New indole derivatives from endophytic fungus Colletotruchum sp. HK-08 originated from leaves of Nerium indicum.

Objective: To study secondary metabolites from endophytic fungus Colletotruchum sp. HK-08 originated from the leaves of Nerium indicum. Methods: The compounds were isolated by various column chromatographic techniques, and their structures were elucidated by spectroscopic techniques [high resolution electrospray ionization mass spectroscopy (HRESIMS), one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance spectroscopy (NMR)], as well as comparison with literature data. The Ellman method was used to determine the acetylcholinesterase (AChE) inhibitory activity. Results: Four indole derivatives were identified from Colletotruchum sp. HK-08, including 6'-hydroxymonaspiloindole (1), 2-(2-oxoindolin-3-yl)ethyl 2-(4-hydroxyphenyl) acetate (2), 2-(2-oxoindolin-3-yl)ethyl 2-(2-hydroxyphenyl)acetate (3), and monaspiloindole (4). Compound 4 presented weak AChE inhibitory activity with IC50 value of (69.30 ± 6.27) µmol/L [tacrine as the positive control, with IC50 value of (0.61 ± 0.07) µmol/L]. Conclusion: Compounds 1-3 were new compounds, and compound 4 had weak AChE inhibitory activity.

Diaporchalasins A-E, New Cytochalasins from the Endophytic Fungus Diaporthe sp. BMX12 Isolated from Aquilaria sinensis.

Five new cytochalasins, diaporchalasins A-E (1-5), together with 14 known congeners (6-19) were isolated from the endophytic fungus Diaporthe sp. BMX12, which was isolated from the branches of Aquilaria sinensis. The structures of the new compounds were elucidated by extensive spectroscopic analyses including high-resolution electron spray ionization mass spectrometry (HR-ESI-MS) and nuclear magnetic resonance (NMR). Their absolute configurations were assigned by theoretical electronic circular dichroism (ECD) calculations. Compounds 11 and 12 featuring a keto carbonyl at C-21 displayed cytotoxicity toward K562, BEL-7402, SGC-7901, A549, and HeLa cell lines with IC50 values ranging from 4.4 to 47.4 µM.

Identification of volatile compounds and their bioactivities from unpolar fraction of Alpinia oxyphylla Miq. and mining key genes of nootkatone biosynthesis.

In this study, analysis of the chemical constituents and bioactivities of the unpolar fractions [petroleum ether (PE) and chloroform (C)] of fruits and leaves of Alpinia oxyphylla Miq. were carried out, as well as the bioactivities of the main compounds nootkatone and valencene. From PE and C fractions of the fruits, and PE fraction of the leaves, 95.80%, 59.30%, and 82.11% of the chemical constituents respectively were identified by GC-MS. Among these identified compounds, nootkatone was the main compound in all of three fractions, while valencene was the second main compound in the PE fractions of the fruits and leaves. The bioactivities results showed that all of the fractions and the major compound nootkatone showed tyrosinase inhibitory, as well as inhibitory effect on NO production in LPS-stimulated RAW264.7 cells. While valencene only presented inhibitory activity on NO production in RAW264.7 cells. The critical genes involved in nootkatone biosynthesis in A. oxyphylla were identified from the public transcriptome datasets, and protein sequences were preliminarily analyzed. Our studies develop the usage of the unpolar fractions of A. oxyphylla, especially its leaves as the waste during its production, and meanwhile provide the gene resources for nootkatone biosynthesis.

Cytotoxic steroids from the stems of Strophanthus divaricatus.

Phytochemical investigation on the stems of Strophanthus divaricatus led to the isolation of four undescribed cardiac glycosides and one undescribed C21 pregnane, together with eleven known steroids. Their structures were elucidated by a comprehensive analysis of HRESIMS, 1D and 2D NMR spectra. The absolute configuration of 16 was determined by comparison of the experimental and computed ECD spectra. Compounds 1-13 and 15 displayed potent to significant cytotoxicity against human cancer cell lines K562, SGC-7901, A549 and HeLa with IC50 values of 0.02-16.08, 0.04-23.13, 0.06-22.31 and 0.06-15.13 µM, respectively.

New Isocoumarins from the Marine Fungus Phaeosphaeriopsis sp. WP-26.

Five new isocoumarins, phaeosphaerins A-E (1-5), were isolated from the fermentation broth of the marine fungus Phaeosphaeriopsis sp. WP-26, along with one known isocoumarin, 6,8-dihydroxy-7-methoxy-3-methylisocoumarin (6), and two known pimarane-type diterpenes, diaportheins A (7) and B (8). Their structures were elucidated via NMR experiments, X-ray diffraction analysis, and comparison of the experimental and computed ECD curves. Compounds 1-7 displayed weak neuroprotective effects against H2O2-induced damage in SH-SY5Y cells. Moreover, compound 8 showed cytotoxicity against BEL-7402, SGC-7901, K562, A549, and HL-60 cell lines.

Seven new 2-(2-phenethyl)chromone derivatives from agarwood of Aquilaria walla.

Two rare flavonoid-2-(2-phenylethyl)chromones and five new dimeric 2-(2-phenylethyl)chromones were isolated from ethanol extract of agarwood of Aquilaria walla by LC-MS-guided fractionation procedure. Their structures were established based on extensive spectroscopic methods including HRESIMS, 1D and 2D NMR, as well as by comparison with the literature. Compound 1 showed cytotoxic activity against five human cancer cell lines with IC50 values ranging from 13.40 to 28.96 µM with cisplatin as the positive control.

LC-MS-guided isolation of 2-(2-phenylethyl)chromone dimers from red soil agarwood of Aquilaria crassna.

Six new 2-(2-phenylethyl)chromone dimers (1-6) were isolated from ethyl ether extract of red soil agarwood of Aquilaria crassna from Vietnam by LC-MS-guided fractionation procedure. Their structures were unambiguously elucidated based on HRESIMS, 1D and 2D NMR spectra. The absolute configuration of 2-(2-phenylethyl)chromone dimers was determined by comparison of the experimental and computed ECD spectra. Compound 6 displayed cytotoxicity against the human myeloid leukemia cell line (K562) with an IC50 value of 39.49 µM.

Three new 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromones and one new dimeric 2-(2-phenylethyl)chromone from agarwood of Aquilaria crassna Pierre ex Lecomte in Laos.

Three new 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromones and one new dimeric 2-(2-phenylethyl)chromone were isolated from the agarwood of Aquilaria crassna Pierre ex Lecomte in Laos. The structures of the isolates were elucidated by spectroscopic methods, and their configurations were determined via ROESY correlations, 3 J H-H coupling constants analyses, comparisons of chemical shifts and specific rotations with known compounds, and ECD calculation in the case of 1. Compounds 1-4 were evaluated for their cytotoxicity. Compounds 1 and 2 exhibited weak cytotoxicity toward HeLa cell line (IC50: 49.8 ± 1.2 µM) and K562 cell line (IC50: 42.66 ± 0.47 µM), respectively.

Metabolites From the Mangrove-Derived Fungus Cladosporium sp. HNWSW-1.

Two new benzoic acids, cladoslide A (1) and cladoslide B (2); one new ß-carboline derivative, cladospomine (3); and one new pyridin-2(1H)-one, cladoslide C (4), were isolated from the fermentation cultures of the mangrove-derived fungus Cladosporium sp. HNWSW-1, along with the previously reported N-acetyl-ß-oxotryptamine (5), (4S,5S,11R)-iso-cladospolide B (6), (4S,5S,11S)-iso-cladospolide B (7), and (4R,5S,11R)-iso-cladospolide B (8). Their structures were elucidated by spectroscopic analysis, Rh2(OCOCF3)4-induced ECD experiments, and Marfey's method. Compound 1 showed cytotoxicity against the K562 cell line with IC50 values of 13.10 ± 0.08 µM. Moreover, compounds 1 and 5 exhibited inhibitory activity against α-glycosidase with IC50 values of 0.32 ± 0.01 mM and 0.17 ± 0.01 mM, respectively.

[A new cytotoxic isoflavane from Dalbergiae Odoriferae Lignum].

Fourteen compounds were isolated from the ethanol extract of Dalbergiae Odoriferae Lignum by various chromatographic techniques, including column chromatographies on silica gel, Sephadex LH-20 and semi-preparative HPLC. Their structures were determined by spectroscopic techniques as S-3'-hydroxy-7,2',4'-trimethoxyisoxane(1), 2-(2',4'-dimethoxyphenyl)-6-hydroxybenzofuran(2), 2-(2'-hydroxy-4'-methoxyphenyl)-6-methoxybenzofuran(3), 7,2',4'-trimethoxydihydroisoflavone(4), sativanone(5), 3,9-dimethoxy-6H-benzofuro[3,2-c]chromen-6-one(6),(6 aS,11 aS)-homopterocarpin(7),(6 aS,11 aS)-8-hydroxy-3,9-dimethoxypterocarpan(8),(6 aS,11 aS)-3,8,9-trimethoxypterocarpan(9), isodalbergin(10), isoliquiritigenin(11), butein(12), butin(13) and 3,7,4'-trihydroxyflavone(14). Among them, compound 1 was a new compound, while 2 and 3 were new natural products, 6, 8, 9 and 14 were isolated for the first time from Dalbergiae Odoriferae Lignum. Compounds 1-14 were tested for their cytotoxic activity against human hepatoma cell line BEL-7402, human gastric cancer cell line SCG-7901, human lung cancer cell line A549, human chronic myeloid leukemia cell line K562 and HeLa human cervical cancer cellline by MTT method. Compound 1 exhibited significant cytotoxicity with IC_(50) values ranging from 2.85 to 11.62 µg·mL~(-1). In addition, 2, 11 and 12 showed weak cytotoxic activities.

Two new sesquiterpenoids from agarwood originated from Aquilaria sp.

Two new sesquiterpenoids (1 and 2), together with two known sesquiterpenoids (3 and 4), were isolated from agarwood originated from Aquilaria sp. Their structures were elucidated by extensive spectroscopic methods including 1D and 2D NMR, IR, HRESIMS, and comparison with the literatures. All compounds were evaluated for cytotoxicity against five human cancer cell lines, but none of them displayed significant activity. [Formula: see text].

Four new guaiane sesquiterpenoids from agarwood of Aquilaria filaria.

Six 8,12-epoxyguaiane sesquiterpenes (1-6), together with two known 2-(2-phenylethyl)chromone derivatives (7-8) were isolated from agarwood originating from Aquilaria filaria. Their structures were established by spectroscopic methods including IR, HRESIMS, 1D, and 2D NMR, and comparison with the published data. The absolute configuration of compound 1 was unambiguously determined by quantum chemical calculation of the electronic circular dichroism (ECD) spectrum. All compounds were tested for their α-glucosidase inhibitory activity and cytotoxicity. Compound 5 showed significant α-glucosidase inhibitory activity with IC50 value of 253.2 ±â€¯9.7 µM (Acarbose, 743. 4 ±â€¯3.3 µM). Compounds 2-4 displayed weak cytotoxicity against K562 tumor cell lines.

[A new eudesmane type sesquiterpene from cultivated Clerodendranthus spicatus in Hainan].

Six compounds were isolated from the aerial part of cultivated Clerodendranthus spicatus in Hainan with various chromatographic techniques,and their structures were determined as:1-dehydroxy-1-oxo-rupestrinol(1),N-trans-feruloyltyramine(2),methyl 3,4-dihydroxyphenyllactate(3),caffein acid(4),methyl caffeate(5) and ethyl caffeate(6),via analysis of physicochemical properties and spectroscopic evidence.Compound 1 was a new compound,while compounds 2 and 3 were isolated from C.spicatus for the first time.Biological activity results showed that compounds 2-4 exhibited α-glucosidase inhibitory activity with different inhibition ratio.

Three new flavanoids from artificially induced dragon's blood of Dracaena cambodiana.

Three new flavanoids, (2R)-7,4'-dihydroxy-8-methylflavan (1), (2R)-7,4'-dihydroxy-6-methylflavan (2), and (3R)-7,3',4'-trihydroxyhomoisoflavan (3), together with seven known compounds (4-10), were isolated from artificially induced dragon's blood of Dracaena cambodiana, and their structures were determined based on HR-ESI-MS and extensive spectroscopic techniques (UV, IR, 1D-, and 2D-NMR). Compound 2 exhibited weak cytotoxicity against BEL-7402 cells line with the IC50 value of 39.2 µM. In addition, compound 3 showed significant acetylcholinesterase (AChE) inhibitory activity.

Metabolites with Insecticidal Activity from Aspergillus fumigatus JRJ111048 Isolated from Mangrove Plant Acrostichum specioum Endemic to Hainan Island.

Fungi residing in mangroves are considered to be a bank of novel bioactive natural products. In the screening for bioactive metabolites from mangrove-derived fungi, the ethyl acetate extract of the fermentation broth of Aspergillus fumigatus JRJ111048, a fungus isolated from the leaves of the mangrove plant Acrostichum specioum endemic to Hainan island, was found to possess insecticidal activity against Spodoptera litura. Bioactivity-guided isolation lead to the discovery of seven metabolites 1-7, including one new anhydride derivative aspergide (1), one new lipid amide 11-methyl-11-hydroxyldodecanoic acid amide (2), and five known compounds; α-ethyl glucoside (3), spiculisporic acid B (4), spiculisporic acid C (5), spiculisporic acid (6), and secospiculisporic acid B (7). Their structures were established by NMR spectroscopic and MS analyses, and by comparison of previously reported data. Insecticidal activity against S. litura and antifungal activity of these compounds were investigated. As a result, the new compound 1 showed potent insecticidal activity against newly hatched larvae of S. litura, and compound 4 displayed weak antifungal activity against Candida albicans.

2-(2-Phenylethyl)chromone Derivatives of Agarwood Originating from Gyrinops salicifolia.

Three new2-(2-phenylethyl)chromone derivatives (1-3) and a new2-(2-phenylethenyl)chromone derivative (4), together with two known 2-(2-phenylethyl)chromone derivatives (5-6), were isolated from agarwood originating from Gyrinops salicifolia Ridl. The structures of compounds 1-4 were elucidated by comprehensive spectroscopic techniques (UV, IR, 1D and 2D-NMR) and MS analysis, as well as by comparison with the literature. Compounds 1, 2, and 5 showed moderate cytotoxicity against human tumor K562, BEL-7402, and SGC-7901 cell lines with IC50 values of 5.76 to 20.1 µM.

Sesquiterpenes of agarwood from Gyrinops salicifolia.

Six new sesquiterpenoids (1-6) and six known sesquiterpenoids (7-12) were isolated from agarwood originated from Gyrinops salicifolia Ridl. Most of them gave off aromatic odor, and all the compounds were isolated from this genus for the first time. The structures of 1-6 were elucidated by spectroscopic techniques (UV, IR, 1D and 2D NMR) and MS analysis, as well as by comparison with literature data. Compounds 1, 6 and 11-12 showed moderate acetylcholinesterase (AChE) inhibitory activity.

Two new phragmalin-type limonoids from Chukrasia tabularis and their α-glucosidase inhibitory activity.

Phytochemical investigation on the stems of C. tabularis (Meliaceae) led to the isolation of two new phragmalin-type limonoids, named tabularisins S and T (1-2), along with five known ones (3-7). The structures of the new limonoids were established by spectroscopic methods including UV, IR, HRESIMS, and 1D and 2D NMR. All the compounds were evaluated for α-glucosidase inhibitory activity in vitro. Compounds 2 and 3 exhibited significant inhibitory activity against α-glucosidase with IC50 values of 0.15 and 0.03 mM, respectively (acarbose as positive control, IC50 0.95 mM).

2-(2-Phenylethyl)chromone derivatives in artificial agarwood from Aquilaria sinensis.

Seven new 2-(2-phenylethyl)chromone derivatives (1-7) including a chlorinated one (4), together with eight known ones (8-15), were isolated from the EtOAc extract of artificial agarwood originating from Aquilaria sinensis (Lour.) Gilg. All structures including the absolute configurations were unambiguously elucidated by spectroscopic (NMR, UV, IR, MS) methods, Mosher's method, and comparison with reported data in the literatures. Among those, compounds 8, 12, and 14 exhibited significant inhibition against α-glucosidase in vitro with IC50 values of 0.15, 0.05, and 0.09 mM, respectively (with acarbose as the positive control; IC50: 0.98 mM). In addition, compounds 3, 9, 11, and 14 showed weak inhibitory activity against AChE; and compounds 12 and 13 displayed weak cytotoxicity against human gastric cell line (SGC-7901) among three types of tested human cancer cell lines (BEL-7402, K562, and SGC-7901).

New Phragmalin-Type Limonoids from Chukrasia tabularis and Their α-Glucosidase Inhibitory Activity.

Phytochemical investigation on the stems of C. tabularis led to the isolation of five new phragmalin-type limonoids and six known ones. The structures of the new compounds 1-5, named chukbularisins A-E, were elucidated by spectroscopic techniques (IR, HRESIMS, 1D and 2D NMR) and comparisons with published data. All the compounds were evaluated for in vitro α-glucosidase inhibitory activity. Compounds 2, 3, 4, 5, and 8 exhibited inhibitory activity against α-glucosidase with IC50 values of 0.06 ± 0.008, 0.04 ± 0.002, 0.52 ± 0.039, 1.09 ± 0.040, and 0.20 ± 0.057 mM, respectively (using acarbose as positive control, IC50 0.95 ± 0.092 mM).