Chlorination reactions serve as one of the most direct approaches for incorporating chlorine atoms into organic frameworks. Herein, we report a novel C(sp2)-H radical chlorination of quinoxalinones utilizing an SOCl2-pyridine system under visible-light irradiation at ambient temperature, without a photocatalyst. Mechanistic studies indicate that pyridinium salts formed from the reaction of SOCl2 with pyridine generate chlorine radicals via the formation of an electron donor-acceptor (EDA) complex with the substrate. The use of cost-effective reagents and mild reaction conditions makes this protocol an efficient and environmentally friendly method for C(sp2)-H chlorination.

A novel visible-light-induced thioacylation method has been developed for the functionalization of unactivated alkenes. This approach utilizes N-thiocyanatosaccharin as a source of SCN radicals, achieved via a photoredox passway, rather than requiring a conventional radical initiator like AIBN. The reaction proceeds via remote quinoxalinone migration. This metal- and catalyst-free method serves as an efficient and environmentally friendly approach for the synthesis of distal thiocyanate-substituted ketones.

A facile regioselective C7-bromination of quinoxalin-2(1 H )-ones with KBr and K 2 S 2 O 8 under catalyst free conditions was developed.

A novel photochemical trifluoromethylation method has been developed for the functionalization of unactivated alkenes. This approach employs trifluoromethylsulfonyl-pyridinium salt as the trifluoromethyl radical precursor, and proceeds through a photoredox pathway. The reaction mechanism involves remote quinazolinone migration. This entirely metal- and catalyst-free methodology provides an efficient and environmentally sustainable route for the synthesis of distal trifluoromethyl-substituted ketones.

Icaritin, a flavonoid compound, has been shown to alleviate osteoporosis by promoting the differentiation of osteoblasts. However, research on the structural modification and optimization of icaritin has been limited. To enhance the anti-osteoporotic efficacy of icaritin, we structurally modified the compound by substituting the hydroxyl groups, resulting in the synthesis of 22 derivatives. The impact of these compounds was examined by evaluating Human embryonic palatal mesenchymal (HEPM) cells viability with the MTT assay, along with assessing osteogenic potential through measurement of alkaline phosphatase (ALP) activity. In vivo validation of anti-osteoporotic activity was conducted using a prednisolone induced zebrafish model. The results indicated that compound 8a exhibited significant osteogenic activity. Structure-activity relationship analysis revealed that 7-OH esterification substantially potentiated osteogenic activity without eliciting cytotoxic effects in HEPM cells. However, modifications at the 3-OH and 5-OH positions enhanced cytotoxicity while diminishing osteogenic activity. Collectively, our findings characterize icaritin derivatives exhibiting enhanced osteogenic efficacy through improved osteoblast differentiation and present a promising compound for development of anti-osteoporotic drug candidate.

A facile and regioselective C7-bromination of quinoxalin-2(1H)-ones has been developed by employing inexpensive inorganic potassium bromide (KBr) as the bromine source and potassium persulfate (K2S2O8) as an oxidant under mild heating conditions without transition-metal catalysts. Moreover, the transformation is also applicable to other related nitrogen-containing heterocyclic skeletons such as benzooxazinones and pyrimidinediones. This cost-effective and operationally simple bromination strategy provides a convenient route to access C7-brominated quinoxalin-2(1H)-one building blocks for subsequent synthetic derivatization.

A visible-light-induced trifluoromethylation of alkenes was accomplished by using trifluoromethylsulfonylpyridinium salt, accompanied by the insertion of SO2 molecules. This reaction proceeded under the catalysis of Ir(ppy)3, resulting in the formation of trifluoromethylated 4H-benzo[e][1,2,4]thiadiazine-1,1-dioxides. The readily available reagents and the mild reaction conditions make this approach an efficient and cost effective method for the synthesis of these compounds.

The Bee venom peptide Anoplin (GLLKRIKTLL) was synthesized and modified by using antibiotics at its N-terminus, resulting in three peptide derivatives: Ano1, Ano2 and Ano3. The synthetic yields were 92.3%, 75.1% and 95.4%, respectively. Multi-spectroscopy methods were employed to investigate the interaction between these peptides and ct-DNA. The experimental results revealed that Anoplin, Ano1 and Ano2 interacted with ct-DNA in a groove-binding mode, whereas Ano3 exhibited a mosaic-binding mode. Moreover, circular dichroism revealed that these peptides have ability to unfold parallel G-quadruplex structures, indicating that they can interact with secondary nucleic acid structure. Notably, antimicrobial activity results indicated that all three derived peptides exhibited excellent antimicrobial activity against both gram-positive and gram-negative bacteria. The synthesized peptide conjugate Ano3 exhibited a MIC value of 1.4 μM to S. flexneri. Scanning electron microscopy results distinctly showed that Ano3 could rupture the cell wall of bacteria. These results provide novel methods to create effective antibacterial agents for both Gram-positive and Gram-negative bacteria by utilizing natural toxic molecules.

S-adenosylmethionine (SAM) is a sulfur-containing natural product present in all cells. SAM is considered a potential protectant and dietary supplement for the prevention and treatment of liver diseases, cancer, nervous system disorders, obesity, and aging. It is also used to reduce pesticide residues in food through its antioxidant effects. Therefore, SAM plays a significant role in food nutrition and safety, and medicine. To enhance the value of SAM, it is essential to focus on the methods and potential mechanisms involved in its biosynthesis and bioassay. This work provided a comprehensive review of the characteristics, action mechanisms, and physiological functions of SAM since 2018. Subsequently, the applications of SAM were summarized in the fields of food and medicine. The latest biosynthesis and bioassay methods, strategies, and regulatory mechanisms of SAM were introduced systematically. The main sources of SAM are biosynthesis methods based on enzyme engineering and cell factories. Bioassay of SAM is typically carried out using biosensors that utilize aptamers, riboswitches, and fluorescent proteins. Furthermore, the challenges of the study were evaluated to identify prospects. However, the existing biosynthetic methods are limited by high costs and low production rate, while bioassay methods lack high sensitivity, portability, and point-of-care testing characteristics. Accordingly, it is essential to construct a reasonable SAM biosynthesis and bioassay strategy to achieve efficient large-scale production and fully unleash its potential applications in food and medicine.

We report, for the first time, a visible-light-induced cascade radical sulfamoylation and cyclization of 2-arylbenzoimidazoles using sulfamoyl chlorides as sulfamoylation reagents to access sulfamoylated benzo[4,5]imidazo[2,1-a]isoquinolin-6(5H)-ones. The readily available nature of sulfamoyl chlorides and the metal-free conditions make this method a promising strategy for the synthesis of these compounds.

A convenient and green method for the straightforward synthesis of (3-amidovinyl sulfones has been described from enamides, high-valent iodine (III) dicarboxylates and DABCO-(SO2)2 under the irradiation of blue LEDs in the catalysis of 4CzIPN. The mild and metal-free reaction conditions make this protocol as an alternative strategy for the synthesis of (3-amidovinyl sulfones.

A tetrahydroxydiboron-mediated radical cyclization of unactivated alkenes under photoinduced reaction conditions was developed to synthesize ring-fused quinazolinones for the first time. The concise, mild and photocatalyst- and oxidant-free conditions, as well as the good functional group tolerance, render this protocol a green and convenient strategy for synthesizing polycyclic ring-fused quinazolinones. Mechanistic studies indicated that the process might involve a radical pathway.

A novel photochemical trifluoromethylation/cyclization of unactivated alkenes to synthesize trifluoromethyl‐substituted quinazolinones with trifluoromethylsulfonyl‐pyridinium salt (TFSP) is achieved under catalyst‐free conditions. Mechanistic studies reveal that an electron‐donating‐accepting complex is formed between the quinazolinone and TFSP, making this the first example of TFSP‐based trifluoromethylation conducted in the absence of expensive iridium photocatalysts.

A convenient and green method for the straightforward synthesis of β-amidovinyl sulfones has been described from enamides, high-valent iodine (III) dicarboxylates and DABCO-(SO2)2 under the irradiation of blue LEDs in the catalysis of 4CzIPN. The mild and metal-free reaction conditions make this protocol as an alternative strategy for the synthesis of β-amidovinyl sulfones.

We have developed a visible-light-induced radical cascade difluoromethylation/cyclization reaction of 1-acryloyl-2-cyanoindoles with [bis(difluoroacetoxy)iodo]benzene under catalyst-free conditions. The use of shelf-stable and easily accessible difluoromethylation reagents, combined with environmentally friendly and mild reaction conditions, makes this method an alternative strategy for the synthesis of difluoroalkylated pyrrolo[1,2- a ]indolediones.

A photochemical trifluoromethylation/cyclization of alkenes to access trifluoromethyl‐substituted fused indoles using trifluoromethylsulfonyl‐pyridinium salt (TFSP) is achieved under photocatalyst‐free conditions. Mechanistic studies revealed the formation of an electron donor–acceptor complex between indole and TFSP, distinguishing this protocol from iridium‐catalyzed TFSP‐based trifluoromethylation reactions and suggesting a different mechanistic pathway.

We report a photocatalyst-free radical cascade heptafluoroisopropylation/cyclization of unactivated alkenes with heptafluoroisopropyl iodides, facilitated by 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) or N,N,N ',N '-tetrame-thylethane-1,2-diamine (TMEDA) as the electron donors. The reaction is compatible with a broad range of quinazolinones containing unactivated alkenes, producing the heptafluoroisopropylated polycyclic quinazolinones with the moderate to high yields. Preliminary mechanistic studies revealed that the reaction is initiated by the in situ generated electron donor-acceptor (EDA) complex.

We have developed a straightforward method for synthesizing distal difluoromethyl-substituted ketones bearing heteroaryl groups. This approach utilizes difluoromethylheteroarylation of unactivated alkenes through remote heteroaryl migration by employing bis(difluoroacetyl) peroxide (generated in situ from DFAA and urea center dot H2O2) as the difluoromethylating agent. Sunlight was proved to promote this transformation.

A series of Andricin B derivatives were designed and synthesized using fatty acid modification at N-terminus of the antimicrobial peptides. The hydrophobicity of Andricin B was altered through fatty acid modification, and the bioactivity was investigated. The interaction between Andricin B and its derivatives with DNA was measured using multi-spectroscopy. Spectroscopic analysis revealed that Andricin B and its derivatives can interact with ct-DNA and G-quadruplexes DNA, and the interaction related with the length of fatty acid chain. Antimicrobial activity tests showed a significant increase using peptides with 8-10 carbons fatty acid chain. C10-Andricin B exhibited the highest antimicrobial activity, with up to a 16-fold enhancement compared to the original peptide Andricin B. Meanwhile, the protease hydrolysis stability test showed that fatty acid modification improved the stability of Andricin B against protease. Scanning electron microscopy results distinctly showed that C8-Andricin B could rupture the cell wall of bacteria. All results indicated that fatty acid modification peptides are an effective strategy for enhancing activity and stability of antimicrobial peptides. This research provides valuable insights for further research on antimicrobial peptides.

The review presents a survey of the latest advancements in light- and phosphine-mediated C–C and C-heteroatom bond formation.