Aspergixanthones I⁻K, New Anti-Vibrio Prenylxanthones from the Marine-Derived Fungus Aspergillus sp. ZA-01.

Marine-derived fungi are a rich source of structurally diverse metabolites. Fungi produce an array of compounds when grown under different cultivation conditions. In the present work, different media were used to cultivate the fungus Aspergillus sp. ZA-01, which was previously studied for the production of bioactive compounds, and three new prenylxanthone derivatives, aspergixanthones I⁻K (1⁻3), and four known analogues (4⁻7) were obtained. The absolute configuration of 1 was assigned by ECD experiment and the Mo2(AcO)4 ICD spectrum of its methanolysis derivative (1a). All the compounds (1⁻7) were evaluated for their anti-Vibrio activities. Aspergixanthone I (1) showed the strongest anti-Vibrio activity against Vibrio parahemolyticus (MIC = 1.56 µM), Vibrio anguillarum (MIC = 1.56 µM), and Vibrio alginolyticus (MIC = 3.12 µM).

Bioactive phenyl ether derivatives from the marine-derived fungus Aspergillus carneus.

A new phenyl ether derivative, 3-hydroxy-5-(3-hydroxy-5-methylphenoxy)-4-methoxybenzoic acid (1), along with two known analogues, 3,4-dihydroxy-5-(3-hydroxy-5-methylphenoxy)benzoic acid (2) and 3-hydroxy-5-(3-hydroxy-5-methylphenoxy)benzoic acid (3), were isolated from the fungus Aspergillus carneus collected from South China Sea. The structure elucidation of 1 was determined based on extensive NMR and MS spectroscopic analyses. Compound 2 showed a strong antioxidant activity with an IC50 value of 19.3 µM which was close to the positive control ascorbic acid (IC50 = 15.3 µM).

[A new phenylpropanoid glycoside compound isolated from Karelinia caspia].

To study the constituents of Karelinia caspia(Pall.) Less, three phenylpropanoid derivatives and other compounds were isolated by silica gel, RP-18 chromatographic methods. Compound 1 was a new phenylpropanoid glycoside named as kareline A. Their structures were determined by spectroscopic analysis, including 1D- and 2D-NMR and mass spectrometry.

Sesquiterpenoids from Incarvillea arguta: absolute configuration and biological evaluation.

Diincarvilones A-D (1-4), incarvilone A (5), and a known compound, argutosine B (6), were isolated from Incarvillea arguta. The structures, including the absolute configurations of the new compounds, were determined by NMR spectroscopy, X-ray diffraction analysis, CD spectroscopy, and a variety of computational methods. The biological properties of these substances, including effects on intracellular Ca(2+) influx, nitric oxide (NO) production, and human cancer cells, were evaluated. The results showed that at the concentration of 10 µM (in HBSS buffer) diincarvilones A and B cause a persistent increase in cytoplasmic calcium levels in A549 cells.

Dihydroberkleasmin A: a new eremophilane sesquiterpenoid from the fermentation broth of the plant endophytic fungus Pestalotiopsis photiniae.

Dihydroberkleasmin A (1), a new ester-substituted sesquiterpenoid related to the eremophilane class, together with the known compound berkleasmin C (2), were isolated from the fermentation broth of the plant endophytic fungus Pestalotiopsis photiniae. The structure of dihydroberkleasmin A (1) was elucidated by extensive spectroscopic analysis. The stereochemistry was assigned by comparison of the NMR spectroscopic data with those of berkleasmin A.

A pair of windmill-shaped enantiomers from Lindera aggregata with activity toward improvement of insulin sensitivity.

(+)-Linderaspirone A and (-)-linderaspirone A, a pair of natural windmill-shaped enantiomers, were isolated from the traditional Chinese medicine plant Lindera aggregate by HPLC using a chiral column, achieving over 98% ee. Their structures and absolute configurations were determined on the basis of extensive analysis of NMR spectra, crystal X-ray diffraction, and calculation of the optical rotations (OR). They have an unprecedented carbon skeleton and showed significant activity against glucosamine-induced insulin resistance.

Compounds from Acorus tatarinowii: determination of absolute configuration by quantum computations and cAMP regulation activity.

A new cadinane-type sesquiterpenoid, tatarinowin A (1), two phenylpropanoids, tatarinoids A (2) and B (3), and a trinorlignan, tatarinoid C (4), along with 15 known compounds including two pairs of mixtures were isolated from the rhizome of Acorus tatarinowii. The absolute configurations of 1-4 were established by computation of specific rotation values. The isolated compounds were evaluated for their cAMP regulatory activity by the AlphaScreen assay.

Structure elucidation and theoretical investigation of key steps in the biogenetic pathway of schisanartane nortriterpenoids by using DFT methods.

Rubrifloradilactone C (4), a novel bioactive nortriterpenoid, along with four other nortriterpenoids (1-3, 5) were isolated from Schisandra rubriflora. The structure of 4 was determined by extensive NMR spectral analysis, computational evidence by using the GIAO method at the B3LYP/6-311++G(2d,p)//B3LYP/6-31G(d) levels, and X-ray analysis. DFT at the B3LYP/6-311+G(d,p) level was selected to clarify the key mechanistic steps in the formation of 1 and 4 through transition-state (TS) investigations. The effect of enzymes on the TS barriers was considered by using the polarized continuum model. Other possible products based on the new mechanism were predicted.

Isolation and structure elucidation of kadlongilactones C-F from Kadsura longipedunculata by NMR spectroscopy and DFT computational methods.

Four new triterpenoids, kadlongilactones C-F (2-5), containing a consecutive hexacyclic [7,7,5,6,6,6] ring system, were isolated from the leaves and stems of Kadsura longipedunculata. In comparison with the NMR data of kadlongilactones A (1) and D (3), a significant phenomena was discovered that ring D of 3 inverted from a half-chair in 1 to a half-boat conformation when the HO-16 group changed from alpha- to beta-orientation. The structures of 2-5 were established on the basis of detailed spectroscopic analysis, and DFT computational methods were applied in the structural validation of compounds 3 and 5. Compounds 1-4 showed significant cytotoxicity against A549, HT-29, and K562 cell lines with IC50 values of 0.49-3.61 microM in vitro.

Trijugin-type limonoids from the leaves of Cipadessa cinerascens.

Four new trijugin-type limonoids, cipatrijugins A-D (1-4), together with the known cipadesin A (5), were isolated from the leaves of Cipadessa cinerascens, and their structures were elucidated on the basis of spectroscopic and computational methods. The ability of compounds 1-5 to inhibit the growth of the A549 and K562 tumor cell lines was evaluated.

Isolation, X-ray crystallography, and computational studies of calydaphninone, a new alkaloid from Daphniphyllum calycillum.

[structure: see text]. A new hexacyclic alkaloid, calydaphninone (1), containing a 4-azatricyclo[5.2.2.0(1,4)]undecan ring system, has been isolated from the leaves and twigs of Daphniphyllum calycillum (Daphniphyllaceae). Its structure was elucidated by spectral and crystallographic means. Furthermore, conformations of calydaphninone (1) in solution are discussed on the basis of NMR spectral analysis and computational (B3LYP/6-31G*) results.

Lancifodilactone G: a unique nortriterpenoid isolated from Schisandra lancifolia and its anti-HIV activity.

[structure: see text]. Lancifodilactone G (1), a novel, highly oxygenated nortriterpenoid featuring a partial enol structure and a spirocyclic moiety, was isolated from the medicinal plant Schisandra lancifolia. Its structure and stereochemistry were determined from extensive one- and two-dimensional NMR and mass spectral data, coupled with single-crystal X-ray analysis. Compound 1 exerted minimal cytotoxicity against C8166 cells (CC50 > 200 microg/mL) and showed anti-HIV activity with EC50 = 95.47 +/- 14.19 microg/mL and a selectivity index in the range of 1.82-2.46.