Acronyrones A-C, unusual prenylated acetophenones from Acronychia pedunculata.

Two novel prenylated acetophenones with new carbon skeletons, acronyrones A and B (1 and 2), and a new analogue, acronyrone C (3), together with two known compounds (4 and 5) were isolated from the leaves of Acronychia pedunculata. Their structures with absolute configurations were identified by interpretation of spectroscopic data, single crystal X-ray diffraction, and electronic circular dichroism (ECD) calculations. Compounds 1 and 2 represent the first example of prenylated acetophenones possessed a C7 (1) and a C6 (2) side chain, forming a 4-isobutylchroman-2-one unit and a 3-(2-methylpropylidene)benzofuran-2(3H)-one moiety with the acetophenone core, respectively. In addition, compound 4 exhibited significant dose-dependent transcriptional activation effect against retinoid X receptor-α (RXRα), and could be regarded as a new type of non-classical RXR ligand.

Investigation on the antitumor effects of paeonol against renal cell carcinoma based on network pharmacology and experimental validation.

ETHNOPHARMACOLOGICAL RELEVANCE: Renal cell carcinoma (RCC) is the most common cancer of the urinary system, the current treatments for RCC are unsatisfactory. Paeonol is the main pharmacologically active ingredient of the traditional Chinese medicine (TCM) moutan cortex (Paeonia suffruticosa Andrews) and Paeonia albiflora Pall, and has been used in TCM to treat various diseases including cancer. However, the underlying therapeutic mechanisms of paeonol in RCC have not been investigated yet. AIM OF THE STUDY: This study aimed to explore the potential antitumor effects and mechanisms of paeonol on RCC based on network pharmacology and experimental validation. MATERIALS AND METHODS: Network pharmacological analysis was performed to predict the potential targets and mechanism of paeonol against RCC. The antitumor effects and the priority targets of paeonol against RCC were further assessed by in vitro experiments. RESULTS: 104 intersection targets shared by paeonol and RCC were collected, 15 hub genes were obtained, among these genes, VEGFA expression was higher in RCC, and the higher expression of IL-6 or lower expression of AKT1, JUN, MAPK1, and MAPK8 were correlated to the shorter overall survival (OS) in RCC patients. GO and KEGG analyses suggested that the genes were mainly enriched in the positive regulation of cell death and apoptosis pathway. In vitro experiments showed that paeonol inhibited 786-O cell proliferation, migration, invasion, and promoted apoptosis. When 786-O cells were treated with paeonol, the expression of Bax increased while Bcl-2 and VEGFA decreased. CONCLUSION: The present study demonstrated that paeonol might play an essential role in RCC by regulating cell proliferation, apoptosis, metastasis, and invasion through the Bcl-2/Bax signaling pathway and VEGFA, providing a theoretical and experimental scientific basis for future investigations of the antitumor effects of paeonol against RCC.

Imidazolylacetophenone oxime-based multifunctional neuroprotective agents: Discovery and structure-activity relationships.

Alzheimer's disease (AD) possesses a complex pathogenetic mechanism. Nowadays, multitarget agents are considered to have potential in effectively treating AD via triggering molecules in functionally complementary pathways at the same time. Here, based on the screening (∼1400 compounds) against neuroinflammation, an imidazolylacetophenone oxime ether (IOE) was discovered as a novel hit. In order to obtain SARs, a series of imidazolylacetophenone oxime derivatives were constructed, and their C=N bonds were confirmed as the Z configuration by single crystals. These derivatives exhibited potential multifunctional neuroprotective effects including anti-neuroinflammatory, antioxidative damage, metal-chelating, inhibition of acetylcholinesterase (AChE) properties. Among these derivatives, compound 12i displayed the most potent inhibitory activity against nitric oxide (NO) production with EC50 value of 0.57 µM 12i can dose-dependently suppress the expression of iNOS and COX-2 but not change the expression of HO-1 protein. Moreover, 12i exhibited evidently neuroprotective effects on H2O2-induced PC12 cells damage and ferroptosis without cytotoxicity at 10 µM, as well as selectively metal chelating properties via chelating Cu2+. In addition, 12i showed a mixed-type inhibitory effect on AChE in vitro. The structure-activity relationships (SARs) analysis indicated that dioxolane groups on benzene ring and rigid oxime ester can improve the activity. Parallel artificial membrane permeation assay (PAMPA) also verified that 12i can overcome the blood-brain barrier (BBB). Overall, this is the first report on imidazolylacetophenone oxime-based multifunctional neuroprotective effects, suggesting that this type of compounds might be novel multifunctional agents against AD.

Natural Benzo/Acetophenones as Leads for New Synthetic Acetophenone Hybrids Containing a 1,2,3-Triazole Ring as Potential Antifouling Agents.

Marine biofouling is a natural process that represents major economic, environmental, and health concerns. Some booster biocides have been used in biofouling control, however, they were found to accumulate in environmental compartments, showing negative effects on marine organisms. Therefore, it is urgent to develop new eco-friendly alternatives. Phenyl ketones, such as benzophenones and acetophenones, have been described as modulators of several biological activities, including antifouling activity (AF). In this work, acetophenones were combined with other chemical substrates through a 1,2,3-triazole ring, a strategy commonly used in Medicinal Chemistry. In our approach, a library of 14 new acetophenone-triazole hybrids was obtained through the copper(I)-catalyzed alkyne-azide cycloaddition "click" reaction. All of the synthesized compounds were evaluated against the settlement of a representative macrofouling species, Mytilus galloprovincialis, as well as on biofilm-forming marine microorganisms, including bacteria and fungi. The growth of the microalgae Navicula sp. was also evaluated after exposure to the most promising compounds. While compounds 6a, 7a, and 9a caused significant inhibition of the settlement of mussel larvae, compounds 3b, 4b, and 7b were able to inhibit Roseobacter litoralis bacterial biofilm growth. Interestingly, acetophenone 7a displayed activity against both mussel larvae and the microalgae Navicula sp., suggesting a complementary action of this compound against macro- and microfouling species. The most potent compounds (6a, 7a, and 9a) also showed to be less toxic to the non-target species Artemia salina than the biocide Econea®. Regarding both AF potency and ecotoxicity activity evaluation, acetophenones 7a and 9a were put forward in this work as promising eco-friendly AF agents.

Lignin-Derived Syringol and Acetosyringone from Palm Bunch Using Heterogeneous Oxidative Depolymerization over Mixed Metal Oxide Catalysts under Microwave Heating.

Biomass valorization to building block chemicals in food and pharmaceutical industries has tremendously gained attention. To produce monophenolic compounds from palm empty fruit bunch (EFB), EFB was subjected to alkaline hydrothermal extraction using NaOH or K2CO3 as a promotor. Subsequently, EFB-derived lignin was subjected to an oxidative depolymerization using Cu(II) and Fe(III) mixed metal oxides catalyst supported on γ-Al2O3 or SiO2 as the catalyst in the presence of hydrogen peroxide. The highest percentage of total phenolic compounds of 63.87 wt% was obtained from microwave-induced oxidative degradation of K2CO3 extracted lignin catalyzed by Cu-Fe/SiO2 catalyst. Main products from the aforementioned condition included 27.29 wt% of 2,4-di-tert-butylphenol, 19.21 wt% of syringol, 9.36 wt% of acetosyringone, 3.69 wt% of acetovanillone, 2.16 wt% of syringaldehyde, and 2.16 wt% of vanillin. Although the total phenolic compound from Cu-Fe/Al2O3 catalyst was lower (49.52 wt%) compared with that from Cu-Fe/SiO2 catalyst (63.87 wt%), Cu-Fe/Al2O3 catalyst provided the greater selectivity of main two value-added products, syringol and acetosyrigone, at 54.64% and 23.65%, respectively (78.29% total selectivity of two products) from the NaOH extracted lignin. The findings suggested a promising method for syringol and acetosyringone production from the oxidative heterogeneous lignin depolymerization under low power intensity microwave heating within a short reaction time of 30 min.

Dibenzofuran, 4-Chromanone, Acetophenone, and Dithiecine Derivatives: Cytotoxic Constituents from Eupatorium fortunei.

Five new compounds, eupatodibenzofuran A (1), eupatodibenzofuran B (2), 6-acetyl-8-methoxy-2,2-dimethylchroman-4-one (3), eupatofortunone (4), and eupatodithiecine (5), have been isolated from the aerial part of Eupatorium fortunei, together with 11 known compounds (6‒16). Compounds 1 and 2 featured a new carbon skeleton with an unprecedented 1-(9-(4-methylphenyl)-6-methyldibe nzo[b,d]furan-2-yl)ethenone. Among the isolates, compound 1 exhibited potent inhibitory activity with IC50 values of 5.95 ± 0.89 and 5.55 ± 0.23 µM, respectively, against A549 and MCF-7 cells. The colony-formation assay demonstrated that compound 1 (5 µM) obviously decreased A549 and MCF-7 cell proliferation, and Western blot test confirmed that compound 1 markedly induced apoptosis of A549 and MCF-7 cells through mitochondrial- and caspase-3-dependent pathways.

An in vitro mechanistic approach towards understanding the distinct pathways regulating insulin resistance and adipogenesis by apocynin.

Adipogenesis is a cascade of processes that entail the differentiation of fibroblasts into mature adipocytes, which results in the accumulation of triglycerides in the adipose cells due to high dietary supplements. This physiological condition increases the risk of type 2 diabetes. Apocynin (4-hydroxy-3-methoxyacetophenone), an organic compound from the root extracts of the medicinal herb Picrorhiza kurroa, has been used in various experimental studies. The current study focuses on deciphering the cellular and molecular mechanisms interlinking obesity and diabetes by validating the various key targets involved in insulin signaling and adipogenesis. Apocynin exhibited enhanced glucose uptake and decreased lipid accumulation in the adipocytes. Furthermore, the expression of molecular markers involved in the insulin signaling pathway, such as IRTK, IRS-1, PI3K, GLUT-4, and the adipogenic pathway, such as PPAR α, adiponectin, C/EBP-α and SREBP1C, by qPCR supported our hypothesis largely. Apocynin mimicked insulin in the insulin-signaling pathway by showing equivalent gene expression. It ameliorated adipogenesis by downregulating the key markers in the adipogenic pathway. Corroborating the hypothesis that Apocynin is antihyperlipidemic in nature, it reduced the expression of PPARα and adiponectin. These results substantiate that Apocynin exerts anti-diabetic and anti-adipogenic effects by regulating resistin and antioxidant enzyme levels in vitro.

Design, synthesis of Cinnamyl-paeonol derivatives with 1, 3-Dioxypropyl as link arm and screening of tyrosinase inhibition activity in vitro.

This study aimed to obtain tyrosinase inhibitors for treating hyperpigmentation. A series of cinnamyl ester analogues were designed and synthesized with cinnamic acid (CA) and peaonol compounds. The safety, melanin content and inhibitory effects of all target compounds were evaluated. In the enzymatic activity test, the inhibitory rate of compounds 8, 13 and 14 had stronger inhibitory activity with the IC50 values of 20.7 µM, 13.98 µM and 15.16 µM, respectively than the positive drug kojic acid (IC50 with 30.83 µM). The cytotoxicity evaluation showed that compounds 13 and 14 have higher safety than the other compounds to the proliferation of B16F10 cells. The result of the melanocyte test supported that compound13 has stronger cellular tyrosinase inhibitory activity than kojic acid and arbutin at 100 µM and 200 µM. The enzyme kinetics mechanism revealed that compound 13 was a non-competitive inhibitor while compounds 8 and 14 were mixed inhibitors. For the experiments of melanin content and tyrosinase activity in the B16F10 melanona cells, the inhibition rates of compounds 8, 14 and 13 were with 19.62%, 20.59% and 23.83%, respectively. In addition, compound 13 revealed the highest inhibitory activity to tyrosinase in the melanocyte with inhibition rates of 23.83%, which was better than kojic acid and arbutin (19.21% and 20.45%) at the same concentration. In the anti-melanogenesis experiment, compounds 8 and 13 had better anti-melanin effects than kojic acid from 25 µM to 100 µM. In summary, the results indicated that compounds 8, 13 and 14 had better tyrosinase inhibitory activity and anti-melanogenesis activity. Especially, the compound 13 has potentiality to develop novel tyrosinase inhibitors and whitening agents. The docking studies results revealed that the functional group of compound 13 mostly depends on the phenolic hydroxyl moiety, and its hydroxyl group did not insert into the active site of tyrosinase, which was in agreement with the results of the kinetics study.

Paeonol alleviates primary dysmenorrhea in mice via activating CB2R in the uterus.

BACKGROUND AND PURPOSE: Primary dysmenorrhea is the most common gynaecologic problem in menstruating women and is characterized by spasmodic uterine contraction and pain symptoms associated with inflammatory disturbances. Paeonol is an active phytochemical component that has shown anti-inflammatory and analgesic effects in several animal models. The aim of this study was to explore whether paeonol is effective against dysmenorrhea and to investigate the potential mechanism of cannabinoid receptor signalling. EXPERIMENTAL APPROACH: Dysmenorrhea was established by injecting oestradiol benzoate into female mice. The effects of paeonol on writhing time and latency, uterine pathology and inflammatory mediators were explored. Isolated uterine smooth muscle was used to evaluate the direct effect of paeonol on uterine contraction. KEY RESULTS: The oral administration of paeonol reduced dysmenorrhea pain and PGE2 and TNF-α expression in the uterine tissues of mice, and paeonol was found to be distributed in lesions of the uterus. Paeonol almost completely inhibited oxytocin-, high potassium- and Ca2+-induced contractions in isolated uteri. Antagonists of CB2R (AM630) and the MAPK pathway (U0126), but not of CB1R (AM251), reversed the inhibitory effect of paeonol on uterine contraction. Paeonol significantly blocked L-type Ca2+ channels and calcium influx in uterine smooth muscle cells via CB2R. Molecular docking results showed that paeonol fits well with the binding site of CB2R. CONCLUSIONS AND IMPLICATIONS: Paeonol partially acts through CB2R to restrain calcium influx and uterine contraction to alleviate dysmenorrhea in mice. These results suggest that paeonol has therapeutic potential for the treatment of dysmenorrhea.

Machine learning decodes chemical features to identify novel agonists of a moth odorant receptor.

Odorant receptors expressed at the peripheral olfactory organs are key proteins for animal volatile sensing. Although they determine the odor space of a given species, their functional characterization is a long process and remains limited. To date, machine learning virtual screening has been used to predict new ligands for such receptors in both mammals and insects, using chemical features of known ligands. In insects, such approach is yet limited to Diptera, whereas insect odorant receptors are known to be highly divergent between orders. Here, we extend this strategy to a Lepidoptera receptor, SlitOR25, involved in the recognition of attractive odorants in the crop pest Spodoptera littoralis larvae. Virtual screening of 3 million molecules predicted 32 purchasable ones whose function has been systematically tested on SlitOR25, revealing 11 novel agonists with a success rate of 28%. Our results show that Support Vector Machine optimizes the discovery of novel agonists and expands the chemical space of a Lepidoptera OR. More, it opens up structure-function relationship analyses through a comparison of the agonist chemical structures. This proof-of-concept in a crop pest could ultimately enable the identification of OR agonists or antagonists, capable of modifying olfactory behaviors in a context of biocontrol.

Two novel eremophylane acetophenone conjugates from Colletotrichum gloeosporioides, an endophytic fungus in Salvia miltiorrhiza.

Two novel eremophylane acetophenone conjugates, colletotricholides A (1) and B (2), were isolated from the solid fermentation cultures of an endophytic fungus Colletotrichum gloeosporioides XL1200 isolated from the aerial parts of Salvia miltiorrhiza. The chemical structures of 1-2 were characterized by extensive spectroscopic methods and single-crystal X-ray crystallography. Structurally, compounds 1-2 are two unusual eremophylane acetophenone conjugates originating from the hybrid pathways of polyketide synthase and sesquiterpene synthase. In addition, compounds 1-2 were inactive against tested pathogens.

Targeting cellular microtubule by phytochemical apocynin exhibits autophagy-mediated apoptosis to inhibit lung carcinoma progression and tumorigenesis.

BACKGROUND: Lung cancer is the leading cause of cancer-related deaths worldwide. Several targets have been identified for lung cancer therapy, amongst which 'Microtubule' and its dynamics are the most widely studied and used in therapy. Tubulin-microtubule polymer dynamics are highly sought after targets in the field of anti-cancer drug designing. Natural compounds are important sources for developing anticancer therapeutics owing to their efficacy and lower cytotoxicity. Evidence suggested that therapeutic targeting of microtubule by natural compounds is amongst the most widely used interventions in numerous cancer therapies including lung cancer. PURPOSE: To determine the efficacy of apocynin (a natural compound) in suppressing the progression of lung carcinoma both in vitro and in vivo, along with the identification of targets and the underlying mechanism for developing a novel therapeutic approach. METHODS: We have demonstrated themicrotubule depolymerizing role of apocynin by established protocols in cellular and cell-free system. The efficacy of apocynin to inhibit lung carcinoma progression was studied on A549 cells.The tumoricidal ability of apocynin was studied in BALB/c mice model as well.Mice were classified into 4 groups namely-group II mice as tumor control; group III-IV mice asalso tumor-induced but treated with differential apocynin doses whereas group I mice were kept as normal. RESULTS: Apocynin, showed selective cytotoxicity towards lung cancer cells rather than normal lung fibroblast cells. Apocynin inhibited oncogenic properties including growth, proliferation (p < 0.05), colony formation (p < 0.05), invasion (p < 0.05) and spheroid formation (p < 0.05) in lung cancer cells. Apart from other established properties, apocynin was found to be a novel and potent component to bind with tubulin and depolymerize cellular microtubule network. Apocynin mediated cellular microtubule depolymerization was the driving mechanism to trigger autophagy-mediated apoptotic cell death (p < 0.05) which in turn retarded lung cancer progression. Furthermore, apocynin showed tumoricidal characteristics to inhibit lung tumorigenesis in mice as well. CONCLUSION: Targeting tubulin-microtubule equilibrium with apocynin could be the key regulator to catastrophe cellular catabolic processes to mitigate lung carcinoma. Thus, apocynin could be a potential therapeutic agent for lung cancer treatment.

Paeonol Derivatives and Pharmacological Activities: A Review of Recent Progress.

Paeonol, 2-hydroxy-4-methoxy acetophenone, is one of the main active ingredients of traditional Chinese medicine such as Cynanchum paniculatum, Paeonia suffruticosa Andr and Paeonia lactiflora Pall. Modern medical research has shown that paeonol has a wide range of pharmacological activities. In recent years, a large number of studies have been carried out on the structure modification of paeonol and the mechanism of action of paeonol derivatives has been studied. Some paeonol derivatives exhibit good pharmacological activities in terms of antibacterial, anti-inflammatory, antipyretic analgesic, antioxidant and other pharmacological effects. Herein, the research progress on paeonol derivatives and their pharmacological activities were systematically reviewed.

Paeonol attenuates inflammation by targeting HMGB1 through upregulating miR-339-5p.

Sepsis is a life-threatening disease caused by infection. Inflammation is a key pathogenic process in sepsis. Paeonol, an active ingredient in moutan cortex (a Chinese herb), has many pharmacological activities, such as anti-inflammatory and antitumour actions. Previous studies have indicated that paeonol inhibits the expression of HMGB1 and the transcriptional activity of NF-κB. However, its underlying mechanism is still unknown. In this study, microarray assay and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) results confirmed that paeonol could significantly up-regulate the expression of miR-339-5p in RAW264.7 cells stimulated by LPS. Dual-luciferase assays indicated that miR-339-5p interacted with the 3' untranslated region (3'-UTR) of HMGB1. Western blot, immunofluorescence and enzyme-linked immunosorbent assay (ELISA) analyses indicated that miR-339-5p mimic and siHMGB1 both negatively regulated the expression and secretion of inflammatory cytokines (e.g., HMGB1, IL-1ß and TNF-α) in LPS-induced RAW264.7 cells. Studies have confirmed that IKK-ß is targeted by miR-339-5p, and we further found that paeonol could inhibit IKK-ß expression. Positive mutual feedback between HMGB1 and IKK-ß was observed when we silenced HMGB1 or IKK-ß. These results indicated that paeonol could attenuate the inflammation mediated by HMGB1 and IKK-ß by upregulating miR-339-5p expression. In addition, we constructed CLP model mice by cecal ligation and puncture. Paeonol was used to intervene to investigate its anti-inflammatory effect in vivo. The results showed that paeonol could improve the survival rate of sepsis mice and protect the kidney of sepsis mice.

[Study on physicochemical properties of paeonol-Helix aspersa muller nanogel and its inhibitory effects on hypertrophic scar tissue in rabbit ear].

To prepare Helix aspersa muller-paeonol nanogel( PAE-HAM-Gels) with anti-proliferative scar effect,evaluate its skin penetration,retention and irritation,and to investigate its prevention and treatment effect for hypertrophic scar in rabbit ears. The dermal retention,transdermal rate and cumulative permeability of paeonol were investigated in vitro by using the modified Franz diffusion cell and the abdominal skin of suckling pigs,SD rats and KM mice,respectively,and the in vitro permeation curves were drawn. The normal skin of the back of New Zealand rabbits was continuously treated with PAE-HAM-Gels for 7 days,and the physiological state of the skin was observed under light microscope after HE staining by using homologous left and right contrast method. The hypertrophic scar model in rabbit ears was established,and the New Zealand rabbits were randomly divided into blank group,model group,positive drug group,PAE-Gels group and PAE-HAM-Gels group. After 28 days of administration,the scar hyperplasia rate and scar elevation index( SEI) of each group were calculated; the scar tissues were taken and stained with Masson for observation of collagen fibers and muscle fibers hyperplasia under light microscope,and the expression level of TGF-ß1 in each group was detected. The Qnof PAE-HAM-Gels in aqueous solution was in line with the Higuchi equation,and its transdermal rate,cumulative permeation and dermal retention in different animal skins were all higher than those of PAE-Gels. The skin of the drug-administered group was intact,without erythema,edema or other phenomena; under light microscope,the subcutaneous tissue and the epidermal cells were neatly arranged with uniform thickness,which showed no difference from the blank group. The scar hyperplasia rate of the PAE-HAM-Gels group was 62. 50%; SEI was 2. 17±0. 33 and TGF-ß1 was( 815. 4±34. 69) ng·L~(-1),significantly different from those in model group( P<0. 01). Masson staining showed that as compared with the model group,the number of collagen fibers and muscle fibers was small and the arrangement was loose and tidy in the PAE-HAM-Gels group,with regular arrangement of chondrocytes and a small number of inflammatory cells and microvessels.PAE-HAM-Gels have good transdermal properties and dermal retention without skin irritation,offering a promising therapeutic strategy for transdermal delivery during the prevention and treatment of hypertrophic scar in rabbit ears.

Prenylated Acetophloroglucinol Dimers from Acronychia trifoliolata: Structure Elucidation and Total Synthesis.

The isolation of 12 secondary metabolites, including seven new acetophenone monomers, from the 50% CH3OH/CH2Cl2 extract (N089419-L/6) of Acronychia trifoliolata was reported previously. In the present work, three new prenylated acetophenone dimers (1-3) and five known dimers (4-8) were isolated, and their structures were elucidated by using various NMR spectroscopic techniques and HRMS. Among the new dimers, an unprecedented 4-isobutyl-3-isopropyltetrahydro-2H-pyran ring was observed in the structure of 1. This study is the first to report the formation of a 2H-pyran ring between two prenylated acetophloroglucinols. Only four related dimers have been reported before, and they were formylated phloroglucinol dimers from the family Eucalypteae. Compounds 2 and 3 are acrovestone-like dimers, and the structure of 3 was confirmed by total synthesis. The evaluation of the antiproliferative activity of isolated and synthesized acrovestone-like dimers indicated that a double bond in the prenyl-like moiety as found in the more active compounds might be important for mediating activity, while the pendant isobutyl group seems to be less important.

(±)-Meliviticines A and B: Rearranged prenylated acetophenone derivatives from Melicope viticina and their antimicrobial activity.

Two new prenylated acetophenone derivatives racemates, meliviticines A (1) and B (2) with unprecedented rearranged skeletons, were isolated from Melicope viticina. Subsequent chiral resolution led to the separation of two pairs of enantiomers, (±)-meliviticines A (1a/1b) and (±)-meliviticines B (2a/2b). Their structures including absolute configurations were elucidated by extensive spectroscopic data, electronic circular dichroism analysis, and X-ray crystallography. A plausible biosynthetic pathway of 1 and 2, involving ring cleavage and rearrangement of the prenylated acetophenone backbone was proposed. All the isolates showed moderate antimicrobial activities with MIC values of 25-50 µg/mL against several bacterial and fungal strains.

Phytochemistry and Biological Activities of Werneria and Xenophyllum species / Fitoquímica y actividades biológicas de especies de Werneria y Xenophyllum

Plants of the genera Werneria (Asteraceae) and Xenophyllum (genus extracted from Werneria) are used in traditional medicine of Latin America for the treatment of mountain sickness, hypertension and gastrointestinal disorders. Only a small number of species of these genera have been studied, leading to the isolation of compounds belonging to the classes of benzofurans, chromenes, acetophenones, coumarates, diterpenes and pyrrolizidine alkaloids. Some of the plant extracts and/or compounds have shown antimicrobial, anti-HIV, hypotensive and photoprotective activities.

Las plantas de los géneros Werneria (Asteraceae) y Xenophyllum (género extraido de Werneria) son usadas en la medicina tradicional de América Latina para el tratamiento del mal de montaña, hipertensión y desórdenes gastrointestinales. Solo un pequeño número de especies de estos géneros ha sido investigado, lográndose aislar compuestos que pertenecen a las clases de benzofuranos, cromenos, acetofenonas, cumaratos, diterpenos y alcaloides pirrolizidínicos. Algunos de los extractos y/o compuestos de dichas plantas han mostrado actividades antimicrobianas, anti-HIV, hipotensoras y fotoprotectoras.

The structural characterization and antioxidant properties of oil palm fronds lignin incorporated with p-hydroxyacetophenone.

This study reports on the effects of unmodified autohydrolyzed ethanol organosolv lignin (AH EOL) and modified autohydrolyzed ethanol organosolv lignin on the structural characteristics and antioxidant properties upon incorporation of p-hydroxyacetophenone (AHP EOL). The lignin samples isolated from black liquor of oil palm fronds (OPF) were evaluated and compared using various complementary analyses; FTIR, 1H and 13C NMR spectroscopy, 2D-NMR spectroscopy (HMBC and HSQC), CHN, GPC, HPLC and thermal analyses (TGA and DSC). Chemically modified organosolv lignin (AHP EOL) provided lignin with lower molecular weight (Mw), which has smaller fragments that leads to higher solubility rate in water in comparison to unmodified organosolv lignin, AH EOL (DAHP EOL: 19.8% > DAH EOL: 14.0%). It was evident that the antioxidant properties of modified organosolv lignin has better reducing power in comparison to the unmodified organosolv lignin. Therefore, the functionalization of lignin polymers enhanced their antioxidant properties and structural features towards a various alternative approach in lignin-based applications.

Acetophenone derivatives from the roots of Melicope ptelefolia.

Five new prenylated acetophenones, melicoptelins A-E (1-5), along with one known congener (6) were isolated from the roots of Melicope ptelefolia. Among them, compounds 2a/2b, 3a/3b, and 4a/4b were obtained as inseparable interconverting mixtures of keto and enol tautomers. Their structures were elucidated on the basis of extensive spectroscopic methods, including 1D, 2D NMR and HRESIMS. Compouds 2a/2b, 4a/4b and 5 exhibit protein tyrosine phosphatase 1B (PTP1B) inhibitory activity with IC50 values of 34.4, 55.2 and 66.6 µM, respectively.