Two ring opened oxetane taxoids containing a C-20 benzoyloxy group from the roots of Taxus wallichiana Zucc.

Two new taxanes, named wallitaxane G (1) and H (2), were isolated from the roots of Taxus wallichiana (Taxaceae), together with nine known compounds (3?11). Their structures were elucidated on the basis of NMR spectroscopic analysis and the relative configurations of 1 and 2 were determined based on NOESY data. Wallitaxane H (2) showed the most potent α-glucosidase inhibitory activity, with an IC₅₀ value of 16.1 μM. Plausible biosynthetic pathways for the formation of 1 and 2 were proposed based on oxetane ring-opening and benzoyl migration.     

Coumarins and flavones from the fruit and root extracts of Micromelum integerrimum

A phytochemical investigation of the fruit and root extracts of Micromelum integerrimum resulted in the isolation and identification of a new compound, integerravone (1), together with 23 known compounds (2–24). Their structures were characterized by spectroscopic methods as well as comparisons made from the literature. Compounds 2, 3–15, 17–18 and 20–23 were evaluated for their cytotoxicities against the colon cancer cell line, HCT116. All of them were inactive at 50?µM. Most of the phenolic compounds were evaluated for their antioxidant activity using the DPPH assay. Compounds 14 and 22–24 showed antioxidant activity with IC₅₀ values ranging from 24.83-135.05?µM.     

Fluorescent properties of coumarins with dual functions constructed by two sequential reactions

A series of coumarins with two aryl moieties was constructed from 3-azide-6-bromocoumarin scaffold by means of two sequential reactions, Huisgen 1,3-cycloaddition and Suzuki-Miyaura coupling reactions. Evaluation of their fluorescence properties indicated that the mode of fluorescent change by substituted group on each aryl group would be different. So this structure could be promising candidates as multi-analyte type fluorescent sensors, whose mode of spectroscopic changes, such as fluorescence intensity, and absorption or fluorescence maximum wavelength, are different for each analyte.     

Simple and convenient conversion of acridones into 9-unsubstituted acridines via acridanes using borane tetrahydrofuran complex

A new method for the synthesis of 9-unsubstituted acridines from acridones using mild conditions is described. Various acridines bearing reduction-sensitive group(s) have been synthesized from the corresponding acridones using a two-step procedure that involved a commercially available borane complex reduction followed by an acridane oxidation.     

Chemical Constituents from the Root Bark of Formosan Zanthoxylum Ailanthoides

Two new N‐isobutylamides, hydroxy lanyuamide I ( 1 ) and hydroxy lanyuamide II ( 2 ), together with one hundred and ten known compounds, have been isolated from the root bark of Formosan Zanthoxylum ailanthoides. These known compounds include twenty coumarins, twenty‐one benzo[c]phenanthridines, ten quinoline derivatives, one aporphine, one purine, seven amides, twelve benzenoids, one lactone, four flavonoids, nine lignans, eight steroids, two chlorophylls, eleven terpenoids and three other compounds, which were determined by means of spectral analyses.     

LC-MS characterization of bioactive metabolites from two Yemeni Aloe spp. with antioxidant and antidiabetic properties

Two Yemeni Aloe(s) have been investigated; the resin from A. perry Baker (APR, Socotran Aloe), and the gel from A. vera (AVG, Saber Yamaniis). LC-MS for APR identified aloin B, aloinoside B/A, homonataloin B and microdontin B/A as the major components, constituting 67.7% w/w of the extract. AVG showed the same pattern of anthrones (19.5% w/w), in addition to the chromones aloesin, aloeresin A, aloeresin D and aloeresin E. Dihydro-isocoumarin glucoside was identified in both Aloe species. Aloe extracts showed high antioxidant activity: DPPH (0.09 & 0.05 mM/g TE), ABTS (0.06 & 0.03 mM/g TE), and FRAP (20.5 & 15.5 mM Fe⁺²E), for APR & AVG, respectively. The antidiabetic properties was evaluated through inhibition of α-glucosidase enzyme. APR showed inhibitory activity with IC₅₀ 0.76 μg/mL higher than AVG (IC₅₀ 0.76 mg/mL). Aloin A showed the highest inhibitory activity with IC₅₀ 0.34 mg/mL that was higher than acarbose (0.54 mg/mL) the positive control, indicating that the activity of Aloe extract is linked to the aloin and other anthrone compounds. These findings highlight the phytochemical profile, antioxidant and potential antidiabetic activity of the Yemeni Aloe species and draw attention to their potential application in food, medicine and cosmetic products.     

A new coumarin from the roots of Micromelum minutum

A new coumarin, minutuminolate (1), together with eleven known coumarins (2–12), was isolated from the roots of Micromelum minutum. The structures of these compounds were established on the basis of their 1D and 2D NMR spectroscopic data. Compounds 2, 5, 10, 11 and 12 showed cytotoxicity against KB cell line. In addition, compounds 2, 3, 4, 7, 11 and 12 also showed weak cytotoxicity against NCI-H187 cell line.     

A New Sesquiterpene, α‐Santalane‐11,12,13‐Triol from the Root Bark of Severinia Buxifolia in Hainan

Anew sesquiterpenoid, α‐santalane‐11,12,13‐triol, together with thirty known compounds were isolated and characterized from the root bark of Severinia buxifolia in Hainan. Their structures were determined by spectroscopic methods. The relationship between constituents and collecting area is also discussed.     

Sesquiterpene coumarins from the roots of Ferula sinkiangensis and Ferula teterrima

Three new natural sesquiterpene coumarins, isofeterin (1), lehmannolol (3), sinkianone (4), and one known compound, lehmannolone (2), were isolated from the roots of Ferula teterrima and Ferula sinkiangensis. Their chemical structures were established on the basis of spectroscopic analysis, including X-ray crystallography and CD spectrum measurements for determining the absolute configuration of compound 2.     

Simultaneous separation and purification of five bioactive coumarins from the Chinese medicinal plant Cnidium monnieri by high-speed counter-current chromatography

Cnidium monnieri (L.) Cusson is a well-known Chinese medicinal plant, which has been used for the treatment of impotence, frigidity, and skin-related diseases, and exhibits strong antipruritic, antiallergic, antidermatophytic, antibacterial, antifungal, and antiosteoporotic activities. A high-speed counter-current chromatography method was developed for the separation and purification of five bioactive coumarins from this plant. The crude coumarins were obtained by ethanol extraction from the dried fruits of Cnidium monnieri (L.) Cusson under sonication. High-speed counter-current chromatography with the two-phase solvent systems n-hexane-ethyl acetate-ethanol-water (5:5:4:6, v/v) and n-hexane-ethyl acetate-ethanol-water (5:5:6:4, v/v) was successfully performed with stepwise elution. The five relatively pure coumarins were obtained from 500 mg of the crude extract in a single run. Their purities were 90.6-98.9%, and the recoveries were 85.7-94.2%.     

Chemical Constituents from the Leaves of Zanthoxylum Schinifolium

cis‐Fagaramide ( 1 ), a new amide, together with fifty known compounds, have been isolated from the leaves of Zanthoxylum schinifolium. These known compounds include twenty‐one coumarins, eleven alkaloids, one furan, four benzenoids, three chlorophylls, four triterpenoids, one diterpenoid, one sesquiterpenoid, and four steroids. The structures of these compounds were determined by means of spectral analyses.     

Biflavanones, diterpenes, and coumarins from the roots of Stellera chamaejasme L

A new biflavanone (1) with a C-3/C-3" linkage, a new daphnane-type diterpene (2) acylated by an unsaturated fatty acid, and a new coumarin glycoside (3), along with six lignans, two phenylpropanoids, five flavonoids, two diterpenes, and three coumarins were isolated from the roots of Stellera chamaejasme L. (Thymelaeaceae). Elucidation of these secondary metabolites of S. chamaejasme L. supplied strong chemical verification of the close taxonomic relationships among the genera Stellera, Daphne, and Wikstroemia, all of which belong to the family Thymelaeaceae.     

Synthesis of 3-sulfonyl coumarins through radical sulfonylation with disulfides under catalyst-free conditions

An efficient and convenient aryl sulfonyl introducing strategy for the synthesis of 3-sulfonyl coumarins via ipso-cyclization/1,2-ester migration from substituted phenyl 3-phenylpropiolates with disulfides and potassium persulfate as sulfonylating reagents was developed, halogen and many other electron-withdrawing or -donating functional groups are tolerated. When naphthalen-1-yl 3-phenylpropiolate was used as a starting material, a spiro compound was obtained via ipso-cyclization.     

Kallisteine A and B, two new coumarins from the roots of Peucedanum paniculatum L, a species endemic to Corsica

From the dichloromethane extract of the roots of Peucedanum paniculatum L., two new coumarins, a species endemic to Corsica, have been isolated. Their structures were elucidated, on the basis of spectroscopic studies, particularly 1D and 2D NMR spectroscopy, as 6-(7'-beta-cyclolavandulyl)-7-hydroxycoumarin 1 and a spirodihydrofurano-coumarin 2 (Kallisteine A and B).     

Carbazole-pyranocoumarin conjugate and two carbazole alkaloids from the stems of Clausena excavata

A carbazole-pyranocoumarin conjugate, carbazomarin B (1), and two carbazole alkaloids, 6-methoxymukonidine (2) and 2-hydroxy-3-methoxycarbazole (3), together with 27 known compounds (4–30), were isolated from the stems of Clausena excavata. Their structures have been elucidated by spectroscopic analyses. Compound 2 showed moderate cytotoxicity to HuCCA-1, MOLT-3 and HepG2 cancer cell lines with IC₅₀ values of 15.09–28.50 μg/mL, but none to A549 cell line. Heptaphylline (6) and nordentatin (23) were found to show moderate cytotoxic activity against HepG2 cell line with IC₅₀ values of 12.33 and 11.33, respectively, while clausine K (27) exhibited strong cytotoxicity with IC₅₀ value of 1.05 μg/mL, better than a standard drug (etoposide, IC₅₀ 13.40 μg/mL).     

Feroniellins A-C, novel cytotoxic furanocoumarins with highly oxygenated C10 moieties from Feroniella lucida

Three new furanocoumarins, named feroniellins A (1), B (2), and C (3), were isolated from the roots of Feroniella lucida. Compounds 1-3 are novel structures having an oxolane, oxane, and oxepane moiety. Their overall structures and configurations were determined by spectral and chemical methods. The cytotoxicities of 1-3 were evaluated against human KB and HeLa carcinoma cells.     

Green and enhanced extraction of coumarins from Cortex Fraxini by ultrasound‐assisted deep eutectic solvent extraction

Green and enhanced extraction of bioactive ingredients from medicinal plants has become a hot research field, and deep eutectic solvents have been considered as a novel kind of sustainable solvents in the extraction process. In this study, hydrogen bond acceptor (choline chloride, etc.) and hydrogen bond donor (l ‐malic acid, etc.) were used to prepare different kinds of deep eutectic solvents to extract coumarins from Cortex Fraxini. The extraction conditions, including the composition and moisture content of deep eutectic solvents, extraction time, and liquid‐solid ratio, were systematically optimized basing on the extraction yield of coumarins. To further investigate the extraction mechanism, Fourier transform infrared spectroscopy was performed, and the microstructures of Cortex Fraxini powders were observed before and after extraction using scanning electron microscope. Results showed that the novel ultrasound‐assisted extraction with conditions of deep eutectic solvent containing betaine/glycerin (1:3), aqueous solution (20%), solid‐liquid ratio (15 mg/mL), and extraction time (30 min) exhibited the best extraction yields for the four target coumarins and much better extraction efficiency than with conventional solvent extractions. This suggests that the new ultrasound‐assisted deep eutectic solvent extraction could be used as a green and high‐efficient approach for extraction of the main coumarins from Cortex Fraxini.     

Two new quinolone alkaloids from the nearly ripe fruits of Tetradium ruticarpum

Abstract

Tetradium ruticarpum (Juss.) Benth. belong to the family of Rutaceae. The complete and nearly ripe fruits of T. ruticarpum is used as traditional Chinese medicine and phytochemical investigations have been conducted on extracts of the seeds of T. ruticarpum to provide scientific validation of its properties. In this study, we successfully isolated two new quinolone alkaloids (1-2) from the MeOH extractive of nearly ripe fruits of T. ruticarpum. The structure elucidation of these compounds was determined by one- and two-dimensional nuclear magnetic resonance, ultraviolet and electrospray ionisation time-of-flight mass spectrometry. This finding expands the understanding of the natural constituents of the Rutaceae, in particular, the Tetradium genera.