Chemical constituents from bulbs of Fritillaria pallidiflora Schrenk

A new steroidal alkaloid, 5α, 14α, 17β-cevanin-6-oxo-3β, 20β, 24β-triol(1), together with ten known compounds (2–11) were isolated from the bulbs of Fritillaria pallidiflora Schrenk. Their structures were determined on the basis of spectroscopic analysis and by comparison of their spectral data with those reported in the literature. Compounds 8, 9, 10 were obtained from the genus Fritillaria for the first time; Compounds 2, 3, 4 and 11 are isolated from this plant for the first time.     

Diterpenoids from the root bark of Jatropha curcas and their cytotoxic activities

Three new diterpenoids, named epi-jatrophol (1), jatrophaldehyde (2) and epi-jatrophaldehyde (3), along with nine known ones (4–12), were isolated from the root bark of Jatropha curcas. The new compounds were identified by spectroscopic data, and their relative configurations were confirmed by X-ray crystallography or chemical methods. The cytotoxic activities of the isolated compounds were evaluated against HEPG2 and LOVO tumor cell lines. Compounds 8, 9 and 10 were found to be cytotoxic toward HEPG2 cells for the first time.     

Structures and biological evaluation of phenylpropanoid derivatives from Murraya koenigii

Four new phenylpropanoid derivatives (1–4), together with eleven known analogues (5–15) were isolated and identified by comparison with their references and extensive spectroscopic methods from Murraya koenigii for the first time. Compounds (1–15) were assayed for their inhibitory activities by measuring IL-6-induced STAT3 promoter activities in HepG2 cells, and found compounds 1, 2, 6, and 15 showed inhibitory effects with IC₅₀ values of 11.5, 18.7, 8.9, and 22.7 μM, respectively. The inhibitory activities of compounds (1–15) were screened against NO production in lipopolysaccharide (LPS)-induced RAW264.7 macrophage cells, and found compounds 3, 4, 9, 11, and 14 exhibited inhibitions against LPS-induced NO production in RAW264.7 macrophages, with IC₅₀ values of 32.7, 7.9, 42.1, 58.9, and 62.4 μM, respectively.     

Chemical constituents from Artemisia argyi and their chemotaxonomic significance

Twelve compounds, including one monoterpene (1), two sesquiterpene lactones (2–3), six flavonoids (4–9), one phenolic glycoside (10), one chromone (11) and one phenolic acid (12), were isolated and identified from the leaves of Artemisia argyi. Compounds 1–2, 4 and 6–7 have not been recorded before in this plant. Compounds 3, 9 and 11 were isolated from the genus Artemisia for the first time. This paper is the first report on the presence of compound 10 in species of Asteraceae. In addition, the chemotaxonomic significance of these compounds was summarized.     

Prenylated chalcones from Desmodium renifolium

Three new prenylated chalcones, renifolins A–C (1–3), together with seven known ones (4–10), were isolated from whole Desmodium renifolium plants. All of their structures were determined by spectroscopic methods including 1D and 2D NMR. Compounds 1 and 2 are the first naturally occurring chalcones possessing a 4-methylfuran-2(5H)-one unit. All of the isolates were evaluated for cytotoxicity using five tumor cell lines. Compounds 3–8, and 10 exhibited moderate cytotoxicity against certain cell lines with IC₅₀ values from 4.2 to 8.8 μM.     

Abietane diterpenoids and other constituents from Clerodendrum trichotomum

The genus Clerodendrum Linn., originally belonging to Verbenaceae, was assigned to Lamiaceae by APG (Angiosperm Phylogeny Group) Ⅱ. Seven abietane diterpenoids (1–7) along with three anthraquinones (8–10) and one neolignan (11) were isolated and identified from the stems of Clerodendrum trichotomum Thunb.. Among them, compounds 4, 6 and 8–11 were reported from the genus Clerodendrum Linn. for the first time. Compounds 1, 3 and 7 were obtained from this species for the first time. Isolation of abietane diterpenoids from C. trichotomum could further comfirm that the genus Clerodendrum belongs to Lamiaceae rather than Verbenaceae.     

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.     

Nigrosphaerin A a new isochromene derivative from the endophytic fungus Nigrospora sphaerica

Nigrosphaerin A, a new isochromene derivative (1), was isolated from the endophytic fungus Nigrospora sphaerica and chemically identified as 3-(3,4-dihydroxyphenyl)-4,6,8-trihydroxy-1H-isochromen-1-one-6-O-β-d-glucopyranoside. In addition nineteen known compounds (2–20) were isolated from the same fungus and chemically identified. Compounds (1–3, 5, and 7–16) were isolated for the first time from this fungus. In vitro antileukemic, antileishmanial, antifungal, antibacterial and antimalarial activities of (1–20) were examined. Compounds 5, 7, 9 and 10 showed good antileukemic activity against HL60 cells with IC₅₀ values of 0.03, 0.39, 0.2 and 0.4 μg/mL, respectively and against K562 cells with IC₅₀ values of 0.35, 0.35, 0.49 and 0.01 μg/mL, respectively. Compounds 3, 4 and 6 showed moderate antileishmanial activity with IC₅₀ values of 30.2, 26.4 and 36.4 μg/ml, respectively. Compound 7 showed moderate antifungal activity against Cryptococcus neoformans with IC₅₀ value of 14.8 μg/mL.     

Three new arylbenzofurans from Lavandula angustifolia and their bioactivities

Three new arylbenzofurans, 2-(7-methoxy-2-(4-methoxyphenyl)-3-methylbenzofuran-5-yl)ethanol (1), 4-(5-(2-hydroxyethyl)-7-methoxy-3-methylbenzofuran-2-yl)phenol (2), and 2-(6-methoxy-2-(4- methoxyphenyl)-3-methylbenzofuran-5-yl)ethanol (3), together with three known ones (4–6) were isolated from the whole plant of Lavandula angustifolia. Their structures were determined by means of HRESIMS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1–3 and 5 were tested for their anti-tobacoo mosaic virus (TMV) activities, and Compounds 1–6 were tested for their cytotoxicity activities. In our assay, Compounds 1–3 showed high anti-TMV activity with inhibition rate of 38.2, 35.2, and 34.0%, which superior to positive control Ningnanmycin. Compounds 1–6 also showed weak inhibitory activities against some tested human tumor cell lines with IC50 values in the range of 2.2–8.2 μM.     

Chemical constituents from Phlomis bovei Noë and their chemotaxonomic significance

A phytochemical investigation of the leaves and roots of Phlomis bovei Noë (Lamiaceae) led to the isolation of sixteen compounds, including iridoids (1, 2, 3), megastigmanes (4, 5), phenylpropanoids (6, 7, 8, 9, 10), lignans (11, 12, 13, 14), a nortriterpene (15), and a phenyl glucoside (16). Compounds (1, 2, 4, 5, 6, 10) were obtained from the leaves and compounds (1, 2, 3, 7, 8, 9, 11, 12, 13, 14, 15, 16) were isolated from the roots. Compounds 1 and 2 were found both in the leaves and in roots.The compounds were identified by analysis of 1D- (¹H, ¹³C), 2D-NMR (¹H–¹H COSY, TOCSY, ROESY, HSQC, HMBC) spectroscopic data, mass spectrometry (ESI- and HR-ESI-MS), and by comparison with previously reported spectral data.Compounds 5, 9, 10, 13 and 14 were isolated from the genus Phlomis for the first time. All these specialized metabolites were described here for the first time in the Algerian Phlomis bovei Noë species. To the best of our knowledge, no reports have appeared on the constituents of the roots of P.bovei Noë. The chemotaxonomic significance of these compounds was summarized.     

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.     

Chemotaxonomic significance of limonoids and triterpenoids from Dictamnus angustifolius G. Don ex Sweet

Phytochemical investigation of the root bark of Dictamnus angustifolius G. Don ex Sweet (Rutaceae) resulted in the isolation and characterization of three degraded limonoids (1–3), five limonoids (4–8) and four triterpenoids (9–12). All structures were elucidated on the basis of spectral analysis. Among them, compounds 4, 6, 8, 9 and 12 were isolated from the genus Dictamnus for the first time. Compounds 10 and 11 were obtained from D. angustifolius for the first time. Moreover, the chemotaxonomic significance of these compounds was summarized.     

Three new xanthones from the stems of Garcinia oligantha and their anti-TMV activity

For more bioactive compounds, phytochemical investigations of the acetone extract of the stems of Garcinia oligantha resulted in the isolation of three new xanthones (1–3) and five known analogues (4–8). Structural elucidations of 1–3 were performed by spectral methods such as 1D and 2D (HMQC, HMBC, and ROESY) NMR spectroscopy, in addition to high resolution mass spectrometry. Compounds 1, 2, 6, 7, and 8 showed anti-tobacco mosaic virus (anti-TMV) activities with inhibition rates above 10%.     

Chemical constituents from the leaves of Cinnamomum parthenoxylon (Jack) Meisn. (Lauraceae)

Phytochemical investigation of the ethanolic extract from the leaves of Cinnamomum parthenoxylon (Jack) Meisn. led to the isolation of (3R, 4R, 3′R, 4′R)-6,6′-dimethoxy-3, 4, 3′, 4′-tetrahydro-2H, 2′H-[3, 3′]bichromenyl-4, 4′-diol (1), 4-hydroxybenzaldehyde (2), 1,2,4-trihydroxybenzene (3), kaempferol-3-O-α-l-rhamnoside (4), herbacetin (5), quercetin-3-O-α-l-rhamnoside (6), daucosterol (7), and β-sitosterol (8). The structures were established by extensive analysis of their MS and NMR spectroscopic data and comparison with literature data. In the present research, all of the isolated compounds 1–8 are reported for the first time in the species C. parthenoxylon. Compounds 1–6 were firstly isolated from genus Cinnamomum. Compounds 1, 3, 5 and 6 have not been reported from any species in Lauraceae family. The chemotaxonomic significance of the isolated compounds is discussed.     

Isolation of three new meroterpenoids and seven known compounds from Albatrellus yasudae and their Aβ-aggregation inhibitory activity

Alzheimer’s disease is a serious neurologic disorder that cannot be cured completely. In this study, we targeted compounds that inhibit amyloid-beta (Aβ) aggregation, based on the amyloid cascade hypothesis. Ten compounds (1–10) were isolated from CHCl₃ extracts of the mushroom Albatrellus yasudae using Aβ-aggregation inhibitory activity–guided separation. The structures of these compounds were elucidated from 1D and 2D NMR and MS spectral data. Compounds 1–3 were novel, whereas 4–10 were identified as the known compounds grifolin, grifolic acid, neogrifolin, confluentin, 2-hydroxyneogrifolin, daurichromenic acid, and a cerebroside derivative. Compounds 1–10 were tested for Aβ-aggregation inhibitory activity. Compounds 1, 3, 5, 6, 8, and 9 have potential as Aβ-aggregation inhibitory activity.     

Chemical constituents from Anemone vitifolia Buch.-Ham. (Ranunculaceae)

A phytochemical investigation of Anemone vitifolia (Buch.-Ham.) led to the isolation of twelve compounds, including six lignans (1–6), four benzoic acid esters (7–10), one norsesquiterpenoid (11) and one lactone (12). The structures of these metabolites were established on the basis of detailed spectroscopic analysis, as well as comparisons with the data available in the literature. Among them, compounds 10 (dimethyl 2-(benzoyloxy)succinate) and 12 (4-hydroxy-5-methyl-γ-butyrolactone) were isolated for the first time as natural products. Compounds 1 and 11, compounds 2, 3, 5–7 and 9, and compounds 4 and 8 were isolated for the first time in family Ranunculaceae, genus Anemone and A. vitifolia respectively. The chemotaxonomic significance of the isolated compounds was discussed.     

Chemical constituents from Schefflera leucantha R.Vig. (Araliaceae)

Processive phytochemistry and pharmacological investigation of Schefflera leucantha R.Vig. (Araliaceae) led to the isolation of fifteen known compounds: a nucleobase (1), six small aromatic molecules (2–7), three phenylpropanoids (8–10), four lignans (11–14) and a fatty acid derivative (15). Spectroscopic methods were used to establish the structure and configuration of isolates, followed by their unambiguous confirmation with literature data. We report for the first time (to the best of our knowledge), the isolation of β-amino-3-methoxy-4-hydroxybenzene-ethanol (4) from a natural source. Furthermore, compounds 1, 5, 9–15 are being reported from Araliaceae family for the first time, whereas compounds 2, 3, 6–8 from the genus Schefflera for the first time. The biological screening results show that compounds 9 and 10 induce a moderate inhibitory effect on aldose reductase, while compounds 3, 5, and 8 display significantly high neuroprotective activities.     

Unusual ent-atisane type diterpenoids with 2-oxopropyl skeleton from the roots of Euphorbia ebracteolata and their antiviral activity against human rhinovirus 3 and enterovirus 71

Two novel ent-atisane type diterpenoids possessing the extra unusal 2-oxopropyl moiety (1 and 2) and four known analogues have been isolated from the roots of Euphorbia ebracteolata. The structures and absolute configurations of these compounds were determined by extensive spectroscopic data analysis, including 2D NMR, single-crystal X-ray crystallography, ¹³C NMR calculation, and electronic circular dichroism spectra calculation. Compounds 1 and 2 are the first examples of natural products with ent-atisane type diterpenoids possessing 2-oxopropyl skeleton. Compounds 2, 3, 5, and 6 show antiviral activities against human rhinovirus 3, with IC₅₀ values of 25.27–90.35 μM. Compounds 5 and 6 showed moderate antiviral activities against EV71 at a concentration of 100 μM.     

Synthesis,antimicrobial, and mosquito larvicidal activity of 1-aryl-4-methyl-3,6-bis-(5-methylisoxazol-3-yl)-2-thioxo-2,3,6,10b-tetrahydro-1H-pyrimido[5,4-c]quinolin-5-ones

A series of 1-aryl-4-methyl-3,6-bis-(5-methylisoxazol-3-yl)-2-thioxo-2,3,6,10b-tetrahydro-1H-pyrimido[5,4-c]quinolin-5-ones (6a–h) have been synthesized by cyclization of ethyl-3-aryl-4-(2-chlorophenyl)-6-methyl-1-(5-methylisoxazol-3-yl)-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates 4a–h with 3-amino-5-methylisoxazole 5. Compounds 4a–h were obtained by Biginelli reaction, by condensation of aromatic aldehyde 1, ethyl acetoacetate 2, and isoxazolyl thioureas 3 in a one-pot reaction catalyzed by ceric ammonium nitrite (CAN). Compounds 6a–h were tested for their antibacterial and antifungal activities against various bacterial and fungal strains. The results showed that these compounds exhibited good antibacterial and antifungal activity compared with that of standard antibiotics. Mosquito larvicidal activity of the newly synthesized compounds 6a–h is also studied against fourth instar larvae Culex quinquefasciatus. Some of the compounds are proved to be lethal for mosquito larvae.     

A new cerebroside and bioactive compounds from Celtis adolphi-friderici Engl. (Cannabaceae)

A phytochemical investigation of the roots of Celtis adolphi-friderici Engl. led to the isolation of a previously undescribed cerebroside named, eloundemnoside (1), alongside with seventeen known compounds (2–18). Their chemical structures were elucidated based on the analysis of their NMR and MS data. All the compounds were isolated from this specie for the first time, while eight known compounds (4–5, 12–13, 15–18) are obtained from the genus Celtis for the first time. The isolates were screened for their antioxidant, lipoxygenase, urease, and butyrylcholinesterase enzyme inhibitory activities. Compounds 4, 7 and 12 showed good antioxidant activities with IC₅₀ values of 22.2, 29.3, and 13.2 μM, respectively. In addition, azelaic acid (12) showed the best lipoxygenase inhibition (IC₅₀ value of 16.3 μM), while friedelin (2) exhibited the highest inhibition of urease with an IC₅₀ value of 15.3 μM. However, all the compounds tested had moderate butyrylcholinesterase inhibitory properties. The chemophenetic relationship of the isolates and their significance were discussed.