The Sulfilimine Analogue of Allicin, S-Allyl-S-(S-allyl)-N-Cyanosulfilimine, Is Antimicrobial and Reacts with Glutathione

Sulfilimine bond formation in collagen IV

The collagen IV network plays a crucial role in providing structural support and mechanical integrity to the basement membrane and surrounding tissues. A key aspect of this network is the formation of intra- and inter-collagen fibril crosslinks. One particular crosslink, an inter-residue sulfilimine bond, has been found, so far, to be unique to collagen IV. More specifically, these crosslinks are primarily formed between methionine and lysine or hydroxylysine residues and can occur within a single collagen fibril or between different collagen fibrils. Due to its significance as the major crosslink in the collagen IV network, the sulfilimine bond plays critical roles in tissue development and various human diseases. While the proposed reaction mechanism for sulfilimine bond formation is supported by experimental evidence, the precise nature of this bond remained uncertain until computational studies were conducted. The process involves the reaction of hypohalous acids (e.g., HOBr, HOCl), produced by a peroxidasin enzyme in the basement membrane, with the sidechain sulfur of methionine or sidechain nitrogen of lysine/hydroxylysine residues in collagen IV, to form halosulfonium or haloamine intermediates, respectively. The halosulfonium/haloamine then reacts with the sidechain amine/sulfide of the lysine (or hydroxylysine) or methionine respectively, eventually resulting in the formation of the sulfilimine (MetSNLys/Hyl) crosslink. The sulfilimine product formed not only plays a crucial role in physiological processes but also finds applications in various industrial and pharmaceutical contexts. In this review, we provide a comprehensive summary of existing studies, including our own research, aimed at understanding the reaction mechanism, protonation states, characteristic nature, and dynamic behavior of the sulfilimine bond in collagen IV. The goal is to offer readers an overview of this critically important biochemical bond.

Allicin promotes functional recovery in ischemic stroke via glutathione peroxidase-1 activation of Src-Akt-Erk

Allicin exhibits various pharmacological activities and has been suggested to be beneficial in the treatment of stroke. However, the underlying mechanisms are largely unknown. Here, we confirmed that allicin protected the brain from cerebral injury, which could be ascribed to its anti‑apoptotic and anti‑inflammatory effects, as well as the regulation of lipid metabolism, using proteomics and metabolomics analysis. Our results suggested that allicin could significantly ameliorate behavioral characteristics, cerebral infarct area, cell apoptosis, inflammatory factors, and lipid metabolic-related factors (arachidonic acid, 15-hydroperoxy-eicosatetraenoic acid (15S-HPETE), palmitoylcarnitine, and acylcarnitine) by recalibrating astrocyte homeostasis in mice with photothrombotic stroke (PT). In astrocytes, allicin significantly increased glutathione peroxidase 1 (GPX1) levels and inhibited the arachidonic acid-related pathway, which was also observed in the brains of mice with PT. Allicin was proven to inhibit hypoxia-induced astrocyte apoptosis by increasing GPX1 expression, activating proto-oncogene tyrosine-protein kinase Src (Src)- protein kinase B (AKT)-extracellular signal-regulated kinase (ERK) phosphorylation, and decreasing lipid peroxidation. Thus, we concluded that allicin significantly prevented and ameliorated ischemic stroke by increasing GPX1 levels to complete the complex physiological process.

N-Cyano sulfilimine functional group as a nonclassical amide bond bioisostere in the design of a potent analogue to anthranilic diamide insecticide

To explore the potential of the N-cyano sulfilimine group as an amide bond isostere, a derivative of the blockbuster anthranilic diamide, chlorantramiliprole, was synthesized and evaluated with regard to its physicochemical properties, permeability, and biological activity. Given the combination of N-cyano sulfilimine chlorantraniliprole 1 and its strong hydrogen bond acceptor character, high permeability, and excellent insecticidal activity, the N-cyano sulfilimine functional group could be considered as an amide bond isostere.

A combination of garlic oil and cooked chilli oil could be effective and efficient for pigeon production

This study was conducted to investigate whether the combination of garlic oil and cooked chilli oil is worth using for pigeon production in the context of a total ban on antibiotics in feed additives in China. Two hundred female white king pigeons aged 23 days were randomly divided into five groups with ten replicates (four birds each). In the 47 days trial, the control group was fed with a basal diet, treatment groups were given a basal diet supplemented with 20 mg/kg neomycin sulphate or 2 g/kg corresponding oil (garlic oil or cooked chilli oil or their mixture) respectively. The mixed oil showed obvious antibacterial activity against gram-positive bacterium and its minimal bactericidal concentration against St. aureus, Salmonella and Escherichia coli were all no more than 1.0 mg/ml. In the feeding experiment, pigeons feed with garlic oil with strong bacteriostatic activity had lower FCR and better protein metabolism, and chilli oil showed strong effects of promoting feed intake and weight gain on pigeons but increased serum glucose and lipid content. Compared with the control and the antibiotic group, the mixed oil got increased growth performance, less drip loss of meat, better protein metabolism promoting, and more complete intestinal structure of pigeon. In addition, the breast meat in the mixed oil group had higher total points in the sensory test. The mixed oil combined the strong bacteriostasis of garlic oil with the feeding promotion effect of cooked chilli oil, it improved the comprehensive performance of pigeons and had the feasibility to be popularized as a non-antibiotic strategy in pigeon production.

Allicin, the Odor of Freshly Crushed Garlic: A Review of Recent Progress in Understanding Allicin's Effects on Cells

The volatile organic sulfur compound allicin (diallyl thiosulfinate) is produced as a defense substance when garlic (Allium sativum) tissues are damaged, for example by the activities of pathogens or pests. Allicin gives crushed garlic its characteristic odor, is membrane permeable and readily taken up by exposed cells. It is a reactive thiol-trapping sulfur compound that S-thioallylates accessible cysteine residues in proteins and low molecular weight thiols including the cellular redox buffer glutathione (GSH) in eukaryotes and Gram-negative bacteria, as well as bacillithiol (BSH) in Gram-positive firmicutes. Allicin shows dose-dependent antimicrobial activity. At higher doses in eukaryotes allicin can induce apoptosis or necrosis, whereas lower, biocompatible amounts can modulate the activity of redox-sensitive proteins and affect cellular signaling. This review summarizes our current knowledge of how bacterial and eukaryotic cells are specifically affected by, and respond to, allicin.

Synthesis of Ajoene Analogues by Novel Synthetic Strategies

Ajoene is a compound found in garlic extracts exhibiting a large range of biological activity. Novel ajoene analogues have been prepared in the search of compounds with superior bioactivity. Modifications include the alteration of the sulfoxide, the central alkene and the terminal allyl groups.

Antioxidant, Antimicrobial and Antiviral Properties of Herbal Materials

Recently, increasing public concern about hygiene has been driving many studies to investigate antimicrobial and antiviral agents. However, the use of any antimicrobial agents must be limited due to their possible toxic or harmful effects. In recent years, due to previous antibiotics' lesser side effects, the use of herbal materials instead of synthetic or chemical drugs is increasing. Herbal materials are found in medicines. Herbs can be used in the form of plant extracts or as their active components. Furthermore, most of the world's populations used herbal materials due to their strong antimicrobial properties and primary healthcare benefits. For example, herbs are an excellent material to replace nanosilver as an antibiotic and antiviral agent. The use of nanosilver involves an ROS-mediated mechanism that might lead to oxidative stress-related cancer, cytotoxicity, and heart diseases. Oxidative stress further leads to increased ROS production and also delays the cellular processes involved in wound healing. Therefore, existing antibiotic drugs can be replaced with biomaterials such as herbal medicine with high antimicrobial, antiviral, and antioxidant activity. This review paper highlights the antibacterial, antiviral, and radical scavenger (antioxidant) properties of herbal materials. Antimicrobial activity, radical scavenger ability, the potential for antimicrobial, antiviral, and anticancer agents, and efficacy in eliminating bacteria and viruses and scavenging free radicals in herbal materials are discussed in this review. The presented herbal antimicrobial agents in this review include clove, portulaca, tribulus, eryngium, cinnamon, turmeric, ginger, thyme, pennyroyal, mint, fennel, chamomile, burdock, eucalyptus, primrose, lemon balm, mallow, and garlic, which are all summarized.