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.

Hexahydroazulene-2(1H)-one Sesquiterpenoids with Bridged Cyclobutane, Oxetane, and Tetrahydrofuran Rings from the Stems of Daphne papyracea with α-Glycosidase Inhibitory Activity.

Chemical investigation of an alcoholic extract from the stem of Daphne papyracea ("Xuehuagou") led to the isolation of the tetracyclic sesquiterpenoid daphnepapytone A (1), containing a unique caged skeleton with a cyclobutane ring having three tetrasubstituted chirality centers. Also isolated were new guaiane sesquiterpenoids, namely, daphnepapytones B-H (2-8), and one 1,5-diphenylpentanone 2-hydroxy-5-oxo-daphneone (9), together with 26 known compounds. The cyclic metabolites share a 5-isoprenyl-hexahydroazulene-2(1H)-one skeleton with different substitution patterns and a bridged cyclobutane, oxetane, or tetrahydrofuran ring. The planar structures and relative configuration of the new compounds were elucidated on the basis of spectroscopic analysis aided by DFT 13C NMR calculations. The absolute configurations of 1-7 were determined by X-ray single-crystal diffraction or TDDFT-ECD calculations. Daphnepapytones A and C (1 and 3), 2-hydroxy-5-oxodaphneone (9), daphnenone (10), daphneone (11), and 3-methyldaphneolone (12) showed α-glycosidase inhibitory activity, with IC50 values of 159.0, 102.3, 139.3, 43.3, 145.0, and 126.1 µM, respectively.

New 2-(2-Phenylethyl)chromone derivatives from agarwood originating from Aquilaria sinensis.

Two new dimeric 2-(2-phenylethyl)chromones, aquilasinenones L and M (1 and 2), and one new monomer analogue, 5S, 6 R, 7S, 8 R-tetrahydroxy-[2-(3-methoxy-4-hydroxyphenyl)ethyl]- 5,6,7,8-tetrahydrochromone (3), together with two known compounds, were isolated from the artificial agarwood originating from Aquilaria sinensis. Compound 1 was the first structure found with C8-O-C4"' linkage among 2-(2-phenylethyl)chromone dimers. Their structures were unambiguously elucidated based on 1 D and 2 D NMR spectroscopy, as well as by comparison with the literature. The absolute configuration was determined by ECD calculation. None of the compounds exhibited acetylcholinesterase inhibitory activity.

New antifungal cycloheximide epimers produced by Streptomyces sp. YG7.

A couple of new cycloheximide epimers, 13(α)-acetoxy-anhydroisoheximide (1) and 13(ß)-acetoxy-anhydroisoheximide (2), together with six known compounds (3-8), were obtained from the cultures of Streptomyces sp. YG7. The structures were elucidated based on a comprehensive spectroscopic data analysis including 1D and 2D NMR, as well as HRESIMS, and by comparison with the literature. The X-ray crystal analysis of 1 further confirmed the structure. All the compounds were tested for antifungal activity. Compounds 1, 2 and 5-8 showed moderate Canidia albicans inhibitory activity, while 5 and 6 presented moderate Pyricularia oryzae inhibitory activity. [Formula: see text].

Zizaane-Type Sesquiterpenoids and Their Rearranged Derivatives from Agarwood of an Aquilaria Plant.

Nine new sesquiterpenoids (1-9) were isolated from ethyl ether extract of agarwood originated from Aquilaria sp., including three novel sesquiterpenoids (1-3) derived from zizaane, together with six zizaane-type sesquiterpenoids (4-9). All structures were unambiguously elucidated based on 1D and 2D NMR spectra as well as by HRESIMS data. The absolute configuration of sesquiterpenoids was determined by comparison of the experimental and computed ECD spectra. In vitro anti-inflammatory assessment showed that compound 9 exhibited inhibition of NO production in LPS-stimulated RAW264.7 cells with an IC50 value of 62.22 ± 1.27 µM.

Two new compounds from the roots of Swietenia macrophylla.

Phytochemical investigation on the roots of Swietenia macrophylla yielded one new pharagmalin-type limonoid named 2-dehydroxyl-swietephragmin C (1) and one new xanthone, 1,5-dihydroxy-6-methoxy-6',6'-dimethyl-2H-pyrano[2',3':3,2]xanthone (2), in addition to three known compounds. The structures of the new compounds were unambiguously determined by comprehensive spectroscopic methods (NMR, UV, IR, MS), as well as by comparison with the reported data in the literature. Xanthones were reported from Swietenia genus for the first time.

Polyacetylenes from the Roots of Swietenia macrophylla King.

A phytochemical investigation of the roots of Swietenia macrophylla led to the isolation of seven polyacetylenes, including five new compounds (1-5) and two known ones (6-7). Their structures were elucidated by extensive spectroscopic analysis and detailed comparison with reported data. All the isolates were tested for their cytotoxicity against the human hepatocellular carcinoma cell line BEL-7402, human myeloid leukemia cell line K562, and human gastric carcinoma cell line SGC-7901. Compounds 1 and 6 showed moderate cytotoxicity against the above three human cancer cell lines with IC50 values ranging from 14.3 to 45.4 µM. Compound 4 displayed cytotoxicity against the K562 and SGC-7901 cancer cell lines with IC50 values of 26.2 ± 0.4 and 21.9 ± 0.3 µM, respectively.

[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.

[Study on sesquiterpenes from agarwood originating from Gyrinops salicifolia].

Two sesquiterpenes were isolated from the agarwood originating from Gyrinops salicifolia with various chromatographic techniques, and their structures were determined as 12-hydroxy-dihydrocyperolone(1) and(rel)-4ß,5ß,7ß-eremophil-9-en-12,8α-olide(2), through a combined analysis of physicochemical properties and spectroscopic evidence. Compound 1 was a new compound. Compound 2 showed cytotoxicities against K562 and BEL-7401 cell lines, with IC_(50) values of(17.85±0.04) and(21.82±0.07) mg·L~(-1), respectively [taxol as positive control, with IC_(50) values of(1.97±0.11) and(6.31±0.08) mg·L~(-1)].

New Eudesmane-Type Sesquiterpenoids from the Mangrove-Derived Endophytic Fungus Penicillium sp. J-54.

Four new eudesmane-type sesquiterpenoids, penicieudesmol A-D (1-4), were isolated from the fermentation broth of the mangrove-derived endophytic fungus Penicillium sp. J-54. Their structures were determined by spectroscopic methods, the in situ dimolybdenum CD method, and modified Mosher's method. The bioassays results showed that 2 exhibited weak cytotoxicity against K-562 cells.

Two New Succinimide Derivatives Cladosporitins A and B from the Mangrove-derived Fungus Cladosporium sp. HNWSW-1.

Two new succinimide-containing derivatives, cladosporitins A (1) and B (2), were isolated from the fermentation cultures of the mangrove-derived fungus Cladosporium sp. HNWSW-1, along with a new pyrone, clapone (3), as well as the previously reported talaroconvolutin A (4) and anthraquinone (5). The structures of the isolated compounds were elucidated by 1D, 2D NMR, and HRMS spectral analysis. Compound 2 showed cytotoxicity against BEL-7042, K562 and SGC-7901 cell lines with IC50 values of 29.4 ± 0.35 µM, 25.6 ± 0.47 µM, and 41.7 ± 0.71 µM, respectively, whereas compound 4 exhibited cytotoxicity against Hela and BEL-7042 cell lines with IC50 values of 14.9 ± 0.21 µM and 26.7 ± 1.1 µM, respectively. In addition, compounds 4 and 5 displayed inhibitory activity against α-glycosidase, with IC50 values of 78.2 ± 2.1 µM and 49.3 ± 10.6 µM, respectively.

A new cytochalasin derivative from the mangrove-derived endophytic fungus Xylaria sp. HNWSW-2.

A new cytochalasin derivative xylarisin B (1), together with four known compounds astropyrone (2), guaidiol (3), xylaropyrone B (4), and xylaropyrone C (5), were isolated from the fermentation broth of Xylaria sp. HNWSW-2. Their structures were elucidated by spectroscopic data. Among them, compounds 2 and 3 at a concentration of 50 µg/ml showed weak inhibitory activity against AChE with inhibition rates of 10.4 and 12.9%, respectively. In addition, compound 2 also exhibited inhibitory activity against α-glycosidase with inhibition rate of 77.0% at a concentration of 0.25 mg/ml.

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.

[A new sesquiterpene from Chinese agarwood induced by artificial holing].

In order to study the chemical constituents of n-butanol fraction of ethanol extract from Chinese agarwood induced by artificial holing, various chromatographic techniques were carried out to isolate compounds, and the structures of compounds were determined through a combined analysis of physicochemical properties and spectroscopic evidence. Seven compounds were obtained and identified as selina-3,11-dien-9,15-diol (1), aquilarone D (2), 5α,6ß,7α,8ß-tetrahydroxy-2-[2-(2-hydroxyphenyl)ethyl]-5,6,7,8-tetrahydrochromone (3), 6,7-dimethoxy-2-[2-(4-methoxyphenyl)ethyl]chromone (4), syringin (5), methyl (Z)-p-coumarate (6), and 4'-methoxycinnamic acid (7), among which compound 1 was a new compound and compounds 5-7 were isolated from agarwood for the first time. The bioactivity assay results concluded that compounds 6 and 7 showed certain nematicidal activity against Panagrellus redivivus, and compounds 4, 6 and 7 exhibited cytotoxicity against BEL-7402, SGC-7901 and A549 carcinoma cell lines.

A new apotirucallane-type triterpenoid from Atalantia buxifolia.

A new triterpenoid (1) with apotirucallane skeleton was isolated from the ethanol extract of the roots of Atalantia buxifolia (Poir.) Oliv. The complete structural assignment of the new compound was elucidated by a combination of 1D, 2D NMR (HMQC, HMBC, COSY, and NOESY), and HR-ESI-MS analysis. Moreover, this new compound was evaluated in vitro for its cytotoxic, antimicrobial and enzymes inhibitory activities.

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.

Sesquiterpenoids and bibenzyl derivative from Dendrobium hercoglossum.

Three new sesquiterpenoids, dendrohercoglin A - C (1-3), and one new bibenzyl derivative, dendronbiline D (4), together with nine known sesquiterpenoids (5-13) were isolated from Dendrobium hercoglossum. The structures of the new compounds were elucidated by extensive spectroscopic analysis as well as NMR and ECD calculations. All the compounds were evaluated for their neuroprotective and anti-inflammatory activities. Compounds 2 and 3 increased the H2O2-damaged SH-SY5Y cell viabilities from 43.3% to 58.6% and 68.4%, respectively. Compound 4 exhibited pronounced anti-inflammatory activity with IC50 value of 9.5 ± 0.45 µM which was superior to the reference compound quercetin (IC50: 15.7 ± 0.89 µM).

Bi-2-(2-phenethyl)chromone derivatives from agarwood of Aquilaria filaria in the Philippines.

Twelve undescribed 2-(2-phenethyl)chromone dimers (1-12) were isolated from EtOAc extract of agarwood originating from Aquilaria filaria in the Philippines, guided by a UHPLC-MS analysis. Their structures were elucidated by 1D NMR, 2D NMR, and HR-ESI-MS spectra. The absolute configuration of 2-(2-phenylethyl)chromone dimers was determined by single-crystal X-ray diffraction analysis and comparison of the experimental and calculated ECD spectra. Compounds 1, 2, 5 and 9-12 exhibited potent to moderate anti-inflammatory activity with IC50 values in the range of 22.43 ± 0.86 to 53.88 ± 4.06 µM.

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.

Dimeric 2-(2-phenethyl)chromones from agarwood of Aquilaria filaria.

Four new 2-(2-phenethyl)chromone dimers (1-4) were isolated from EtOAc extract of agarwood originating from Aquilaria filaria from Philippines. Their structures were elucidated by spectroscopic analysis (1D and 2D NMR, and HRESIMS) and comparison of the experimental and computed ECD curves. Compounds 1-4 exhibited inhibition of nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells with IC50 values in the range from 33.94 to 57.53 µM.