New phenylpropenoids, bis(1-phenylethyl)phenols, bisquinolinone alkaloid, and anti-inflammatory constituents from Zanthoxylum integrifoliolum

Anti-diabetic and anti-inflammatory bioactive hits from Coriaria intermedia Matsum. stem and Dracontomelon dao (Blanco) Merr. & Rolfe bark through bioassay-guided fractionation and liquid chromatography-tandem mass spectrometry

Women have been found to be at a higher risk of morbidity and mortality from type 2 diabetes mellitus (T2DM) and asthma. α-Glucosidase inhibitors have been used to treat T2DM, and arachidonic acid 15-lipoxygenase (ALOX15) inhibitors have been suggested to be used as treatments for asthma and T2DM. Compounds that inhibit both enzymes may be studied as potential treatments for people with both T2DM and asthma. This study aimed to determine potential anti-diabetic and anti-inflammatory bioactive hits from Coriaria intermedia Matsum. stem and Dracontomelon dao (Blanco) Merr. & Rolfe bark. A bioassay-guided fractionation framework was used to generate bioactive fractions from C. intermedia stem and D. dao bark. Subsequently, dereplication through ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and database searching was performed to putatively identify the components of one bioactive fraction from each plant. Seven compounds were putatively identified from the C. intermedia stem active fraction, and six of these compounds were putatively identified from this plant for the first time. Nine compounds were putatively identified from the D. dao bark active fraction, and seven of these compounds were putatively identified from this plant for the first time. One putative compound from the C. intermedia stem active fraction (corilagin) has been previously reported to have inhibitory activity against both α-glucosidase and 15-lipoxygenase-1. It is suggested that further studies on the potential of corilagin as an anti-diabetic and anti-inflammatory treatment should be pursued based on its several beneficial pharmacological activities and its low reported toxicity.

Horsetail (Equisetum hyemale) Extract Accelerates Wound Healing in Diabetic Rats by Modulating IL-10 and MCP-1 Release and Collagen Synthesis

Traditionally, Equisetum hyemale has been used for wound healing. However, its mechanism of action remains to be elucidated. For this purpose, a 40% ethanolic extract of E. hyemale was prepared. Phytochemical screening revealed the presence of minerals, sterols, phenolic acids, flavonols, a lignan, and a phenylpropenoid. The extract reduced the viability of RAW 264.7 cells and skin fibroblasts at all times evaluated. On the third day of treatment, this reduction was 30–40% and 15–40%, respectively. In contrast, the extract increased the proliferation of skin fibroblasts only after 48 h. In addition, the extract increased IL-10 release and inhibited MCP-1 release. However, the extract did not affect both TGF-β1 and TNF-α released by RAW 264.7 cells. The higher release of IL-10 could be related to the up-/downregulation of inflammatory pathways mediated by the extract components associated with their bioactivity. The extract inhibited the growth of Staphylococcus aureus and Escherichia coli. Topical application of the extract accelerated wound healing in diabetic rats by increasing fibroblast collagen synthesis. These results suggest that E. hyemale extract has great potential for use in the treatment of wounds thanks to its phytochemical composition that modulates cytokine secretion, collagen synthesis, and bacterial growth.

Ethnobotanical uses, phytochemistry and pharmacology of pantropical genus Zanthoxylum L. (Rutaceae): An update

ETHNOPHARMACOLOGICAL RELEVANCE

Plants have been used in various parts of the world to treat various diseases. The genus Zanthoxylum L. (Rutaceae) is the second largest genus of this family and comprises approximately 225-549 species distributed in the tropical and temperate regions of the world. Plants of this genus are trees and shrubs with various applications in folklore medicine for food, medicine, construction, and other uses.

AIM OF THE REVIEW

The goal of this review is to give an updated data on the ethnobotanical applications, phytochemistry, and pharmacology of the Zanthoxylum species to investigate their medicinal potential and identify research gaps for future research studies.

MATERIALS AND METHODS

Data was obtained through a systematic search of published literature and online databases such as Google Scholar, Web of Science, PubMed, Science Direct, and Sci-Finder. The botanical names were confirmed using the World Flora Online and chemical structures were drawn using the ChemBio Draw Ultra Version 14.0 Software.

RESULTS

The Zanthoxylum species have a wide use in different parts of the continents as a remedy for various diseases such as digestive diseases, gastrointestinal disorders, venereal diseases, respiratory diseases, rheumatism, bacterial diseases, viral, and other diseases. Various parts of the plant comprising fruits, seeds, twigs, leaves, oils, and stems are administered singly or in the form of decoction, infusion, powder, paste, poultice, juice, or mixed with other medicinal plants to cure the disease. More than 400 secondary metabolites have been isolated and characterized in this genus with various biological activities, which comprise alkaloids, flavonoids, coumarins, lignans, alcohols, fatty acids, amides, sesquiterpenes, monoterpenes, and hydrocarbons. The crude extracts, fractions, and chemical compounds isolated from the genus have demonstrated a wide range of biological activities both in vivo and in vitro, including; anti-cancer, antimicrobial, anti-sickling, hepatoprotective, antipyretic, antitumor, and other pharmacological activities.

CONCLUSION

This genus has demonstrated an array of phytoconstituents with therapeutic potential. The ethnobotanical uses of this genus have been confirmed in modern pharmacological research. This genus is a potential source for modern drug discovery and health care products. Further and extensive research is therefore required on the safety approval and therapeutic application of the species of this genus as well as clinical trials and pharmacokinetic studies.

(±)-Zanthonitidumines A and B: Two new benzophenanthridine alkaloids enantiomers from Zanthoxylum nitidum and their anti-inflammatory activity

Two new benzophenanthridine alkaloids enantiomers (±)-zanthonitidumines A (1) and B (2), along with seven known analogues (3-9), were isolated from Zanthoxylum nitidium. Their structures were elucidated on the basis of extensive spectroscopic techniques and ECD data. Compound 2 exhibited the most significant inhibition of IL-6 generation as well as TNF-α release which suggest that it may be a potential anti-inflammatory agent.

Tandem Protocol for the Synthesis of Pyrano[3,2-c]quinolone Derivatives Using Taurine as a Green Bio-Organic Catalyst in Aqueous Medium

A series of pyrano[3,2-c]quinolone derivatives has been synthesized in the presence of taurine (2-aminoethanesulfonic acid) as a green bio-organic catalyst and water as the solvent. The target compounds were synthesized through the three-component reaction between aldehydes, malononitrile/ethylcyanoacetate, and 4-hydroxy-1-methyl-2(1H)-quinolone. The advantages of this protocol are excellent yields of products, short reaction times, cost efficiency, atom economy, and a simple work-up procedure with no need for extra purification techniques. Moreover, the catalyst can be easily recovered and reused for up to three cycles without losing any significant activity.

Synthesis of pyrano[3,2-c]quinolones and furo[3,2-c]quinolones via acid-catalyzed tandem reaction of 4-hydroxy-1-methylquinolin-2(1H)-one and propargylic alcohols

Two acid-catalyzed tandem reactions between 4-hydroxy-1-methylquinolin-2(1H)-one and propargylic alcohols are described. Depending mainly on the propargylic alcohol used, these tandem reactions proceed via either a Friedel–Crafts-type allenylation followed by 6-endo-dig cyclization sequence to form pyrano[3,2-c]quinolones or a Friedel–Crafts-type alkylation and 5-exo-dig ring closure sequence to afford furo[3,2-c]quinolones in moderate-to-high yields. The pyrano[3,2-c]quinolones products could be further transformed to tetracyclic 4,9-dihydro-5H-cyclopenta[lmn]phenanthridin-5-one derivatives.

Two acid-catalyzed tandem reactions between 4-hydroxy-1-methylquinolin-2(1H)-one and propargylic alcohols are described.

A review on the synthesis of heteroannulated quinolones and their biological activities

The quinoline scaffold has become an important construction motif for the development of new drugs. The quinolones and their heteroannulated derivatives have high importance due to their diverse spectrum of biological activities as antifungal, anti-inflammatory, anti-diabetes, anti-Alzheimer's disease, antioxidant and diuretic activities. This review summarizes the various new, efficient and convenient synthetic approaches to synthesize diverse quinolone-based scaffolds and their biological activities. We also dealt with the important mechanism, the route and type of reactions of the obtained products. The biological activities of some heteroannulated quinolones were also discussed.

A Review on Classification and Biological Activities of Alkaloids from the Genus Zanthoxylum Species

Many plants in the genus Zanthoxylum, belonging to the Rutaceae family, are used as folk medicines for the treatment of various diseases, which have gained much attention for their phytochemical and pharmacological activity investigations. Alkaloids are the largest secondary metabolites with structurally diverse types found in this genus and they demonstrate a wide range of biological activities. The aim of this review is to provide a summary on the isolation, classification, and biological properties of alkaloids from Zanthoxylum species, which also will bring more attention to other researchers for further biological study on alkaloids for the new drug development.

Alkaloid and benzopyran compounds of Melicope latifolia fruit exhibit anti-hepatitis C virus activities

BACKGROUND

New agents for developing alternative or complementary medicine to treat the hepatitis C virus (HCV) are still needed due to high rates of HCV infection globally and the current limitations of available treatments. Treatment of HCV with a combination of direct acting antivirals have been shown to be approximately 90% effective but will be limited in the future due to the emergence of drug resistance and high cost. The leaves of Melicope latifolia have previously been reported to have anti-HCV activity and are a potential source of bioactive compounds for future novel drug development. This study aimed to evaluate the efficacy of the extract of M. latifolia fruit to treat HCV and to isolate its active compounds.

METHOD

M. latifolia fruit was extracted using methanol and purified using vacuum liquid chromatography (VLC) and Radial Chromatography. The anti-HCV activity was analyzed using cell culture lines Huh7it-1 and JFH1 (genotype 2a). Time-of-addition and immunoblotting studies were performed to identify the mode of action of the isolated active compounds. The structures of the active compounds were determined using nuclear magnetic resonance (NMR) spectra, UV, IR, and Mass Spectra.

RESULTS

Six known compounds were isolated from M. latifolia fruit: O-methyloktadrenolon, alloevodionol, isopimpinellin, alloxanthoxyletin, methylevodionol, and N-methylflindersine. N-methylflidersine was the most active compound with IC50 value of 3.8 μg/ml while methylevodionol, isopimpinellin, and alloevodionol were less active. O-methyloktadrenolon and alloxanthoxyletin were moderately active with IC50 values of 10.9 and 21.72 μg/ml, respectively. N-methylflidersine decreased level of HCV NS3 protein expression in the cells.

CONCLUSION

The alkaloid compound, N-methylflindersine which was isolated from M. latifolia possesses anti-HCV activity through post-entry inhibition and suppressed NS3 protein expression.

Ring expansion and ring opening of 3-halooxindoles with N-alkoxycarbonyl-O-tosylhydroxylamines for divergent access to 4-aminoquinolin-2-ones and N-Cbz-N’-arylureas

The reaction of N-alkoxycarbonyl-O-tosylhydroxylamines with indol-2-ones in situ generated from 3-halooxindoles has been developed for divergently accessing 4-aminoquinolin-2-ones and N-Cbz-N’-arylureas in good to excellent yields.

Anticancer activity of novel Schiff bases and azo dyes derived from 3-amino-4-hydroxy-2H-pyrano[3,2-c]quinoline-2,5(6H)-dione

New Schiff bases and azo dyes derivatives have been synthesized via appropriate conventional methods using pyranoquinolinone as a starting material. The compounds obtained were characterized by spectral analysis and evaluated for anticancer activity in several human tumor cell lines: MCF-7 breast cancer, HepG2 liver cancer and HCT-116 colon carcinoma. 5-fluorouracil was used as a reference drug. The in vitro cytotoxicity screening results revealed that all tested compounds showed promising activity against MCF-7 cells. In particular, compounds 6a, 6b, and 7b showed excellent activity against the three human tumor cell lines. Structure-activity relationship studies indicated that the azo derivative with a trifluoromethoxy group (compound 7b) was the most potent candidate against the three human tumor cell lines (IC50, 1.82-8.06 μg/mL). Our findings highlight pyranoquinolinone analogues as a promising class of compounds for new anticancer therapies.

New dihydrochromene and xanthone derivatives from Lisotrigona furva propolis

A new dihydrochromene derivative, named lisofurvin (1) and a xanthone, named dihydrobrasixanthone B (2) together with twenty one known compounds (3-23) were isolated from propolis of the stingless bee Lisotrigona furva. Their chemical structures were determined by means of spectroscopic methods including 1D and 2D NMR, and MS. The chemical constituents are predominantly geranyl(oxy) xanthones and Cratoxylum cochinchinense was suggested as a resin source, besides two other plants Mangifera indica and dammar trees (Dipterocarpaceae). Compound 1 showed significant cytotoxic activity against KB, HepG-2, and Lu-1 cancer cell lines with IC₅₀ values range from 12.63 to 15.17 μg/mL. Several isolated compounds were active against one to four tested cancer cell lines. In addition, among the isolated compounds, α-mangostin (15) displayed the strongest antimicrobial activity against three Gram (+) strains, P. aeruginosa, and C. albicans with MIC values ranging between 1 and 2 μg/mL. Compound 22 showed good activity against three Gram (+) strains and C. albicans.

Structural characterization, antiproliferative and anti-inflammatory activities of alkaloids from the roots of Zanthoxylum austrosinense

Three new carbazole alkaloids, zanthoaustrones A-C (1-3), as well as nine known compounds 4-12, were isolated and characterized from the roots of Zanthoxylum austrosinense Huang (Rutaceae). Their chemical structures were elucidated on the basis of extensive and comprehensive spectroscopic methods, while the known alkaloids were identified by the comparison of their observed spectroscopic data including NMR data, MS data and optical rotation values with the data described in the literature. Furthermore, the antiproliferative activities as well as the anti-inflammatory effects of all isolated alkaloids in vitro were evaluated. All obtained alkaloids 1-12 displayed notable antiproliferative activities against diverse human cancer cell lines exhibiting IC₅₀ values in range of 0.85 ± 0.06 to 29.56 ± 0.17 µM, which is equivalent to the positive control (cisplatin) showing IC₅₀ values ranging from 1.58 ± 0.09 to 28.69 ± 0.21 µM. Moreover, compounds 1-12 exhibited pronounced inhibitory activities on nitric oxide (NO) production with IC₅₀ values displaying IC₅₀ values in range of 0.89 ± 0.05 to 9.62 ± 0.15 µM, which is comparable to the positive control (hydrocortisone) holding an IC₅₀ value of 4.06 ± 0.11 µM. These findings indicate that the separation and characterization of these alkaloids displaying significant antiproliferative activities together with anti-inflammatory effects from the roots of Z. austrosinense could be meaningful to the research and development of new anti-cancer drugs as well as anti-inflammatory agents.

Three New Lignan Glycosides from the Firmiana simplex

In our quest for structurally intriguing compounds from Korean medicinal plant sources, chromatographic separation of the 80% MeOH extract from Firmiana simplex resulted in the isolation and identification of three new lignan glycosides (1-3), together with six known lignan glycosides (4-9). The structures of 1-3 were determined on the basis of spectroscopic analyses, including extensive 2D-NMR and enzyme hydrolysis. Nitric oxide (NO) production was evaluated in the lipopolysaccharide-activated microglial cell line, BV-2 to investigate the anti-neuroinflammatory effects of the isolated compounds (1-9). Compound 7 marginally inhibited NO levels with IC₅₀ values of 59.83 µM.

Design, synthesis and biological evaluation of fused naphthofuro[3,2-c] quinoline-6,7,12-triones and pyrano[3,2-c]quinoline-6,7,8,13-tetraones derivatives as ERK inhibitors with efficacy in BRAF-mutant melanoma

Approximately 60% of human cancers exhibit enhanced activity of ERK1 and ERK2, reflecting their multiple roles in tumor initiation and progression. Acquired drug resistance, especially mechanisms associated with the reactivation of the MAPK (RAF/MEK/ERK) pathway represent a major challenge to current treatments of melanoma and several other cancers. Recently, targeting ERK has evolved as a potentially attractive strategy to overcome this resistance. Herein, we report the design and synthesis of novel series of fused naphthofuro[3,2-c]quinoline-6,7,12-triones 3a-f and pyrano[3,2-c]quinoline-6,7,8,13-tetraones 5a,b and 6, as potential ERK inhibitors. New inhibitors were synthesized and identified by different spectroscopic techniques and X-ray crystallography. They were evaluated for their ability to inhibit ERK1/2 in an in vitro radioactive kinase assay. 3b and 6 inhibited ERK1 with IC50s of 0.5 and 0.19 µM, and inhibited ERK2 with IC50s of 0.6 and 0.16 µM respectively. Kinetic mechanism studies revealed that the inhibitors are ATP-competitive inhibitors where 6 inhibited ERK2 with a K_i of 0.09 µM. Six of the new inhibitors were tested for their in vitro anticancer activity against the NCI-60 panel of tumor cell lines. Compound 3b and 6 were the most potent against most of the human tumor cell lines tested. Moreover, 3b and 6 inhibited the proliferation of the BRAF mutant A375 melanoma cells with IC50s of 3.7 and 0.13 µM, respectively. In addition, they suppressed anchorage-dependent colony formation. Treatment of the A375 cell line with 3b and 6 inhibited the phosphorylation of ERK substrates p-90RSK and ELK-1 and induced apoptosis in a dose dependent manner. Finally, a molecular docking study showed the potential binding mode of 3b and 6 within the ATP catalytic binding site of ERK2.

High diastereoselective amine-catalyzed Knoevenagel-Michael-cyclization-ring-opening cascade between aldehydes, 3-arylisoxazol-5(4H)-ones and 3-aminocyclohex-2-en-1-ones

A highly diastereoselective three-component cascade reaction among aromatic aldehydes, 3-arylisoxazol-5(4H)-ones and 3-aminocyclohex-2-en-1-ones takes place under the catalysis of triethylamine, providing (3SR,4SR)-4-aryl-3-[(E)-(hydroxyimino)(aryl)methyl]-4,6,7,8-tetrahydroquinoline-2,5(1H,3H)-diones in 45-85% yields. The transformation presumably proceeds through a sequential cascade of Knoevenagel/Michael-addition/cyclization/ring-opening reactions. This process was carried out in green media (EtOH/water, 1:1-1:3) at reflux. Products are crystallized directly from the reaction mixture and their isolation includes only filtration. The structure of (3SR,4SR)-3-[(E)-(hydroxyimino)(phenyl)methyl]-7,7-dimethyl-4-phenyl-4,6,7,8-tetrahydroquinoline-2,5(1H,3H)-dione was confirmed by X-ray diffraction analysis.

Anti-Inflammatory Prenylated Phenylpropenols and Coumarin Derivatives from Murraya exotica

Three new prenylated phenylpropenols, exotiacetals A-C (1-3), 10 new coumarin derivatives, exotimarins A-I (4-13), and 35 known analogues (14-48) were isolated from the roots of Murraya exotica. The absolute configurations of the new compounds were assigned via comparison of their specific rotations, single-crystal X-ray diffraction data, Mosher's method, the ECD exciton coupling method, comparison of experimental and calculated ECD data, and the ECD data of the in situ formed transition metal complexes. Compounds 1-3, which possess an unprecedented hexahydro-1H-isochromen-1-ol system, are presumably biosynthesized from two prenylated p-coumaryl alcohol moieties via Diels-Alder [4+2] cycloaddition and cyclic hemiacetal formation reactions. Compounds 1, 28, 33, and 35 demonstrated inhibition against LPS-induced NO production in BV-2 microglial cells with IC₅₀ values of 8.6 ± 0.3, 11.8 ± 0.9, 15.5 ± 0.9, and 16.9 ± 1.0 μM, respectively.

Stereoselective synthesis of natural product inspired carbohydrate fused pyrano[3,2-c]quinolones as antiproliferative agents

Design and efficient synthesis of new carbohydrate fused pyrano[3,2-c]quinolone derivatives and their submicromolar anticancer activity.

Wacker-Type Oxidation Using an Iron Catalyst and Ambient Air: Application to Late-Stage Oxidation of Complex Molecules

A practical and general iron-catalyzed Wacker-type oxidation of olefins to ketones is presented, and it uses ambient air as the sole oxidant. The mild oxidation conditions enable exceptional functional-group tolerance, which has not been demonstrated for any other Wacker-type reaction to date. The inexpensive and nontoxic reagents [iron(II) chloride, polymethylhydrosiloxane, and air] can, therefore, also be employed to oxidize complex natural-product-derived and polyfunctionalized molecules.

Photoredox-catalyzed procedure for carbamoyl radical generation: 3,4-dihydroquinolin-2-one and quinolin-2-one synthesis

A reductive approach for carbamoyl radical generation from N-hydroxyphthalimido oxamides under photoredox catalysis is outlined. This strategy was applied to the synthesis of 3,4-dihydroquinolin-2-ones via the intermolecular addition/cyclization of carbamoyl radicals with electron deficient olefins in a mild, redox-neutral manner. Under a general set of reaction conditions, diversely substituted 3,4-dihydroquinolin-2-ones, including spirocyclic systems can be prepared. By using chlorine-substituted olefins, aromatic quinolin-2-ones can also be accessed.

Brønsted acidic ionic liquid catalyzed tandem reaction of 4-hydroxy-1-methyl-2-quinolone with chalcone: regioselective synthesis of pyrano[3,2-c]quinolin-2-ones

Task specific ionic liquid [1-methyl-3-(4-sulfobutyl)imidazolium-4-methylbenzenesulfonate] is an excellent catalyst for the synthesis of pyrano[3,2-c]quinolin-2-one derivatives.