Chromones from the stems of Cassia fistula and their anti-tobacco mosaic virus activities

Three new chromones, 5-methoxy-2,2-dimethyl-7-(2-oxopropyl)-2,3-dihydrochromen-4-one (1), 5-methoxy-2,2-dimethyl-8-(2-oxopropyl)-2,3-dihydrochromen-4-one (2), and 1-(3,4-dihydro-5-methoxy-2,2-dimethyl-2H-chromen-7-yl)propan-2-one (3), together with four known chromones (4–7) were isolated from the stems of Cassia fistula. Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D-NMR techniques. Compounds 1–5 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compound 5 exhibited high anti-TMV activity with inhibition rate of 30.8% at a concentration of 20 μM. The other compounds also exhibited potential anti-TMV activities with inhibition rates in the range of 15.6–22.1% at the same concentration.     

Three new phenolic glycosides from the whole plant of Aconitum tanguticum (Maxim.) Stapf

Three new phenolic glycosides 2-(3-O-β-d-glucopyranosyl-4-hydroxyphenyl) ethanol 1-O-β-d-glucopyranoside (1), 2-(4-O-β-d-fructopyranosylphenyl) ethanol 1-O-β-d-galactopyranoside (2) and 3-methoxy-4-O-β-d-allopyranosyl acetophenone (3), along with nine known compounds (4–12), were isolated from the ethanol extract of the whole plant of Aconitum tanguticum (Maxim.) Stapf. Their structures were elucidated by analysis of spectroscopic data including 1D-, 2D-NMR and HRESIMS, and the reported literature data comparison. All the compounds were evaluated for their potential anti-inflammatory effects by the inhibition of TNF-α production on LPS-stimulated RAW264.7 macrophages. Compounds 1, 3, 5 and 7–9 showed certain inhibition activity and their IC₅₀ values were 38.18, 27.64, 3.25, 84.45, 12.76 and 18.44 μg/mL, respectively.     

One new α-pyrone and one new fatty acid derivative from mangrove-derived fungus Phomopsis sp. HYP11

One new α-pyrone derivative (S)-3-(4-methoxy-3-methyl-2-oxo-2H-pyran-6-yl)butyl acetate (1) and one new fatty acid derivative (4S,5S)-5-acetoxy-4-hydroxyhexanoic acid (2), along with six known compounds (3–8) were obtained from the mangrove-derived fungus Phomopsis sp. HYP11. Their structures and absolute configurations were determined by detailed 1D and ²D NMR, HR-ESI-MS spectral, and quantum chemical electronic circular dichroism (ECD) calculations. Compounds 2, 3, 5, 6 and 8 showed antioxidant activity with the IC₅₀ values range of 0.09–0.67 mM, especially compounds 5 and 6 showed stronger antioxidant activity than the positive control trolox (IC₅₀ = 0.29 mM). Compound 8 showed weak antagonistic effect on Ralstonia solanacearum with the MIC value of 50 μg/mL.     

Investigation of fluorinated and bifunctionalized 3-phenylchroman-4-one (isoflavanone) aromatase inhibitors

Fluorinated isoflavanones and bifunctionalized isoflavanones were synthesized through a one-step gold(I)-catalyzed annulation reaction. These compounds were evaluated for their in vitro inhibitory activities against aromatase in a fluorescence-based enzymatic assay. Selected compounds were tested for their anti-proliferative effects on human breast cancer cell line MCF-7. Compounds 6-methoxy-3-(pyridin-3-yl)chroman-4-one (3c) and 6-fluoro-3-(pyridin-3-yl)chroman-4-one (3e) were identified as the most potent aromatase inhibitors with IC₅₀ values of 2.5 μM and 0.8 μM. Therefore, these compounds have great potential for the development of pharmaceutical agents against breast cancer.     

Bioactive compounds from Stuhlmannia moavi from the Madagascar dry forest

Bioassay-directed fractionation of the leaf and root extracts of the antiproliferative Madagascar plant Stuhlmannia moavi afforded 6-acetyl-5,8-dihydroxy-2-methoxy-7-methyl-1,4-naphthoquinone (stuhlmoavin, 1) as the most active compound, with an IC₅₀ value of 8.1 μM against the A2780 human ovarian cancer cell line, as well as the known homoisoflavonoid bonducellin (2) and the stilbenoids 3,4,5′-trihydroxy-3′-methoxy-trans-stilbene (3), piceatannol (4), resveratrol (5), rhapontigenin (6), and isorhapontigenin (7). The structure elucidation of all compounds was based on NMR and mass spectroscopic data, and the structure of 1 was confirmed by a single crystal X-ray analysis. Compounds 2?5 showed weak A2780 activities, with IC₅₀ values of 10.6, 54.0, 41.0, and 74.0 μM, respectively. Compounds 1?3 also showed weak antimalarial activity against Plasmodium falciparum with IC₅₀ values of 23, 26, and 27 μM, respectively.     

Synthesis and evaluation of pharmacological properties of some new xanthone derivatives with piperazine moiety

A series of new xanthone derivatives with piperazine moiety [1–7] was synthesized and evaluated for their pharmacological properties. They were subject to binding assays for α₁ and β₁ adrenergic as well as 5-HT_1A, 5-HT₆ and 5-HT_7b serotoninergic receptors. Five of the tested compounds were also evaluated for their anticonvulsant properties. The compound 3a 3-methoxy-5-{[4-(2-methoxyphenyl)piperazin-1-yl]methyl}-9H-xanthen-9-one hydrochloride exhibited significantly higher affinity for serotoninergic 5-HT_1A receptors (K_i = 24 nM) than other substances. In terms of anticonvulsant activity, 6-methoxy-2-{[4-(benzyl)piperazin-1-yl]methyl}-9H-xanthen-9-one (5) proved best properties. Its ED₅₀ determined in maximal electroshock (MES) seizure assay was 105 mg/kg b.w. (rats, p.o.). Combining of xanthone with piperazine moiety resulted in obtaining of compounds with increased bioavailability after oral administration.     

2-Thienyl-4-furyl-6-aryl pyridine derivatives: Synthesis,topoisomerase I and II inhibitory activity,cytotoxicity, and structure–activity relationship study

Designed and synthesized 60 2-thienyl-4-furyl-6-aryl pyridine derivatives were evaluated for their topoisomerase I and II inhibitory activities at 20 μM and 100 μM and cytotoxicity against several human cancer cell lines. Compounds 8, 9, 11–29 showed significant topoisomerase II inhibitory activity and compounds 10 and 11 showed significant topoisomerase I inhibitory activity. Most of the compounds (7–21) possessing 2-(5-chlorothiophen-2-yl)-4-(furan-3-yl) moiety showed higher or similar cytotoxicity against HCT15 cell line as compared to standards. Most of the selected compounds displayed moderate cytotoxicity against MCF-7, HeLa, DU145, and K562 cell lines. Structure–activity relationship study revealed that 2-(5-chlorothiophen-2-yl)-4-(furan-3-yl) moiety has an important role in displaying biological activities.     

Anti-tobacco mosaic virus phenylpropanoids from the stems of Nicotiana tabacum

Three new phenylpropanoids, 3-(6-methoxy-3-oxo-1, 3-dihydroisobenzofuran-5-yl)-3-oxopropyl acetate (1), 3-hydroxy-1-(6-methoxy-1, 3-dihydroisobenzofuran-5-yl)propan-1-one (2), and 3-hydroxy-1-(6- methyl-1, 3-dihydroisobenzofuran-5-yl)propan-1-one (3), together with three known phenylpropanoids (4–6) were isolated from the stems of Nicotiana tabacum. Their structures were examined using different spectroscopic techniques, including extensive 1D- and 2D NMR. Compounds 1–6 were also evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The anti-TMV results demonstrated that compounds 1 and 6 exhibited high anti-TMV activities, with inhibition rates of 34.6 and 35.4%, both of which were higher than the positive control (32.5%). The other compounds (2–5) also had anti-TMV activities, with inhibition rates between 16.8 and 28.6%.     

Identification and biological evaluation of flavonoids from the fruits of Prunus mume

This Letter describes the identification of potent antioxidant and anti-osteoporosis agents from the fruits of Prunus mume. From the methanol extract, a novel flavan dimer, characterized as 2β,3β-epoxy-5,7,4′-trihydroxyflavan-(4α → 8)-epicatechin (1), was isolated along with five known flavonoids (2–6). Their structures were determined based on extensive spectroscopic analysis, including IR, HRESIMS, 1D- and 2D-NMR, and CD spectra. The antioxidant activities of compounds 1–6 were evaluated in terms of their peroxyl radical-scavenging (Trolox equivalent) and reducing capacities. All isolates showed potent peroxyl radical-scavenging and reducing activities at concentrations of 1–10 μM. Among them, compounds 1 and 2 were the most active at 1 μM. Anti-osteoporosis activities were investigated using both murine osteoblastic MC3T3-E1 cells and osteoclastic RAW 264.7 cells. Compounds 2, 3, and 6 significantly stimulated the differentiation of osteoblastic MC3T3-E1 cells to increase collagen synthesis or mineralization functions of osteoblasts. Compounds 1, 3, 4, and 6 significantly suppressed tartrate-resistant acid phosphatase (TRAP) activity in receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastic RAW 264.7 macrophage cells.     

Three new benzophenone glycosides with MAO-A inhibitory activity from Hypericum thasium Griseb.

Purification of n-BuOH fraction from 80% ethanol extract of Hypericum thasium Griseb. resulted in the isolation of three new compounds 3′,4,5′-trihydroxy-6-methoxy-2-O-α-l-arabinosylbenzophenone (1), 3′,4,5′,6-tetrahydroxy-2-O-α-l-arabinosylbenzophenone (2), and 3′,4-dihydroxy-5′-methoxy-2-O-α-l-arabinosyl-6-O-β-d-xylosylbenzophenone (3) along with a known flavonoid glycoside quercetin-3-O-α-l-arabinofuranoside (4). The structures of the new compounds were elucidated by 1D and 2D NMR analysis as well as HRESIMS. The isolated compounds (1–4), as well as quercetin, and kaempferol previously isolated from EtOAc fraction were screened against MAO-A inhibitory activity. When tested against the MAO-A quercetin and kaempferol displayed IC₅₀ values of 19.6, and 17.5 μM, respectively. The IC₅₀ values for MAO-A inhibition by compounds (1–4) were 310.3, 111.2, 726.0, and 534.1 μM, respectively. Standard inhibitor (clorgyline) exhibited MAO-A inhibition with an IC₅₀ value of 0.5 μM.     

Phytochemicals from the stem wood of Sorbus lanata (D. Don.) Schauer

Three new phenolic compounds, sorlanin (4-(3-(hydroxymethyl)-5-methoxy-7-phenyl-2,3-dihydrobenzo[b][1,4]dioxin-2-yl)-2-methoxyphenol, 1), sorbanin (2-((3,5-dimethoxy-[1,1′-biphenyl]-4-yl)oxy)-1-(4-hydroxy-3-methoxyphenyl)propane-1,3-diol, 2) and sorbalanin (4-(3-(hydroxymethyl)-5,6-dimethoxy-2,3-dihydrobenzo[b][1,4]dioxino[2,3-g]benzofuran-2-yl)-2-methoxyphenol, 3), together with eight known compounds, polystachyol (4), isolariciresinol (5), dihydrodehydrodiconiferyl alcohol (6), tuberculatin (7), ovafolinin E (8), aucuparin (9), 2′-methoxyaucuparin (10), and tetracosyl-3-(3,4-dihydroxyphenyl)acrylate (11), were isolated from Sorbus lanata. The structures of these phytoconstituents were elucidated through extensive spectroscopic techniques, including UV, IR, 1D and 2D NMR, ESI-MS and HRESI-MS experiments. All the compounds except 9 and 10 were isolated for the first time from the genus Sorbus. The isolated compounds were also tested in DPPH radical scavenging reaction where compounds 6, 7, 10 and 11 showed significant activities with IC₅₀ values of 9.2, 11.7, 23.0 and 33.7 μM, respectively.     

Schiff’s base derivatives bearing nitroimidazole moiety: New class of antibacterial,anticancer agents and potential EGFR tyrosine kinase inhibitors

New Schiff’s base derivatives 5a–5h have been synthesized by reaction between 1-(4-bromophenyl)-2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethanone 3 and various benzohydrazide 4a–4h in presence of nickel (II) nitrate as a catalyst in ethanol at room temperature in good yield (54–88%). All compounds were tested for antibacterial as well as anticancer and inhibition of EGFR. Of the compounds studied, compounds 5d, 5f and 5g in the case of antiproliferation and inhibition of EGFR as well as compounds 5b, 5c, 5e and 5h in the case of antibacterial activity were found to be most effective compounds in the series. Compound 5f shows effective inhibition (IC₅₀ = 0.21 ± 0.02 μM) by binding in to the active pocket of EGFR receptor with minimum binding energy (ΔG_b = ?49.4869 kcal/mol).     

New p-terphenyls from the endophytic fungus Aspergillus sp. YXf3

Five new p-terphenyls named prenylterphenyllin D (1), prenylterphenyllin E (2), 2′-O-methylprenylterphenyllin (3), 4-O-methylprenylterphenyllin (4) and 3′-O-methylterphenyllin (5) together with seven known compounds (6–12), were isolated from cultures of Aspergillus sp. YXf3. The structures of the new compounds were elucidated by extensive MS and NMR analyses. The NMR and MS data of 5 is reported for the first time, as its structure was listed in SciFinder Scholar with no associated reference. Compounds 6 and 7 were distinguished from each other on the basis of 2D NMR experiments. Compounds 1, 2, 3 and 8 showed antibacterial activities against X. oryzae pv. oryzicola Swings and E. amylovora with the same MIC values of 20 μg/mL while 10 exhibited activities against E. amylovora with an MIC value of 10 μg/mL.     

Tirucallane triterpenoids from the stem bark of Araliopsis synopsis

Two new tirucallane triterpenoids, 21-methoxy-21,23-epoxy-tirucalla-7,24-dien-3α-ol (1) and 21-methoxy-21,23-epoxy-tirucalla-7,24-diene-1α,3α-diol (2), together with thirteen known compounds were isolated from the CH₂Cl₂ extract of the stem bark of Araliopsis synopsis. The structures of the compounds were determined by comprehensive analyses of their 1D and 2D NMR, mass spectral (EI and ESI) data and comparison with previously known analogs. Compounds 1–10 were tested against bacteria, fungi and plant pathogen oomycetes by the paper disk agar diffusion assay resulting in missing to low activities corresponding with MICs > 1 mg/mL. However, compounds 5–10 exhibited high cytotoxic activity against the human Caucasian prostate adenocarcinoma cell PC-3 line, with IC₅₀ 8.5–12.5 μM compared to the standard Doxorubicin with IC₅₀ = 0.9 μM, while compounds 1, 3 and 4 showed low activity.     

Four new triterpenoidal saponins from Ilex cornuta and their cytotoxic activities

Four new triterpenoidal saponins (1–4), oleanolic acid 3β-O-α-l-arabinopyranosyl-(1 → 2)-β-d-glucuronopyranoside-6-O-butyl ester (1), oleanolic acid 3β-O-[α-l-arabinopyranosyl-(1 → 2)-β-d-glucuronopyranoside-6-O-butyl ester]-28-O-β-d-glucopyranoside (2), 19α-hydroxy oleanolic acid 3β-O-β-d-glucuronopyranoside-6-O-methyl ester (3), and 19α-hydroxy urs-12-en-28-oic acid 3β-O-α-l-arabinopyranosyl-(1 → 2)-β-d-glucuronopyranoside-6-O-methyl ester (4) were isolated from the roots of Ilex cornuta. Their structures were determined by means of extensive spectroscopic analyses (IR, ESIMS, HRESIMS, 1D and 2D NMR). Compounds 1–9 were tested for their cytotoxic activities by MTT assay, and 1, 3, 5 and 6 showed moderate cytotoxic activities against HeLa, SMMC-7721, and HL-60 human tumor cell lines.     

Neolignans and phenylpropanoids from the roots of Piper taiwanense and their antiplatelet and antitubercular activities

Bioassay-guided fractionation of roots from Piper taiwanense led to isolation of three neolignans, diallylcatechol (1) and neotaiwanensols A, B (2, 3), two diphenylpropanoid ethers, taiwandimerols A, B (4, 5), with one phenylpropanoid, 2,3-diacetoxy-1-methoxy-5-allylbenzene (6), previously unknown in nature, together with 18 known compounds (7–24). Their structures were elucidated by spectroscopic evidence. Among the isolates, hydroxychavicol acetate (7), and 4-allylcatechol (8) showed potent inhibitory activities against platelet aggregation induced by collagen, with IC₅₀ values of 2.1, and 5.3 μM, respectively. Hydroxychavicol acetate (7), 4-allylcatechol (8), and trans-caffeicaldehyde (9) showed antitubercular activities against Mycobacterium tuberculosis H₃₇Rv, with MIC values of 30.3, 27.6, and 25.5 μg/mL, respectively.     

Design,synthesis of 2,3-disubstitued 4(3H)-quinazolinone derivatives as anti-inflammatory and analgesic agents: COX-1/2 inhibitory activities and molecular docking studies

A new series, 2-substituted mercapto-3-[2-(pyridin-2-yl)ethyl]-4(3H)-quinazolinone 1–21, was synthesized and evaluated for in vivo anti-inflammatory and analgesic activities and in vitro COX-1/COX-2 inhibition. Compounds 1, 4, 5, 6, 8, 10, 13, 14, 15, 16, and 17 exhibited potent anti-inflammatory and analgesic properties, with ED₅₀ values of 50.3–112.1 mg/kg and 12.3–111.3 mg/kg, respectively. These values may be compared with those of diclofenac sodium (ED₅₀ = 112.2 and 100.4 mg/kg) and celecoxib (ED₅₀ = 84.3 and 71.6 mg/kg). Compounds 4 and 6 possessed strong COX-2 inhibitory activity with IC₅₀ (0.33 μM and 0.40 μM, respectively) and selectivity index (SI > 303.0 and >250.0, respectively) values that are similar to those of the reference drug celecoxib (IC₅₀ 0.30 μM and COX-2 SI > 333). Compounds 5, 8, and 13 demonstrated effective COX-2 inhibitory activity with IC₅₀ values of 0.70–0.80 μM and COX-2 SI > 125–142. Potent COX-2 inhibitors, such as compounds 4, 6, and 13, were docked into the active site pockets of COX-1 and COX-2, with the greatest recognition occurring at the COX-2 binding site and insignificant interactions at the binding site of the COX-1 pocket.     

Synthesis,estrogen receptor binding affinity and molecular docking of pyrimidine-piperazine-chromene and -quinoline conjugates

Substituted 2-amino-7-((6-(4-(2-hydroxyethyl) piperazin-1-yl)-2-methylpyrimidin-4-yl)oxy)-4-phenyl-4H-chromene-3-carbonitriles and 2-amino-7-((6-(4-(2-hydroxyethyl)piperazin-1-yl)-2-methylpyrimidin-4-yl)oxy)-4-phenyl-1,4-dihydroquinoline-3-carbonitriles were synthesized via an efficient multi-component one pot synthesis under mild conditions. These compounds 1–20 were evaluated against human breast cancer cell lines (MCF-7) and human embryonic kidney cells (HEK293) for cytotoxic activities. Among them, compounds 6, 7, 15, 17 and 19 showed better anti-proliferative activities as (IC₅₀ value 48 ± 1.70, 65 ± 1.13, 92 ± 1.18, 30 ± 1.17 and 16 ± 1.10 µM) than curcumin drug (48 ± 1.11 µM). Molecular docking was also performed with active compounds 6, 7 and 15 against Bcl-2 protein which gave good binding affinity (ΔG = ?9.08, ?8.29 and ?7.70 kcal/mol) respectively. Furthermore, the structure-activity relationship (SAR) analysis revealed that the chromene and quinoline moieties, when attached with pyrimide and piperazine moieties, enhanced anti-proliferative activities.     

Synthesis and positive inotropic evaluation of [1,2,4]triazolo[3,4-a]phthalazine and tetrazolo[5,1-a]phthalazine derivatives bearing substituted piperazine moieties

Four series of [1,2,4]triazolo[3,4-a]phthalazine and tetrazolo[5,1-a]phthalazine derivatives bearing substituted piperazine moieties were synthesized and evaluated for their positive inotropic activity by measuring the left atrium stroke volume in isolated rabbit-heart preparations. Several compounds were developed and showed favorable activities compared to the standard drug milrinone, with (4-([1,2,4]triazolo[3,4-a]phthalazin-6-yl)piperazin-1-yl)(p-tolyl)methanone (5g) being identified as the most potent with an increased stroke volume of 19.15 ± 0.22% (milrinone: 2.46 ± 0.07%) at a concentration of 3 × 10^–5 M. A preliminary study of mechanism of action revealed that 5g displayed its positive inotropic effect may be related to the PDE-cAMP-PKA signaling pathway. Compounds exhibiting inotropic effects were also evaluated in terms of the chronotropic effects.     

Three new isobenzofurans from Lavandula angustifolia and their bioactivities

Three new isobenzofurans, lavandulactones A–C (1–3), together with three known ones (4–6), were isolated from the whole herb of Lavandula angustifolia. Their structures were established on the basis of detailed spectroscopic analysis (1D- and 2D-NMR, HRESIMS, UV, and IR) and comparison with data reported in the literature. New isolates were evaluated for their anti-tobacco mosaic virus (TMV) activities and cytotoxicity activities. The results revealed that compounds 1–3 showed high anti-TMV activity with inhibition rate of 31.8, 29.6 and 33.4%, respectively. These rates are higher than that of positive control. Compounds 1–3 also showed weak inhibitory activities against some tested human tumor cell lines with IC₅₀ values ranging from 1.5 to 5.7 μM.