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.

Chemistry and biology of marine-derived Trichoderma metabolites.

Marine-derived fungi of the genus Trichoderma have been surveyed for pharmaceuticals and agrochemicals since 1993, with various new secondary metabolites being characterized from the strains of marine animal, plant, sediment, and water origin. Chemical structures and biological activities of these metabolites are comprehensively reviewed herein up to the end of 2022 (covering 30 years). More than 70 strains that belong to at least 18 known Trichoderma species have been chemically investigated during this period. As a result, 445 new metabolites, including terpenes, steroids, polyketides, peptides, alkaloids, and others, have been identified, with over a half possessing antimicroalgal, zooplankton-toxic, antibacterial, antifungal, cytotoxic, anti-inflammatory, and other activities. The research is highlighted by the molecular diversity and antimicroalgal potency of terpenes and steroids. In addition, metabolic relevance along with co-culture induction in the production of new compounds is also concluded. Trichoderma strains of marine origin can transform and degrade heterogeneous molecules, but these functions need further exploration.

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.

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.

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.

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.

Four dodecanoic acid derivatives from the cold-seep-derived fungus Cladosporium cladosporioides 8-1.

Two new compounds, cladospolides I (1) and J (2), together with two new naturally occurring ones, methyl 11-hydroxy-4-oxododecanoate (3) and 11-hydroxy-4-oxododecanoic acid (4), were isolated from the culture extract of the cold-seep sediment-derived fungus Cladosporium cladosporioides 8-1. Their structures and configurations were established by analysis of 1D/2D NMR, MS, ECD, and specific optical rotation data. Compound 3 was possibly formed by methyl esterification of 4 during the purification process due to the utilization of methanol. All compounds were evaluated for inhibition of four marine phytoplankton species and five marine-derived bacteria.

Myrochromanol analogues and trichothecene derivatives from the shellfish-derived fungus Albifimbriaverrucaria.

Eight myrochromanol analogues, including three pairs of epimers at C-2 with the myrochromanol scaffold and two examples of myrochromanol with sugar moiety linked at C-4, together with twelve trichothecene derivatives were isolated from the cultures of a shellfish-derived fungus Albifimbria verrucaria CD1-4. Among them, eight compounds named 2-epi-myrochromanol, ent-myrochromanol B, 4-epi-myrochromanol B, 2-epi-myrochromanol A, myrochromanosides A and B, 6',7'-erythro-(2'E,4'Z)-trichoverrol B, 3R,8S-dihyroxyroridin H were previously undescribed fungal metabolites. Their planar structures and relative configurations were established by 1D and 2D NMR, and HR-MS data analysis, and their absolute configurations were determined using the modified Mosher's method and electronic circular dichrosim calculations. Almost all isolates were evaluated for growth rate inhibition of three marine harmful microalgae Chattonella marina, Heterosigma akashiwo, and Prorocentrum donghaiense, and lethal activity to one marine zooplankton, Artemia salina. Myrochromanosides A and B exhibited obvious inhibitory against three tested microalgae with IC50 values in the range of 9.2-108.9 µM. 8α-Hydroxyroridin H, roridin A and verrucarin A exhibited significant inhibition against P. donghaiense with IC50 values of 6.1, 5.8, and 6.0 µM and toxicity against brine shrimp larvae with LC50 values of 1.4, 2.8, and 0.26 µM, respectively.

Cyclopentenone and wickerol derivatives from the marine algicolous fungus Trichoderma atroviride A-YMD-9-4.

A new cyclopentenone derivative, 4-hydroxyhypocrenone A, and a new naturally-occurring wickerol derivative, 8-acetoxywickerol A, as well as two known compounds, hypocrenone A and wickerol B, were purified from Trichoderma atroviride A-YMD-9-4, an endophytic fungus isolated from the marine red alga Gracilaria verrucosa. The structures and relative configurations of two new isolates were established by a combination of 1 D/2D NMR, IR, and mass spectroscopic methods, and the absolute configuration of 1 was assigned on the basis of ECD data analyzed by quantum chemical calculations. Compounds 1 and 2 exhibited weak inhibition of one or two marine phytoplankton species.

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.