Distribution of Bibenzyls, Prenyl Bibenzyls, Bis-bibenzyls, and Terpenoids in the Liverwort Genus Radula

Dendrobium nobile active ingredient Dendrobin A against hepatocellular carcinoma via inhibiting nuclear factor kappa-B signaling

OBJECTIVE

Dendrobin A, a typical active ingredient of the traditional Chinese medicine Dendrobium nobile, has potential clinical application in cancer treatment; however, its effect and mechanism in anti-hepatocellular carcinoma (HCC) remain unsolved.

METHOD

The effects of Dendrobin A on the viability, migration, invasion, cycle, apoptosis, and epithelial-mesenchymal transition of HepG2 and SK-HEP-1 cells were verified by in vitro experiments. mRNA sequencing was performed to screen the differentially expressed genes (DEGs) of HCC cells before and after Dendrobin A treatment, following GO enrichment and KEGG signaling pathway analyses. Mechanistically, molecular docking was used to evaluate the binding of Dendrobin A with proteins p65 and p50, before further verifying the activation of nuclear factor kappa-B (NF-κB) signaling. Finally, the antiproliferative effect of Dendrobin A on HCC cells was explored through animal experiments.

RESULTS

Dendrobin A arrested cell cycle, induced apoptosis, and inhibited proliferation, migration, invasion, and blocked epithelial-mesenchymal transition in HepG2 and SK-HEP-1 cells. mRNA sequencing identified 830 DEGs, involving various biological processes. KEGG analysis highlighted NF-κB signaling. Molecular docking revealed strong binding of Dendrobin A with p65 and p50 proteins, and western blotting confirmed reduced levels of p-p65 and p-p50 in HCC cells post Dendrobin A treatment. NF-κB agonist PMA reversed Dendrobin A-inhibited cell proliferation migration and invasion. In vivo experiments showed that Dendrobin A inhibited HCC cell growth.

CONCLUSION

Our findings suggest that Dendrobin A exhibits anti-HCC properties by inhibiting the activation of the NF-κB pathway. These results provide a scientific basis for utilizing Dendrobium nobile in anti-HCC therapies.

Parallel Evolution of Asco- and Basidiomycete O-Prenyltransferases

Prenyltransferases (PTs) are involved in the biosynthesis of a multitude of pharmaceutically and agriculturally important plant, bacterial, and fungal compounds. Although numerous prenylated compounds have been isolated from Basidiomycota (mushroom-forming fungi), knowledge of the PTs catalyzing the transfer reactions in this group of fungi is scarce. Here, we report the biochemical characterization of an O- and C-prenylating dimethylallyltryptophan synthase (DMATS)-like enzyme LpTyrPT from the scurfy deceiver Laccaria proxima. This PT transfers dimethylallyl moieties to l-tyrosine at the para-O position and to l-tryptophan at atom C-7 and represents the first basidiomycete l-tyrosine PT described so far. Phylogenetic analysis of PTs in fungi revealed that basidiomycete l-tyrosine PTs have evolved independently from their ascomycete counterparts and might represent the evolutionary origin of PTs acting on phenolic compounds in secondary metabolism.

Mode-of-action of the natural herbicide radulanin A as an inhibitor of photosystem II

BACKGROUND

Radulanin A is a natural 2,5-dihydrobenzoxepin synthesized by several liverworts of the Radula genus. Breakthroughs in the total synthesis of radulanin A paved the way for the discovery of its phytotoxic activity. Nevertheless, its mode-of-action (MoA) has remained unknown so far and thus was investigated, in Arabidopsis thaliana.

RESULTS

Radulanin A phytotoxicity was associated with cell death and partially depended on light exposure. Photosynthesis measurements based on chlorophyll-a fluorescence evidenced that radulanin A and a Radula chromene inhibited photosynthetic electron transport with IC50 of 95 and 100 μm, respectively. We established a strong correlation between inhibition of photosynthesis and phytotoxicity for a range of radulanin A analogs. Based on these data, we also determined that radulanin A phytotoxicity was abolished when the hydroxyl group was modified, and was modulated by the presence of the heterocycle and its aliphatic chain. Thermoluminescence studies highlighted that radulanin A targeted the QB site of the Photosystem II (PSII) with a similar MoA as 3-(3,4-dichloropheny)-1,1-dimethylurea (DCMU).

CONCLUSION

We establish that radulanin A targets PSII, expanding QB sites inhibitors to bibenzyl compounds. The identification of an easy-to-synthesize analog of radulanin A with similar MoA and efficiency might be useful for future herbicide development. © 2023 Society of Chemical Industry.

Recent Advances in the Phytochemistry of Bryophytes: Distribution, Structures and Biological Activity of Bibenzyl and Bisbibenzyl Compounds

Research on bryophyte phytochemistry has revealed the presence of different phytochemicals like fatty acids, terpenoids, small phenolic molecules, etc. Small phenolic molecules, i.e., bibenzyls (of two aromatic rings) and bisbibenzyls (four aromatic rings), are unique signature molecules of liverworts. The first bisbibenzyls marchantin A and riccardin A were discovered in two consecutive years, i.e., 1982 and 1983, respectively, by Asakawa and coworkers. Since then, about 70 bisbibenzyls have been reported. These molecules are characterized and identified using different spectroscopic techniques and surveyed for different bioactivity and structure-activity relations. Biochemistry is determined by the season, geography, and environment. In this review, quantitative and qualitative information on bibenzyls and bisbibenzyl compounds and their distribution in different liverworts across, geographies along withtraditional to advanced extraction methods, and characterization techniques are summarized. Also, a comprehensive account of characteristic spectra of different bisbibenzyl compounds, their subtypes, and their basic skeleton patterns are compared. A comprehensive table is provided here for the first time presenting the quantity of bibenzyls, bisbenzyls, and their derivatives found in bryophytes, mentioning the spectroscopic data and mass profiles of the compounds. The significance of these compounds in different bioactivities like antibiotic, antioxidative, antitumor, antivenomous, anti-influenza, insect antifeedant, cytotoxic, and anticancerous activities are surveyed and critically enumerated.

Influence of phytocenosis on the medical potential of moss extracts: the Pleurozium schreberi (Willd. ex Brid.) Mitt. case

The question was asked "whether plant phytocenosis has an impact on the medical potential of the extracts from Pleurozium schreberi". Moss samples were collected from four different phytocoenoses: mixed forest (oak-pine forest), a forest tract in pine forest, 5-15-year-old pine forest and 50-year-old pine forest. Chemical composition of the extracts, antioxidative capacity (FRAP and ABTS·+ assays), as well as biological activities including cytotoxicity for the mouse fibroblasts L929 line (MTT reduction assay), biostatic/biocidal effect against selected bacteria and fungi (broth microdilution method followed by culture on solid media), and regenerative properties on human fibroblasts HFF-1 line (scratch assay) were tested. The conducted research clearly proves that phytocenosis determines the quality of moss extracts. The analyses showed that in every examined aspect the IV-7 extract (obtained from a specimen collected in a Pinus sylvestris L. forest, monoculture up to 15 years old) exhibited the highest values and the strongest activity. Other extracts of the same species but growing in other phytocenoses-in a mixed forest (IV-5), a forest tract in a Pinus sylvestris monoculture forest (IV-6) and in a P. sylvestris forest of pine monoculture about 50 years old (IV-8) showed much weaker activity and lower values of the above-mentioned parameters. At the same time, none of the tested extracts exerted a pro-regenerative effect. The P. schreberi extracts were characterized by a varied total content of phenolic compounds in the range from 0.63 ± 0.02 to 14.01 ± 0.25 mg/g of plant material. UPLC/MS analysis showed a varied phenolic profile of the extracts, with caffeoylquinic acid and quercetin triglucoside predominating in all of them.

Discovery and Anticancer Activity of the Plagiochilins from the Liverwort Genus Plagiochila

The present analysis retraces the discovery of plagiochilins A-to-W, a series of seco-aromadendrane-type sesquiterpenes isolated from diverse leafy liverworts of the genus Plagiochila. Between 1978, with the first isolation of the leader product plagiochilin A from P. yokogurensis, and 2005, with the characterization of plagiochilin X from P. asplenioides, a set of 24 plagiochilins and several derivatives (plagiochilide, plagiochilal A-B) has been isolated and characterized. Analogue compounds recently described are also evoked, such as the plagiochianins and plagicosins. All these compounds have been little studied from a pharmacological viewpoint. However, plagiochilins A and C have revealed marked antiproliferative activities against cultured cancer cells. Plagiochilin A functions as an inhibitor of the termination phase of cytokinesis: the membrane abscission stage. This unique, innovative mechanism of action, coupled with its marked anticancer action, notably against prostate cancer cells, make plagiochilin A an interesting lead molecule for the development of novel anticancer agents. There are known options to increase its potency, as deduced from structure–activity relationships. The analysis shed light on this family of bryophyte species and the little-known group of bioactive terpenoid plagiochilins. Plagiochilin A and derivatives shall be further exploited for the design of novel anticancer targeting the cytokinesis pathway.

Impact of in vitro phytohormone treatments on the metabolome of the leafy liverwort Radula complanata (L.) Dumort

INTRODUCTION

Liverworts are a group of non-vascular plants that possess unique metabolism not found in other plants. Many liverwort metabolites have interesting structural and biochemical characteristics, however the fluctuations of these metabolites in response to stressors is largely unknown.

OBJECTIVES

To investigate the metabolic stress-response of the leafy liverwort Radula complanata.

METHODS

Five phytohormones were applied exogenously to in vitro cultured R. complanata and an untargeted metabolomic analysis was conducted. Compound classification and identification was performed with CANOPUS and SIRIUS while statistical analyses including PCA, ANOVA, and variable selection using BORUTA were conducted to identify metabolic shifts.

RESULTS

It was found that R. complanata was predominantly composed of carboxylic acids and derivatives, followed by benzene and substituted derivatives, fatty acyls, organooxygen compounds, prenol lipids, and flavonoids. The PCA revealed that samples grouped based on the type of hormone applied, and the variable selection using BORUTA (Random Forest) revealed 71 identified and/or classified features that fluctuated with phytohormone application. The stress-response treatments largely reduced the production of the selected primary metabolites while the growth treatments resulted in increased production of these compounds. 4-(3-Methyl-2-butenyl)-5-phenethylbenzene-1,3-diol was identified as a biomarker for the growth treatments while GDP-hexose was identified as a biomarker for the stress-response treatments.

CONCLUSION

Exogenous phytohormone application caused clear metabolic shifts in Radula complanata that deviate from the responses of vascular plants. Further identification of the selected metabolite features can reveal metabolic biomarkers unique to liverworts and provide more insight into liverwort stress responses.

Electroreduction Enables Regioselective 1,2-Diarylation of Alkenes with Two Electrophiles

Precisely introducing two similar functional groups into bulk chemical alkenes represents a formidable route to complex molecules. Especially, the selective activation of two electrophiles is in crucial demand, yet challenging for cross-electrophile-coupling. Herein, we demonstrate a redox-mediated electrolysis, in which aryl nitriles are both aryl radical precursors and redox-mediators, enables an intermolecular alkene 1,2-diarylation with a remarkable regioselectivity, thereby avoiding the involvement of transition-metal catalysts. This transformation utilizes cyanoarene radical anions for activating various aryl halides (including iodides, bromides, and even chlorides) and affords 1,2-diarylation adducts in up to 83 % yield and >20 : 1 regioselectivity with more than 80 examples, providing a feasible approach to complex bibenzyl derivatives.

Integrated analysis of Dendrobium nobile extract Dendrobin A against pancreatic ductal adenocarcinoma based on network pharmacology, bioinformatics, and validation experiments

Background: Dendrobium nobile (D. nobile), a traditional Chinese medicine, has received attention as an anti-tumor drug, but its mechanism is still unclear. In this study, we applied network pharmacology, bioinformatics, and in vitro experiments to explore the effect and mechanism of Dendrobin A, the active ingredient of D. nobile, against pancreatic ductal adenocarcinoma (PDAC). Methods: The databases of SwissTargetPrediction and PharmMapper were used to obtain the potential targets of Dendrobin A, and the differentially expressed genes (DEGs) between PDAC and normal pancreatic tissues were obtained from The Cancer Genome Atlas and Genotype-Tissue Expression databases. The protein-protein interaction (PPI) network for Dendrobin A anti-PDAC targets was constructed based on the STRING database. Molecular docking was used to assess Dendrobin A anti-PDAC targets. PLAU, one of the key targets of Dendrobin A anti-PDAC, was immunohistochemically stained in clinical tissue arrays. Finally, in vitro experiments were used to validate the effects of Dendrobin A on PLAU expression and the proliferation, apoptosis, cell cycle, migration, and invasion of PDAC cells. Results: A total of 90 genes for Dendrobin A anti-PDAC were screened, and a PPI network for Dendrobin A anti-PDAC targets was constructed. Notably, a scale-free module with 19 genes in the PPI indicated that the PPI is highly credible. Among these 19 genes, PLAU was positively correlated with the cachexia status while negatively correlated with the overall survival of PDAC patients. Through molecular docking, Dendrobin A was found to bind to PLAU, and the Dendrobin A treatment led to an attenuated PLAU expression in PDAC cells. Based on clinical tissue arrays, PLAU protein was highly expressed in PDAC cells compared to normal controls, and PLAU protein levels were associated with the differentiation and lymph node metastatic status of PDAC. In vitro experiments further showed that Dendrobin A treatment significantly inhibited the proliferation, migration, and invasion, inducing apoptosis and arresting the cell cycle of PDAC cells at the G2/M phase. Conclusion: Dendrobin A, a representative active ingredient of D. nobile, can effectively fight against PDAC by targeting PLAU. Our results provide the foundation for future PDAC treatment based on D. nobile.

Volatile chemical composition of Octoblepharum albidum Hedw. (Bryophyta) from the Brazilian Amazon

Bryophytes have a variety of bioactive compounds that can be used in biotechnological processes. The objective of this study was to know the volatile chemical composition of Octoblepharum albidum Hedw. from the Amazon and investigate its association with possible bioactive effects on insects. The volatile concentrate of O. albidum was obtained by micro-scale simultaneous distillation–extraction and analyzed by gas chromatography coupled to mass spectrometry and the identification of the compounds was based on system libraries and specialized literature. Twelve organic compounds (92.44% of the total) were identified. Hexadecanoic acid, oleic acid, E-isoeugenol, 1-octen-3-ol, and stearic acid were the major compounds. Most of the compounds have already been reported from bryophytes, while others have an unprecedented occurrence in the group. All identified compounds have biological activities reported in the literature and may participate in plant defense mechanisms against insects, causing mortality or developmental inhibition. In this study, we describe for the first time the volatile chemical composition of O. albidum from Brazil and provide evidence that this species is a source of bioactive compounds. The identified compounds have been reported in the literature to cause mortality or affect the biological parameters of insects, what suggests the possibility of their usage in the formulation of bioinsecticides.

Structural diversification of bioactive bibenzyls through modular co-culture leading to the discovery of a novel neuroprotective agent

Bibenzyls, a kind of important plant polyphenols, have attracted growing attention for their broad and remarkable pharmacological activities. However, due to the low abundance in nature, uncontrollable and environmentally unfriendly chemical synthesis processes, these compounds are not readily accessible. Herein, one high-yield bibenzyl backbone-producing Escherichia coli strain was constructed by using a highly active and substrate-promiscuous bibenzyl synthase identified from Dendrobium officinale in combination with starter and extender biosynthetic enzymes. Three types of efficiently post-modifying modular strains were engineered by employing methyltransferases, prenyltransferase, and glycosyltransferase with high activity and substrate tolerance together with their corresponding donor biosynthetic modules. Structurally different bibenzyl derivatives were tandemly and/or divergently synthesized by co-culture engineering in various combination modes. Especially, a prenylated bibenzyl derivative (12) was found to be an antioxidant that exhibited potent neuroprotective activity in the cellular and rat models of ischemia stroke. RNA-seq, quantitative RT-PCR, and Western-blot analysis demonstrated that 12 could up-regulate the expression level of an apoptosis-inducing factor, mitochondria associated 3 (Aifm3), suggesting that Aifm3 might be a new target in ischemic stroke therapy. This study provides a flexible plug-and-play strategy for the easy-to-implement synthesis of structurally diverse bibenzyls through a modular co-culture engineering pipeline for drug discovery.

Potential Anti-allergic Effects of Bibenzyl Derivatives from Liverworts, Radula perrottetii

The liverwort Radula perrottetii contains various bibenzyl derivatives which are known to possess various biological activities, such as anti-inflammatory effects. Mast cells (MC) play crucial roles in allergic and inflammatory diseases; thus, inhibition of MC activation is pivotal for the treatment of allergic and inflammatory disorders. We investigated the effects of perrottetin D (perD), isolated from Radula perrottetii, and perD diacetate (Ac-perD) on antigen-induced activation of MCs. Bone marrow-derived MCs (BMMCs) were generated from C57BL/6 mice. The degranulation ratio, histamine release, and the interleukin (IL)-4 and leukotriene B₄ productions on antigen-triggered BMMC were investigated. Additionally, the effects of the bibenzyls on binding of IgE to FcεRI were observed by flow cytometry, and signal transduction proteins was examined by Western blot. Furthermore, binding of the bibenzyls to the Fyn kinase domain was calculated. At 10 µM, perD decreased the degranulation ratio (p < 0.01), whereas 10 µM Ac-perD down-regulated IL-4 production (p < 0.05) in addition to decreasing the degranulation ratio (p < 0.01). Both compounds tended to decrease histamine release at a concentration of 10 µM. Although 10 µM perD reduced only Syk phosphorylation, 10 µM Ac-perD diminished phosphorylation of Syk, Gab2, PLC-γ, and p38. PerD appeared to selectively bind Fyn, whereas Ac-perD appeared to act as a weak but broad-spectrum inhibitor of kinases, including Fyn. In conclusion, perD and Ac-perD suppressed the phosphorylation of signal transduction molecules downstream of the FcεRI and consequently inhibited degranulation, and/or IL-4 production. These may be beneficial potential lead compounds for the development of novel anti-allergic and anti-inflammatory drugs.

Protecting-Group-Free Synthesis of Novel Cannabinoid-Like 2,5-Dihydrobenzoxepines

An efficient synthesis of 2,5-dihydrobenzoxepine analogues was developed without using protecting groups. Regioselective allylation was optimized through a recent method utilizing magnesium dicarboxylates. Grubbs catalysts were applied to investigate ring-closing metathesis. The scope of the present route was extended to produce four analogues, which provided novel cannabinoid-like 2,5-dihydrobenzoxepines in sufficient quantities to permit in vitro assays on recombinant CB1/CB2 receptors. In vitro assays related to CB1/CB2 receptors did not indicate any activity.

Liverwort oil bodies: diversity, biochemistry, and molecular cell biology of the earliest secretory structure of land plants

Liverworts are known for their large chemical diversity. Much of this diversity is synthesized and enclosed within oil bodies (OBs), a synapomorphy of the lineage. OBs contain the enzymes to biosynthesize and store large quantities of sesquiterpenoids and other compounds while limiting their cytotoxicity. Recent important biochemical and molecular discoveries related to OB formation, diversity, and biochemistry allow comparison with other secretory structures of land plants from an evo-devo perspective. This review addresses and discusses the most recent advances in OB origin, development, and function towards understanding the importance of these organelles in liverwort physiology and adaptation to changing environments. Our mapping of OB types and chemical compounds to the current liverwort phylogeny suggests that OBs were present in the most recent common ancestor of liverworts, supporting that OBs evolved as the first secretory structures in land plants. Yet, we require better sampling to define the macroevolutionary pattern governing the ancestral type of OB. We conclude that current efforts to find molecular mechanisms responsible for the morphological and chemical diversity of secretory structures will help understand the evolution of each major group of land plants, and open new avenues in biochemical research on bioactive compounds in bryophytes and vascular plants.

Antimicrobial and Antioxidant Metabolites From the Cultured Suspension Cells of Marchantia polymorpha L

Cell suspension culture is an attractive alternative source to wild plant for the production of novel biological metabolites. Hence, in this study, chemical investigation of cell suspension cultivated Marchantia polymorpha L. was performed, and led to the isolation of one new bis-bibenzyl (1), along with nine known analogues (2-10). Those chemical structures were elucidated based on the comprehensive analysis of NMR and MS data. The antioxidant and antibacterial effects of isolated components and crude extracts were evaluated, resulting in the identification of some antioxidant and antibacterial components. Meanwhile, Compare to that of wild grown M. polymorpha, the cell cultivated one was found to produce superior phenol yields, these constituents are of great importance for their antioxidant and antimicrobial activities. The studies conducted so far have established that the cell culture of M. polymorpha can be considered not only as a rich source of phenolic but as promising source of natural antioxidants and antibiotics as well, which is also expected to develop for better usage of this medicinal herb.

Naturally occurring prenylated stilbenoids: food sources, biosynthesis, applications and health benefits

Prenylated stilbenoids are a unique class of natural phenolic compounds consisting of C6-C2-C6 skeleton with prenyl substitution. They are potential nutraceuticals and dietary supplements presented in some edible plants. Prenylated stilbenoids demonstrate promising health benefits, including antioxidant, anti-cancer, anti-inflammatory, anti-microbial activities. This review reports the structure, bioactivity and potential application of prenylated stilbeniods in food industry. Edible sources of these compounds are compiled and summarized. Structure-activity relationship of prenylated stilbenoids are also highlighted. The biosynthesis strategies of prenylated stilbenoids are reviewed. The findings of these compounds as food preservative, nutraceuticals and food additive are discussed. This paper combines the up-to-date information and gives a full image of prenylated stilbenoids.

Bis-bibenzyls, Bibenzyls, and Terpenoids in 33 Genera of the Marchantiophyta (Liverworts): Structures, Synthesis, and Bioactivity

The Marchantiophyta (liverworts) are rich sources of phenolic substances, especially cyclic and acyclic bis-bibenzyls, which are rare natural products in the plant kingdom, together with bibenzyls and characteristic terpenoids. At present, more than 125 bis-bibenzyls have been found in liverworts. They are biosynthesized from the dimerization of lunularic acid via dihydrocoumaric acid and prelunularin. The structurally unusual cyclic and acyclic bis-bibenzyls show various biological activities such as antimicrobial, antifungal, cytotoxic, muscle relaxation, antioxidant, tubulin polymerization inhibitory, and antitrypanosomal activities, among others. The present review article deals with the distribution and structure of bis-bibenzyls, bibenzyls, and several characteristic ent-sesqui- and diterpenoids in liverworts. Furthermore, the biosynthesis and total syntheses and biological activities of bis-bibenzyls are also surveyed.

Sesquiterpene biosynthesis in a leafy liverwort Radula lindenbergiana Gottsche ex C. Hartm

Liverworts (Marchantiophyta) are among the earliest diverging lineages of extant land plants. Among their unique features, most liverworts contain membrane-bound oil bodies, organelles that accumulate diverse secondary metabolites, especially terpenoids. In contrast to the rich information on liverwort terpenoid chemistry, little is known about their biosynthesis. Recently, terpenoid biosynthesis was studied in a model thalloid species Marchantiapolymorpha, in which sesquiterpenes and monoterpenes are biosynthesized by a new type of terpene synthases termed microbial terpene synthase-like (MTPSL) proteins. Here we study terpenoid biosynthesis in a leafy liverwort Radula lindenbergiana. Vegetative plants of R.lindenbergiana were found to contain a mixture of sesquiterpenes, with (E,E)-α-farnesene/β-curcumene and (Z)-β-bisabolene being the most abundant constituents. From the analysis of the R. lindenbergiana transcriptome, five full-length MTPSL genes were identified. They were designated RlMTPSL1-5, respectively. Recombinant RlMTPSL proteins were produced in Escherichia coli and tested for sesquiterpene synthase activities using farnesyl diphosphate (FPP) as substrate. All except RlMTPSL5 were demonstrated to catalyze the formation of different sesquiterpenes. RlMTPSL1 produced multiple sesquiterpenes with eremophilene and an unidentified sesquiterpene as major products. The major products of RlMTPSL2 and RlMTPSL3 were β-elemene and an unidentified sesquiterpene, respectively. RlMTPSL4 was also a multi-product sesquiterpene synthase with an unidentified sesquiterpene being the major product. Homology-based structural modeling was performed to understand the structural basis underlying different product profiles of the RlMTPSLs proteins. Most of the sesquiterpene products of the four active RlMTPSLs were also detected in R. lindenbergiana plants. Expression levels of the four RlMTPSL genes encoding active enzymes in vegetative plants were compared. In phylogenetic analysis, RlMTPSL genes were found to cluster together, indicating lineage-specific expansion of MTPSL genes in lineages leading to R.lindenbergiana and M. polymorpha. This study strengthens evidence for the contribution of MTPSL genes to terpenoid biosynthesis in liverworts.

Diverse Prenylated Bibenzyl Enantiomers from the Chinese Liverwort Radula apiculata and Their Cytotoxic Activities

An EtOH extract of the Chinese liverwort Radula apiculata showed cytotoxic activity against the A549 lung cancer cell line. Bioassay-guided fractionation led to the isolation of 19 prenylated bibenzyls, including eight previously unknown dimeric prenylated bibenzyls [radulapins A-H (1-8)], four new prenylated bibenzyls (9-12), and seven known compounds (13-19). Compounds 1-11 were analyzed as racemates by chiral-phase separation. Their structures were determined by detailed analysis of their spectroscopic data and by single-crystal X-ray diffraction, chiral resolutions, and electronic circular dichroism measurements. Using an MTT assay, these dimers (1-8) showed significant cytotoxic activity against a panel of human cancer cell lines. Further investigation revealed that compound 4 induces PC-3 cell death via mitochondrial-derived apoptosis.

Bryo-Activities: A Review on How Bryophytes Are Contributing to the Arsenal of Natural Bioactive Compounds against Fungi

Usually regarded as less evolved than their more recently diverged vascular sisters, which currently dominate vegetation landscape, bryophytes seem having nothing to envy to the defensive arsenal of other plants, since they had acquired a suite of chemical traits that allowed them to adapt and persist on land. In fact, these closest modern relatives of the ancestors to the earliest terrestrial plants proved to be marvelous chemists, as they traditionally were a popular remedy among tribal people all over the world, that exploit their pharmacological properties to cure the most different diseases. The phytochemistry of bryophytes exhibits a stunning assortment of biologically active compounds such as lipids, proteins, steroids, organic acids, alcohols, aliphatic and aromatic compounds, polyphenols, terpenoids, acetogenins and phenylquinones, thus it is not surprising that substances obtained from various species belonging to such ancestral plants are widely employed as antitumor, antipyretic, insecticidal and antimicrobial. This review explores in particular the antifungal potential of the three Bryophyta divisions-mosses (Musci), hornworts (Anthocerotae) and liverworts (Hepaticae)-to be used as a sources of interesting bioactive constituents for both pharmaceutical and agricultural areas, providing an updated overview of the latest relevant insights.

The Chemistry of Cannabis and Cannabinoids

The science of cannabis and cannabinoids encompasses a wide variety of scientific disciplines and can appear daunting to newcomers to the field. The encroachment of folklore and ‘cannabis culture’ into scientific discussions can cloud the situation further. This Primer Review is designed to give a succinct overview of the chemistry of cannabis and cannabinoids. It is hoped that it will provide a useful resource for chemistry undergraduates, postgraduates and their instructors, and experienced chemists who require a comprehensive and up to date summary of the field. The Review begins with a brief overview of the history and botany of cannabis, then goes on to detail important aspects of the chemistry of phytocannabinoids, endocannabinoids and synthetic cannabinomimetics. Other natural constituents of the cannabis plant are then described including terpenes and terpenoids, polyphenolics, alkaloids, waxes and triglycerides, and important toxic contaminants. A discussion of key aspects of the pharmacology associated with cannabinoids and the endocannabinoid system then follows, with a focus on the cannabinoid receptors, CB1 and CB2. The medicinal chemistry of cannabis and cannabinoids is covered, highlighting the range of diseases targeted with cannabis and phytocannabinoids, as well as key aspects of phytocannabinoid metabolism, distribution, and delivery. The modulation of endocannabinoid levels through the inhibition of key endocannabinoid-degrading enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) is then discussed. The Review concludes with an assessment of the much touted ‘entourage effect’. References to primary literature and more specialised reviews are provided throughout.