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The solid-state cultivation of Acaulium sp. H-JQSF isolated from Armadillidium vulgare produces acautalides A-C (1-3) as skeletally unprecedented Diels-Alder adducts of a 14-membered macrodiolide to an octadeca-9,11,13-trienoic acid. The acautalide structures, along with the intramolecular transesterifications of 1-acylglycerols, were elucidated by mass spectrometry, nuclear magnetic resonance, chemical transformation, and single-crystal X-ray diffraction. Compounds 1-3 were found to be neuroprotective with antiparkinsonic potential in the 1-methyl-4-phenylpyridinium-challenged nematode model, with the magnitude impacted by the glycerol esterification.

From a single alkene to two different alkenes! A convenient Fe-catalyzed A–D–A–T-type radical-dual-difunctionalization and cross-coupling of two different alkenes to provide chain elongated and tri...

A cyclodipeptide synthase-containing gene cluster (pcm) was identified in Streptomyces chrestomyceticus NA4264 through genome mining. Heterologous expression of the cryptic pcm gene cluster in Streptomyces albus led to the production of a new highly modified cyclodipeptide named purincyclamide (1). Bioinformatic analysis and gene knockout experiments revealed the biosynthetic pathway. The production of 1 was achieved through a one-pot enzymatic reaction.

The solid-state cultivation of

A convenient Fe-catalyzed four-component radical dual difunctionalization and ordered assembly of two alkenes with aromatic/aliphatic aldehydes and TBHP to provide chain elongated β,δ-functionalized ketones via a one-pot procedure has been developed. Aldehydes were homolytically cleavaged to produce acyl radicals and subsequently allowed for the successive construction of C(sp2)-C(sp3), C(sp3)-C(sp3), and C(sp3)-O bonds via dual radical insertions and radical-radical coupling, following the intrinsic nucleo/electrophilic reactivity of both the radicals and alkenes.

Genome mining of an indolocarbazole-type gene cluster from a marine-derived Nocardiopsis flavescens NA01583 strain led to the discovery of three new indolocarbazole alkaloids (1-3). Heterologous expression of the intact loo gene cluster in a surrogate host Streptomyces lividans K4-114 led to the successful production of 3. Notably, compound 1 showed potent cytotoxic activities toward eight cancer cell lines with IC50 values ranging from 41 to 283 nM.

Acaulin A (1) and its macrolactone ring-opened congener acaulin B (2) were characterized from the culture of Acaulium sp. H-JQSF (an isopod-associated fungus) as architecturally undescribed trimeric macrodiolides, with the former being antiosteoporotic at 0.4 μM in the prednisolone-induced osteoporotic zebrafish. Identification of acaudiolic acid (3) as the monomeric macrodiolide precursor facilitated the proposal of the acaulin biosynthetic pathway.

Acaulide (1), a macrodiolide with an unprecedented framework, was characterized along with its shunt products-acaulones A (2) and B (3)-from the culture of Acaulium sp. H-JQSF associated with the isopod Armadillidium vulgare. The spiro-linked 14-, 14-, and 6-membered cycles of 1 arise likely from iterative intermolecular Michael addition reactions. Biological evaluation in the prednisolone-induced osteoporotic zebrafish demonstrated that 1 is antiosteoporotic at 0.4 and 2.0 μM.

Autoimmune and inflammatory diseases are associated with inappropriate activation of the NOD-like receptor protein 3 (NLRP3) inflammasome, but suitable inhibitors against such improper activations remain scarce. Here, spirodalesol (1) from Daldinia eschscholzii was structurally characterized and is biosynthetically proposed as an NLRP3 inflammasome activation inhibitor with an unprecedented carbon skeleton.

A convenient Fe-catalyzed four-component radical dual difunctionalization and ordered assembly of two alkenes with aromatic/aliphatic aldehydes and TBHP to provide chain elongated β,δ-functionalized ketones via a one-pot procedure has been developed. Aldehydes were homolytically cleavaged to produce acyl radicals and subsequently allowed for the successive construction of C(sp

Genome mining of the marine Streptomyces seoulensis A01 enabled the identification of a giant type I polyketide synthase gene cluster ( asm). Heterologous expression of the cryptic asm cluster using a bacterial artificial chromosome vector in heterologous host led to the production of ansaseomycins A (1) and B (2). A plausible biosynthetic pathway was also proposed. Additionally, compounds 1 and 2 are active against K562 cell lines with IC50 values of 13.3 and 18.1 μM, respectively.

Citrofulvicin (1), along with its early shunt product fulvionol (2), was characterized as a skeletally unprecedented antiosteoporotic agent from a human sputum-derived fungus Penicillium velutinum. The unique citrofulvicin framework is likely formed by a nonenzymatic intermolecular Diels–Alder cycloaddition between heptaketide-based intermediates. Citrofulvicin and fulvionol were demonstrated to be osteogenic at 0.1 μM in the prednisolone-induced osteoporotic zebrafish.

Two novel enediyne-derived natural products, amycolamycins A and B (1 and 2), were characterized from a locust-associated actinomycete Amycolatopsis sp. HCa4. Amycolamycins A and B contain a unique 2-(cyclopenta[a]inden-5-yl)oxirane core with suspected enediyne polyketide biosynthetic origin. Sequencing and analysis of the acm biosynthetic gene cluster allowed us to propose the biosynthetic pathway of 1 and 2. Moreover, amycolamycin A (1) was selectively cytotoxic to the M231 breast cancer cell line.

The conversion from triene- to diene-typed ansamycins is clarified step by step in Streptomyces seoulensis IFB-A01. Such an intertype convertibility is adopted to establish for the first time the simultaneous mutasynthesis of both types of C17-benzene ansamycins (C17BAs). Three of the newly generated unnatural compounds showed potent cytotoxicity.

The white croaker (Argyrosomus argentatus) derived Curvularia sp. IFB-Z10 produces curvulamine as a skeletally unprecedented alkaloid incorporating two undescribed extender units. Curvulamine is more selectively antibacterial than tinidazole and biosynthetically unique in the new extenders formed through a decarboxylative condensation between an oligoketide motif and alanine.

Microbial constructions of secondary metabolites are generally biosynthetic gene cluster (BGC)-based, and the forging of different BGC-sourced intermediates tends to be overlooked. Here, we show that the dalesconol bioassembly lines in Daldinia eschscholzii can sequester guest intermediates (i.e., building blocks produced outside the dalesconol biosynthetic gene cluster) to form arrays of skeletally undescribed molecules such as (+)-dalescone A, a potent inhibitor against the NLRP3 inflammasome activation.

Owing to the negligible or acceptable immunogenicity, small molecules capable of inducing the differentiation of undifferentiated stem cells into organ-specific cell types are particularly promising in developing replacement therapy, but such compounds with undescribed architectures are extremely rare. Selesconol (1) is discovered from the culture of Daldinia eschscholzii IFB-TL01 as a skeletally unprecedented inducer for the differentiation of rat bone marrow mesenchymal stem cells into neural cells, with its unique framework clarified to derive from the intermediate tautomerization of the dalesconol A biosynthetic pathway.

Curvularia sp. IFB-Z10, a white croaker-associated fungus, generates a skeletally unprecedented indolizine alkaloid named curindolizine (1), which displays an anti-inflammatory action in lipopolyssacharide (LPS)-induced RAW 264.7 macrophages with an IC50 value of 5.31 ± 0.21 μM. The enzymatic transformation test demonstrated that the unique curindolizine architecture was most likely produced by the regiospecific in-cell Michael addition reaction between pyrrole alkaloids, curvulamine, and 3,5-dimethylindolizin-8(5H)-one.

An asymmetric Michael-type reaction of phosphorus ylides and α,β-unsaturated ketones under the catalysis of a chiral ion pair catalyst has been described. The ion pair catalyst containing a chiral counteranion was prepared by simply mixing 9-amino-(9-deoxy)-epi-quinine with l-N-Boc-proline. The optically active α-methylene-δ-ketoesters could be obtained with good to excellent enantioselectivities (up to 95% ee) under mild reaction conditions.

Three new phloroglucinols, named lysidicins F-H (1-3), were isolated from the roots of Lysidice rhodostegia. These compounds have a unprecedented benzyl benzo[b]furo[3,2-d]furan skeleton, and lysidicin F (1) is the first example of natural product with trans-fused furan rings. Their structures were established on the basis of extensive spectroscopic analysis, and the absolute configurations of them were determined by computational methods. A possible biosynthetic pathway for 1-3 was also postulated.

Dalesindole, an antibacterial and anti-inflammatory indole alkaloid with an undescribed carbon skeleton, was stereoselectively constructed by Daldinia eschscholzii through class II aldolase catalyzed Michael addition of fungal chromone with 3,3′-diindolylmethane (DIM) formed in situ from indole-3-carbinol (I3C) under catalyses of monooxygenase and 8-amino-7-oxononanoate synthase (AONS). Dalesindole isomerizes via a retro-Michael reaction to give stereoisomers with bioactivities. The work provides an access to new bioactive hybrids of fungal oligoketide with microbially decorated exogenous chemistry.

A mutasynthetic strategy is introduced for the mycosynthesis of naphthalene-based molecules (mutadalesols A–F) with directed substitution patterns and new frameworks by generating and using the ΔpksTL mutant strain of Daldinia eschscholzii. (±)-Mutadalesol A and its (+)-enantiomer are cytotoxic, and its (−)-enantiomer inhibits Toll-like receptor 5 (TLR5). The in-culture reactability of fungal oligoketide intermediates with 5-aminonaphthalen-1-ol (ANL) is demonstrated, shedding light on bioorthogonal accesses to unnatural molecule libraries valuable in drug discovery pipelines.