Bletilla striata polysaccharide alleviates chronic obstructive pulmonary disease via modulating gut microbiota and NR1H4 expression in mice.

Bletilla striata polysaccharide (BSP) is the main component of Bletilla striata and has been revealed to enhance immune responses. Chronic obstructive pulmonary disease (COPD) results from the chronic inhalation of toxic particles and gases, which initiates innate and adaptive immune responses in the lungs. This study aimed to evaluate whether the effects of BSP on COPD were related to the abundance of gut microbiota and explored the underlying mechanism. COPD mice were induced with cigarette smoke and human bronchial epithelial cells (HBEC) were subjected to cigarette smoke extract (CSE) for in vitro studies. BSP alleviated the inflammatory response and the inflammatory cell infiltration in lung tissues and promoted the recovery of respiratory function in COPD mice. BSP mitigated CSE-induced HBEC injury by repressing inflammation and oxidative stress. 16s rRNA sequencing revealed that BSP increased the abundance of Bacteroides intestinalis. Bacteroides intestinalis colonization enhanced the therapeutic effect of BSP in COPD mice by upregulating NR1H4 and its encoded protein FXR. Reduction of NR1H4 impaired the therapeutic impact of BSP and Bacteroides intestinalis in COPD. These data demonstrate that BSP inhibits COPD by upregulating NR1H4 through Bacteroides intestinalis, which underpins the application of BSP as a therapeutic agent for COPD.

Bletilla striata Polysaccharide-Containing Carboxymethyl Cellulose Bilayer Structure Membrane for Prevention of Postoperative Adhesion and Achilles Tendon Repair.

Postoperative tissue adhesion and poor tendon healing are major clinical problems associated with tendon surgery. To avoid postoperative adhesion and promote tendon healing, we developed and synthesized a membrane to wrap the surgical site after tendon suturing. The bilayer-structured porous membrane comprised an outer layer [1,4-butanediol diglycidyl ether cross-linked with carboxymethyl cellulose (CX)] and an inner layer [1,4-butanediol diglycidyl ether cross-linked with Bletilla striata polysaccharides and carboxymethyl cellulose (CXB)]. The morphology, chemical functional groups, and membrane structure were determined. In vitro experiments revealed that the CX/CXB membrane demonstrated good biosafety and biodegradability, promoted tenocyte proliferation and migration, and exhibited low cell attachment and anti-inflammatory effects. Furthermore, in in vivo animal study, the CX/CXB membrane effectively reduced postoperative tendon-peripheral tissue adhesion and improved tendon repair, downregulating inflammatory cytokines in the tendon tissue at the surgical site, which ultimately increased tendon strength by 54% after 4 weeks.

Evolution of Acquired Perfumes and Endogenous Lipid Secretions in Orchid Bees.

Male orchid bees are unique in the animal kingdom for making perfumes that function as sex pheromone. Males collect volatile chemicals from the environment in the neotropical forests, including floral and non-floral sources, creating complex but species-specific blends. Male orchid bees exhibit several adaptations to facilitate perfume collection and storage. When collecting volatile compounds, males apply lipid substances that they secrete from cephalic labial glands onto the fragrant substrate. These lipids help dissolve and retain the volatiles, similar to the process of 'enfleurage' in the traditional perfume industry. We investigated how the chemical composition of acquired perfume and labial gland secretions varied across the phylogeny of orchid bees, including 65 species in five genera from Central and South America. Perfumes showed rapid evolution as revealed by low overall phylogenetic signal, in agreement with the idea that perfume compounds diverge rapidly and substantially among closely related species due to their role in species recognition. A possible exception were perfumes in the genus Eulaema, clustering closely in chemospace, partly mediated by high proportions of carvone and trans-carvone oxide. Labial gland secretions, in contrast, showed a strong phylogenetic signal at the genus level, with secretions of Eufriesea and Exaerete dominated by fatty acids and Eulaema dominated by saturated acetates of chain lengths 12 to 16 C-atoms. Secretions of the majority of Euglossa were heavily dominated by one unsaturated long chain diacetate, (9Z)-Eicosen-1,20-diyldiacetate. However, we also identified few highly divergent species of Euglossa in four subclades (11 species) that appear to have secondarily replaced the diacetate with other compounds. In comparison with environment-derived perfumes, the evolution of labial gland secretion is much slower, likely constrained by the underlying biochemical pathways, but perhaps influenced by perfume-solvent chemical interactions.

Axially chiral dihydrophenanthrene dimers from Pholidota yunnanensis with anti-neuroinflammatory activities.

Axially chiral compounds are well known in medicinal chemistry of natural products, but their absolute configurations and bioactivities are rarely reported and studied. In this study, eleven undescribed axially chiral dihydrophenanthrene dimers, as well as twenty-five known dihydrophenanthrenes, were isolated from the entire plant of Pholidota yunnanensis. Their structures were elucidated by comprehensive spectroscopic analysis. A method for determining the absolute configurations of enantiomers was developed based on the rotational barriers and calculated ECD spectra. Additionally, the activities of all isolated compounds were assessed in LPS-induced BV-2 microglial cells. Most dihydrophenanthrenes exhibited significant NO inhibitory activities, and compound 7 showed the most potent inhibitory effect with an IC50 value of 1.5 µM, compared to the positive control minocycline. The immunofluorescence and western blot results revealed that compound 7 suppressed the expression of Iba-1, iNOS and COX-2 in LPS-stimulated BV-2 microglial cells.

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.

Distribution, Chemical Constituents and Biological Properties of Genus Malaxis.

The genus Malaxis (family Orchidaceae), comprises nearly 183 species available across the globe. The plants of this genus have long been employed in traditional medical practices because of their numerous biological properties, like the treatment of infertility, hemostasis, burning sensation, bleeding diathesis, fever, diarrhea, dysentery, febrifuge, tuberculosis, etc. Various reports highlight their phytochemical composition and biological activities. However, there is a lack of systematic review on the distribution, phytochemistry, and biological properties of this genus. Hence, this study aims to conduct a thorough and critical review of Malaxis species, covering data published from 1965 to 2022 with nearly 90 articles. Also, it examines different bioactive compounds, their chemistry, and pharmacotherapeutics as well as their traditional uses. A total of 189 unique compounds, including the oil constituents were recorded from Malaxis species. The highest active ingredients were obtained from Malaxis acuminata (103) followed by Malaxis muscifera (49) and Malaxis rheedei (33). In conclusion, this review offers an overview of the current state of knowledge on Malaxis species and highlights prospects for future research projects on them. Additionally, it recommends the promotion of domestication studies for rare medicinal orchids like Malaxis and the prompt implementation of conservation measures.

Phytochemical Research and Anti-Inflammatory Activities of the Ethanol Extract from Anoectochilus Roxburghii (Wall.) Lindl.

Anoectochilus roxburghii is a well-known and valuable traditional Chinese herb due to various medicinal and functional benefits. In-depth investigation is necessary to discover active ingredients and expand its application. In this study, four new compounds (1-4) along with ten known compounds (5-14) were isolated from the ethanol extract of A.roxburghii. Their structures were elucidated by spectroscopic data interpretation. The isolates were screened for their inhibitory activities on the production of NO in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Among them, compounds 5, 6, 9, 10, 12, 13 and 14 exhibited significant anti-inflammatory activity through inhibiting the release of NO.

Dihydrophenanthro[b]furan derivatives from the tubers of Bletilla striata.

Two pairs of new dihydrophenanthro[b]furan enantiomers blephebibnols G-H (1-2), one new dihydrophenanthro[b]furan derivative blephebibnol I (3), along with four known analogues (4-7), were isolated from the tubers of Bletilla striata. Their structures including the absolute configurations were determined by the combination of spectroscopic data analysis, ECD and NMR calculations. Compounds 1a, 1b, and 2b showed inhibition of NO production in LPS-stimulated BV-2 cells, with IC50 values ranging from 4.11 to 14.65 µM. Further mechanistic study revealed that 1a suppressed the phosphorylation of p65 subunit to regulate the NF-κB signaling pathway. In addition, some compounds displayed selective cytotoxic activities against HCT-116, HepG2, A549, or HGC27 cancer cell lines with IC50 values ranging from 0.1 to 8.23 µM.

Preparation, Characterization, and Wound Healing Promotion of Hydrogels Containing Glucosyloxybenzyl 2-Isobutylmalates Extract from Bletilla striata (Thunb.) Reichb.f.

Plant-derived medicinal materials have significant potential and promising applications in wound healing and skin regeneration. This study aims to develop a plant-based extract hydrogel from Bletilla striata (Thunb.Reichb.f.), specifically a glucosyloxybenzyl 2-isobutylmalates extract (B), and characterize its potential effects on wound healing. We synthesized the hydrogel using carbomer (C), glycerol (G), and triethanolamine (T) as the matrix, incorporating B into the hydrogel base, and evaluated its physical and chemical properties. In vitro tests assessed the biocompatibility of the glucosyloxybenzyl 2-isobutylmalates-carbomer-glycerol-triethanolamine (B-CGT) hydrogel and its effects on cell proliferation, migration, and adhesion. Animal model experiments evaluated its potential to promote wound healing. The results showed that the prepared B-CGT hydrogel possessed a good three-dimensional network structure and stability, demonstrating significant free radical scavenging capacity in antioxidant tests. In cell experiments, the B-CGT hydrogel exhibited no potential cytotoxicity and showed good hemocompatibility and promotion of cell proliferation. Animal experiments indicated that wounds treated with the B-CGT hydrogel healed significantly faster, with improved formation of new epithelial tissue and collagen. This study suggests that the developed B-CGT hydrogel is a promising candidate for wound dressings, with excellent physicochemical properties and controlled drug release capabilities, effectively promoting the wound healing process.

Optimization of an Ultrasound-Assisted Extraction Technique and the Effectiveness of the Sunscreen Components Isolated from Bletilla striata.

Bletilla striata is the dried tuber of B. striata (Thund.) Reichb.f., which has antibacterial, anti-inflammatory, anti-tumor, antioxidant and wound healing effects. Traditionally, it has been used for hemostasis therapy, as well as to treat sores, swelling and chapped skin. In this study, we used the ultraviolet (UV) absorbance rate of B. striata extracts as the index, and the extraction was varied with respect to the solid-liquid ratio, ethanol concentration, ultrasonic time and temperature in order to optimize the extraction process for its sunscreen components. The main compounds in the sunscreen ingredients of Baiji (B. striata) were analyzed using ultra-high-performance liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry. The sunscreen properties were subsequently evaluated in vitro using the 3M tape method. The results show that the optimal extraction conditions for the sunscreen components of B. striata were a solid-liquid ratio of 1:40 (g/mL), an ethanol concentration of 50%, an ultrasonic time of 50 min and a temperature of 60 °C. A power of 100 W and an ultrasonic frequency of 40 Hz were used throughout the experiments. Under these optimized conditions, the UV absorption rate of the isolated sunscreen components in the UVB region reached 84.38%, and the RSD was 0.11%. Eighteen compounds were identified, including eleven 2-isobutyl malic acid glucose oxybenzyl esters, four phenanthrenes, two bibenzyl and one α-isobutylmalic acid. An evaluation of the sunscreen properties showed that the average UVB absorption values for the sunscreen samples from different batches of B. striata ranged from 0.727 to 1.201. The sunscreen ingredients of the extracts from B. striata had a good UV absorption capacity in the UVB area, and they were effective in their sunscreen effects under medium-intensity sunlight. Therefore, this study will be an experimental reference for the extraction of sunscreen ingredients from the B. striata plant, and it provides evidence for the future development of B. striata as a candidate cosmetic raw material with UVB protection properties.

Bioactivity-Guided Isolation of Antistroke Compounds from Gymnadenia conopsea (L.) R. Br.

A bioactivity-guided separation strategy was used to identify novel antistroke compounds from Gymnadenia conopsea (L.) R. Br., a medicinal plant. As a result, 4 undescribed compounds (1-2, 13, and 17) and 13 known compounds, including 1 new natural product (3), were isolated from G. conopsea. The structures of these compounds were elucidated through comprehensive spectroscopic techniques, such as 1D/2D nuclear magnetic resonance (NMR) spectroscopy, high-resolution electrospray ionization mass spectrometry (HRESIMS), and quantum chemical calculations. An oxygen-glucose deprivation/reoxygenation (OGD/R)-injured rat pheochromocytoma (PC12) cell model was used to evaluate the antistroke effects of the isolates. Compounds 1-2, 10-11, 13-15, and 17 provided varying degrees of protection against OGD/R injury in the PC12 cells at concentrations of 12.5, 25, and 50 µM. Among the tested compounds, compound 17 demonstrated the most potent neuroprotective effect, which was equivalent to that of the positive control drug (edaravone). Then, transcriptomic and bioinformatics analyses were conducted to reveal the regulatory effect of compound 17 on gene expression. In addition, quantitative real-time PCR (qPCR) was performed to verify the results of the transcriptomic and bioinformatics analyses. These results suggest that the in vitro antistroke effect of compound 17 may be associated with the regulation of the Col27a1 gene. Thus, compound 17 is a promising candidate for the development of novel antistroke drugs derived from natural products, and this topic should be further studied.

Comprehensive Screening and Characterization of α-glucosidase Inhibitory Components in the Edible Medicinal Plant Pholidota cantonensis Rolfe Using UPLC-Q-TOF-MS/MS Analysis and Molecular Docking.

Pholidota cantonensis Rolfe is an edible medicinal plant in the genus Pholidota of the family Orchidaceae. This plant is used to prepare medicated food in China and has been reported to possess anti-α-glucosidase activity. To date, little is known about the active substances responsible for the observed anti-α-glucosidase activity. In the present study, we aimed to screen and characterize the α-glucosidase inhibitory fraction of P. cantonensis using ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) analysis and molecular docking. As a result, the 50% ethanol fraction obtained from D101 macroporous adsorption resin column chromatography (D50 fraction) had the highest total phenol content (353.83 ± 6.06 mg GAE/g) and the most prominent α-glucosidase inhibitory activity (IC50 = 30.01 ± 7.30 µg/mL). Forty-five compounds were identified from the D50 fraction by using UPLC-Q-TOF-MS/MS analysis. Molecular docking results showed that six main constituents, namely, crepidatin, 2,7-dihydroxy-4-methoxyl-9,10-dihydrophenylene, 4,4',5,6-tetrahydroxystilbene, 4,7-dihydroxy-2-methoxyl-9,10-dihydrophenylene, (-)-lariciresinol, and thunalbene, in the D50 fraction occupied the catalytic sites of α-glucosidase through strong hydrophobic interactions, hydrogen bonding, and other patterns. The binding energies were between - 29.95 and - 11.41 kJ/mol, indicating good binding between the tested compounds and α-glucosidase. The active ingredients responsible for the α-glucosidase inhibitory activity may include phenanthrenes, stilbenes, dibenzyls, and lignans. The D50 fraction has potential value for developing innovative drugs for the prevention and treatment of diabetes mellitus (DM) and is worthy of in-depth research.

[Material basis and mechanism of Bletillae Rhizoma for melasma, gastrointestinal hemorrhage, lung cancer and bronchoplumonary inflammation as "homotherapy for heteropathy" based on UHPLC-Q-Exactive Orbitrap HRMS coupled with network pharmacology and molecular docking].

Based on UHPLC-Q-Exactive Orbitrap HRMS coupled with the network pharmacology and molecular docking, the common material basis and molecular mechanisms of Bletillae Rhizoma for melasma, gastrointestinal hemorrhage, lung cancer and bronchoplumonary inflammation as "homotherapy for heteropathy" were explored. The fingerprint of 17 batches of Bletillae Rhizoma from different areas was established using HPLC, and the similarity analysis was carried out. The common chemical components of the 17 batches of Bletillae Rhizoma were identified using UHPLC-Q-Exactive Orbitrap HRMS. Depending on the bioavailability and drug-like properties of the common components, the active chemical components were screened, and then their protein targets were collected using the Traditional Chinese Medicine Database and Analysis Platform(TCMSP) and SwissTargetPrediction database. The protein targets related to diseases were retrieved from the databases DrugBank, TTD and GeneCards to produce a Venn diagram. The shared targets were obtained between drugs and diseases as "homotherapy for heteropathy" targets. The protein-protein interaction(PPI) was analyzed with the STRING database, and KEGG and GO analyses of the "homotherapy for heteropathy" targets were performed using the Bioconductor database. Cytoscape 3.7.2 software was employed to construct the "chemical components of Bletillae Rhizoma-homotherapy for heteropathy targets" network and PPI network, and topological analysis was conducted to screen out the key active chemical components and core targets. Finally, the affinity between the active components and core targets was evaluated using the molecular docking by AutoDock Vina 4.2.6, which verified the interaction between them. Thirteen common peaks were identified by fingerprint chromatography, and the similarity between different batches was 0.941-0.998. Fifty-three chemical components were identified by mass spectrometry in Bletillae Rhizoma, and 18 common chemical constituents were obtained in the 17 batches of Bletillae Rhizoma. Network pharmacologic screening showed that the pharmacodynamic substances of Bletillae Rhizoma for melasma, gastrointestinal hemo-rrhage, lung cancer and bronchoplumonary inflammation with "homotherapy for heteropathy" were 11 compounds, such as polysaccharides, biphenanthrenes, dihydrophenanthrenes and bibenzyls. There were 42 common targets identified for the treatment of different diseases. These targets were involved in biological processes such as cell response to chemical stress, reactive oxygen species and positive regulation of protein kinase B signal transduction. They were also involved in 121 signaling pathways, encompassing vital pathways such as PI3K-Akt, ErbB, Rap1, FoxO, MAPK and estrogen. Molecular docking results showed a strong affinity between the key active components and the core targets. This study provides a preliminary explanation of how Bletillae Rhizoma exerts its therapeutic effect on chloasma, gastrointestinal hemorrhage, lung cancer, and bronchopneumonic lesions as "homotherapy for heteropathy" through a combined action involving multiple components, targets, and pathways. These findings offer a certain theoretical basis for the further deve-lopment and application of Bletillae Rhizoma.

The volatile chemistry of orchid pollination.

Covering: up to September 2022Orchids are renowned not only for their diversity of floral forms, but also for their many and often highly specialised pollination strategies. Volatile semiochemicals play a crucial role in the attraction of a wide variety of insect pollinators of orchids. The compounds produced by orchid flowers are as diverse as the pollinators they attract, and here we summarise some of the chemical diversity found across orchid taxa and pollination strategies. We focus on compounds that have been experimentally demonstrated to underpin pollinator attraction. We also highlight the structural elucidation and synthesis of a select subset of important orchid pollinator attractants, and discuss the ecological significance of the discoveries, the gaps in our current knowledge of orchid pollination chemistry, and some opportunities for future research in this field.

Phytochemical Analysis of Anacamptis coriophora Plant Cultivated Using Ex Vitro Symbiotic Propagation.

This study aims to investigate the functional groups and phytochemical profile of Anacamptis coriophora seeds, tubers, and flowers. Symbiotic seedlings produced using the ex vitro method were transferred to their natural habitat and grown to analyze the functional groups and phytochemical profiles of tubers and flowers. The life cycles of the transferred seedlings were monitored, and tubers and flowers were harvested for analysis. ATR-FTIR spectroscopy revealed the presence of functional groups such as polysaccharides, lignin, and proteins in both tubers and flowers. Differences in spectral frequencies between first-year and second-year tubers were observed. Fatty acid analysis identified 30 different compounds in seeds, flowers, and tubers, with linoleic acid being the most abundant (27 % in seeds, 33 % in tubers), and palmitic acid present in flowers (24 %). GC-MS analysis of ethanol extracts from these components highlighted the presence of 32 compounds, including hydroxyacetic acid, hydrazide, cytidine (Z)-7-hexadecenal, 2,2-dimethoxyethane, 2,5,6-trimethyldecane, and butanamide, 4-amino-N-hydroxy. A. coriophora's tubers, flowers, and seeds may contain active metabolites with therapeutic potential. These results are valuable for the commercial cultivation of the plant.

Effect of Flowering Stages on the Content of Active Ingredients and Antioxidant Capability of Bletilla striata Flowers.

Bletilla striata (Thunb.) Reichb.f. is a perennial herb with abundant active ingredients. Previous research mainly focused on its tubers, however, the study on flowers, especially the variation of active ingredient contents at different flowering stages, was rarely seen. This study analyzed the total phenols, flavonoids, polysaccharides, anthocyanins, and cyanidin-3-O-glucoside content of B. striata flowers which were in cultivated in Herb Garden of Zhejiang A&F University and collected in May, 2019, in order to investigate the changes in active ingredients and antioxidant capacity among different flowering stages (bud, initial, and full bloom). Changes in radical scavenging capability of DPPH (1,1-Diphenyl-2-picrylhydrazyl radical), ABTS (2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonate)), and hydroxy were analyzed. Significant differences in active ingredient content of flowers were detected among different flowering stages. The total phenolic content increased continuously during the entire flowering stage. The contents of total flavonoid, total polysaccharide, and cyanidin-3-O-glucoside reached peaks at the initial blooming stage and then fell as the flowering process continued. The antioxidant activity in initial stage was the highest than in any other flowering stages. Therefore, we conclude that the initial blooming stage is the best harvesting stage of B. striata flowers. This study provides a robust basis for the harvest and utilization of B. striata flowers in food, medical, and cosmetic industries.

Active Compounds with Medicinal Potential Found in Maxillariinae Benth. (Orchidaceae Juss.) Representatives-A Review.

Orchids are widely used in traditional medicine for the treatment of a whole range of different health conditions, and representatives of the Neotropical subtribe Maxillariinae are not an exception. They are utilized, for instance, for their spasmolytic and anti-inflammatory activities. In this work, we analyze the literature concerning the chemical composition of the plant extracts and secretions of this subtribe's representatives published between 1991 and 2022. Maxillariinae is one of the biggest taxa within the orchid family; however, to date, only 19 species have been investigated in this regard and, as we report, they produce 62 semiochemicals of medical potential. The presented review is the first summary of biologically active compounds found in Maxillariinae.

Why does an obligate autogamous orchid produce insect attractants in nectar? - a case study on Epipactis albensis (Orchidaceae).

BACKGROUND: The flowers of some species of orchids produce nectar as a reward for pollination, the process of transferring pollen from flower to flower. Epipactis albensis is an obligatory autogamous species, does not require the presence of insects for pollination, nevertheless, it has not lost the ability to produce nectar, the chemical composition of which we examined by gas chromatography-mass spectrometry (GC-MS) method for identification of potential insect attractants. RESULTS: During five years of field research, we did not observe any true pollinating insects visiting the flowers of this species, only accidental insects as ants and aphids. As a result of our studies, we find that this self-pollinating orchid produces in nectar inter alia aliphatic saturated and unsaturated aldehydes such as nonanal (pelargonal) and 2-pentenal as well as aromatic ones (i.e., syringaldehyde, hyacinthin). The nectar is low in alkenes, which may explain the absence of pollinating insects. Moreover, vanillin and eugenol derivatives, well-known as important scent compounds were also identified, but the list of chemical compounds is much poorer compared with a closely related species, insect-pollinating E. helleborine. CONCLUSION: Autogamy is a reproductive mechanism employed by many flowering plants, including the orchid genus Epipactis, as an adaptation to growing in habitats where pollinating insects are rarely observed due to the lack of nectar-producing plants they feed on. The production of numerous chemical attractants by self-pollinated E. albensis confirms the evolutionary secondary process, i.e., transition from ancestral insect-pollinating species to obligatory autogamous.

Atropisomeric 9,10-dihydrophenanthrene/bibenzyl trimers with anti-inflammatory and PTP1B inhibitory activities from Bletilla striata.

Two pairs of novel trimeric dihydrophenanthrene-bibenzyl-dihydrophenanthrene enantiomers (1 and2), the first examples of a dihydrophenanthrene dimer linked to a bibenzyl or dihydrophenanthrene through a C-O-C bond (3 and4), and a pair of rare polymers with a bibenzyl connected to C-8' of the dihydrophenanthro[b]furan moiety via a methylene (5), together with four known compounds (6-9) were isolated from the tubers of Bletilla striata. Their structures including the absolute configurations were determined using spectroscopic data analysis and ECD and NMR calculations, combined with the exciton chirality method or the reversed helicity rule. The atropisomerism of dihydrophenanthrenes and related polymers was considered based on their chiral optical properties, and QM torsion profile calculations, which revealed the racemic mixture form of the polymers. Compounds 4, 5b, 6a and 7b significantly inhibited the production of NO in LPS-induced BV-2 cells, with IC50 values ranging from 0.78 to 5.52 µM. Further mechanistic study revealed that 7b suppressed the expression of iNOS, and suppressed the phosphorylation of the p65 subunit to regulate the NF-κB signaling pathway. Furthermore, compounds 2b, 5a, 5b, 7a and 7b displayed significant protein tyrosine phosphatase 1B (PTP1B) inhibitory activities with IC50 values of 3.43-12.30 µM.

Drakolide Structure-activity Relationships for Sexual Attraction of Zeleboria Wasp Pollinator.

Orchids pollinated by sexual deception lure their specific male pollinators by sex pheromone mimicry. Despite the growing list of chemically diverse semiochemicals known to be involved, the chemical basis and flexibility of this extreme pollinator specificity are not fully understood. One promising but rarely applied tool is the synthesis and field testing of chemically related variants for investigating the structural specificity of the pheromone mimics. Here, we build on the discovery of the unusual semiochemical blend used by Drakaea micrantha to sexually lure its male Zeleboria thynnine wasp pollinator. This blend consists of a ß-ketolactone (drakolide) and two specific hydroxymethylpyrazines, presumably drawn from two distinct biosynthetic pathways. Here, we synthesized and tested the activity of various stereo- and structural isomers of the naturally occurring drakolide. Our study confirmed that in blends with the two pyrazines, both a mixture of stereoisomers, and the specific stereoisomer of the natural drakolide, elicit high rates of landings and attempted copulations. However, in the absence of pyrazines, both the number of responses and the level of sexual attraction were significantly reduced. When structural analogs were substituted for the natural drakolide, attractiveness and degree of sexual behaviour varied but were generally reduced. Based on our findings, and prior knowledge that related hydroxymethylpyrazines are active in other Drakaea spp., we conclude that the dual sex pheromone mimicry of D. micrantha likely evolved via initial changes in just one of the two biosynthetic pathways. Most plausibly, this involved modifications in the drakolides, with the pyrazines as a 'pre-adaption' enhancing the sexual response.