Chemical constituents and cytotoxic activity from the wood-decaying fungus Xylaria sp. SWUF08-37

Abstract

A new cyclic pentapeptide, pentaminolarin (1), and a new cytochalasin, xylochalasin (2), along with thirteen known compounds (3–15) were isolated from the wood-decaying fungus Xylaria sp. SWUF08-37. The absolute configurations of 1 were determined by a combination of Marfey’s method and TDDFT ECD calculation and the absolute configurations of 2 were established by TDDFT ECD calculation. Compound 12 showed moderate cytotoxicity against HeLa (IC₅₀?=?19.60?µg/mL), HT29 (IC₅₀?=?17.31?µg/mL), HCT116 (IC₅₀?=?14.28?µg/mL), MCF-7 (IC₅₀?=?15.38?µg/mL), and Vero (IC₅₀?=?24.97?µg/mL) cell lines by MTT assay. Compounds 1 and 2 showed slight cytotoxicity against all tested cancer cell lines.     

Antimalarial and cytotoxic constituents of Xylaria cf. cubensis PK108

Xylaria cf. cubensis PK108 was identified by its distinctive morphological characteristics and its internal transcribed spacers sequence analysis. The chromatographic separation and structural elucidation based on spectroscopic analysis of fungal crude extracts led to 10 compounds; tryptoquivaline L (1), fiscalin C (2), epi-fiscalin C (3), cytochalasin D (4), ergosterol (5), ergosterol peroxide (6), chevalone C (7), xylaranol B (8), helvolic acid (9) and cyclo-(l-Pro-l-Leu) (10). The bioassay screening showed that 4 displayed cytotoxicity against KB and NCI-H187 cancer cell lines with IC₅₀ values of 3.25 and 5.95 μg mL^? 1. 6 exhibited cytotoxicity against NCI-H187 with an IC₅₀ value of 5.81 μg mL^? 1. 7 and 9 showed antimalarial activity with IC₅₀ values of 25.00 and 6.25 μg mL^? 1, respectively. This result establishes Xylaria as broad spectrum bioactive compound producers.     

Two new benzolactones from the leaves of Nicotiana tabacum and their anti-tobacco mosaic virus activities

Two new benzolactones, 5-methyl-6-prenyl-isobenzofuran-1(3H)-one (1), 5-hydroxymethyl-6-prenyl-isobenzofuran-1(3H)-one (2), together with four known phenolic compounds (3–6), were isolated from the leaves of Nicotiana tabacum. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1–6 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compounds 1–6 exhibited high anti-TMV activities with inhibition rates in the range of 16.9–26.2%, respectively.     

New anti-bacterial halogenated tricyclic sesquiterpenes from Bornean Laurencia majuscula (Harvey) Lucas

Three new halogenated tricyclic sesquiterpenes, omphalaurediol (1), rhodolaurenones B (2) and C (3) were isolated together with nine known haloganated sesquiterpenes such as rhodolaurenone A (4), rhodolaureol (5), isorhodolaureol (6), (?)-laurencenone D (7), elatol (8), (+)-deschloroelatol (9), cartilagineol (10), (+)-laurencenone B (11) and 2-chloro-3-hydroxy-α-chamigren-9-one (12) from a population of Bornean red algae Laurencia majuscula. The structures of three new metabolites were determined based on their spectroscopic data (IR, 1D and 2D NMR, and MS). These compounds showed antibacterial activity against three human pathogenic bacteria (Escherichia coli, Salmonella typhi and Vibrio cholera).     

Secondary Metabolites from the Endophytic Fungus Xylaria cubensis

Seven new metabolites, including three sesquiterpenoids, 10‐hydroxythujopsene ( 1 ), akotriol ( 2 ), and xylaritriol ( 3 ), one diterpenoid, cubentriol ( 4 ), one aliphatic derivative, akoenic acid ( 5 ), one alkaloid, akodionine ( 6 ), and one isocoumarin, akolitserin ( 7 ), together with seven known compounds, 8 – 14 , were isolated from the AcOEt‐soluble fraction of the fermentation broth of the endophytic fungus Xylaria cubensis, derived from the leaves of Litsea akoensis Hayata (Lauraceae). Their structures were elucidated by spectroscopic analyses, including 1D‐ and 2D‐NMR experiments, and by HR‐ESI‐MS mass spectrometry. Among the isolates, (?)‐(R)‐7‐hydroxymellein showed IL‐6 inhibitory activity with an IC₅₀ value of 9.41 μM .     

Xylaropyrones B and C,new γ-pyrones from the endophytic fungus Xylaria sp. SC1440

Two new γ-pyrones, xylaropyrones B (1) and C (2), together with three known compounds, xylaropyrone (3), annularin A (4) and annularin C (5), were isolated from solid cultures of the endophytic fungus Xylaria sp. SC1440. The structures of these compounds were determined mainly by analysis of their NMR spectroscopic data. The relative configurations of 1 and 2 were assigned on the basis of J-based configurational analysis, and the absolute configurations were established by experimental and TDDFT calculated ECD spectra. The isolated compounds were evaluated for cytotoxic and tyrosinase inhibitory activity.     

A new dihydrofurocoumarin from the fruits of Pandanus tectorius Parkinson ex Du Roi

From the fruit of Pandanus tectorius Parkinson ex Du Roi, one new dihydrofurocoumarin, named pandanusin A (1) and 15 known compounds, including one furanocoumarin (2), two coumarins (3, 4), four lignans (5–8), one neolignan (9), two flavonoids (10, 11), three phenolics (12–14), one monoglyceride (15) and one monosaccharide (16) were isolated by various chromatography methods. Among them, compounds (3–5) were obtained from the Pandanus genus for the first time and compounds (9–14, 16) were reported from this species for the first time. Their structures were elucidated by HR–ESI–MS, NMR 1D and 2D experiments and comparison with previous reported data. The α-glucosidase inhibitory activity of all compounds was measured. The isolated compounds (1–12, 14) showed better α-glucosidase inhibitory activity (IC₅₀ = 42.2, 36.5, 84.7, 73.2, 40.8, 26.7, 76.5, 33.8, 68.1, 14.4, 22.1, 81.5, 43.8 μM, respectively) than the standard drug acarbose (IC₅₀ = 214.5 μM).     

Phytochemical studies on the Australian native plant species Acacia pycnantha and Jacaranda mimosifolia D.Don*

In ongoing investigations into colours in Nature, the chemical constituents from the flowers of Acacia pycnantha and Jacaranda mimosifolia D.Don grown in Australia are reported. Eight known secondary metabolites were isolated from the A. pycnantha flower including isosalipurposide (7) which may be responsible for their distinctive colouration. Nine secondary metabolites were isolated from the J. mimosifolia D.Don flower including the new phenylethanoid β-D-glucopyranose (10). All isolated compounds were inactive against bacteria tested at concentration of 32 μg/mL.     

A new di-C-prenylated coumarin from Sophora interrupta

A new di-C-prenylated coumarin, 7-methoxy-6,8-bis-(2,3-dihydroxy-3-methylbutyl)-coumarin (1), together with seven known compounds, isopimpinellin (2), an arylbenzofuran (3), three flavonoids (4–6), (+)-maackianin (7) and echinoisoflavanone (8), were isolated from the leaves of Sophora interrupta Bedd. The structure of the new compound 1 as well as known compounds was elucidated by extensive 1D and 2D NMR spectral studies.     

A new phthalide from the endophytic fungus Xylaria sp. GDG-102

A new phthalide derivative, xylarphthalide A (1), along with two known compounds (-)-5-carboxylmellein (2) and (-)-5-methylmellein (3), were isolated from the endophytic fungus Xylaria sp. GDG-102 cultured from the Chinese medicinal plant Sophora tonkinensis. Their structures were identified by MS and NMR experiments, and the absolute configuration of 1 was further confirmed by single-crystal X-ray diffraction analysis. Compound 1–3 showed antibacterial activities against Bacillus megaterium, Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Shigella dysenteriae with MIC values of 12.5–25 μg/mL.     

Four new anthraquinones from a soil actinomycete Streptomyces sp. WS-13394 and their bioactivities

Further chemical study of secondary metabolites from the soil actinomycete Streptomyces sp. WS-13394 resulted in the isolation of four new alkylated anthraquinone analogues (5–8). Their structures were elucidated on the basis of extensive spectroscopic analysis, including HR-ESI-MS, 1D and 2D NMR. The new compounds, together with analogues obtained before (1–4), were tested for their in vitro cytotoxicity against Huh-7 and SGC-7901.     

Pleiocarpumlignan A,a new dineolignan from Piper pleiocarpum Chang ex Tseng

Abstract

The investigation of chemical constituents from the whole plants Piper pleiocarpum Chang ex Tseng resulted in the isolation of one new dineolignan, pleiocarpumlignan A (1), along with one known benzoate derivative, trans-2,3-diacetoxy-1-[(benzoy1oxy)methyl]-cyclohexa-4,6-diene (2), and two known neolignans (3–4) as (±)-trans-dehydrodiisoeugenol (3), (7R,8R,3′S)-△^8′-3′,6′-dihydro-3′-methoxy-3,4-methylenedioxy-6′-oxo-8,3′,7,O,4′-lignan (4). Their structures were elucidated through extensive spectroscopic analyses including 1D, 2D NMR, HR-ESI-MS, and by comparison with the literature. All compounds (1–4) were firstly isolated from Piper pleiocarpum Chang ex Tseng. The ¹³C NMR spectra of 2 were completely assigned for the first time. Cytotoxic activities of these isolated compounds against five human cancer cell lines (including A-549, SMMC-7721, HL-60, MCF-7, and SW-480) were evaluated.     

Isolation and identification of a new neo-clerodane diterpenoid from Teucrium chamaedrys L.

Teucrium chamaedrys L. is an aromatic and medicinal plant used as traditional medicine. Aerial parts of the plant material were dried and extracted with hexane–dichloromethane (extract 1), ethyl acetate–dichloromethane (extract 2) and methanol–dichloromethane (extract 3) in a ratio of 1:1 at rt successively. The solvents were evaporated to give crude extracts. Extract 1 was suspended in water at 60°C then partitioned successively with hexane and ethyl acetate to give hexane and ethyl acetate portions. After the column chromatography (silica gel) of ethyl acetate extract, one new and four known compounds were isolated. The new compound was named as 1(12S,18R)-15,16-epoxy-2β,6β-dihydroxy-neo-cleroda-13(16),14-dien-20,l2-olide-l8,l9-hemiacetal (teuchamaedryn D) (4). The known compounds were teucrin A (1), dihydroteugin (2), teucroxide (3), syspirensin A (5). The chromatographic methods were also applied for extract 3 to isolate verbascoside (6) and teucrioside (7). The structure of isolated compounds was elucidated by spectroscopic methods including LC-TOF/MS, 1D NMR and 2D NMR.     

A new phenolic glycoside and two new monoterpenoid furocoumarins from Aurantii Fructus Immaturus

A new phenolic glycoside, citrauranoside A (1), and two new monoterpenoid furocoumarins, citraurancoumarin A (2) and citraurancoumarin B (3), along with four known compounds (4–7) were isolated from the young fruit of Citrus aurantium L. The structures were elucidated by their comprehensive analysis including 1D, 2DNMR, IR and mass spectra.     

Isolation and characterisation of three new anthraquinone secondary metabolites from Symplocos racemosa

Three new anthraquinone secondary metabolites were isolated from Symplocos racemosa, a small tree of family symplocaceae. The structures of compounds (1–3) were elucidated to be 1,4-dihydroxy-6-(ethoxymethyl)-8-propylanthracene-9,10-dione (1), 1,4-dihydroxy-6-(hydroxymethyl)-8-butylanthracene-9,10-dione (2) and 1,4-dihydroxy-6-(hydroxymethyl)-8-propyl anthracene-9,10-dione (3) using their spectral data, i.e. through IR, UV, ¹H NMR, ¹³C NMR and two-dimensional (2D) NMR techniques including heteronuclear multiple quantum coherence, heteronuclear multiple bond correlation and correlation spectroscopy.     

Protein tyrosine phosphatase 1B inhibitors from a marine-derived fungal strain aspergillus sp. SF-5929

Abstract

In the course of our continuing investigation of bioactive secondary metabolites from marine-derived fungal strains, a racemate of a novel diphenolic derivative named (±)-tylopilusin D (1) along with ten previously known secondary metabolites (2–11) were isolated from a marine-derived fungal strain Aspergillus sp. SF-5929. Their structures were elucidated mainly by analysis of NMR and MS data. In addition, the inhibitory effects of the isolated compounds against protein tyrosine phosphatase 1B (PTP1B) activity were evaluated, and compounds 1, 2, and 5–7 inhibited PTP1B activity with IC₅₀ values ranging from 3.3 to 8.1?µM. Kinetics studies suggested that compounds 1, 2, and 5 had noncompetitive inhibitory effects against PTP1B.     

Ascomycotin A,a new citromycetin analogue produced by Ascomycota sp. Ind19F07 isolated from deep sea sediment

A new citromycetin analogue, ascomycotin A (1), together with eight known compounds, wortmannilactone E (2), orcinol (3), orsellinic acid (4), isosclerone (5), (3R,4S)-( ? )-4-hydroxymellein (6), diorcinol (7), chaetocyclinone B (8) and 2,5-dimethoxy-3,6-di(p-methoxypheny1)-1,4-benzoquinone (9), was isolated from the fungal strain Ascomycota sp. Ind19F07, which was isolated from the deep sea sediment of the Indian Ocean. The structures of the compounds were established by spectroscopic data including 1D and 2D NMR and HR-ESI-MS. Compounds (1–9) were evaluated for antibacterial activity.     

Heliotropium bacciferum Forssk. (Boraginaceae) extracts: chemical constituents,antioxidant activity and cytotoxic effect in human cancer cell lines

Heliotropium bacciferum (Boraginaceae) is a perennial herb, growing in the Bechar region of Algeria, where it is traditionally used for skin diseases and tonsillitis. Herein, we report the isolation and characterization of sixteen secondary metabolites from the aerial part extracts. They include a sterol (1), megastigman type nor-isoprenoids (2, 3, 4, 6, 8, 10), C-11 terpene lactones (5 and 9), and a monoterpene (7) from the chloroform extract (HB-C); monoterpene glucoside (14), and phenolic compounds (11–13, 15, 16) from the methanol one (HB-M). Their structures were elucidated by spectroscopic methods including 1D and 2D NMR experiments, and ESIMS analysis. HB-M showed a significant and concentration dependent scavenging activity in vitro against the radicals DPPH and ABTS, related to the phenol derivatives (11–13, and 15–16), and HB-C inhibited the growth of colon cancer cell lines, mainly for the presence of the antiproliferative C-11 terpene lactones (5 and 9).     

Chemical constituents from Piper wallichii

Fifteen known compounds including four triterpenoids (1–4), one sterol (5), one diketopiperazine alkaloid (6) and nine phenolics (7–15) were isolated from the stems of Piper wallichii. Their structures were elucidated by means of spectroscopic analysis, and acidic hydrolysis in case of the 2-oxo-3β,19α,23-trihydroxyurs-12-en-28-oic acid β-D-glucopyranosyl ester (1). The structure of compound 1 was fully assigned by 1D and 2D NMR experiments for the first time. All isolates were tested for their antibacterial, antifungal, anti-inflammatory and antiplatelet aggregation bioactivities.     

Characterization and bioactive potentials of secondary metabolites from Fusarium chlamydosporum

Abstract

A search for bioactive secondary metabolites from the endophytic fungus Fusarium chlamydosporum, isolated from the root of Suaeda glauca, led to the isolation of three indole derivatives (1–3), three cyclohexadepsipeptides (4–6), and four pyrones (7–10). The structures of new (1) and known compounds (2–10) were elucidated on the basis of extensive spectroscopic analysis. All these compounds were evaluated for phytotoxic, antimicrobial activities, and brine shrimp lethality. Compound 1 showed significant phytotoxic activity against the radicle growth of Echinochloa crusgalli, even better than the positive control of 2,4-D. Cyclohexadepsipeptides (4–6) and pyrones (7–10) exhibited brine shrimp lethality, especially 4 and 7 with the LD₅₀ values of 2.78 and 7.40?μg mL^?1, respectively, better than the positive control.