Characterization of Optical, Thermal, and Viscoelastic Properties of Pollenkitt in Angiosperm Pollen Using In-Line Digital Holographic Microscopy.

Pollen grains are remarkable material composites, with various organelles in their fragile interior protected by a strong shell made of sporopollenin. The outermost layer of angiosperm pollen grains contains a lipid-rich substance called pollenkitt, which is a natural bioadhesive that helps preserve structural integrity when the pollen grain is exposed to external environmental stresses. In addition, its viscous nature enables it to adhere to various floral and insect surfaces, facilitating the pollination process. To examine the physicochemical properties of aqueous pollenkitt droplets, we used in-line digital holographic microscopy to capture light scattering from individual pollenkitt particles. Comparison of pollenkitt holograms to those modeled using the Lorenz-Mie theory enables investigations into the minute variations in the refractive index and size resulting from changes in local temperature and pollen aging.

Sesquiterpenes from Chloranthus holostegius with anti-inflammatory activities.

The phytoconstituents of the whole plants of Chloranthus holostegius were investigated. As a result, thirteen undescribed sesquiterpenes (chloranholosins A-M, 1-13), including ten acorane-type sesquiterpenes (1-10), one germacrene-type sesquiterpene (11), and two lindenane-type sesquiterpenes (12-13), together with fifteen known sesquiterpenes were isolated. Their structures and absolute configurations were elucidated by a comprehensive method including the spectroscopic data, electronic circular dichroism (ECD) calculations, and single-crystal X-ray diffraction. Chloranholosin L (12) was elucidated as a rare lindenane-type sesquiterpene featuring 14α-Me and 5-OH moieties. And chloranholosin M (13) was the first lindenane-type sesquiterpene possessing ß-cyclopropane, 14α-Me, and 5ß-H configuration from the family Chloranthaceae. Furthermore, twelve new isolates and some known sesquiterpenes were evaluated for their inhibitory activity against LPS-induced nitric oxide (NO) production in RAW 264.7 macrophage cells. Among them, compounds 12, 16, and 23 showed comparable inhibitory activity to that of the positive control, with IC50 values of 47.9, 41.5, and 48.3 µM, respectively.

Suppression of lipopolysaccharide-induced COX-2 expression via p38MAPK, JNK, and C/EBPß phosphorylation inhibition by furomagydarin A, a benzofuran glycoside from Magydaris pastinacea.

The phytochemical investigation of the methanol extract of the seeds of Magydaris pastinacea afforded two undescribed benzofuran glycosides, furomagydarins A-B (1, 2), together with three known coumarins. The structures of the new isolates were elucidated after extensive 1D and 2D NMR experiments as well as HR MS. Compound 1 was able to inhibit the COX-2 expression in RAW264.7 macrophages exposed to lipopolysaccharide, a pro-inflammatory stimulus. RT-qPCR and luciferase reporter assays suggested that compound 1 reduces COX-2 expression at the transcriptional level. Further studies highlighted the capability of compound 1 to suppress the LPS-induced p38MAPK, JNK, and C/EBPß phosphorylation, leading to COX-2 down-regulation in RAW264.7 macrophages.

Lindenane sesquiterpenoid dimers from Chloranthus holostegius with anti-neuroinflammatory activities in BV-2 microglia.

Fifteen undescribed lindenane-type sesquiterpenoid dimers, designated chloranholides F-T (1-15), together with twenty-five known analogs (16-40), were isolated from the whole plants of Chloranthus holostegius. The isolate structures were elucidated by analysis of spectroscopic data and chemical methods, and their absolute configurations were determined by X-ray crystallography and electronic circular dichroism spectra. In anti-neuroinflammatory assays, all isolates were evaluated by examination of their inhibitory effect on nitric oxide (NO) in LPS-stimulated BV-2 cells, and the results showed that 21-24, 26, 30, 32 and 36 significantly inhibited the production of the inflammatory mediator NO, with IC50 values ranging from 3.18 to 11.46 µM, which was better than that of quercetin. Structure-activity relationship analysis revealed that two essential functional groups played an indispensable role in the anti-inflammatory effects. Moreover, 22 and 24 inhibited the LPS-induced upregulation of iNOS and COX-2 enzymes in BV-2 microglia at the protein level.

Lindenane sesquiterpenoid monomers and oligomers: Chemistry and pharmacological activities.

Lindenane sesquiterpenoid monomers and oligomers, characterized by a sterically congested cyclopentane and an unusual trans-5/6 ring junction, are mainly found in Chloranthaceae species and the genus Lindera Thunb (Lauraceae). Numerous studies have shown that lindenane sesquiterpenoid monomers and oligomers exhibit a broad range of biological activities, such as cytotoxicity, anti-inflammation, neuroprotection, antifungal, and anti-malarial activities. This review covers publications from the first identification of lindeneol in 1925-2023 and classifies the lindenane sesquiterpenoid derivatives into sesquiterpenoid monomers, sesquiterpenoid-monoterpene conjugates, sesquiterpenoid homodimers, sesquiterpenoid heterodimers, and trimeric sesquiterpenoids. In addition, their biological activities are summarized. This review will establish a scientific basis and provide guidance for utilizing this unique class of natural products as potential lead compounds to develop their application in treating diseases corresponding to inflammation, cancer, and plasmodium.

Terpenoid phytocompounds from mangrove plant Xylocarpus moluccensis as possible inhibitors against SARS-CoV-2: In silico strategy.

COVID-19 shook the world during the pandemic, where the climax it reached was vaccine manufacturing at an unfathomable pace. Alternative promising solutions to prevent infection from SARS-CoV-2 and its variants will remain crucial in the years to come. Due to its key role in viral replication, the major protease (Mpro) enzyme of SARS-CoV-2 can be an attractive therapeutic target. In the present work, natural terpenoids from mangrove medicinal plant Xylocarpus moluccensis (Lam.) M. Roem. were screened using computational methods for inhibition of Mpro protein. Out of sixty-seven terpenoids, Angolensic acid methyl ester, Moluccensin V, Thaixylomolin F, Godavarin J, and Xylomexicanolide A were shortlisted based on their docking scores and interaction affinities (- 13.502 to - 15.52 kcal/mol). The efficacy was validated by the 100 ns molecular dynamics study. Lead terpenoids were within the acceptable range of RMSD and RMSF with a mean value of 2.5 Å and 1.5 Å, respectively indicating that they bound tightly within Mpro and there was minimal fluctuation and stability of Mpro upon binding of these terpenoids. The utmost favorable binding strengths as calculated by MM-GBSA, were of Angolensic acid methyl ester and Moluccensin V with binding free energies (ΔGbind) of - 39.084, and - 43.160 kcal/mol, respectively. The terpenoids showed no violations in terms of Drug Likeliness and ADMET predictions. Overall, the findings indicate that Angolensic acid methyl ester and Moluccensin V are effective terpenoids having strong binding interaction with Mpro protein, which must be tested in vitro as an effective anti-SARS-CoV-2 drug.

A novel integrated automatic strategy for amino acid composition analysis of seeds from 67 species.

The composition and quantity of amino acids (AAs) in seeds are complicated due to the various origins and modifications of different species. In this study, a novel automatic neutral loss filtering (ANLF) strategy based on accurate mass searching by Python was developed to analyze the free and hydrolyzed AA-phenyl isothiocyanate (PITC) derivatives from seeds of Gymnosperm and Angiosperm phyla. Compared with traditional strategies, ANLF showed much higher accuracy in screening AA derivatives by filtering nitrogen-containing non-AA compounds and efficiency in processing large datasets. Meanwhile, the content phenotype of 20 proteinogenic AAs from seeds of these two families was characterized by a 35-min HPLC method combined with an automated peak-matching strategy. AA profiles of 232 batches of seeds from 67 species, consisting of 19 proteinogenic AAs, 21 modified AAs, and 77 unknown AAs, would be a good reference for their application in food and medicine.

Yellow pigments produced by oxidative oligomerization of dihydrochalcone glucoside and the reaction mechanism.

From the dried leaves of Lithocarpus polystachyus, yellow pigments, lithocarputins B (11) and C (12), were isolated with a colorless dihydrochalcone dimer, lithocarputin A (10). The pigments 11 and 12 are dimeric dihydrochalcone glycosides with bicyclo[3.2.1]octane structures. Each pigment is a diastereomeric mixture with enantiomeric aglycones that could not be separated. The production mechanisms of the pigments were proposed based on the in vitro enzymatic preparation from trilobatin (1), the major dihydrochalcone glucoside of L. polystachyus. The majority of the pigments in the dried leaves were the oligomers of the dihydrochalcone glycosides generated by a mechanism similar to dimerization. The pigments are probably artifacts produced in the drying process. This is the first report disclosing a detailed chemical mechanism for pigment formation from dihydrochalcone.

Fortunilides M-O, anti-inflammatory lindenane sesquiterpenoid dimers from Chloranthus fortunei.

Fortunilides M-O (1-3), three new lindenane-type sesquiterpenoid dimers, together with eighteen known dimers (4-21), were isolated from the roots of Chloranthus fortunei. The structures were determined by their NMR, HRESIMS, ECD data and quantum chemical calculations. All compounds were classical [4 + 2] lindenane-type sesquiterpenoid dimers, in which compounds 2-4 and 16-17 had rare additional carbon­carbon link between C-11 and C-7'. Their anti-inflammatory activity in LPS-induced RAW 264.7 and BV2 microglial cells were screened, and compounds 9 (IC50: 10.70 ± 0.25 µM) and 2 (IC50: 12.26 ± 2.43 µM) showed significant effect, respectively.

Phytochemical Analysis of Nothapodytes tomentosa and Distribution and Content of Camptothecin and its Analogues in Four Plants.

Camptothecin (CPT) and its derivatives have attracted worldwide attention because of their notable anticancer activity. However, the growing demand for CPT in the global pharmaceutical industry has caused a severe shortage of CPT-producing plant resources. In this study, phytochemical analysis of Nothapodytes tomentosa results in the isolation and identification of CPT (13: ) and 16 analogues (1:  - 12, 14:  - 17: ), including a new (1: ) and five known (9, 10, 12, 15: , and 17: ) CPT analogues with an open E-ring. In view of the potential anticancer activity of CPT analogues with an open E-ring, the fragmentation pathways and mass spectra profiles of these six CPT analogues (1, 9, 10, 12, 15: , and 17: ) are investigated, providing a reference for the rapid detection of these compounds in other plants. Furthermore, based on the fragmentation patterns of CPT (13: ) and known analogues (2:  - 8, 11, 14, 16, 18:  - 26: ), the distribution and content of these compounds in different tissues of N. tomentosa, N. nimmoniana, Camptotheca acuminata, and Ophiorrhiza japonica are further studied. Our findings not only provide an alternative plant resource for further expanding the development and utilization of CPT and its analogues, but also lay a foundation for improving the utilization of known CPT-producing plant resources.

Cellular localisation and quantification of Camptothecin in different plant parts of Nothapodytes nimmoniana (J. Graham) Mabberley of Sri Lankan origin.

INTRODUCTION: Nothapodytes nimmoniana (Icacinaceae) is a rich source of Camptothecin (CPT), an anti-cancer prodrug. Efficient extraction of CPT from various plant parts is crucial for better recovery of this pre-drug. OBJECTIVES: To investigate the distribution of CPT in plant parts and to compare the methods of extraction on CPT yield to evaluate how cellular localisation affects the efficiency of extraction methods. METHODS: Transverse sections of plant parts were observed under a ultraviolet (UV)-fluorescence microscope for the fluorescence that the CPT molecule emits when exposed to UV radiation. Dried plant parts were extracted using 90% methanol with ultrasonic assistance, hot ethanol (61% ethanol at 60°C), and chloroform-methanol (4:1, v/v). The CPT in plant parts were detected by thin-layer chromatography (TLC) and confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and high-performance liquid chromatography (HPLC). Quantification was carried out by HPLC. RESULTS: Blue fluorescence indicated a prominent accumulation of CPT in roots compared to leaf with petiole, twigs, and stembark. This accumulation was observed in upper and lower epidermis of the leaf, isolated strands of fibres in the phloem in the petiole, and groups of idioblast cells in the cortex. The ultrasonic-assisted extraction with 90% methanol showed the highest CPT yield in the root (1.91 ± 0.02 mg/g of dry weight), followed by stembark and the least in leaves [0.02 ± 0.01 mg/g (dry weight)] irrespective of the method of extraction. However, hot ethanol extraction gave the highest CPT yield for twig and leaf, indicating the necessity of tissue-specific extraction methods for better recovery of CPT.

Wood from Hardwood Angiosperms and Coniferous Gymnosperms Shows Distinctive Lignin Peaks in Direct Analysis in Real Time (DART) Mass Spectra.

A data set was constructed consisting of 3021 mass spectra randomly selected from all available families in the ForeST© (Forensic Spectra of Trees) database of mass spectra for wood analyzed by Direct Analysis in Real Time ionization coupled with time-of-flight mass spectrometry (DART-TOFMS). Clear and reproducible differences were observed between the lignin peaks for hardwood angiosperms and coniferous gymnosperms, with DART-TOFMS spectra of angiosperms showing significantly higher relative abundances for peaks associated with syringyl subunits. Application of the method to processed wood samples demonstrated that these differences can be used to provide support for enforcing trade laws by accurately identifying the source of finished wood products from hardwood angiosperms and coniferous gymnosperms.

New diterpenoids and phenolic amides from Icacina mannii Oliv.

Fourteen undescribed compounds including five neoclerodanes (1-5), three labdanes (12-14), three pimarane (15-17) derivatives, one carbamate (24) and two clovamide-type amides (25 and 26), along with twenty-two known compounds (6-11, 18-23 and 27-36) were isolated from the tuber and stem of Icacina mannii. Their structures were elucidated by 1D and 2D NMR and HR-ESI-MS data analysis, and by comparing their NMR data with those of the literature.

Neuroprotective Effects of Ethanol Extract of Polyscias fruticosa (EEPF) against Glutamate-Mediated Neuronal Toxicity in HT22 Cells.

In traditional herbal medicine, the Polyscias fruticosa has been frequently used for the treatment of ischemia and inflammation. Oxidative stress mediated by elevated glutamate levels cause neuronal cell death in ischemia and various neurodegenerative diseases. However, so far, the neuroprotective effects of this plant extract against glutamate-mediated cell death have not been investigated in cell models. The current study investigates the neuroprotective effects of ethanol extracts of Polyscias fruticosa (EEPF) and elucidates the underlying molecular mechanisms of EEPFs relevant to neuroprotection against glutamate-mediated cell death. The oxidative stress-mediated cell death was induced by 5 mM glutamate treatment in HT22 cells. The cell viability was measured by a tetrazolium-based EZ-Cytox reagent and Calcein-AM fluorescent dye. Intracellular Ca2+ and ROS levels were measured by fluorescent dyes, fluo-3 AM and 2',7'-dichlorodihydrofluorescein diacetate (DCF-DA), respectively. Protein expressions of p-AKT, BDNF, p-CREB, Bax, Bcl-2, and apoptosis-inducing factor (AIF) were determined by western blot analysis. The apoptotic cell death was measured by flow cytometry. The in vivo efficacy of EEPF was evaluated using the Mongolian gerbil mouse by surgery-induced brain ischemia. EEPF treatment showed a neuroprotective effect against glutamate-induced cell death. The EEPF co-treatment reduced the intracellular Ca2+ and ROS and apoptotic cell death. Furthermore, it recovered the p-AKT, p-CREB, BDNF, and Bcl-2 levels decreased by glutamate. The EEPF co-treatment suppressed the activation of apoptotic Bax, the nuclear translocation of AIF, and mitogen-activated protein kinase (MAPK) pathway proteins (ERK1/2, p38, JNK). Further, EEPF treatment significantly rescued the degenerative neurons in the ischemia-induced Mongolian gerbil in vivo model. EEPF exhibited neuroprotective properties that suppress glutamate-mediated neurotoxicity. The underlying mechanism of EEPF is increasing the level of p-AKT, p-CREB, BDNF, and Bcl-2 associated with cell survival. It has therapeutic potential for the treatment of glutamate-mediated neuropathology.

Diaporthe sp. F18; a new source of camptothecin-producing endophytic fungus from Nothapodytes nimmoniana growing in Sri Lanka.

An endophytic fungus producing camptothecin (CPT) was isolated from the leaf of Nothapodytes nimmoniana (Sri Lanka), and culture conditions were optimised to enhance the yield of CPT. The TLC, HPLC-PDA, LC-MS/MS and spectroscopic data were used to identify and quantify CPT. Solvent extraction (chloroform: methanol 4:1 v/v) of submerged cultures in Sabouraud Dextrose Broth (SDB) detected CPT in the mycelial extract but not in the culture broth. The fungus was (KX212080) closely related to Diaporthe guangxiensis (MK335772) with 99% sequence similarity, thus tentatively identified as Diaporthe sp. F18. A significantly high CPT content (72.0 ± 0.2 µg/g) was produced in SDB, pH, 5.6 incubated at 30 °C under shake flask condition (150 rpm) for 14 days. Tryptophan significantly (p > 0.05) enhanced CPT production while ethanol increased it by 8-fold. This endophytic source produced higher CPT content than what has been reported hitherto in the literature, with fairly stable production up to sixth subculture generations.

Anti-neuroinflammatory sesquiterpenoids from Chloranthus henryi.

Hupelactones A (1) and B (2), two new eudesmanolide-type enantiomers of the corresponding compounds, along with four mono- (3-6) and nine dimeric- (7-15) known sesquiterpenoids were isolated from the whole plant of Chloranthus henryi var. hupehensis (syn. C. henryi). The new structures including the absolute configurations were determined by comparison with previously reported enantiomers, extensive spectroscopic methods in combination with electronic circular dichroism (ECD) calculations. All the isolates were evaluated for their inhibitory activities against the lipopolysaccharide (LPS)-induced nitric oxide (NO) production in murine BV-2 microglial cells. Among them, the dimeric lindenane sesquiterpenoids shizukaols F (8) and G (11) exhibited the most potent activities, with IC50 values of 2.65 and 4.60 µM, respectively.

Rearranged Lindenane Sesquiterpenoid Trimers from Chloranthus fortunei: Target Discovery and Biomimetic Conversion.

Seven lindenane-type sesquiterpenoid trimers, including four new ones (1-4) and three known analogues (5-7), were isolated from Chloranthus fortunei guided by high-performance liquid chromatography with photodiode array detection with characteristic absorption at 210 and 350 nm. Their structures, including absolute configurations, were achieved by high-resolution mass spectrometry, nuclear magnetic resonance, electronic circular dichroism, and quantum chemical calculations. Compound 1 was the first example of two lindenane units connected by a C-15-C-15' bond. The 5/7/5-fused ring system in 2 was presumably formed biogenetically by key keto-enol tautomerism and Cope rearrangement from 5. The 5/3/6 carbon skeleton in 3-5 and epi-cyclopropane in 3 and 6 might have originated from trishizukaol A (7) with a normal 3/5/6-fused ring system through vinylcyclopropane rearrangement. The biomimetic conversion from 7 to 3-6 was successfully achieved by adding a 365 nm ultraviolet lamp and a free radical initiator, and 2 was also spontaneously converted to 5 in methanol and CDCl3, which proved the correctness of the structural identification and the speculation described above. Compounds 1-7 exhibited anti-inflammatory activity with IC50 values in the range of 2.90-22.80 µmol/L.

Natural and Pseudonatural Lindenane Heterodimers from Sarcandra glabra by Molecular Networking.

Sarglaoxolane A (1), the first lindenane-normonoterpene heterodimer fused by tetrahydrofuran, was discovered in Sarcandra glabra guided by the first proposed single-node-based molecular networking approach. Moreover, two pseudonatural derivatives (2 and 3) with an oxa-difuranofurone moiety were transformed from 1 and confirmed by X-ray diffraction, and also proven to exist in the plant extract. A combination of molecular networking and biomimetic transformation can significantly promote the discovery and structural elucidation of novel natural products.

Concentration-dependent effects of effusol and juncusol from Juncus compressus on seedling development of Arabidopsis thaliana.

Juncus species are valuable sources of phenanthrene compounds that have been used in traditional Chinese medicine for thousands of years. Effusol and juncusol are the most investigated compounds reported to have antimicrobial and anticancer effects; however, to date, their effects on higher plants have not been investigated. In this study, we examined the effects of effusol and juncusol on the growth and other biochemical parameters of the dicot model plant Arabidopsis thaliana in a concentration-dependent manner with a focus on polyamine metabolism. Phenanthrene induced toxic effects on plant growth and development, while effusol and juncusol induced higher biomass and maintained antioxidant defence mechanisms associated with reduced polyamine degradation. Taken together, our results suggest that these compounds could be good candidates for new biopesticide or biostimulant plant growth regulators in the future.

Coumarins from Sarcandra glabra (Thunb.) Nakai and Acetylcholinesterase Inhibiting Activity.

Nine coumarins including a pair of new enantiomers (1a/1b) and seven known compounds (2-8) were isolated from Sarcandra glabra (Thunb.) Nakai. Among them, compounds 1a and 1b were naturally occurring coumarin-phenylpropanoid conjugate enantiomers. Their structures were identified by NMR and ECD calculations. Compounds 1-8 were tested for acetylcholinesterase (AchE) inhibiting activity. The results of the enzymology experiment showed that compound 3 demonstrated obvious AchE inhibitory activity which showed the IC50 value of 1.982±0.003 µM, and the binding sites were predicted by molecular docking.