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The coronavirus disease 2019 (COVID-19) pandemic has affected people globally. In many countries, the situation is getting worse with the rapid transmission of COVID-19. The daily incidence is drastically increasing. In this review, we aim to summarise epidemiological information and adverse health outcomes of severe acute respiratory syndrome coronavirus 2 infections. The major outcomes are described based on information from the literature and hospital reports. COVID-19 has affected individuals both physiologically and psychologically. The physiological effect on human health includes respiratory distress, pneumonia, cardiac injury, kidney failure, nervous system symptoms, and gastrointestinal symptoms. The psychological effect was observed in patients, health care workers, and the general population in the community. This review could be a source of clinical information on COVID-19 for physicians, researchers, and the general population for further studies to deal with this pandemic.

The current study aims to explore the effectiveness of communication-based intervention on the reduction in TB stigma and discrimination among high-school students in Bangkok, Thailand, during the COVID-19 outbreak. This study is quasi-experimental in nature and is conducted in two high schools (n = 216 students). The study adopts purposive and systematic sampling techniques to select schools and students. The experimental group received a communication program for three months, whereas the control group received no intervention. The study uses generalized estimating equations to assess the overall program between the experimental and control groups at baseline, intervention, and follow-up periods. The outcomes reveal that the communication program effectively reduced TB stigma (p-value < 0.05, CI = 4.962, −1.723) and increased knowledge about TB (p-value < 0.05, CI = 1.825, 2.537), attitudes toward TB (p-value < 0.05, CI = 4.493, 6.280), and self-efficacy on TB stigma and discrimination (p-value < 0.05, CI = 7.133, 9.483) compared with the control group. However, the study finds no significant within- and between-group differences in TB discrimination (p-value > 0.05, CI = −1.398, 0.810). This study is applicable as a supplement for knowledge and attitudes about TB and to the reduction in TB stigma in schools.

Graphic abstract The outbreak of COVID-19 disease has led to a search for effective vaccines or drugs. However, insufficient vaccine supplies to meet global demand and no effective approved prescribed drugs for COVID-19 have led some people to consider the use of alternative or complementary medicines, such as traditional herbal medicine. Medicinal plants have various therapeutic properties that depend on the active compounds they contain. Obviously, herbal medicine has had an essential role in treatment and prevention during COVID-19 outbreak, especially in Asian cultures. Hence, we reviewed the uses of herbal medicine in Asian cultures and described the prominent families and species that are sources of antiviral agents against COVID-19 on the basis of case reports, community surveys, and guidelines available in the literature databases. Antiviral efficacy as determined in laboratory testing was assessed, and several promising active compounds with their molecular targets in cell models against SARS-CoV-2 viral infection will be discussed. Our review findings revealed the highly frequent use of Lamiaceae family members, Zingiber officinale, and Glycyrrhiza spp. as medicinal sources for treatment of COVID-19. In addition, several plant bioactive compounds derived from traditional herbal medicine, including andrographolide, panduratin A, baicalein, digoxin, and digitoxin, have shown potent SARS-CoV-2 antiviral activity as compared with some repurposed FDA-approved drugs. These commonly used plants and promising compounds are recommended for further exploration of their safety and efficacy against COVID-19.

Isoxazoline derivatives of the natural products eugenol, 1’- S-acetoxychavicol acetate and sclareol are prepared through 1,3-dipolar cycloaddition reactions in an aqueous buffered system. The compounds are evaluated for their antitubercular and antibacterial activities. Compounds 2, 2a and 3f display strong antitubercular activity with minimum inhibitory concentration values of 26.68, 17.89 and 14.58 µM, respectively. Furthermore, derivative 3f exhibits antibacterial activity against Bacillus cereus (minimum inhibitory concentration value of 29.16 µM). Isoxazoline derivatives of 1’- S-acetoxychavicol acetate demonstrate improvements in cytotoxicity, and derivative 3f of sclareol demonstrates improved antitubercular and antibacterial activities. Isoxazolines derived from natural products exhibit Mycobacterium tuberculosis enoyl-acyl carrier protein reductase (InhA) inhibitory activity, and molecular modelling predicts that they form hydrogen bonding and hydrophobic interactions with NADH and with the key residues of the InhA binding site.

Olefin cross-metathesis (CM) is a viable reaction for the modification of alkene-containing proteins. Although allyl sulfide or selenide side-chain motifs in proteins can critically enhance the rate of CM reactions, no efficient method for their site-selective genetic incorporation into proteins has been reported to date. Here, through the systematic evaluation of olefin-bearing unnatural amino acids for their metabolic incorporation, we have discovered S-allylhomocysteine (Ahc) as a genetically encodable Met analogue that is not only processed by translational cellular machinery but also a privileged CM substrate residue in proteins. In this way, Ahc was used for efficient Met codon reassignment in a Met-auxotrophic strain of E. coli (B834 (DE3)) as well as metabolic labeling of protein in human cells and was reactive toward CM in several representative proteins. This expands the use of CM in the toolkit for "tag-and-modify" functionalization of proteins.

INTRODUCTION Natural posttranslational modifications (PTMs) to proteins expand the chemical groups available to proteins. The ability to expand posttranslational functional group diversity in an unbounded manner could, in principle, allow exploration and understanding of how these groups modulate biological function. Natural PTMs feature bonds to heteroatoms (non-carbon) made at the γ (Cys Sγ, Thr Oγ, Ser Oγ) or ω (Lys Nω, Tyr Oω) positions of side chains. However, one of the central features of biomolecules is C (sp 3 )–C (sp 3 ) bond formation. Because all amino acid side chains contain this C–C bond, mastering its construction on proteins could allow free-ranging structural alteration of residues in proteins (both natural and unnatural). RATIONALE In principle, C (sp 3 )–C (sp 3 ) disconnections at the β,γ C–C bond would allow the chemical installation of a wide range of amino acid functionalities. Traditional two-electron chemistry (using nucleophiles and electrophiles) requires reagents that are often incompatible with biological substrates and/or water. Free radicals can be tolerant of aqueous conditions and unreactive (and thereby compatible) with the majority of functionality present in biomolecules. We therefore reasoned that mild, carbon-centered free radical chemistry would be enabled by matching free-radical reactivity with a suitable, uniquely reactive functional group partner that possesses a chemical affinity for such singly occupied molecular orbitals. The amino acid residue dehydroalanine (Dha) can be readily introduced in a site-selective manner genetically, biosynthetically, or chemically; upon reaction with a suitable radical, Dha would favorably generate a stabilized Cα radical 1 . Suitable “quenching” of the central Cα radical intermediate 1 generated after formation of the critical C–C bond would thus allow “chemical mutation” of the side chain. RESULTS A range of precursor halides ( R -Hal, Hal = I or Br) allowed the creation of radicals R •. These radicals reacted selectively with Dha in peptides and proteins with excellent site selectivity and regioselectivity (>98% β,γ) and typically with a diastereoselectivity of ~1:1. Combined use of R-Hal with NaBH 4 under low-oxygen conditions suppressed competing oxidation and disubstitution side reactions of intermediates 1 . This allowed for rapid reactions (typically 30 min) with improved efficiency across a range of representative protein types and scaffolds (all α, α/β folds, all β, receptor, enzyme, antibody). The reactivity of primary, secondary, and tertiary alkyl halides allowed installation of natural, simple hydrophobic residue side chains. Charged or polar protic (e.g., OH, NH) functionality in amino acid side chains was also possible. Even the use of side-chain reagents in unprotected form proved possible, thus highlighting not only exquisite chemoselectivity but also compatibility with common biological functional groups. These transformations enabled the creation of a wide diversity of natural, unnatural, posttranslationally modified (methylated, glycosylated, phosphorylated, hydroxylated) and labeled (fluorinated, isotopically labeled) side chains, as well as difficult-to-access but important residues in proteins (e.g., methyl-Arg, citrulline, ornithine, methyl-Gln, phospho-Ser). CONCLUSION This approach to chemical editing of amino acid residues, outside of the rigid constraints of the ribosome and enzymatic processing, may prove to be a general technology for accessing diverse, previously unattainable proteins.

New naphthalene derivatives (1 and 2) and a new isomer (3) of ventilagolin, together with known anthraquinones, chrysophanol (4), physcion or emodin 3-methyl ether (5), and emodin (6), were isolated from vines of Ventilago denticulata. The isolated compounds exhibited cytotoxic activity with IC50 values of 1.15 - 40.54 μg/ml. Compounds 1 - 3 selectively exhibited weak antibacterial activity (MIC values of 200.0 - 400.0 μg/ml), while emodin (6) displayed moderate antibacterial activity with MIC value of 25.0 μg/ml. The isolated compounds showed nitric oxide and DPPH radical scavenging activities. Compounds 1 - 3 and 6 exhibited weak xanthine oxidase inhibitory activity, while emodin (6) acted as an aromatase inhibitor with the IC50 value of 10.1 μm. Compounds 1 and 2 exhibited phosphodiesterase 5 inhibitory activity with IC50 values of 8.28 μm and 6.48 μm, respectively.

A versatile method for the synthesis of orthogonally protected d-xylose 1-thioethers is described using unusual silyl group migrations which were pivotal in the synthesis of 4,8-dimethyl-6-O-(2′,4′-di-O-methyl-β-d-xylopyranosyl)hydroxyquinoline confirming the structure and absolute configuration of the natural product.