Article
Chemistry, Multidisciplinary
Zenghui Li, Jing Wang, Xiaoyang Liu, Pin Gao, Guoping Li, Gang He, Bin Rao
Summary: A series of organoradical boron reagents were successfully synthesized through the key step of C-H borylation for the first time. These reagents showed air stability and could be stored for several months in the solid state. They were fully investigated through various analysis techniques and found to be suitable for Suzuki-Miyaura coupling reactions while retaining the carbon radical center. Additionally, they exhibited fluorescent properties and can potentially be used for the synthesis of luminescent organic radicals and other functionalized open-shell materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Polymer Science
Chisa Takahara, Masashi Nakamura, Yuto Aoyama, Takumi Yanagihara, Shunichiro Ito, Kazuo Tanaka, Hiroaki Imoto, Kensuke Naka
Summary: Arsenic-containing conjugated polymers have gained significant attention recently. To improve solubility in organic solvents, long alkyl chains are commonly introduced on the coupling partner and/or at the 3-positions of fused thiophene rings in traditional polymer design. However, this strategy is not applicable for comonomers with difficulties in alkyl group substitution, and the steric hindrance of alkyl chains can distort the planarity of polymer chains. Therefore, a novel monomer with an alkoxyphenyl group substituted on the arsenic atom was developed. By using benzothiadiazole and benzoxadiazole monomers, polymers with high planarity and solubility were developed, exhibiting near-infrared emissions.
Article
Polymer Science
Chisa Takahara, Masashi Nakamura, Yuto Aoyama, Takumi Yanagihara, Shunichiro Ito, Kazuo Tanaka, Hiroaki Imoto, Kensuke Naka
Summary: Arsenic-containing conjugated polymers, with dithieno[3,2-b:2',3'-d]arsole as a typical monomer unit, have gained significant attention recently. However, the traditional polymer design for improved solubility often involves introducing long alkyl chains, which may lead to steric hindrance and distort the planarity of the polymer chain. To overcome this, a novel monomer with an alkoxyphenyl group substituted on the arsenic atom was developed. These polymers, using benzothiadiazole and benzoxadiazole monomers, exhibited high planarity and solubility, as well as near-infrared emissions.
Editorial Material
Chemistry, Multidisciplinary
Soji Shimizu
Summary: Porphyrin analogues have attracted intensive investigations due to their rich coordination chemistry and unique optical and electrochemical properties. Among them, subporphyrins, especially the boron-free ones, have long been awaited. Recently, Kim, Osuka, and Song successfully synthesized a boron-free subporphyrin by introducing an exocyclic double bond at the meso-position and subsequent reduction to obtain macrocyclic conjugation. This seminal work will significantly facilitate studies on coordination chemistry and applications in materials science, as the availability of free base porphyrins is crucial for the development of porphyrin chemistry.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Biochemistry & Molecular Biology
Vitor A. S. Almodovar, Augusto C. Tome
Summary: This article presents a convenient two-step synthesis of various DPP dyes from Pigment Red 254, showing large Stokes shifts and high fluorescence quantum yields, which are important properties for their potential use in technical and biological applications.
Article
Chemistry, Multidisciplinary
Miki B. Kurosawa, Kenta Kato, Kei Muto, Junichiro Yamaguchi
Summary: A deoxygenative transformation method was developed for the synthesis of multiply arylated alkanes from various diarylketones. The method involves a phospha-Brook rearrangement of diarylketones by reacting with diphenylphosphine oxide, followed by palladium-catalyzed cross-couplings or a Friedel-Crafts type alkylation. The method also enables the one-pot conversion from arylcarboxylic acids to diarylmethanes and tetraarylethanes, as well as the synthesis of tetraarylmethane and triphenylethane using sequential coupling reactions.
Article
Chemistry, Physical
Zeinab Ahmadvand, Mehdi Bayat
Summary: This research aims to establish a more suitable reaction pathway and cross-coupling mechanism for the formation of certain derivatives of quinoxaline and benzofuran by comparing the mechanisms of Suzuki-Miyaura and Hiyama cross-coupling reactions. The findings suggest that the Pd-NHC type complex approach is more desirable for the development of regioselective compounds in competition between different types of cross-coupling reactions.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Multidisciplinary
Angus Olding, Curtis C. Ho, Allan J. Canty, Nigel T. Lucas, James Horne, Alex C. Bissember
Summary: This study reports the synthesis of a family of unprecedented arylpalladium(II) boronates that are kinetically stable at ambient temperature, and their chemical competence in a Suzuki-Miyaura reaction was demonstrated.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Materials Science, Multidisciplinary
Khaoula Oudghiri, Lahoucine Bahsis, Said Eddarir, Hafid Anane, Moha Taourirte
Summary: A green protocol for the in situ synthesis of Pd nanoparticles on chitosan beads (Pd NPs-CS) without toxic reducing agents was reported. The Pd nanoparticles catalyst was prepared by a simple coordination reaction between chitosan beads and palladium ions. The Pd NPs-CS catalyst showed high catalytic activity and selectivity in Suzuki-Miyaura cross-coupling reaction and Heck reaction, with the bead form of the catalyst easily separated from the reaction mixture.
Article
Chemistry, Inorganic & Nuclear
Sepideh Samiee, Fatemeh Esmipour Noorabadi, Roya Azadi
Summary: A series of heteroleptic mononuclear cyclopalladated benzo[h]quinolinate complexes were synthesized and characterized. These complexes showed unique UV-visible absorption properties, with palladacycle C-3 exhibiting excellent catalytic activity. This study is of significance for further understanding these complex compounds.
Review
Chemistry, Multidisciplinary
Anna-Carin C. Carlsson, Staffan Karlsson, Rachel H. Munday, Matthew R. . Tatton
Summary: Atropisomerism is a stereochemical phenomenon exhibited by molecules with a rotationally restricted sigma bond. Atropisomers exist as a dynamic mixture and can be interconverted without breaking and reforming bonds. They are frequent targets in medicinal chemistry projects due to their axial chirality and unique 3D structures. However, selecting a single atropisomer presents problems such as interconversion and separation challenges. Chromatography, enzymatic or chiral catalysts can be used for separation, but each method has limitations. This Account discusses the successes, failures, and challenges of developing methods for resolution and synthesis of atropisomeric drug candidates.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Anindita Dewan, Manashi Sarmah, Prantika Bhattacharjee, Pankaj Bharali, Ashim J. Thakur, Utpal Bora
Summary: This study reports the design, synthesis, and application of naturally occurring cellulose from agro waste pomegranate peel as a novel support for active biogenic Pd nanoparticles for Suzuki-Miyaura and Sonogashira cross-coupling reactions at room temperature. The cellulose matrix enables well dispersion of Pd nanoparticles over the support to generate Pd@cellulose, exhibiting excellent catalytic activity and recyclability under ligand-free mild reaction conditions. The synthesized cellulose nanofibers and Pd-anchored heterogeneous nanofibers were characterized through various analytical techniques.
SUSTAINABLE CHEMISTRY AND PHARMACY
(2021)
Article
Chemistry, Multidisciplinary
Tamae Seo, Koji Kubota, Hajime Ito
Summary: Mechanochemical synthesis using transition-metal catalysts has advantages such as low solvent waste and short reaction times. However, the direct use of transition-metal catalysts in mechanochemical reactions without modifications limits the development of efficient cross-coupling processes. This study presents a new approach, using mechanochemistry-directed design to develop ligands for Suzuki-Miyaura cross-coupling reactions. The embedding of the ligand into a poly(ethylene glycol) polymer prevents catalyst deactivation and shows high catalytic activity at room temperature.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Lara E. Zetzsche, Jessica A. Yazarians, Suman Chakrabarty, Meagan E. Hinze, Lauren A. M. Murray, April L. Lukowski, Leo A. Joyce, Alison R. H. Narayan
Summary: This study demonstrates the use of cytochrome P450 enzymes for biocatalytic cross-coupling reactions, enabling the formation of sterically hindered biaryl bonds through oxidative C-C bond formation. By engineering the substrate and atroposelectivity of the P450 enzyme, a highly efficient and selective process has been developed.
Review
Chemistry, Physical
Brijesh S. Kadu
Summary: Palladium has been widely used in the Suzuki-Miyaura cross coupling reaction for over 30 years, but it comes with drawbacks such as high cost, tedious work-ups, product contamination, and metal leaching. In recent years, other metals like Ni, Cu, Co, Fe, Rh, and Ru have attracted attention for their potential in SMCR, allowing for the synthesis of industrially important compounds with various functional groups. This review discusses recent advancements in catalysis related to SMCR, providing valuable insights for researchers in designing synthetic protocols for pharmacophores and drug molecules.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Abdolkarim Farrokhzadeh, Farideh Badichi Akher, Fisayo A. Olotu, Fanie R. Van Heerden
Summary: Chirality in drug design plays a crucial role in enhancing the selectivity and efficacy of therapeutic molecules. Computational approaches were used to explore the binding modes of (R,R) and (R,S)-HEC72702 on hepatitis B virus capsid, revealing that chirality change affects the inhibitory affinity of (R,R)-HEC72702. Analysis of energy decomposition highlighted the importance of van der Waals interactions in the binding process.
CHEMICAL BIOLOGY & DRUG DESIGN
(2021)
Article
Biochemistry & Molecular Biology
Bamigboye J. Taiwo, Temidayo D. Popoola, Fanie R. van Heerden, Amos A. Fatokun
Summary: The research found compounds in okra that exhibited mild toxicity to cancer cells while also possessing antioxidant properties. These findings provide insight into the traditional use of okra for cancer, cardiovascular complications, and diabetes treatment, and suggest it as a potential source of novel therapeutics.
CHEMISTRY & BIODIVERSITY
(2021)
Article
Plant Sciences
Sushil K. Chaudhary, Maxleene Sandasi, Felix Makolo, Fanie R. van Heerden, Alvaro M. Viljoen
Summary: Aspalathin, a natural compound found in South African rooibos, possesses various pharmacological properties and is widely used in nutraceuticals and cosmeceuticals. Research has shown its potential in antioxidant, antidiabetic, and anti-inflammatory activities.
PHYTOCHEMISTRY REVIEWS
(2021)
Article
Biochemistry & Molecular Biology
Nasir Tajuddeen, Tarryn Swart, Heinrich C. Hoppe, Fanie R. van Heerden
Summary: The phytochemical constituents, antiplasmodial, and cytotoxic effects of Ozoroa obovata var. obovata from South Africa were investigated, leading to the isolation of various bioactive compounds with antiplasmodial and antiproliferative activities. The study revealed significant activities of the plant leaf extract against malaria and HeLa cells, along with the identification of several novel compounds in O. obovata.
CHEMISTRY & BIODIVERSITY
(2021)
Article
Biochemistry & Molecular Biology
Nasir Tajuddeen, Tarryn Swart, Heinrich C. Hoppe, Fanie R. van Heerden
Summary: This study investigated the phytochemical and antiplasmodial properties of Pappea capensis leaves, commonly used by indigenous communities in Africa for treating malaria. The leaf extract showed strong anti-malarial activity but also cytotoxicity against human cervix adenocarcinoma cells. The isolated compounds displayed similar activity patterns, indicating the potential of P. capensis for malaria treatment but the need for further research on its cytotoxic effects on noncancerous cells.
Article
Chemistry, Applied
Nasir Tajuddeen, Tarryn Swart, Heinrich C. Hoppe, Fanie R. van Heerden
Summary: Previous studies showed that the methanol extract of Gardenia thunbergia had antiplasmodial activity, but no compounds had been isolated from the plant. This study identified a new saponin and eight other known compounds from the plant's methanol leaf extract, which displayed non-selective antiplasmodial activity. The presence of these isolated compounds in the leaf extract may explain the traditional use of Gardenia thunbergia in treating malaria.
NATURAL PRODUCT RESEARCH
(2022)
Article
Plant Sciences
Nontembeko Dube, Fanie R. van Heerden, Costas Zachariades, Osariyekemwen O. Uyi, Thinandavha C. Munyai
Summary: This study investigated the alkaloids and PAs from Chromolaena odorata in different regions and habitats in South Africa, with and without the specialist herbivore Pareuchaetes insulata, and isolated two pyrrolizidine alkaloids from the root extract of the plant. The presence of alkaloids and pyrrolizidine alkaloids in the SAB C. odorata was detected for the first time in this study, with implications for plant defense and herbivore interactions.
SOUTH AFRICAN JOURNAL OF BOTANY
(2021)
Article
Plant Sciences
Talent Chipiti, Alvaro M. Viljoen, Maria L. Cordero-Maldonado, Clinton G. L. Veale, Fanie R. Van Heerden, Maxleene Sandasi, Weiyang Chen, Alexander D. Crawford, Gill M. Enslin
Summary: This study screened 20 medicinal plants traditionally used in South Africa for epilepsy treatment, and identified compounds from Rauvolfia caffra Sond. that showed potential anti-epileptic activity in a zebrafish larvae model. The findings suggest the possibility of developing new anti-seizure therapeutic compounds from these natural sources.
JOURNAL OF ETHNOPHARMACOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Tshifhiwa Ramabulana, Musawenkosi Ndlovu, Rebamang A. Mosa, Molahlehi S. Sonopo, Mamoalosi A. Selepe
Summary: In this study, analysis of Leucosidea sericea leaf and stem extracts using ultraperformance liquid chromatography-quadrupole time-of-flight-mass spectrometry identified various types of compounds. Further purification led to the isolation of 22 compounds, including a new triterpenoid. Some of these compounds were evaluated for their inhibitory activity against digestive enzymes, and two compounds showed higher potency than the positive control.
Article
Chemistry, Medicinal
Nasir Tajuddeen, Tarryn Swart, Heinrich C. Hoppe, Fanie R. van Heerden
Summary: This study identified methyl gallate as the compound responsible for the antiplasmodial activity of Vachellia xanthophloea leaf extract. Other compounds isolated from the plant were also determined. Methyl gallate showed good inhibitory activity against P. falciparum and low cytotoxicity. These findings explain the traditional use of the plant as an antimalarial remedy.
Article
Biochemistry & Molecular Biology
Mamoalosi A. Selepe, Phaladi Kunyane, Pule Seboletswe, Shankari Nair, Nosipho Cele, Monique Engelbrecht, Daniel F. Joubert, Charlot Vandevoorde, Parvesh Singh, Molahlehi S. Sonopo
Summary: Isoflavone derivatives synthesized from benzoylbenzofuran precursors were evaluated for their inhibitory effects on cell proliferation and SIRT1 activity in breast cancer cells. The results showed potent antiproliferative effects of several isoflavone and benzoylbenzofuran derivatives, with most of the isoflavone compounds attenuating SIRT1 activity to below 50%. The most active compounds exhibited IC50 values comparable to the reference compound suramin, indicating their potential as SIRT1 inhibitors.
BIOORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Edward T. Khunoana, Jacobus N. Eloff, Thanyani E. Ramadwa, Sanah M. Nkadimeng, Mamoalosi A. Selepe, Lyndy J. McGaw
Summary: Extracts from Ptaeroxylon obliquum exhibit in vitro anticancer and antioxidant activities with selective cytotoxicity against human cancer cells lines, indicating their potential as a source of anticancer therapy.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Medicinal
Danielle Twilley, Velaphi C. Thipe, Navneet Kishore, Pierce Bloebaum, Catarina Roma-Rodrigues, Pedro V. Baptista, Alexandra R. Fernandes, Mamoalosi A. Selepe, Lenka Langhansova, Kattesh Katti, Namrita Lall
Summary: Melanoma cells secrete pro-angiogenic factors which play a key role in growth, proliferation, and metastasis. In this study, Buddleja saligna and a triterpenoid mixture were found to inhibit the growth of melanoma cells with minimal effects on normal cells. Additionally, these compounds showed inhibitory effects on vascular endothelial growth factor and interleukins, as well as reducing new blood vessel formation.
Article
Plant Sciences
T. E. Ramadwa, M. A. Selepe, M. S. Sonopo, L. J. McGaw, J. N. Eloff
Summary: The study aimed to develop a method for quantifying obliquumol in Ptaeroxylon obliquum leaves using UPLC-MS/MS and investigate the biological activity of ptaeroxylinol. Obliquumol was isolated from the leaves and converted to ptaeroxylinol. The method was able to quantify obliquumol in different P. obliquum extracts, and ptaeroxylinol showed good antimicrobial activity with low cytotoxicity. Rating: 8/10
SOUTH AFRICAN JOURNAL OF BOTANY
(2023)
Article
Chemistry, Multidisciplinary
Musawenkosi Ndlovu, June C. Serem, Mamoalosi A. Selepe, Andrew R. Opoku, Megan J. Bester, Zeno Apostolides, Rebamang A. Mosa
Summary: This study aimed to investigate the hypocholesterolemic potential of two triterpenoids isolated from Protorhus longifolia stembark. In silico techniques and in vitro enzyme assays were used to evaluate their potential inhibition of cholesterol esterase and HMG-CoA reductase. The results showed that both triterpenoids exhibited inhibitory effects on cholesterol esterase and HMG-CoA reductase, with promising drug-likeness properties and favorable ADMET profiles. Moreover, they enhanced hepatic cellular LDL uptake and upregulated LDL-R and SREBP-2 gene expression.
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.
