal medicinal ingredients. A question arises as to whether these animal materials can be removed replaced from TCM applications due to their valuable rare resources or animal ethics. Here, we select a classical UM Yimusake formula, which contains 3 animal drugs and other 8 herbs, and has got wealthy experience and remarkable achievements in treating erectile dysfunction (ED) in China. The active components, drug targets and therapeutic mechanisms have been comprehensively analyzed by systems-pharmacology methods. Additionally, to validate the inhibitory effects of all candidate compounds on their related targets, in vitro experiments, computational analysis and molecular dynamics simulations were performed. The results show that the modified, original and three animal materials display very similar mechanisms for an effective treatment of ED, indicating that it is quite possible to remove these three animal drugs from the original formula while still keep its efficiency. This work provides a new attempt for deleting animal materials from TCM, which should be important for optimization of traditional medicines.

Gymnadenia conopsea (L.) R. Br.: A Systemic Review of the Ethnobotany, Phytochemistry, and Pharmacology of an Important Asian Folk Medicine

Gymnadenia conopsea (L.) R. Br. (Orchidaceae) is a perennial herbaceous orchid plant that grows widely throughout Europe and in temperate and subtropical zones of Asia. In China, its tuber has been used in traditional Chinese medicines, Tibetan medicines, Mongolian medicines and other ethnic medicines, and taken to treat numerous health conditions. The present paper provides a review of the traditional uses, phytochemistry, biological activities, and toxicology to highlight the future prospects of the plant. More than 120 chemical compounds have been isolated, and the primary components are glucosides, dihydrostilbenes, phenanthrenes, aromatic compounds, and other compounds. G. conopsea and its active constituents possess broad pharmacological properties, such as the tonifying effect, anti-oxidative activity, anti-viral activity, immunoregulatory, antianaphylaxis, antigastric ulcer, sedative, and hypnotic activities, etc. However, overexploitation combined with the habitat destruction has resulted in the rapid decrease of the resources of this plant, and the sustainable use of G. conopsea is necessary to study. Meanwhile, the toxicity of this plant had not been comprehensively studied, and the active constituents and the mechanisms of action of the tuber were still unclear. Further, studies on G. conopsea should lead to the development of scientific quality control and new drugs and therapies for various diseases; thus, its use and development require additional investigation.

Isolation and characterization of two new 2-isobutylmalates from Bletilla striata

The present study isolated 17 compounds from the tubers of Bletilla striata (Orchidaceae), using various chromatographic techniques. Their structures were identified based on their physical-chemical properties and spectroscopic analyses. Among them, two new 2-isobutylmalates, named bletimalates A (1) and B (2), together with other fifteen known compounds (3-17), were isolated and identified. Additionally, compounds 3, 4, and 8 were isolated from this plant for the first time.

Shancigusins E-I, five new glucosides from the tubers of Pleione yunnanensis

Five new glucosides, shancigusins E-I (1-5) were isolated from the tubers of Pleione yunnanensis (Rolfe) together with 18 known compounds. The structures of these compounds were determined by extensive analyses of their spectroscopic data.

Flavonoids from the capitula of Eriocaulon australe

A flavan, eriocaulin A (1), and three flavone acyl glucosides, eriocaulosides A-C (2-4) were isolated from the capitula of Eriocaulon australe R. Br. (Eriocaulaceae), a Chinese medicine and an herb for health care beverages, together with seven known flavones and three isoflavones (5-14). The new flavonoids were elucidated as (2S)-3',4'-methylenedioxy-5-methoxy-7-hydroxyflavan (1), hispidulin 7-O-β-D-(6-O-cinnamoyl)glucopyranoside (2), jaceosidin 7-O-β-D-(6-O-p-coumaroyl)glucopyranoside (3), jaceosidin 7-O-β-D-(6-O-p-hydroxybenzoyl)glucopyranoside (4) based on their spectroscopic data. All the 14 flavonoids were obtained from this species for the first time. The in vitro cytotoxicity of compounds 1-14 against human lung adenocarcinoma A549, human breast adenocarcinoma MCF-7, and human cervical carcinoma HeLa cell lines was evaluated using the MTT colourimetric assay. Compounds 1, 7, and 9 were cytotoxic to A549, compounds 1, 2, 7, 9, 12, and 14 to MCF-7, and compounds 7, 9, and 14 to HeLa cells, with IC50 values ranging from 7.17 to 29.57 μg/ml, while the others were inactive (IC50>50 μg/ml).

Glucosyloxybenzyl eucomate derivatives from Vanda teres stimulate HaCaT cytochrome c oxidase

Eucomic acid [(2R)-2-(p-hydroxybenzyl)malic acid)] (1) and three new glucopyranosyloxybenzyl eucomate derivatives, vandaterosides I (2), II (3), and III (4), were isolated and identified from the stems of Vanda teres. Their cellular antiaging properties were evaluated in a human immortalized keratinocyte cell line (HaCaT) by monitoring their effect on cytochrome c oxidase activity, implicated in mitochondrial respiratory function and cellular energy production. Eucomic acid (1) and vandateroside II (3) increased cytochrome c oxidase activity and/or expression, without enhancing cellular mitochondrial content. These two V. teres biomarkers apparently contributed to stimulate respiratory functions in keratinocytes. Since aging and its pathologies may be ascribed to a decline in mitochondrial functions, these biomarkers have the potential to become new natural ingredients for antiaging preparations to remedy age-related disorders such as skin aging.

Bioactive constituents from Chinese natural medicines. XXXII. aminopeptidase N and aldose reductase inhibitors from Sinocrassula indica: structures of sinocrassosides B(4), B(5), C(1), and D(1)-D(3)

From the methanolic extract of the whole plant of Sinocrassula indica (Crassulaceae), six new flavonol glycosides, sinocrassosides B(4) (1), B(5) (2), C(1) (3), D(1) (4), D(2) (5), and D(3) (6), were isolated together with 30 compounds. The structures of 1-6 were elucidated on the basis of chemical and physicochemical evidence. In addition, several constituents were found to show inhibitory effects on aminopeptidase N and aldose reductase.

Glycosidic constituents of the tubers of Gymnadenia conopsea

Ten minor new glycosidic constituents (1- 10), together with 10 known compounds, have been isolated from a neuroprotective fraction of an ethanolic extract of the tubers of Gymnadenia conopsea. The structures of 1-10 were determined using spectroscopic and chemical methods. The compounds isolated were evaluated for activity in in vitro assays for acetylcholine esterase and monoamine oxidase inhibitory activities.

Bioactive constituents from Chinese natural medicines. XXVI. Chemical structures and hepatoprotective effects of constituents from roots of Rhodiola sachalinensis

The methanolic extract from the roots of Rhodiola sachalinensis was found to show a protective effect on D-galactosamine-induced cytotoxicity in primary cultured mouse hepatocytes. From the methanolic extract, five new glycosides, two monoterpene glycosides, two flavonol bisdesmosides, and a cyanogenic glycoside, were isolated together with 34 known compounds. The structures of new constituents were elucidated on the basis of chemical and physicochemical evidence. In addition, the principal constituents, sachalosides III and IV, rhodiosin, and trans-caffeic acid, displayed hepatoprotective effects.

Bioactive constituents from chinese natural medicines. XXIV. Hypoglycemic effects of Sinocrassula indica in sugar-loaded rats and genetically diabetic KK-A(y) mice and structures of new acylated flavonol glycosides, sinocrassosides A(1), A(2), B(1), and B(2)

The methanolic extract from the whole plant of Sinocrassula indica (Crassulaceae) was found to inhibit the increase in serum glucose levels in oral administration of sucrose and glucose in rats at a dose of 250 mg/kg (p.o.). However, the extract did not inhibit the increase in serum glucose levels after intraperitoneal administration of glucose in these animals but did partly inhibit the gastric emptying. On the other hand, this extract significantly inhibited the increase in serum glucose levels after administration for 2 weeks in KK-A(y) mice, a genetically type II diabetic mice, at a dose of 250 mg/kg/d (p.o.) without significant changes of the weights of body, liver, and visceral fat. From the extract, four new acylated flavonol glycosides, sinocrassosides A(1), A(2), B(1), and B(2), were isolated together with 11 flavonoids and 2 megastigmanes. The absolute stereostructures of the four new compounds were elucidated on the basis of chemical and physicochemical evidence.

Bioactive constituents from Chinese natural medicines. XXIII. Absolute structures of new megastigmane glycosides, sedumosides A(4), A(5), A(6), H, and I, and hepatoprotective megastigmanes from Sedum sarmentosum

The methanol-eluted fraction of the hot water extract from the whole plant of Sedum sarmentosum (Crassulaceae) was found to show hepatoprotective effect on D-galactosamine-induced cytotoxicity in primary cultured mouse hepatocytes. From the active fraction, five new megastigmane glycosides, sedumosides A(4), A(5), A(6), H, and I, were isolated together with 22 megastigmane constituents. Their absolute stereostructures were elucidated on the basis of chemical and physicochemical evidence. Among them, sedumoside F(1) (IC(50)=47 microM), (3S,5R,6S,9R)-megastigmane-3,9-diol (61 microM), and myrsinionosides A (52 microM) and D (62 microM) were found to show the strong hepatoprotective activity.

Bioactive constituents from Chinese natural medicines. XX. Inhibitors of antigen-induced degranulation in RBL-2H3 cells from the seeds of Psoralea corylifolia

The ethyl acetate-soluble fraction of the methanolic extract from the seeds of Psoralea corylifolia was found to inhibit the release of beta-hexosaminidase, as a marker of antigen-IgE-induced degranulation in RBL-2H3 cells. Sixteen constituents were isolated from the ethyl acetate-soluble fraction and several constituents, Delta(1),3-hydroxybakuchiol (IC(50) = 49 microM), Delta(3),2-hydroxybakuchiol (69 microM, bavachin (58 microM), and psoralidin (ca. 100 microM), showed inhibitory activities against the antigen-induced degranulation.

Bioactive Saponins and Glycosides. XXVII. Structures of New Cucurbitane-Type Triterpene Glycosides and Antiallergic Constituents from Citrullus colocynthis

The methanolic extract from the fruit of Citrullus colocynthis showed an inhibitory effect on ear passive cutaneous anaphylaxis reactions as a type I allergic model in mice. From the methanolic extract, two new cucurbitane-type triterpene glycosides, colocynthosides A and B, were isolated together with 17 known constituents. The structures of colocynthosides A and B were elucidated on the basis of chemical and physicochemical evidence. In addition, the principal cucurbitane-type triterpene glycoside, cucurbitacin E 2-O-beta-D-glucopyranoside, and its aglycon, cucurbitacin E, exhibited the antiallergic activity at a dose of 100 and 1.25 mg/kg, p.o., respectively.

Medicinal Flowers. XII.1) New Spirostane-Type Steroid Saponins with Antidiabetogenic Activity from Borassus flabellifer

The methanolic extract from the male flowers of Borassus flabellifer was found to inhibit the increase of serum glucose levels in sucrose-loaded rats at a dose of 250 mg/kg, p.o. From the methanolic extract, six new spirostane-type steroid saponins, borassosides A-F (1-6), were isolated together with 23 known constituents. The structures of borassosides (1-6) were elucidated on the basis of chemical and physicochemical evidences. In addition, the principal steroid saponin, dioscin (13), inhibited the increase of serum glucose levels in sucrose-loaded rats at a dose of 50 mg/kg, p.o.

Bioactive Constituents from Chinese Natural Medicines. XXII. Absolute Structures of New Megastigmane Glycosides, Sedumosides E1, E2, E3, F1, F2, and G, from Sedum sarmentosum (Crassulaceae)

Six new megastigmane glycosides, sedumosides E1, E2, E3, F1, F2, and G, were isolated from the whole plant of Sedum sarmentosum (Crassulaceae). The structures of new constituents including the absolute configuration were elucidated on the basis of chemical and physicochemical evidence.

Phenylethanoid oligoglycosides and acylated oligosugars with vasorelaxant activity from Cistanche tubulosa

The methanolic extract from the dried stems of Cistanche tubulosa (Schrenk) R. Wight was found to show an inhibitory effect on contractions induced by noradrenaline in isolated rat aortic strips. From the extract, new phenylethanoid oligoglycoside constituents, kankanosides F and G, and an acylated oligosugar, kankanose, were isolated together with 14 known compounds. The structures of these new compounds were determined on the basis of their chemical and physicochemical evidence. In addition, principal constituents, kankanoside F, kankanose, echinacoside, acteoside, and cistanoside F, showed vasorelaxant activity, and several structural requirements for the activity were clarified.

Monoterpene constituents from Cistanche tubulosa--chemical structures of kankanosides A-E and kankanol-

Four new iridoid glycosides, kankanosides A (1), B (2), C (3), and D (4), a chlorinated iridoid, kankanol (5), and an acyclic monoterpene glycoside, kankanoside E (6), were isolated from the methanolic extract of dried stems of Cistanche tubulosa (SCHRENK) R. WIGHT (Orobanchaceae) together with 16 known compounds. The structures of these new compounds (1-6) were determined on the basis of the chemical and physicochemical evidence.

Bioactive constituents from Chinese natural medicines. XVII. constituents with radical scavenging effect and new glucosyloxybenzyl 2-isobutylmalates from Gymnadenia conopsea

The methanol-eluted fraction of the methanolic extract from the tubers of Gymnadenia conopsea was found to show radical scavenging activities for DPPH and super oxide anion (.O2-) radicals. Three new glucosyloxybenzyl 2-isobutylmalates, gymnosides VIII, IX, and X, were isolated from this natural medicine together with 58 known constituents. The stereostructures of gymnosides were elucidated on the basis of chemical and physicochemical evidence. In addition, the phenanthrene and dihydrostilbene constituents showed radical scavenging activities and suggested the following structural requirements on radical scavenging activities; a) phenanthrenes: 1) dihydrogenation at the 9,10-positions enhances the activities, 2) the 1 or 3-p-hydroxybenzyl group enhances the activities; b) dihydrostilbenes: 1) methylation of the 3'-position reduces the activities, 2) the 2- and/or 6-p-hydroxybenzyl groups enhance the activities.