Journal of Natural Products

Paraphaeoketones A-C ( 1 - 3 ) were isolated from the culture broth of Paraphaeosphaeria sp. KT4192. Their structures and relative configurations were determined using spectroscopic analysis and verified through density functional theory (DFT)-based chemical shift calculations. The absolute configurations of these compounds were determined by comparing the experimental electronic circular dichroism (ECD) spectra with those based on DFT calculations. We also propose a plausible biosynthetic route to 1 - 3 . While our prior studies on the isolation and structural elucidation of paraphaeolactones (e...

Two novel polyketides, accraspiroketides A ( 1 ) and B ( 2 ), which feature unprecedented [6 + 6+6 + 6] + [5 + 5] spiro chemical architectures, were isolated from Streptomyces sp. MA37 Δ accJ mutant strain. Compounds 1 - 2 exhibit excellent activity against Gram-positive bacteria (MIC = 1.5-6.3 μg/mL). Notably, 1 and 2 have superior activity against clinically isolated Enterococcus faecium K60-39 (MIC = 4.0 μg/mL and 4.7 μg/mL, respectively) than ampicillin (MIC = 25 μg/mL).

A detailed chemical study of the extract from the soft coral Stereonephthya bellissima resulted in the isolation and identification of seven new sesquiterpenoids, bellissinanes A-G ( 1 - 7 ), along with four new diterpenes ( 8 - 11 ). Bellissinane A ( 1 ) is the third reported nardosinane-type sesquiterpene bearing a 6/5/6 tricyclic system. Bellissinanes C and D ( 3 , 4 ) contain a phenylethylamine fragment, which is relatively unusual in marine organisms. Bellissinanes E-G ( 5 - 7 ) belong to the rare class of nornardosinane sesquiterpenoids...

The tear film lipid layer (TFLL) plays a vital part in maintenance of ocular health and represents a unique biological barrier comprising unusual and specialized lipid classes and species. The wax and cholesteryl esters (WEs and CEs) constitute roughly 80-90% of the TFLL. The majority of species in these lipid classes are branched and it is therefore surprising that the synthesis and properties of the second largest category of species, i.e., the anteiso -branched species, remain poorly characterized. In this study, we have developed a total synthesis route and completed a detailed NMR spectroscopic characterization of two common anteiso -branched species, namely: (22 S )-22-methyltetracosanyl oleate and cholesteryl (22' S )-22'-methyltetracosanoate...

Penicilloneines A ( 1 ) and B ( 2 ) are the first reported quinolone-citrinin hybrids. They were isolated from the starfish-derived fungus Penicillium sp. GGF16-1-2, and their structures were elucidated using spectroscopic, chemical, computational, and single-crystal X-ray diffraction methods. Penicilloneines A ( 1 ) and B ( 2 ) share a common 4-hydroxy-1-methyl-2(1 H )-quinolone unit; however, they differ in terms of citrinin moieties, and these two units are linked via a methylene bridge. Penicilloneines A ( 1 ) and B ( 2 ) exhibited antifungal activities against Colletotrichum gloeosporioides , with lethal concentration 50 values of 0...

Waixenicin A, a xenicane diterpene from the octocoral Sarcothelia edmondsoni , is a selective, potent inhibitor of the TRPM7 ion channel. To study the structure-activity relationship (SAR) of waixenicin A, we isolated and assayed related diterpenes from S. edmondsoni . In addition to known waixenicins A ( 1 ) and B ( 2 ), we purified six xenicane diterpenes, 7 S ,8 S -epoxywaixenicins A ( 3 ) and B ( 4 ), 12-deacetylwaixenicin A ( 5 ), waixenicin E ( 6 ), waixenicin F ( 7 ), and 20-acetoxyxeniafaraunol B ( 8 )...

The plant Goniothalamus leiocarpus of the Annonaceae family is used as an alternative medicine in tropical regions. Applying high-speed counter current chromatography (HSCCC), eight new bioactive styrylpyrone isomers, including 6 R ,7 S ,8 R ,2' S -goniolactone B ( 1 ), 6 S ,7 S ,8 S ,2' S -goniolactone B ( 2 ), 6 R ,7 R ,8 R ,2' S -goniolactone B ( 3 ), 6 R ,7 S ,8 S ,2' S -goniolactone C ( 4 ), 6 R ,7 S ,8 R ,2' S -goniolactone C ( 5 ), 6 S ,7 R ,8 S ,2' S -goniolactone C ( 6 ), and two positional isomers, 6 R ,7 R ,8 R ,2' S -goniolactone G ( 7 ) and 6 S ,7 R ,8 R ,2' S -goniolactone G ( 8 ), were isolated from a chloroform fraction (2...

A comprehensive phytochemical investigation of aerial parts obtained from Centaurea sicula L. led to the isolation of 14 terpenoids ( 1 - 14 ) and nine polyphenols ( 15 - 23 ). The sesquiterpenoid group ( 1 - 11 ) included three structural families, namely, elemanolides ( 1 - 6 ), eudesmanolides ( 7 and 8 ), and germacranolides ( 9 - 11 ) with four unreported secondary metabolites ( 5 - 8 ), whose structure has been determined by extensive spectroscopic analysis, including 1D/2D NMR, HR-MS, and chemical conversion...

Investigation of the secondary metabolites of Streptomyces virginiae CMB-CA091 isolated from the quartz-rich (tepui) soil of a cave in Venezuela yielded two new dimeric phenazine glycosides, tepuazines A and B ( 1 and 2 ); three new monomeric phenazine glycosides, tepuazines C-E ( 3 - 5 ); and a series of known analogues, baraphenazine G ( 6 ), phenazinolin D ( 7 ), izumiphenazine C ( 8 ), 4-methylaminobenzoyl-l-rhamnopyranoside ( 9 ), and 2-acetamidophenol ( 10 ). Structures were assigned to 1 - 10 on the basis of detailed spectroscopic analysis and biosynthetic considerations, with 1 and 2 featuring a rare 2-oxabicyclo[3...

A diverse array of biologically active derivatives was derived by modifying the chemically active sites of dehydroabietylamine. Herein, we describe the synthesis of a new series of C-19-arylated dehydroabietylamine derivatives using a palladium-catalyzed C(sp3 )-H activation reaction. Five analogues ( 3b , 3d , 3h , 3n , and 4a ) exhibited antibacterial activity against Escherichia coli . Compound 4a exhibited strong inhibitory activity against DNA Topo II and Topo IV. Molecular docking modeling indicated that it can bind effectively to the target through interactions with amino acid residues...

HPLC-MS analysis revealed the presence of an unreported peptide in the extract of the marine sponge Neopetrosia sp. Its structure was determined as a tripeptide, named neopetromin ( 1 ), composed of two tyrosine and one tryptophan residues with a heteroaromatic C-N cross-link between side chains. The absolute configuration of amino acids was determined using Marfey's method after ozonolysis and hydrolysis of 1 . Compound 1 promoted vacuole fragmentation in an actin-independent manner in tobacco BY-2 cells.

Six undescribed and six known bisbenzylisoquinoline alkaloids were isolated from the embryo of Nelumbo nucifera seeds. Their structures were fully characterized by a combination of 1 H, 13 C NMR, 2D NMR, and HRESIMS analyses, as well as ECD computational calculations. The antiadipogenic activity of 11 alkaloids was observed in a dose-responsive manner, leading to the suppression of lipid accumulation in 3T3-L1 cells. Luciferase assay and Western blot analysis showed that the active alkaloids downregulated peroxisome proliferator-activated receptor gamma ( PPARγ , a key antiadipogenic receptor) expression in 3T3-L1 cells...

Advancements in small-molecule research have created the need for sensitive techniques to accurately study biological processes in living systems. Fluorescent-labeled probes have become indispensable tools, particularly those that use boron-dipyrromethene (BODIPY) dyes. Terpenes and terpenoids are organic compounds found in nature that offer diverse biological activities, and BODIPY-based probes play a crucial role in studying these compounds. Monoterpene-BODIPY conjugates have exhibited potential for staining bacterial and fungal cells...

Cannabichromene (CBC) is a nonpsychoactive phytocannabinoid well-known for its wide-ranging health advantages. However, there is limited knowledge regarding its human metabolism following CBC consumption. This research aimed to explore the metabolic pathways of CBC by various human liver cytochrome P450 (CYP) enzymes and support the outcomes using in vivo data from mice. The results unveiled two principal CBC metabolites generated by CYPs: 8'-hydroxy-CBC and 6',7'-epoxy-CBC, along with a minor quantity of 1″-hydroxy-CBC...

Snake venoms contain various bradykinin-potentiating peptides (BPPs). First studied for their vasorelaxant properties due to angiotensin converting enzyme (ACE) inhibition, these molecules present a range of binding partners, among them the argininosuccinate synthase (AsS) enzyme. This has renewed interest in their characterization from biological sources and the evaluation of their pharmacological activities. In the present work, the low molecular weight fraction of Bothrops moojeni venom was obtained and BPPs were characterized by mass spectrometry...

Ginsenosides, the primary pharmacologically active constituents of the Panax genus, have demonstrated a variety of medicinal properties, including anticardiovascular disease, cytotoxic, antiaging, and antidiabetes effects. However, the low concentration of ginsenosides in plants and the challenges associated with their extraction impede the advancement and application of ginsenosides. Heterologous biosynthesis represents a promising strategy for the targeted production of these natural active compounds. As representative triterpenoids, the biosynthetic pathway of the aglycone skeletons of ginsenosides has been successfully decoded...

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Utilizing a gene evolution-oriented approach for gene cluster mining, a cryptic cytochalasin-like gene cluster ( sla ) in Antarctic-derived Simplicillium lamelliciola HDN13430 was identified. Compared with the canonical cytochalasin biosynthetic gene clusters (BGCs), the sla gene cluster lacks the key α,β-hydrolase gene. Heterologous expression of the sla gene cluster led to the discovery of a new compound, slamysin ( 1 ), characterized by an N -acylated amino acid structure and demonstrating weak anti- Bacillus cereus activity...

Oxabornyl polyenes represent a unique group of polyketides characterized by a central polyene core flanked by a conserved oxabornyl moiety and a structurally diverse oxygen heterocyclic ring. They are widely distributed in fungi and possess a variety of biological activities. Due to the significant spatial separation between the two stereogenic ring systems, it is difficult to establish their overall relative configurations. Here, we isolated three oxabornyl polyenes, prugosenes A1-A3 ( 1 - 3 ), from Talaromyces sp...

A new polyol polyketide, named retinestatin ( 1 ), was obtained and characterized from the culture of a Streptomyces strain, which was isolated from a subterranean nest of the termite Reticulitermes speratus kyushuensis Morimoto. The planar structure of 1 was elucidated on the basis of the cumulative analysis of ultraviolet, infrared, mass spectrometry, and nuclear magnetic resonance spectroscopic data. The absolute configuration of 1 at 12 chiral centers was successfully assigned by employing a J -based configuration analysis in combination with ROESY correlations, a quantum mechanics-based computational approach to calculate NMR chemical shifts, and a 3 min flash esterification by Mosher's reagents followed by NMR analysis...