Article
Biochemistry & Molecular Biology
Chi-Jen Tai, Chih-Hua Chao, Atallah F. Ahmed, Chia-Hung Yen, Tsong-Long Hwang, Fang-Rong Chang, Yusheng M. Huang, Jyh-Horng Sheu
Summary: Chemical investigation of the Red Sea sponge Spongia sp. resulted in the discovery of four new compounds, secodinorspongins A-D (1-4), as well as a known compound sponginolide (5). The structures of these compounds and their absolute configurations were elucidated using spectroscopic methods and a comparison of calculated and experimental CD spectra. A possible biosynthetic pathway for compounds 1-4 was proposed. The cytotoxic, antibacterial, and anti-inflammatory activities of compounds 1-5 were also evaluated, with compound 1 showing inhibitory activity against Staphylococcus aureus growth, and compounds 4 and 5 suppressing superoxide-anion generation and elastase release in human neutrophils.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Multidisciplinary
Xiao-Lu Li, Song-Wei Li, Li-Gong Yao, Ernesto Mollo, Margherita Gavagnin, Yue-Wei Guo
Summary: A new spongian-type diterpene compound was discovered in the nudibranch Glossodoris atromarginata collected from Weizhou Island, South China Sea. The study also provided evidence for the absolute stereochemistry of a known compound for the first time using time-dependent density functional theory electronic circular dichroism calculation.
MAGNETIC RESONANCE IN CHEMISTRY
(2021)
Article
Materials Science, Biomaterials
Katarzyna Berent, Marta Gajewska, Antonio G. Checa
Summary: Molluscs are able to produce various calcified materials to construct their shells, including plywood-like microstructures. By studying the crossed-foliated calcitic layers secreted by the limpet family Patellidae, researchers discovered a progressive organization of the material and a crystallographic texture development to adapt to different lamellar orientations. They hypothesized the development of a secretional zebra pattern on the shell-secreting mantle surface to explain this progressive organization.
ACS BIOMATERIALS SCIENCE & ENGINEERING
(2023)
Article
Chemistry, Organic
Xiaohong Lin, Yu Huang, Long Min, Chuang-Chuang Li
Summary: We present a novel approach for the efficient synthesis of the tricyclic core of diterpene bonnadiene. The challenging and unusual [6-7-5] spirotricyclic skeleton, including the all-carbon quaternary stereocenter, was selectively constructed via a type II [5 + 2] cycloaddition followed by a unique vinylogous semipinacol rearrangement. This methodology demonstrates the possibility of transforming the strained bridged [7-8-5] ring system into the [6-7-5] spirotricyclic skeleton of the target compound.
Article
Chemistry, Applied
Tram Le Huyen, Van Thong Nguyen, Hoang Minh Nguyen, Tuan Anh Nguyen, Thuong Quang Tran, Thu Ha Tran, Thu Huong Tran
Summary: A new diterpene compound, along with eight known compounds, were isolated from Excoecaria agallocha leaves. The structure and relative configuration of the new compound were determined through spectroscopic data analysis and confirmed by NMR chemical shifts calculation. Additionally, the cytotoxicity of the isolated compounds was evaluated.
NATURAL PRODUCT RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Tsubasa Hirata, Yoshihiro Ogasawara, Shu Kobayashi, Yasuhiro Yamashita
Summary: In this study, photocatalytic addition reactions of ketene silyl acetals with alkenes were achieved through the formation of alpha-carbonyl radicals. The reactions proceeded smoothly under blue-light irradiation in the presence of an appropriate protic additive, resulting in moderate to high yields of the desired products.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Changkang Li, Shuai Wang, Xinxi Yin, Aobo Guo, Kebo Xie, Dawei Chen, Songyang Sui, Yaotian Han, Jimei Liu, Ridao Chen, Jungui Dai
Summary: CsCTS, a diterpene synthase from Cephalotaxus sinensis, was characterized for its ability to synthesize Cephalotene, the core skeleton of cephalotane-type diterpenoids. The stepwise cyclization mechanism of CsCTS was proposed based on structural investigation, isotopic labeling experiments, density functional theory calculations, and molecular dynamics simulations. The critical amino acid residues for CsCTS's unique carbocation-driven cascade cyclization mechanism were identified through homology modeling and site-directed mutagenesis. This study provides important insights into the biosynthesis of cephalotane-type diterpenoids and lays the foundation for further research on their complete biosynthetic pathway.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Mamiko Hayakawa, Hisashi Shirota, Souta Hirayama, Ryuusei Yamada, Tadashi Aoyama, Akihiko Ouchi
Summary: Sunlight-induced C-C bond formation reactions with di-tert-butyl peroxide showed higher yields and faster reaction rates compared to conventional Xe lamp photolysis, especially with olefins bearing two EWGs. Gram-scale experiments demonstrated similar yields to small-scale experiments.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Panpan Zhang, Shang Xue, Pengfei Tang, Zhirong Cui, Zefan Wang, Jun Luo, Lingyi Kong
Summary: In this study, three pairs of unprecedented acyclic diterpene dimer enantiomers with a unique polymerization pattern were discovered from Aphanamixis polystachya and their novel carbon skeletons were elucidated using spectroscopic analysis, exciton chirality, and calculated electronic circular dichroism (ECD). Compounds 1 and 3 showed inhibitory effects on nitric oxide (NO) production and reduced the expression of iNOS in LPS-induced RAW 264.7 macrophages.
CHINESE CHEMICAL LETTERS
(2021)
Article
Chemistry, Applied
Minh Hao Hoang, Thi Anh Tuyet Nguyen, Vu Nhat Ha Nguyen, Thi Nga Vo
Summary: A new cafestol-type diterpenoid and three known diterpenoids were identified from Coffea canephora trunks. The new compound and one known compound showed activity against alpha-glucosidase, while the other two compounds did not. Docking simulations suggested that the active compounds formed hydrogen bonds with a specific residue in the enzyme pocket.
NATURAL PRODUCT RESEARCH
(2022)
Article
Chemistry, Organic
Yaping Liu, Taro Ozaki, Atsushi Minami, Hideaki Oikawa
Summary: Oxidative modifications are essential for the biosynthesis of indole diterpenes (IDTs), and this study focused on the role of prenyltransferases and flavoprotein oxidases in the synthesis of nodulisporic acid-type and shearinine-type bicyclic rings on the indole moiety. The enzymatic reaction of prenyltransferase JanD showed that it recognizes a C13 hydroxy group on the diterpene moiety. Flavoprotein oxidases JanO and NodO exhibited different substrate specificities for penta/hexacyclic IDTs and pentacyclic IDTs, respectively.
TETRAHEDRON LETTERS
(2023)
Article
Chemistry, Applied
Yi He, Fengyan He, Yumei Zhang, Feifei Wang, Xiaowei Zheng, Zhong Dai, Shuangcheng Ma
Summary: Cinnamaldehyde is a principal compound in cinnamon essential oil used for quality control. A reaction product, cinnamaldehyde dimethyl acetal, was observed during HPLC analysis in methanol solution. Further studies indicated that parameters like cinnamaldehyde concentration, storage temperature, and light illumination could affect this reaction, advising caution when using methanol for cinnamaldehyde analysis.
JOURNAL OF ESSENTIAL OIL RESEARCH
(2021)
Article
Biotechnology & Applied Microbiology
Shing Yiu Tam, Kenichi Uchida, Hirofumi Enomoto, Senji Takahashi, Koichi Makimura, Shohei Sakuda
Summary: Schizophyllum commune specifically produces two acyclic terpene mannosides at 37 degrees Celsius, and one of them shows slightly stronger antibiotic activity than the other.
JOURNAL OF ANTIBIOTICS
(2022)
Article
Multidisciplinary Sciences
Yifeng Zhang, Jie Gao, Lin Ma, Lichan Tu, Tianyuan Hu, Xiaoyi Wu, Ping Su, Yujun Zhao, Yuan Liu, Dan Li, Jiawei Zhou, Yan Yin, Yuru Tong, Huan Zhao, Yun Lu, Jiadian Wang, Wei Gao, Luqi Huang
Summary: In this study, the authors identify two CYP82D enzymes as the 14-hydroxylases in triptolide biosynthesis and successfully produce the precursor of triptolide in engineered Saccharomyces cerevisiae. This discovery provides important genetic elements for understanding the downstream biosynthetic pathways and enabling the production of other 14-hydroxyl labdane-type secondary metabolites.
NATURE COMMUNICATIONS
(2023)
Article
Polymer Science
Denise Besghini, Michele Mauri, Payam Hashemi, Matthias Knarr, Roland Adden, Petra Mischnick, Roberto Simonutti
Summary: The reversible gelation process of aqueous methylcellulose (MC) solutions at high temperature was studied using low-field time-domain nuclear magnetic resonance (LF-TD-NMR). The gel transition did not affect the water self-diffusion coefficient, but resulted in a decrease of the proton transverse relaxation times H-1 T (2) by more than 60%. The effects of molecular weight and concentration of polysaccharide chains on gel transition temperature and strength were investigated. The findings were in agreement with literature results from more advanced techniques, such as small-angle X-ray and neutron scattering (SAXS and SANS), and supported the idea of a network structure of disorderly arranged fibrils with an inhomogeneous mesh size at the order of tens of microns.
Article
Plant Sciences
Taizong Wu, Angela A. Salim, Paul Bernhardt, Robert J. Capon
Summary: Chemical analysis of the Australian mullet fish gastrointestinal tract-derived fungus Amauroascus sp. CMB-F713 using a molecular networking guided strategy led to the discovery of a family of polyketide pyrones, amaurones A-I, with unique carbon skeletons. Detailed spectroscopic analysis, biosynthetic considerations, and chemical interconversions were used to assign structures to these compounds and provide insights into their reactivity and conversion mechanisms.
JOURNAL OF NATURAL PRODUCTS
(2021)
Article
Chemistry, Medicinal
Shamsunnahar Khushi, Angela A. Salim, Ahmed H. Elbanna, Laizuman Nahar, Robert J. Capon
Summary: Thorectandra choanoides (CMB-01889) was identified as a potential source of new chemistry from marine sponge extracts in southern Australia, leading to the discovery of a new alkaloid. Detailed spectroscopic analysis and biosynthetic origins shed light on pharmaceutical potential, with insights into the specificity of IDO substrates and the reactive transformation of Michael acceptors.
Review
Chemistry, Medicinal
Angela A. Salim, Zeinab G. Khalil, Ahmed H. Elbanna, Taizong Wu, Robert J. Capon
Summary: This review provides an account of the microbial biodiscovery methodology developed and applied in the laboratory at The University of Queensland, Institute for Molecular Bioscience, with examples from studying natural products produced by Australian marine-derived (and terrestrial) fungi and bacteria.
Article
Multidisciplinary Sciences
Michael R. Crossland, Angela A. Salim, Robert J. Capon, Richard Shine
Summary: Chemical cues produced by the parotoid glands of cane toad embryos attract conspecific larvae, which can cannibalize an entire clutch. The attraction is mainly attributed to bufadienolides, with some toxins being stronger attractants than others. Tadpole attractant potency is strongly correlated with Na+/K+ ATPase inhibitory activity, indicating that tadpoles monitor and react to disturbances in Na+/K+ ATPase activity.
SCIENTIFIC REPORTS
(2021)
Article
Biochemistry & Molecular Biology
Fuhang Song, Na Yang, Zeinab G. Khalil, Angela A. Salim, Jiahui Han, Paul Bernhardt, Rui Lin, Xiuli Xu, Robert J. Capon
Summary: An investigation on a Streptomyces sp. strain MS180069 isolated from sediment in the South China Sea led to the discovery of a new benzo[f]isoindole-dione alkaloid, bhimamycin J. Extensive spectroscopic analysis and molecular docking study revealed that this compound inhibits human ACE2, the cell surface receptor responsible for 2019-CoV-2 uptake, by 79.7% at 25 μg/mL.
CHEMISTRY & BIODIVERSITY
(2021)
Article
Plant Sciences
Taizong Wu, Angela A. Salim, Hui Cui, Zeinab G. Khalil, Paul Bernhardt, Robert J. Capon
Summary: Chemical investigations into a pasture plant-derived Streptomyces sp. from an Australian sheep station yielded rare compounds with potential anticancer properties that can reverse drug resistance in cells.
JOURNAL OF NATURAL PRODUCTS
(2022)
Article
Chemistry, Organic
Taizong Wu, Angela A. Salim, Robert J. Capon
Summary: The brown rice cultivation of Aspergillus sp. CMB-MRF324 produced six new meroterpenes and four known analogues, with millmerranone A exhibiting a unique carbon skeleton and undergoing a base mediated rearrangement. Unexpected base rearrangements, a biosynthetic relationship between various compounds, and acetylcholinesterase inhibitory properties were also reported.
Article
Chemistry, Organic
Taizong Wu, Angela A. Salim, Zeinab G. Khalil, Robert J. Capon
Summary: A novel polycyclic C-aminoglycoside-pyranonaphthoquinone polyketides compounds were isolated from Streptomyces sp. CMB-PB042 derived from Australian plant pasture, including unprecedented glenthamine A, rare glenthimine A, spiropolyketide glenthol A, and highly rearranged glenthamide A. The structures and absolute configurations of these compounds were determined by spectroscopic analysis, chemical interconversion, and biosynthetic considerations.
Article
Plant Sciences
Taizong Wu, Angela A. Salim, Zeinab G. Khalil, Paul V. Bernhardt, Robert J. Capon
Summary: This study identified 13 new macrocyclic spirotetronates, glenthmycins A-M (1-13), with potential antibacterial activity against multidrug-resistant bacteria, such as MRSA and VRE. Furthermore, a semisynthetic derivative, glenthmycin K 9-valerate (26), showed potent inhibitory effects on a wide range of Gram-positive pathogens.
JOURNAL OF NATURAL PRODUCTS
(2022)
Article
Cell Biology
Rabina Giri, Emily C. Hoedt, Shamsunnahar Khushi, Angela A. Salim, Anne-Sophie Bergot, Veronika Schreiber, Ranjeny Thomas, Michael A. McGuckin, Timothy H. Florin, Mark Morrison, Robert J. Capon, Paraic O. Cuiv, Jakob Begun
Summary: An emerging research suggests that certain strains of Clostridium bacteria can suppress immune-mediated NF-KB activation, which could potentially alleviate inflammatory bowel diseases. Using an ex vivo organoid-based approach, researchers have identified a strain that could alleviate colitis in a relevant pre-clinical animal model of inflammatory bowel diseases.
Article
Chemistry, Organic
Angela A. Salim, Kaumadi Samarasekera, Taizong Wu, Robert J. Capon
Summary: In this study, rare phosphorylated natural products were detected through molecular network analysis of Streptomyces sp. CMB-MW079. Optimal conditions for the production, isolation, and identification of these natural products were established using miniaturized cultivation profiling (MATRIX). Novel compounds, including the polyketide delta-lactone phoslactomycin E and new ester homologues, as well as unprecedented heterocyclic analogues, were successfully synthesized, isolated, and identified. A biogenetic relationship was proposed between these cometabolites and the known lactomycins A-C.
Article
Plant Sciences
Kaumadi Samarasekera, Waleed M. Hussein, Taizong Wu, Angela A. Salim, Robert J. Capon
Summary: Chemical analysis of a fungus derived from a Queensland mud dauber wasp nest revealed the presence of duclauxin (1) and a group of new compounds called glyclauxins A-E (2-6). The structures and absolute configuration of these compounds were determined through spectroscopic analysis, synthetic conversions, and chemical interconversion. Despite their potential as artifacts, the detection of glyclauxins B (3) and A (2) in a fresh culture extract confirmed their natural product status.
JOURNAL OF NATURAL PRODUCTS
(2023)
Article
Chemistry, Medicinal
Shamsunnahar Khushi, Angela A. A. Salim, Robert J. J. Capon
Summary: In reviewing recent case studies, we found that the application of mass spectrometry molecular networking has provided valuable lessons and benefits in the field of marine sponge natural products. Molecular networking played a crucial role in discovering new natural products and even new classes of natural products that were not detected by other dereplication and prioritization strategies. These case studies include the discovery of rare trachycladindoles, unprecedented dysidealactams, novel cacolides, and a new class of indole alkaloids called thorectandrins, which provided unexpected insights into the properties of aplysinopsins.
Article
Chemistry, Medicinal
Angela A. Salim, Waleed M. Hussein, Pradeep Dewapriya, Huy N. Hoang, Yahao Zhou, Kaumadi Samarasekera, Zeinab G. Khalil, David P. Fairlie, Robert J. Capon
Summary: The application of a miniaturized 24-well plate system allowed for the optimization of cultivation conditions for the marine-derived fungus Talaromyces sp. CMB-TU011, leading to the discovery of a rare cycloheptapeptide talarolide A and three new analogues. Detailed spectroscopic analysis, supported by Marfey's analysis methodology, helped confirm the structures of these compounds. The investigation of hydroxamates' influence on cyclic peptide conformation through ROESY correlations and solution structure determination offers insights into the potential use of hydroxamates as molecular bridges for accessing new cyclic peptide conformations.
Review
Biochemistry & Molecular Biology
Angela A. Salim, Mark S. Butler, Mark A. T. Blaskovich, Ian R. Henderson, Robert J. Capon
Summary: This review summarizes all natural products (500 compounds, including 17 semi-synthetic derivatives) reported in the primary literature up to December 2022 that have been shown to inhibit the egg hatching, motility, larval development, and/or survival of helminths (nematodes, flukes, and tapeworms). These parasites infect and harm the health, welfare, productivity, and lives of commercial livestock, companion animals, and other valuable, endangered, and exotic animals. The review focuses on chemical structures, source organisms, and anthelmintic properties, including the target species, animal hosts, and potency measures used in bioassays.
NATURAL PRODUCT REPORTS
(2023)
Article
Chemistry, Organic
Fuying Zhu, Yamei Lin
Summary: In this study, a low-metal iron-supported catalyst (Fe20/NC-Mg) was reported for the efficient synthesis of quinoxaline compounds, using water as a solvent and without additional bases. The synergistic effect of FeNx site and Mg (OH)2 nanorods in the catalyst played a key role in achieving high yields (82-91%) in 16 examples. The gram-level synthesis and reusability of the catalysts after four cycles demonstrated its industrial application potential.
Article
Chemistry, Organic
Mikhail Kozlov, Alexey Tyurin, Andrey Dmitrenok, Vyacheslav Rusak, Aleksander Fedorov, Igor Zavarzin, Yulia Volkova
Summary: This study presents a novel and practical synthesis method for phosphorus-substituted 1,3,4-thiadiazolines using phosphorylthioformic acid hydrazides and ketones. The protocol demonstrates operational simplicity, availability of reagents, and tolerance towards different functional groups.
Article
Chemistry, Organic
Jisna Jose, Thomas Mathew
Summary: 2-Cyclopentenone and its derivatives are highly esteemed synthetic intermediates with exceptional utility in organic synthesis. They are favored structural motifs in numerous pharmaceutical drugs and natural products, highlighting their significance. The review discusses the various methods used to synthesize cyclopentenones from 2016 to 2023.
