iridoids and crocin

Plant secondary product glycosyltransferases belong to family 1 of the glycosyltransferase superfamily and mediate the transfer of a glycosyl residue from activated nucleotide sugars to lipophilic small molecules, thus affecting the solubility, stability and pharmacological activities of the sugar-accepting compounds. The biotechnological application of plant glycosyltransferases in glycoside synthesis has attracted attention because enzymatic glycosylation offers several advantages over chemical methods, including (1) avoiding the use of harsh conditions and toxic catalysts, (2) providing strict control of regio-and stereo-selectivity and (3) high efficiency. This review describes the in vivo and in vitro glycosylation of natural organic compounds using glycosyltransferases, focusing on our investigation of enzymatic synthesis of curcumin glycosides. Our current efforts toward functional characterization of some glycosyltransferases involved in the biosynthesis of iridoids and crocin, as well as in the sugar chain elongation of quercetin glucosides, are described. Finally, I describe the relationship of the structure of sugar chains and the intestinal absorption which was investigated using chemoenzymatically synthesized quercetin glycosides.

Topics: Animals; Biological Products; Carbohydrates; Carotenoids; Curcumin; Glucosyltransferases; Glycosides; Glycosylation; Intestinal Absorption; Iridoids; Molecular Conformation; Plants; Quercetin; Rats; Solubility

Gardenia jasminoides Ellis is a perennial evergreen shrub of G. jasminoides of Rubiaceae. Geniposide and Crocin are important components in the fruit of G. jasminoides. In addition to being used as medicinal materials, they are also widely used in food, medicine, cosmetics, and other fields. They have high medicinal value, economic value, and ornamental value. However, at present, the utilization rate of G. jasminoides resources is low, mainly focused on germplasm cultivation, primary processing, and clinical pharmacology, and there are few studies on the quality of Gardenia fruit.. Based on transcriptome sequencing and metabolic group analysis, the morphological and structural changes of Gardenia fruit with young fruit, middle fruit, and ripe fruit were analyzed, and the formation mechanism and content changes of Geniposide and Crocin in Gardenia fruit were studied. The content of Geniposide decreased with the development of fruit, so did the expression of the main structural gene GES, G10H, and IS in its synthesis pathway, while the content of Crocin increased with the development of fruit, and the expression of the main structural gene CCD, ALDH, and UGT in its synthesis pathway also increased. The relationship between the morphological structure of G. jasminoides and the accumulation of Geniposide and Crocin was summarized.. This study not only provides a theoretical basis for the mining and utilization of Geniposide and Crocin, but also provides a theoretical basis for genetic background for the identification and cloning of bioactive substances in gardenia fruit in future. At the same time, it provides support for increasing the dual-use value of G. jasminoides and breeding excellent germplasm resources.

Topics: Fruit; Gardenia; Iridoids; Metabolome; Plant Breeding; Transcriptome

Crocins are valuable bioactive components of gardenia fruit, and their biosynthesis and accumulation have attracted widespread interest. Studies have investigated the biosynthesis and accumulation of crocin based on Illumina sequencing, but there is a lack of reports based on full-length transcriptome sequencing. Utilising SMRT sequencing and high-performance liquid chromatography (HPLC), we explored crocin biosynthesis and accumulation in the fruit of

Topics: Carotenoids; Chromatography, High Pressure Liquid; Fruit; Gardenia; High-Throughput Nucleotide Sequencing; Iridoids

Gardenia jasminoides Ellis (G. jasminoides) fruits are used as a resource for obtaining natural colorants and in traditional Chinese herbal medicine. However, G. jasminoides presents a relatively long flowering period and different ripening periods, so there are significant differences in the accumulation of metabolites in fruits of different colors. In addition, the complete metabolic pathways of iridoidsand crocins, which are used as medicinal composition of G. jasminoides, are poorly understood at present. In this research, we comprehensively compared the transcriptome and metabolites profiles of the developmental stages and locations of iridoid and crocin biosynthesis. A large number of differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) were detected in four groups of samples, and clear variation in the pattern of metabolite abundance and gene expression were observed among different fruit colors and parts. Geniposide and gardenoside mainly accumulated in the sarcocarp of green fruit (GFS) and the sarcocarp of red fruit (FS), respectively. Crocin mainly accumulated in the peel and sarcocarp of red fruits. In the iridoid pathway, we hypothesized that there was a transport mechanism from the sarcocarp to the peel of G. jasminoides because of the inconsistent expression of G8O, 10-HGO and IS associated with differences in fruit ripening. UGTs play an important role in the biosynthesis of the active components of G. jasminoides. Combined transcriptome and metabonomics analysis showed a negative correlation between the biosynthesis of geniposide and crocin. The redirection of the metabolic flux and the regulation of key enzymes may be the main reasons for the changes in the biosynthesis of iridoid and crocin in G. jasminoides fruit. Our study expended valuable information for functional genomic library and provided new insights for metabolic engineering of secondary metabolite in G. Jasminoides.

Topics: Carotenoids; Fruit; Gardenia; Iridoids; Metabolome; Transcriptome

Discovering novel compounds with higher activities is a key aim of natural products research. Gardenia jasminoides Ellis is a herb with anti-inflammatory properties. Iridoid glycosides (mainly geniposide) and crocetin derivatives (crocins) are the two major active constituents in this herb and are considered its active ingredients. However, which components are responsible for the anti-inflammatory properties of gardenia have remained to be investigated.. Here, we prepared total iridoid glycocides (TIG) and total crocins (TC) from G. jasminoides Ellis, determined their main chemical constituents, and performed animal studies to evaluate their anti-adjuvant arthritis activities, thus, proposing a reasonable mechenism to explain the anti-inflammatory activities of the active components in this herbal remedy.. TIG and TC were prepared by using HPD-100 macroporous resin, and characterized by UHPLC-DAD-MS and UV-Vis spectrophotometer. Then, freund's complete adjuvant-injected rats underwent drug treatments with TIG (160 mg/kg) and TC (160 mg/kg) for 14 days, and their ankle diameters were measured. Moreover, X-ray radiographs of the adjuvant injected hind paws were evaluated. Finally, histopathological examinations of the ankle joints, spleens and thymus were carried out to evaluate inflammatory reactions, and immunohistochemical measurements were conducted to evaluate TNF-α and TGF-β1 expression in the ankle joint of the rats.. The chemical composition determination of the current study showed that TIG was mainly composed of geniposide and TC was a fraction predominantly with crocin-1, crocin-2 and crocin-3. Calculation of results showed that TIG and TC contained 58.2% total iridoid glycosides and 54.7% total crocins, respectively. Our study suggested TIG and TC treatments markedly decreased paw swelling and ankle diameters of AA rats (both p < 0.05). The radiological analysis showed that administration of TIG and TC ameliorated bone destruction, and reduced the radiological bone destruction scores (TIG p < 0.05, TC p>0.05). Moreover, data from histological assessment demonstrated considerable mitigation of inflammation in the joints (both p < 0.01), spleen and thymus of AA rats treated with TIG and TC. TNF-α and TGF-β1 protein expression according to immunohistochemistry staining also supported the anti-arthritis activities of TIG and TC (TNF-α: TIG p < 0.01 and TC p < 0.05, TGF-β1: TIG p < 0.01 and TC p>0.05).. In the current study, fractionation of gardenia prior to further in vivo investigation has for the first time provided reasonable explanation for the anti-inflammatory activity of this herbal remedy. Our study showed that both TIG and TC from gardenia have anti-inflammatory properties. Overall, these experimental findings suggest that gardenia could be regarded as a potential therapeutic target for arthritis. However, as geniposide has a higher content than crocins in this herbal drug, TIG (mainly geniposide) seems to be primarily responsible for the anti-inflammatory properties of gardenia. Taken together, this maiden attempt demonstrated that TIG (mainly geniposide) is more important in evaluating the anti-inflammatory activity of G. jasminoides Ellis.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arthritis, Experimental; Carotenoids; Chromatography, High Pressure Liquid; Drug Evaluation, Preclinical; Freund's Adjuvant; Gardenia; Iridoid Glycosides; Iridoids; Male; Rats, Sprague-Dawley; Transforming Growth Factor beta1; Tumor Necrosis Factor-alpha; Vitamin A

Crocin (CRO), chlorogenic acid (CGA), geniposide (GEN), and quercetin (QUE) are all natural compounds with anti-obesity properties, in particular, hypolipidemic effects, which have been widely used for the treatment of obesity-related metabolic diseases. However, it is not yet known whether these compounds interact synergistically. Here, we investigated the effects and molecular mechanisms of CRO, CGA, GEN, QUE, and a combination of all four compounds (CCGQ), on lipid accumulation in human hepatoma (HepG2 cells).. The optimal concentration of CRO, CGA, GEN, QUE to stimulate HepG2 cells proliferation was determined using MTT assay. HepG2 cells were pretreated with 10 μmol/L simvastatin, 1 μmol/L CRO, 30 μmol/L CGA, 10 μmol/L GEN, 10 μmol/L QUE, and CCGQ (a combination of 1 μmol/L CRO, 30 μmol/L CGA, 10 μmol/L GEN, and 10 μmol/L QUE) for 24 or 48 h. Oil red O staining and extracellular TC and TG levels were detected. The RT-PCR was used to observe on cholesterol metabolism-related gene expression. Immunocytochemistry and western-blot assayed the 3-hydroxy-3-methylglutaryl-coenzyme (HMGCR) protein expression in HepG2 cells.. Compared to those of control, we demonstrated that treating HepG2 cells for 48 h with CCGQ resulted in a strong synergistic effect, causing a marked decrease in lipid deposition in comparison to individual treatments, in both triglyceride and total cholesterol (CRO, 5.74- and 1.49-folds; CGA, 3.38- and 1.12-folds; GEN, 4.04- and 1.44-folds; QUE, 3.36- and 1.24-folds; simvastatin, 5.49- and 1.83-folds; and CCGQ, 7.75- and 2.20-folds), and Oil red O staining assays. In addition, CCGQ treatment increased ATP-binding cassette transporter (ABCA1), cholesterol 7α-hydroxylase (CYP7A1), and AMP-activated protein kinase 2α (AMPKα2) mRNA expression, while decreasing sterol regulatory element binding protein 2 (SREBP2), and liver X receptor alpha (LXRα) mRNA expression. Notably, CCGQ was more effective in decreasing HMGCR expression than the individual treatments.. The CCGQ combination has potential, both as a complementary therapy for hyperlipemia, and in preventing further obesity-related complications.

Topics: Carotenoids; Chlorogenic Acid; Cholesterol; Drug Synergism; Hep G2 Cells; Humans; Iridoids; Lipid Metabolism; Phytochemicals; Quercetin

Hollow fiber cell fishing (HFCF) based on human hepatoma cell HepG-2 or human renal tubular cell ACHN coupled with high performance liquid chromatography/ultraviolet detection (HPLC/UV) was developed and used for simultaneous study of the major antitumor active components in a formula of Yinchenhao decoction (YCHD) in vitro and in vivo, and in its constituent herbs, namely, Artemisia capillaris Thunb, Gardenia jasminoides Ellis, Radix et Rhizoma Rhei in vitro. Before application, chlorogenic acid, geniposide, p-hydroxyacetophenone, crocin and rhein were chosen as model compounds, the various validations, e.g., cell growth and cell viability on the fiber inner wall, binding between fiber active center and component, repeatability of retention time or relative peak area of the active components were investigated. We screened and identified the major antitumor active components of YCHD, verified their synergetic or antagonistic effect, correlated the major active components between in vitro and in vivo and determined major effective components. Our study will serve as a valuable reference in probing the antitumor material basis of YCHD and its three constituent herbs, as well as in identifying novel clinical aspects of traditional Chinese medicines. The results showed that HCFC-HPLC is a simple, rapid, and reliable method that simultaneously researches the interaction between multiple targets and multiple components of herbal medicine.

Topics: Acetophenones; Animals; Anthraquinones; Antineoplastic Agents; Carotenoids; Cell Culture Techniques; Cell Proliferation; Cell Survival; Chlorogenic Acid; Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Hep G2 Cells; Humans; Iridoids; Male; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Sensitivity and Specificity; Tissue Distribution

A novel, rapid and simple analytical method was developed for the quantitative determination of crocin, crocetin and geniposide in soft drink, pastry and instant noodles. The solid samples were relatively homogenized into powders and fragments. The gardenia yellow colorants were successively extracted with methanol using ultrasound-assisted extraction. The analytes were quantitatively measured in the extracts by liquid chromatography coupled with electrospray ionization tandem mass spectrometry. High correlation coefficients (r(2)>0.995) of crocin, crocetin and geniposide were obtained within their linear ranges respectively (50-1000ng/mL, 50-1000ng/mL, 15-240ng/mL) by external standard method. The limits of detection (LODs) were 0.02μg/g for crocin, 0.01μg/g for crocetin and 0.002μg/g for geniposide. And the limits of quantitation (LOQs) were in the ranges of 0.05-0.45μg/g for crocin, and in the ranges of 0.042-0.32μg/g for crocetin, and in the ranges of 0.02-0.15μg/g for geniposide in soft drink, pastry and instant noodles samples. The average recoveries of crocin, crocetin and geniposide ranged from 81.3% to 117.6% in soft drink, pastry and instant noodles. The intra- and inter-day precisions were respectively in the range of 1.3-4.8% and 1.7-11.8% in soft drink, pastry and instant noodle. The developed methods were successfully validated and applied to the soft drink, pastry, and instant noodles collected from the located market in Beijing from China. Crocin, crocetin and geniposide were detected in the collected samples. The average concentrations ranged from 0.84 to 4.20mg/g for crocin, and from 0.62 to 3.11mg/g for crocetin, and from 0.18 to 0.79mg/g for gardenia in various food samples. The method can provide evidences for government to determine gardenia yellow pigments and geniposide in food.

Topics: Beijing; Carbonated Beverages; Carotenoids; Chromatography, High Pressure Liquid; Coloring Agents; Food Analysis; Gardenia; Iridoids; Plant Extracts; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Vitamin A

In this paper, an analysis strategy integrating macroporous resin (AB-8) column chromatography and high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) combined with ion mobility spectrometry (IMS) was proposed and applied for identification and structural characterization of compounds from the fruits of Gardenia jasminoides. The extracts of G. jasminoides were separated by AB-8 resin column chromatography combined with reversed phase liquid chromatography (C18 column) and detected by electrospray ionization tandem mass spectrometry. Additionally, ion mobility spectrometry (IMS) was employed as a supplementary separation technique to discover previously undetected isomers from the fruits of G. jasminoides. A total of 71 compounds, including iridoids, flavonoids, triterpenes, monoterpenoids, carotenoids and phenolic acids were identified by the characteristic high resolution mass spectrometry and the ESI-MS/MS fragmentations. In conclusion, the IMS-MS technique achieved the separation of isomers in crocin-3 and crocin-4 according to their acquired mobility drift times differing from classical analysis by mass spectrometry. The proposed strategy can be used as a highly sensitive and efficient procedure for identification and separation isomeric components in extracts of herbal medicines.

Topics: Carotenoids; Chromatography; Chromatography, High Pressure Liquid; Chromatography, Reverse-Phase; Flavonoids; Fruit; Gardenia; Hydroxybenzoates; Ion Exchange Resins; Iridoids; Plant Extracts; Plants, Medicinal; Spectrometry, Mass, Electrospray Ionization; Spectrum Analysis; Tandem Mass Spectrometry; Terpenes

To establish a method of quantitative analysis of multi-components, by single marker(QAMS)for simultaneously determining six ingredients in Gardenia jasminoides fruits.. A multi-wavelength segmentation detection method was used. A methodological mode was found to analysis six ingredients in Gardenia jasminoides fruits by quantitative analysis of QAMS. Taken geniposide as reference to create RCF with gardenia acid, chlorogenic acid, crocin I, crocin II and crocin III.. The good reproducibility and acceptable durability of method was validated between two HPLC systems and three columns. 20 batches of Gardenia jaminoides fruits was analysis, and the results showed good linear correlation compared to external standard method (r > 0. 999).. QAMS can be used as quality evaluation method of multi-component Gardenia jaminoides fruits.

Topics: Carotenoids; Chlorogenic Acid; Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Fruit; Gardenia; Iridoids; Phytochemicals; Reproducibility of Results

Gardenia fruits contain valuable natural food colorants including crocins (gardenia yellow) and geniposide. In this study, a process for the enrichment of crocins and geniposide simultaneously from gardenia fruits was developed using macroporous resin and RP chromatography. The performance of eight different types of macroporous resins was evaluated. Static absorption/desorption experiments revealed that LX60 possessed optimal separating capacity. Further dynamic absorption/desorption experiments on LX60 columns were conducted to obtain the optimal parameters. After one run treatment with LX60, the content of crocin-1 in gardenia yellow reached 29.6%, while geniposide in another fraction reached 83.4%. An extract of crocins was obtained from gardenia yellow in a second-stage separation using RP medium-pressure LC, with its color value to be 756 and the content of crocin-1 reaching 60.8%. The separation process was highly efficient, low cost, and compact, which may be informative for purifications of other natural products from complex plant extracts.

Topics: Carotenoids; Chromatography, High Pressure Liquid; Chromatography, Reverse-Phase; Fruit; Gardenia; Iridoids; Plant Extracts; Porosity; Resins, Synthetic

In present study, the performance and separation characteristics of nine macroporous resins for the enrichment and purification of gardenia yellow from Gardenia jasminoides var. radicans Makino have been evaluated. The adsorption and desorption properties of crude gardenia yellow solution on macroporous resins including HPD722, HPD100, HPD100A, HPD400, HPD400A, D101, AB-8, XAD-16, and NKA-9 have been compared. Then, HPD722 was chosen to purify gardenia yellow because of its strong adsorption and desorption abilities as well as high selectivity. Column packed with HPD722 resin was used to perform dynamic adsorption and desorption tests to optimize the separation process of gardenia yellow. The optimal conditions were as follows: The crude gardenia yellow solution with concentration of 15 mg/mL was loaded in column packed with HPD722 resin at the flow rate of 1.0 mL/min, and the adsorbate-laden column was washed with 800 mL water, 600 mL 15% ethanol water solution respectively at the speed of 2.5 mL/min, then desorbed with 200 mL 80% ethanol water solution at the speed of 3.5 mL/min. The colority of the product obtained were up to 300. The method developed in this study provides a new approach for scale-up separation and purification of gardenia yellow from G. jasminoides var. radicans Makino.

Topics: Adsorption; Carotenoids; Chromatography, Affinity; Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Ethanol; Gardenia; Iridoids; Laboratory Chemicals; Plant Extracts; Spectrophotometry, Ultraviolet; Water

Optimized-SopungSunkiwon (OSS) is a multi-herbal formula that contains six medicinal herbs from SopungSunkiwon, a traditional medicine used for neurodegenerative disorders. In this study, we investigated the anti-amnesic effects of OSS in a dementia model. Acetylcholinesterase (AChE) inhibition assay was performed to investigate the cholinergic antagonistic effect of OSS. In addition, a step-through passive-avoidance test was performed with scopolamine-induced memory impairment in mice, and immunohistochemistry was analyzed to investigate synaptic formation with synaptic proteins. OSS inhibited AChE activity, resulting in significant improvement of memory functions. In the passive-avoidance test, the latency time of OSS-treated mice was significantly longer than that of either the control or scopolamine-treated group. In the immunohistochemical analysis, synaptic proteins such as synaptophysin and PSD-95 were significantly increased in OSS-treated mice. These results demonstrate that OSS may affect impairment and enhancement of memory and increase synaptophysin and PSD-95 facilitating acetylcholine release and synaptic growth.

Topics: Acetylcholinesterase; Animals; Anthraquinones; Avoidance Learning; Brain; Carotenoids; Chromatography, High Pressure Liquid; Immunohistochemistry; Iridoids; Male; Maze Learning; Medicine, Korean Traditional; Memory; Memory Disorders; Mice; Mice, Inbred ICR; Neuroprotective Agents; Phytotherapy; Plant Extracts; Plants, Medicinal; Senna Extract; Sennosides

To develop a HPLC- ELSD method for determination the contents of geniposide, crocin and crocetin in different processing products of Fructus Gardeniae.. The separation was performed in the HyperClone ODS C18 column (250 mm x 4. 6 mm, 5 microm) with linear gradient elution using methanol-water and 0.05% phosphoric acid in water, the flowing rate was 0.8 mL/min, the column temperature was 30 degrees C, and the ELSD parameter was as follow: 70 degrees C as atomization temperature and 2.0 L/min as the gas flowing rate.. The contents of geniposide and crocin in raw, yellowish, carbocoal and scorched Fructus Gardeniae decreased with the deepening of processing degree. However, the content of crocetin in carbocoal and scorched Fructus Gardeniae increased comparing with the raw one.. This is a simple and credible quality control method, and can be used for the quality control and comprehensive evaluation for different processed products of Fructus Gardeniae.

Topics: Carotenoids; Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Fruit; Gardenia; Iridoids; Quality Control; Reproducibility of Results; Technology, Pharmaceutical; Vitamin A

The major components of gardenia fruits are geniposide and water soluble pigment crocins. In this study, we investigate crocins and geniposide profiles of gardenia fruits from different cultivars and at the various stages of maturation. DPPH scavenging activity of gardenia fruits from different cultivars and at the various stages of fruit maturation was also assayed. Quantitative determination of crocins in the gardenia at the various stages of maturation revealed a significant increase when ripening. However, geniposide content was negatively correlated with ripening stages. A significant difference was observed when comparing crocin content of different gardenia from various cultivars and geniposide content also showed marked variety. Current study indicated no relationship between crocin and geniposide content in gardenia fruits at the various stages of maturation and DPPH radical scavenging activity. Data showed that, although crocins feature markedly less DPPH scavenging activity than gardenia ethanol extract, total crocin content of gardenias collected in various cultivars correlate, to a certain degree, with radical scavenging effects of the Chinese traditional medicine (r=0.75).

Topics: Antioxidants; Biphenyl Compounds; Carotenoids; Free Radical Scavengers; Fruit; Gardenia; Genotype; Iridoids; Molecular Structure; Picrates; Plant Extracts

To estimate the uncertainty for quantitative analysis results of geniposide, chloregenic acid and crocinl I in Gardenia jasminoides Ellis.. HPLC method was employed to determine the amounts of geniposide, choloregenic acid and crocinl I in Gardenia jasminoides Ellis. Analyzing the uncertainty sources arising from the procedure of analysis, the standard uncertainty and combined uncertainty and expanded uncertainty were calculated according to the data of HPLC.. This method met the requirements of modern pharmaceutical analysis, and the expand uncertainties for the HPLC method of the three components are 0.1024, 0.2254, 0.1264, respectively.. Applying measurement uncertainty to the evaluation of quantitative analysis results of active components in Gardenia jasminoides Ellis. is an improvement to the actual error evaluation system.

Topics: Algorithms; Carotenoids; Chlorogenic Acid; Chromatography, High Pressure Liquid; Fruit; Gardenia; Iridoids; Models, Statistical; Plants, Medicinal; Pyrans; Quality Control; Uncertainty

To determine 3 kinds of biologically active components (9 compounds) in Gardenia, namely geniposidic acid, gentiobioside, gardenoside, genipin geniposide, chlorogenic acid, crocin 1, crocin 2, crocin 3 and crocetin simultaneously and quantitatively.. An HPLC method detected by 3 different UV-vis waves--240 nm for geniposidic acid, geniposide, gardenoside, genipin gentiobioside, 330 nm for chlorogenic acid, 440 nm for crocin 1, crocin 2, crocin 3 and crocetin respectively, has been developed: Phenomenex Luna C18 column(250 mm x 4.6 mm ID, 5 microns) with linear gradient elution using methanol-acetotrile (9:1) and 0.3% aqueous formic acid.. This method successfully determined 9 compounds in Gardenia (from 5 different areas) simultaneously and quantitatively.. This is a more reasonable and credible quality control method for the Chinese traditional medicine.

Topics: Carotenoids; Chlorogenic Acid; Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Fruit; Gardenia; Glucosides; Iridoid Glucosides; Iridoids; Plants, Medicinal; Quality Control

Topics: Carotenoids; Glucosides; Glycosides; Iridoids; Plants, Medicinal; Pyrans