Penicianstinoids F-K, six undescribed meroterpenoids from the marine algicolous fungus Penicillium sp. RR-DL-1-7.

Six previously undescribed meroterpenoids, penicianstinoids F-K (1-6), together with four known analogues, dehydroaustinol (7), dehydroaustin (8), penicianstinoid A (9), and furanoaustinol (10), were isolated from the cultures of the algicolous fungus Penicillium sp. RR-DL-1-7, derived from the red alga Rhodomela confervoides. Their structures and relative configuration were established by detailed spectroscopic analysis of NMR and HR-MS experiments, and the absolute configurations were assigned by X-ray diffraction and ECD spectral analysis. None of the isolates showed obvious growth inhibitory effects against five plankton and four bacteria species tested.

A New Harziane Diterpene, Harziaketal A, and a New Sterol, Trichosterol A, from the Marine-Alga-Epiphytic Trichoderma sp. Z43.

One new diterpene, harziaketal A (1), and one new highly degraded sterol, trichosterol A (2), along with three known compounds, including one diterpene, harzianone (3), and two steroids, (22E,24R)-5α,6α-epoxy-ergosta-8(14),22-dien-3ß,7α-diol (4) and isoergokonin B (5), were isolated from the culture of the marine-alga-epiphytic fungus Trichoderma sp. Z43 by silica gel column chromatography (CC), Sephadex LH-20 CC, and preparative thin-layer chromatography (TLC). Their structures and relative configurations were assigned by nuclear magnetic resonance (NMR) and high resolution electrospray ionisation mass spectrometry (HR-ESI-MS) data, and the absolute configuration of 1 was established by X-ray diffraction. Compound 1 features a hemiketal unit situated at the four-membered ring of harziane-type diterpenes for the first time, while 2 represents the rare occurrence of sterols with rings A and B being degraded. Compounds 1 and 2 displayed weak inhibition against the tested phytoplankton (Amphidinium carterae, Heterocapsa circularisquama, Heterosigma akashiwo, and Prorocentrum donghaiense) with half maximal inhibitory concentration (IC50 ) ranging from 14 to 53 µg/mL.

Lipids and Terpenoids from the Deep-Sea Fungus Trichoderma lixii R22 and Their Antagonism against Two Wheat Pathogens.

Five new lipids, tricholixins A-E (1-5), and two known terpenoids, brasilane A (6) and harzianone A (7), were discovered from a deep-sea strain (R22) of the fungus Trichoderma lixii isolated from the cold seep sediments of the South China Sea. Their structures and relative configurations were identified by meticulous analysis of MS and IR as well as NMR data. The absolute configuration of 5 was ascertained by dimolybdenum-induced ECD data in particular. Compounds 1 and 2 represent the only two new butenolides from marine-derived Trichoderma, and they further add to the structural diversity of these molecules. Although 6 has been reported from a basidiomycete previously, it is the first brasilane aminoglycoside of Trichoderma origin. During the assay against wheat-pathogenic fungi, both 1 and 2 inhibited Fusarium graminearum with an MIC value of 25.0 µg/mL, and 6 suppressed Gaeumannomyces graminis with an MIC value of 12.5 µg/mL. Moreover, the three isolates also showed low toxicity to the brine shrimp Artemia salina.

Trichoderols B-G, Six New Lipids from the Marine Algicolous Fungus Trichoderma sp. Z43.

Six new lipids, trichoderols B-G (1-6), along with a known one, triharzianin B (7), were isolated from the culture of Trichoderma sp. Z43 obtained from the surface of the marine brown alga Dictyopteris divaricata. Their structures and relative configurations were identified by interpretation of 1D/2D NMR and MS data. Compounds 1-7 were assayed for inhibiting the growth of three phytopathogenic fungi (Fusarium graminearum, Gaeumannomyces graminis, and Glomerella cingulata), four marine phytoplankton species (Amphidinium carterae, Heterocapsa circularisquama, Heterosigma akashiwo, and Prorocentrum donghaiense), and one marine zooplankton (Artemia salina). Compounds 1, 4, and 7 exhibited weak antifungal activities against three phytopathogenic fungi tested with MIC ≥ 64 µg/mL. All compounds displayed moderate antimicroalgal activity with IC50 ≥ 15 µg/mL and low toxicity to the brine shrimp Artemia salina.

New ophiobolin sesterterpenoid and drimane sesquiterpenoids from a marine-alga-derived fungus Aspergillus sp.

Further investigation of secondary metabolites of a marine-alga-derived fungus Aspergillus sp. RR-YLW-12 led to isolate one new ophiobolin-type sesterterpenoid (1), four new drimane-type sesquiterpenoids (2-5) and one natural occurring compound (6), together with seven known compounds (7-13). Their structures and stereochemistry were elucidated by extensive spectroscopic analysis of NMR and HRMS experiments, and by comparison with the literature data. All isolates were evaluated for growth inhibition of five marine harmful microalgae. The new compounds exhibited significant to moderate inhibitory effects towards all tested microalgae species with IC50 values ranging from 5.8 to 54.5 µg/mL.

Sorbicillinoids from the alga-epiphytic fungus Trichoderma reesei Z56-8.

A new highly transformed sorbicillinoid derivative, trichoreesin A (1), and four known monomeric sorbicillinoids, sorbicillin (2), 2',3'-dihydrosorbicillin (3), 3-demethylsorbicillin (4), and sohirnone A (5), were discovered from Trichoderma reesei Z56-8, an epiphyte from the marine brown alga Sargassum sp. The structure and relative configuration of 1 were determined by interpretation of UV, IR, NMR, and MS signals, and its absolute configuration was assigned by analysis of ECD data aided by quantum chemical calculations. This is the first survey of metabolites from marine algicolous T. reesei. Compound 1 represents the first bicyclic vertinolide derivative, and it possesses inhibition of several marine phytoplankton species.

Sesquiterpenoids and a steroid from the algicolous Trichoderma brevicompactum.

Six new sesquiterpenoids including three bisabolane derivatives, trichobisabolins O1, O2, and P (1-3), two nerolidol derivatives, trichonerolins A and B (4 and 5), one acorane, trichoacorin A (6), along with one new steroid, isoergokonin B (7), were isolated from the culture of Trichoderma brevicompactum A-DL-9-2 obtained from the inner tissue of the red alga Chondria tenuissima. Their structures and relative configurations were assigned by interpretation of 1D/2D NMR and MS data. As acyclic sesquiterpenoids, compounds 4 and 5 were discovered from Trichoderma for the first time. Compounds 1-7 were evaluated for the inhibition of some marine-derived organisms, in which, 3 and 4/5 exhibited potent inhibition against Amphidinium carterae and Chattonella marina with IC50 of 1.8 µg/mL and 1.2 µg/mL, respectively. In addition, compound 7 could inhibit the growth of Pseudoalteromonas citrea with an MIC value of 64 µg/mL.

Phenylhydrazone and Quinazoline Derivatives from the Cold-Seep-Derived Fungus Penicillium oxalicum.

Three new phenylhydrazones, penoxahydrazones A-C (compounds 1-3), and two new quinazolines, penoxazolones A (compound 4) and B (compound 5), with unique linkages were isolated from the fungus Penicillium oxalicum obtained from the deep sea cold seep. Their structures and relative configurations were assigned by analysis of 1D/2D NMR and mass spectroscopic data, and the absolute configurations of 1, 4, and 5 were established on the basis of X-ray crystallography or ECD calculations. Compound 1 represents the first natural phenylhydrazone-bearing steroid, while compounds 2 and 3 are rarely occurring phenylhydrazone tautomers. Compounds 4 and 5 are enantiomers that feature quinazoline and cinnamic acid units. Some isolates exhibited inhibition of several marine phytoplankton species and marine-derived bacteria.

Antifungal and Antimicroalgal Trichothecene Sesquiterpenes from the Marine Algicolous Fungus Trichoderma brevicompactum A-DL-9-2.

Eight new trichothecene derivatives, trichodermarins G-N (1-8), and two new cuparene derivatives, trichocuparins A (9) and B (10), as well as six known trichothecenes (11-16) were isolated from the fungal strain Trichoderma brevicompactum A-DL-9-2 obtained from the inner tissue of the marine red alga Chondria tenuissima. The structures and relative configurations of 1-10 were assigned by NMR and MS data, and the absolute configurations of 1, 2, and 9 were established by X-ray diffraction. Compound 8 features an aminosugar unit bond to the trichothecene framework for the first time, while 9 and 10 represent the first occurrence of cuparene sesquiterpenes in Trichoderma. All the isolates were assayed for growth inhibition of five phytopathogenic fungi (Botrytis cinerea, Cochliobolus miyabeanus, Fusarium oxysporum f. sp. cucumerium, Fusarium oxysporum f. sp. niveum, and Phomopsis asparagi) and four marine phytoplankton species (Amphidinium carterae, Heterocapsa circularisquama, Heterosigma akashiwo, and Prorocentrum donghaiense). Several of them exhibited significant inhibitory activities against the fungi and phytoplankton tested of which trichodermin (12) showed the highest antifungal and antimicroalgal activities with MIC and IC50 values being 4.0 and 0.82 µg/mL, respectively.

Post-processing of computed tomography perfusion in patients with acute cerebral ischemia: variability of inter-reader, inter-region of interest, inter-input model, and inter-software.

OBJECTIVE: To determine the reproducibility of quantitative computed tomography perfusion (CTP) parameters generated using different post-processing methods and identify the relative impact of subjective factors on the robustness of CTP parameters in acute ischemic stroke (AIS). MATERIALS AND METHODS: A total of 80 CTP datasets from patients with AIS or transient ischemic attack (TIA) were retrospectively post-processed by two observers using different regions of interest (ROI) types, input models, and software. The CTP parameters were derived for 10 parenchymal ROIs. The intra-class correlation coefficients (ICCs) were used to assess the reproducibility of the CTP parameters for various post-processing methods. The Spearman correlation test was used to detect potential relationships between software and input models. RESULTS: The ICCs with 95% confidence intervals (CIs) were 0.94 (0.93-0.96), 0.94 (0.92-0.96), 0.82 (0.79-0.86), and 0.87 (0.85-0.90) for inter-reader agreement by using elliptic ROI, irregular ROI, single-input model, and dual-input model, respectively. The ICCs with 95% CI were 0.98 (0.98-0.98), 0.46 (0.43-0.50), and 0.25 (0.20-0.30) for inter-ROI type, inter-input model, and inter-software agreement, respectively. CONCLUSIONS: Although the CTP parameters were stable when measured using different readers with different ROI types, they varied for different input models and software. The standardization of CTP post-processing is essential to reduce variability of CTP values. KEY POINTS: • The CTP parameters derived by different readers with different ROI types have agreements that range from good to excellent. • The CTP parameters derived from different input models and software programs have poor agreement but significant correlations.

Synthesis of a novel 2D zinc(ii) metal-organic framework for photocatalytic degradation of organic dyes in water.

A novel 2D zinc(ii) metal-organic framework, formulated as [Zn(L)(H2O)]·H2O (1) (H2L = 4-(pyridine-4-yl) phthalic acid), has been successfully obtained under solvothermal conditions. This metal-organic framework (MOF) material exhibits efficient photocatalytic activity towards the degradation of organic dyes in the absence of any photosensitizer or cocatalyst. Its catalytic performance for rhodamine B (RhB) and methyl orange (MO) degradation was superior to most reported MOFs with a degradation efficiency of 98.5% for RhB and 83.8% for MO within 120 min in the absence of H2O2, which could be attributed to its high efficiency in generating ·O2- (an effective oxidant for the degradation of dyes). The possible mechanism of the reaction was discussed in detail. In addition, 1 shows stable catalytic efficiency after five reaction cycles, which indicates that 1 exhibits efficient catalytic activity and good reusability toward the degradation of organic dyes, enabling it to be a potential candidate for environmental governance.

Optimization of an integrated feedback control for a pest management predator-prey model.

In this paper, a Leslie-Gower predator-prey model with ratio-dependence and state pulse feedback control is established to investigate the effect of spraying chemical pesticides and supplement amount of beneficial insects at the same time. Firstly, the existence, uniqueness and asymptotic stability of the periodic solution are proved by using successor function method and the analogue of the Poincaré criterion when the equilibria E∗ and E0 are stable, and the existence of limit cycles without impulse system is verified when the equilibrium E∗ is unstable. Furthermore, to obtain the minimum cost per period of controlling pests, we propose the optimization problem and calculate the optimal threshold. Finally, the feasibility of our model is proved by numerical simulation of a concrete example.

[Regulation of extracellular ATP onchlorophyll content and fluorescence characteristics of Angelica sinensis seedlings under drought and low temperature stress].

As an important signal molecule, extracellular ATP(eATP) can regulate many physiological and biochemical responses to plant stress. In this study, the regulation of extracellular ATP(eATP) on chlorophyll content and chlorophyll fluorescence parameters of Angelica sinensis seedlings were studied under drought and low temperature stress. The results showed that all the chlorophyll content, the actual photochemical efficiency [Y(Ⅱ)], the electron transfer rate(ETR), the photochemical quenching coefficient(qP and qL) of A. sinensis leaves were significantly decreased under drought and low temperature stress, respectively. At the same time, non-photochemical quenching(NPQ and qN) were also all significantly increased, respectively. The application of eATP alleviated the decrease of chlorophyll content, Y(Ⅱ), ETR, qP and qL of A. sinensis leaves under drought and low temperature stress, and eliminated the increase of qN and NPQ. The results indicated that eATP could effectively increase the open ratio of PSⅡ reaction centers, and improve the electron transfer rate and light energy conversion efficiency of PSⅡ of A. sinensis leaves under drought and low temperature stress. It is beneficial to enhance the chlorophyll synthesis and the adaptability of PSⅡ about A. sinensis seedlings to drought and low temperature stress.

Trichobisabolins A-H, eight new bisabolane derivatives from the marine-alga-epiphytic fungus Trichoderma asperellum Y6-2.

Eight new bisabolane derivatives, trichobisabolins A-H, along with two known ones, (3R,6R,7R)-1,10-bisaboladien-3-ol (9) and (3R,6R,7S)-1,10-bisaboladien-3,6-diol (10) were isolated from the culture of Trichoderma asperellum Y6-2, obtained from the surface of the marine red alga Chondrus ocellatus. Their structures and relative configurations were identified by interpretation of 1D/2D NMR and MS data. Compounds 1-8 were assayed for inhibiting the growth of some marine-derived organisms, including four marine phytoplankton species, one marine zooplankton species, and five pathogenic bacteria. All of them exhibited inhibition against the marine phytoplanktons with IC50 values ranging from 2.1-78 µg/mL, compounds 4 and 8 showed weak lethality to the marine zooplankton, and none of them had inhibition against the five pathogenic bacteria.

Tricholumin A, a Highly Transformed Ergosterol Derivative from the Alga-Endophytic Fungus Trichoderma asperellum.

Tricholumin A (1) with an unprecedented carbon skeleton was isolated from the fungus Trichoderma asperellum cf44-2, an endophyte from the marine brown alga Sargassum sp. Its structure and relative configuration were identified by extensive 1D/2D NMR and mass spectrometric data, and the absolute configuration was assigned by X-ray diffraction and ECD calculations. Compound 1 represents a highly transformed ergosterol derivative, and it exhibited inhibition of some pathogenic microbes and marine phytoplankton species.

Trichocarotins A-H and trichocadinin A, nine sesquiterpenes from the marine-alga-epiphytic fungus Trichoderma virens.

In addition to CAF-603, 14-hydroxy CAF-603 (trichocarane B), 7-ß-hydroxy CAF-603, and trichocarane A, eight new carotane sesquiterpenes, trichocarotins A-H, and one new cadinane sesquiterpene, trichocadinin A, were isolated from the culture of Trichoderma virens Y13-3, obtained from the surface of a marine red alga. Their structures and relative configurations were unambiguously assigned by interpretation of 1D/2D NMR and MS data, and their absolute configurations were established by X-ray diffraction or ECD spectra aided by quantum chemical calculations. These compounds represent two rarely occurring sesquiterpene types from filamentous fungi, and six of them feature potent inhibition against some marine plankton species.

Bisabolane, cyclonerane, and harziane derivatives from the marine-alga-endophytic fungus Trichoderma asperellum cf44-2.

Three undescribed bisabolane derivatives, trichaspin, trichaspsides A and B, three undescribed cyclonerane sesquiterpenes, 9-cycloneren-3,7,11-triol, 11-cycloneren-3,7,10-triol, and 7,10-epoxycycloneran-3,11,12-triol, and one undescribed harziane diterpene, 11-hydroxy-9-harzien-3-one, were obtained from the culture of Trichoderma asperellum cf44-2, an endophyte of the marine brown alga Sargassum sp. Their structures and relative configurations were assigned by analysis of 1D/2D NMR and MS data, and their absolute configurations were established by ECD or specific optical rotation data. Trichaspin features an unprecedented ethylated bisabolane skeleton, while trichaspsides A and B represent the first aminoglycosides of bisabolane and norbisabolane sesquiterpenes, respectively. Nine of the compounds were evaluated for inhibition of five marine-derived pathogenic bacteria and toxicity to a marine zooplankton.

Trichorenins A-C, Algicidal Tetracyclic Metabolites from the Marine-Alga-Epiphytic Fungus Trichoderma virens Y13-3.

Three novel polyketide-like metabolites, trichorenins A-C (1-3), with a unique tetracyclic carbon skeleton were obtained from the culture of Trichoderma virens Y13-3, an epiphyte of the marine red alga Gracilaria vermiculophylla. Their structures and relative configurations were established by analysis of 1D/2D NMR and MS data, and their absolute configurations were unequivocally assigned by X-ray diffraction and ECD spectra aided by quantum chemical calculations. Compounds 1-3 exhibited potent inhibition against two marine phytoplankton species, Chattonella marina and Karlodinium veneficum.

Two new tricycloalternarene esters from an alga-epiphytic isolate of Alternaria alternata.

Two new tricycloalternarene-type meroterpenes, 17-O-methyltricycloalternarene D (1) and methyl nortricycloalternarate (4), and two known congeners, TCA D (2) and TCA 1b (3), were isolated from the culture of a marine red alga-epiphytic fungal strain (k21-1) of Alternaria alternata. The planar structures and relative configurations of these two new compounds were unequivocally identified by a combination of 1D/2D NMR, UV, IR, and mass spectra and by comparison with literature data, and the absolute configurations were assigned by analysis of ECD spectra. Compounds 1-4 were evaluated for growth inhibition of four marine plankton species, but they appeared weak or moderate to inhibit them.