Asperuloside Activates Hepatic NRF2 Signaling to Stimulate Mitochondrial Metabolism and Restore Lipid Homeostasis in High Fat Diet-Induced MAFLD.

BACKGROUND: Nutrient overload predisposes the development of metabolic dysfunction-associated fatty liver disease (MAFLD). However, there are no specific pharmacological therapies for MAFLD. Asperuloside (ASP), an iridoid glycoside extracted from Eucommia ulmoides leaves, can alleviate obesity and MAFLD. However, the underlying mechanism and pharmacological effects of ASP on ameliorating MAFLD remain largely investigated. This study aimed to explore the effects of ASP in ameliorating MAFLD and to unravel its underlying mechanism using a high fat diet-induced MAFLD mice model. METHODS: Six-week-old C57BL/6 male mice were fed a high fat diet for 12 weeks to induce MAFLD, followed by daily ASP treatment (50 mg/kg via oral gavage) for 7 weeks. HepG2 cells were used for in vitro studies. Nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor, ML385, was employed to explore the mechanisms of ASP's action. RESULTS: ASP stimulated lipolysis and inhibited de novo lipogenesis, contributing to alleviating lipid deposition in obese mice livers and HepG2 cells. ASP restored ATP production and reversed the impairments of mitochondrial energetics and biogenesis in obese mice livers and HepG2 cells. ASP attenuated oxidative stress in obese mice livers and HepG2 cells, exhibiting its antioxidant value. Impressively, ASP significantly promotes Nrf2 nuclear translocation and Nrf2/ARE binding, thereby activating Nrf2/ARE pathway in obese mice livers and HepG2 cells, demonstrating its potential as a hepatic Nrf2 activator. Nrf2 inhibition abolishes the protective effects of ASP against lipid deposition, oxidative stress and mitochondrial dysfunction, emphasizing the critical role of ASP-activated hepatic Nrf2 signaling in ameliorating MAFLD. CONCLUSIONS: This study provides the first line of evidence demonstrating the pivotal role of ASP-stimulated Nrf2 activation in alleviating MAFLD, emphasizing its potential as a hepatic Nrf2 activator targeting fatty liver diseases. These findings offer new evidence of ASP-stimulated mitochondrial metabolism and lipolysis in MAFLD, paving the way for the development of ASP as a therapeutic agent and dietary supplement to attenuate MAFLD progression.

One-pot sequential synthesis of unsymmetrical diarylmethanes using methylene chloride as a C1-synthon.

Bisindolylmethane (BIM) and its derivatives are widely used in the pharmaceutical industry due to their significant biological activities. However, most reported synthetic methods are focused on the synthesis of symmetric BIMs, while the synthesis of unsymmetrical BIMs remains a challenge. Herein, an unprecedented two-step one-pot method to afford unsymmetrically substituted 3,3'-BIM frameworks, using methylene chloride (DCM) as the C1-synthon is reported. In this protocol, the formation of two C-C bonds can be achieved via a one-pot reaction. The utility of commercially available phenols and anilines was also demonstrated in the construction of unsymmetrical diarylmethanes. This protocol provides a straightforward approach to access diverse unsymmetrical diarylmethane derivatives under simple and mild conditions. The broad substrate compatibility and good functional group tolerance of the protocol support its practical application potential.

m-Polar interval-valued fuzzy hypergraphs and its application in decision-making problems.

This study introduces the novel concept of m-polar interval-valued fuzzy hypergraph (m-PIVFHG), an advancement that combines the strengths of fuzzy theory and hypergraph models to improve decision-making processes. m-PIVFHGs allow vertices to have degrees of membership across multiple polarities within sub-interval values of [ 0 , 1 ] . This offers better adaptability and precision than traditional models. This paper systematically explores the theoretical foundations of m-PIVFHGs, detailing their unique characteristics and presenting duality concepts with illustrative examples. It also defines various cut and level types specific to m-PIVFHGs and examines their properties. The practical utility of m-PIVFHGs is demonstrated through a real-world application aimed at optimizing decision-making in a university setting, showcasing significant improvements over existing fuzzy graph methodologies.

Capital and profitability: The moderating role of economic freedom.

Using the GMM framework, this paper examines the nexus between capital and profitability in the presence of economic freedom using annual data of US banks ranging from 2002 to 2022. consistent with both the financial stability and regulatory hypotheses, the present study's empirical findings reveal that economic freedom exerts a positive moderating influence on the relationship between bank capital ratio and profitability. The findings are heterogeneous across banks' specific characteristics and market conditions. Furthermore, the results are robust to alternative proxies of profitability. The study's finding is beneficial for policymakers and regulators as liberalization is not always adversely impact the economy; rather, it's a double-edged sword, and they must maintain that delicate balance. The conclusions of this study have meaningful implications for senior bankers and policymakers when formulating strategies for preserving bank value. Specifically, it highlights the importance of considering the interactive role of economic freedom in their decision-making process.

Modeling method of local financial dependence: Evidence from Mongolia.

Many countries have been striving to equalize the balance between the central government and sub-government financial disparities without considering political interference. This paper aims to summarize the theory of local financial federalism and propose an unprecedented model for identifying the factors that affect local financial dependence. The proposed model is based on a theoretical framework incorporating five assumptions and is applied through panel regression analysis. Utilizing panel data from 2013 to 2022 in 21 provinces of Mongolia, a total of nine variables have been identified and econometrically tested within the proposed model. The findings from the panel regression analysis reveal that local budget investment, local personal income tax, local property tax, and other local taxes positively impact the reduction of local financial dependence. However, it is observed that an increase in local budget expenditures and GDP leads to an escalation in local financial dependence.

A NRAS mRNA G-quadruplex structure-targeting small-molecule ligand reactivating DNA damage response in human cancer cells for combination therapy with clinical PI3K inhibitors.

The Neuroblastoma RAS (NRAS) oncogene homologue plays crucial roles in diverse cellular processes such as cell proliferation, survival, and differentiation. Several strategies have been developed to inhibit NRAS or its downstream effectors; however, there is no effective drug available to treat NRAS-driven cancers and thus new approaches are needed to be established. The mRNA sequence expressing NRAS containing several guanine(G)-rich regions may form quadruplex structures (G4s) and regulate NRAS translation. Therefore, targeting NRAS mRNA G4s to repress NRAS expression at translational level with ligands may be a feasible strategy against NRAS-driven cancers but it is underexplored. We reported herein a NRAS mRNA G4-targeting ligand, B3C, specifically localized in cytoplasm in HeLa cells. It effectively downregulates NRAS proteins, reactivates the DNA damage response (DDR), causes cell cycle arrest in G2/M phase, and induces apoptosis and senescence. Moreover, combination therapy with NARS mRNA G4-targeting ligands and clinical PI3K inhibitors for cancer cells inhibition treatment is unexplored, and we demonstrated that B3C combining with PI3Ki (pictilisib (GDC-0941)) showed potent antiproliferation activity against HeLa cells (IC50 = 1.03 µM (combined with 10 µM PI3Ki) and 0.42 µM (combined with 20 µM PI3Ki)) and exhibited strong synergistic effects in inhibiting cell proliferation. This study provides new insights into drug discovery against RAS-driven cancers using this conceptually new combination therapy strategy.

The study of honokiol as a natural product-based antimicrobial agent and its potential interaction with FtsZ protein.

Multidrug resistant bacteria have been a global health threat currently and frontline clinical treatments for these infections are very limited. To develop potent antibacterial agents with new bactericidal mechanisms is thus needed urgently to address this critical antibiotic resistance challenge. Natural products are a treasure of small molecules with high bioactive and low toxicity. In the present study, we demonstrated that a natural compound, honokiol, showed potent antibacterial activity against a number of Gram-positive bacteria including MRSA and VRE. Moreover, honokiol in combination with clinically used ß-lactam antibiotics exhibits strong synergistic antimicrobial effects against drug-resistant S. aureus strains. Biochemical studies further reveal that honokiol may disrupt the GTPase activity, FtsZ polymerization, cell division. These biological impacts induced by honokiol may ultimately cause bacterial cell death. The in vivo antibacterial activity of honokiol against S. aureus infection was also verified with a biological model of G. mellonella larvae. The in vivo results support that honokiol is low toxic against the larvae and effectively increases the survival rate of the larvae infected with S. aureus. These findings demonstrate the potential of honokiol for further structural advancement as a new class of antibacterial agents with high potency against multidrug-resistant bacteria.

Therapeutic effect of Sheng Mai San, a traditional Chinese medicine formula, on inflammatory bowel disease via inhibition of NF-κB and NLRP3 inflammasome signaling.

Introduction: Inflammatory bowel disease (IBD) is a globally emergent chronic inflammatory disease which commonly requires lifelong care. To date, there remains a pressing need for the discovery of novel anti-inflammatory therapeutic agents against this disease. Sheng Mai San (SMS) is a traditional Chinese medicine prescription with a long history of use for treating Qi and Yin deficiency and recent studies have shown that SMS exhibits anti-inflammatory potential. However, the effects of SMS on the gastrointestinal system remain poorly studied, and its therapeutic potential and underlying molecular mechanisms in IBD have yet to be discovered. In this study, we examined the therapeutic efficacy of SMS in IBD and its anti-inflammatory activity and underlying molecular mechanism, in vivo and in vitro. Methods: The therapeutic efficacy of SMS in IBD was assessed in the DSS-induced acute colitis mouse model. Body weight, stool consistency, rectal bleeding, colon length, organ coefficient, cytokine levels in colon tissues, infiltration of immune cells, and colon pathology were evaluated. The anti-inflammatory activity of SMS and related molecular mechanisms were further examined in lipopolysaccharide (LPS)-induced macrophages via assessment of pro-inflammatory cytokine secretion and NF-κB, MAPK, STAT3, and NLRP3 signalling. Results: SMS significantly ameliorated the severity of disease in acute colitis mice, as evidenced by an improvement in disease activity index, colon morphology, and histological damage. Additionally, SMS reduced pro-inflammatory cytokine production and infiltration of immune cells in colon tissues. Furthermore, in LPS-induced macrophages, we demonstrated that SMS significantly inhibited the production of cytokines and suppressed the activation of multiple pro-inflammatory signalling pathways, including NF-κB, MAPK, and STAT3. SMS also abolished NLRP3 inflammasome activation and inhibited subsequent caspase-1 activation and IL-1ß secretion, suggesting a new therapeutic target for the treatment of IBD. These mechanistic findings were also confirmed in in vivo assays. Conclusion: This study presents the anti-inflammatory activity and detailed molecular mechanism of SMS, in vitro and in vivo. Importantly, we highlight for the first time the potential of SMS as an effective therapeutic agent against IBD.

Asperuloside as a Novel NRF2 Activator to Ameliorate Endothelial Dysfunction in High Fat Diet-Induced Obese Mice.

Aims: Current treatments are inadequate in alleviating obesity-associated vascular diseases. The development of effective therapies to ameliorate endothelial dysfunction and attenuate oxidative stress is of utmost importance. Asperuloside (ASP), a bioactive compound extracted from Eucommia species, exhibits antiobesity properties. However, the effects of ASP on vasculopathy have not been investigated. Therefore, the effects of ASP on vascular dysfunction and related mechanisms were elucidated. Results: ASP significantly reversed the impaired endothelium-dependent relaxations (EDRs) in obese mice and interleukin (IL)-1ß-treated aortas. ASP suppressed endothelial activation in obese mice aortas and IL-1ß-treated endothelial cells. ASP attenuated oxidative stress, scavenged mitochondrial reactive oxygen species (ROS), and upregulated heme oxygenase-1 (HO-1) expression in endothelium, independent of its anti-inflammatory properties. HO-1 knockdown diminished the protective effects of ASP against impaired EDRs, ROS overproduction, and endothelial activation. Endothelial cell-specific nuclear factor erythroid 2-related factor 2 (Nrf2) knockdown eliminated the ASP-mediated vascular protective effects and endothelial HO-1 upregulation, emphasizing that ASP improves endothelial function by activating Nrf2/HO-1 signaling. ASP facilitated Nrf2 nuclear translocation and the direct binding of Nrf2 to antioxidant response element, thereby enhancing HO-1 transcription and scavenging ROS. The cellular thermal shift assay results provide the first experimental characterization of the direct binding of ASP to Nrf2. Conclusions: These findings demonstrate that ASP ameliorates obesity-associated endothelial dysfunction by activating Nrf2/HO-1 signaling and thereby maintaining redox hemostasis, suggesting its potential as a novel Nrf2-targeted therapeutic agent and dietary supplement for vasculopathy.

Does US monetary policy uncertainty affect returns of Asian Developed, emerging, and frontier equity markets? Empirical evidence by using the quantile-on-quantile approach.

This paper examines the impact of the Monetary Policy Uncertainty (MPU) of the United States on Asian developed, emerging, and frontier stock markets using a Quantile-on-Quantile (QQR) approach by using monthly data from January 2006 to December 2022 of 14 Asian countries. The study finds that US monetary policy significantly negatively influences Asian stock markets. This is primarily due to the widespread use of the US dollar as a universal currency, resulting in substantial ripple effects on other nations through trade relationships. In Asian developed markets, MPU is negatively related to Australia and New Zealand. At the same time, it has a positive relationship with Hong Kong and Japan at the upper quantiles. Among Asian emerging markets, MPU negatively impacts Taiwan's, India's, and China's returns, increasing this negative relationship at higher MPU quantiles. Additionally, MPU has a significant negative relationship with Thailand, Indonesia, Korea, and Malaysia returns. In contrast, higher quantiles of MPU have no discernible impact on the Philippines stock returns. In Asian frontier markets, MPU negatively impacts Pakistan's and Sri Lanka's returns. The implications of these findings are twofold: for investors, this study provides valuable insights for hedging activities, allowing for more informed decisions based on the MPU of other countries to identify profitable stocks. For policymakers, this research aids in formulating effective monetary policy strategies. Furthermore, future studies can build upon these results by exploring other markets and comparing their outcomes with the findings presented in this study.

Ligand-Receptor Interaction-Induced Intracellular Phase Separation: A Global Disruption Strategy for Resistance-Free Lethality of Pathogenic Bacteria.

Addressing the global challenge of bacterial resistance demands innovative approaches, among which multitargeting is a widely used strategy. Current strategies of multitargeting, typically achieved through drug combinations or single agents inherently aiming at multiple targets, face challenges such as stringent pharmacokinetic and pharmacodynamic requirements and cytotoxicity concerns. In this report, we propose a bacterial-specific global disruption approach as a vastly expanded multitargeting strategy that effectively disrupts bacterial subcellular organization. This effect is achieved through a pioneering chemical design of ligand-receptor interaction-induced aggregation of small molecules, i.e., DNA-induced aggregation of a diarginine peptidomimetic within bacterial cells. These intracellular aggregates display affinity toward various proteins and thus substantially interfere with essential bacterial functions and rupture bacterial cell membranes in an "inside-out" manner, leading to robust antibacterial activities and suppression of drug resistance. Additionally, biochemical analysis of macromolecule binding affinity, cytoplasmic localization patterns, and bacterial stress responses suggests that this bacterial-specific intracellular aggregation mechanism is fundamentally different from nonselective classic DNA or membrane binding mechanisms. These mechanistic distinctions, along with the peptidomimetic's selective permeation of bacterial membranes, contribute to its favorable biocompatibility and pharmacokinetic properties, enabling its in vivo antimicrobial efficacy in several animal models, including mice-based superficial wound models, subcutaneous abscess models, and septicemia infection models. These results highlight the great promise of ligand-receptor interaction-induced intracellular aggregation in achieving a globally disruptive multitargeting effect, thereby offering potential applications in the treatment of malignant cells, including pathogens, tumor cells, and infected tissues.

Resolving the 22q11.2 deletion using CTLR-Seq reveals chromosomal rearrangement mechanisms and individual variance in breakpoints.

We developed a generally applicable method, CRISPR/Cas9-targeted long-read sequencing (CTLR-Seq), to resolve, haplotype-specifically, the large and complex regions in the human genome that had been previously impenetrable to sequencing analysis, such as large segmental duplications (SegDups) and their associated genome rearrangements. CTLR-Seq combines in vitro Cas9-mediated cutting of the genome and pulse-field gel electrophoresis to isolate intact large (i.e., up to 2,000 kb) genomic regions that encompass previously unresolvable genomic sequences. These targets are then sequenced (amplification-free) at high on-target coverage using long-read sequencing, allowing for their complete sequence assembly. We applied CTLR-Seq to the SegDup-mediated rearrangements that constitute the boundaries of, and give rise to, the 22q11.2 Deletion Syndrome (22q11DS), the most common human microdeletion disorder. We then performed de novo assembly to resolve, at base-pair resolution, the full sequence rearrangements and exact chromosomal breakpoints of 22q11.2DS (including all common subtypes). Across multiple patients, we found a high degree of variability for both the rearranged SegDup sequences and the exact chromosomal breakpoint locations, which coincide with various transposons within the 22q11.2 SegDups, suggesting that 22q11DS can be driven by transposon-mediated genome recombination. Guided by CTLR-Seq results from two 22q11DS patients, we performed three-dimensional chromosomal folding analysis for the 22q11.2 SegDups from patient-derived neurons and astrocytes and found chromosome interactions anchored within the SegDups to be both cell type-specific and patient-specific. Lastly, we demonstrated that CTLR-Seq enables cell-type specific analysis of DNA methylation patterns within the deletion haplotype of 22q11DS.

Targeting hTERT Promoter G-Quadruplex DNA Structures with Small-Molecule Ligand to Downregulate hTERT Expression for Triple-Negative Breast Cancer Therapy.

Human telomerase reverse transcriptase (hTERT) may have noncanonical functions in transcriptional regulation and metabolic reprogramming in cancer cells, but it is a challenging target. We thus developed small-molecule ligands targeting hTERT promoter G-quadruplex DNA structures (hTERT G4) to downregulate hTERT expression. Ligand 5 showed high affinity toward hTERT G4 (Kd = 1.1 µM) and potent activity against triple-negative breast cancer cells (MDA-MB-231, IC50 = 1 µM). In cell-based assays, 5 not only exerts markedly inhibitory activity on classical telomere functions including decreased telomerase activity, shortened telomere length, and cellular senescence but also induces DNA damage, acute cellular senescence, and apoptosis. This study reveals that hTERT G4-targeting ligand may cause mitochondrial dysfunction, disrupt iron metabolism and activate ferroptosis in cancer cells. The in vivo antitumor efficacy of 5 was also evaluated in an MDA-MB-231 xenograft mouse model and approximately 78.7% tumor weight reduction was achieved. No observable toxicity against the major organs was observed.

Design and synthesis of unique indole-benzosulfonamide oleanolic acid derivatives as potent antibacterial agents against MRSA.

The rapid emergence of antibiotic resistance and the scarcity of novel antibacterial agents have necessitated an urgent pursuit for the discovery and development of novel antibacterial agents against multidrug-resistant bacteria. This study involved the design and synthesis of series of novel indole-benzosulfonamide oleanolic acid (OA) derivatives, in which the indole and benzosulfonamide pharmacophores were introduced into the OA skeleton semisynthetically. These target OA derivatives show antibacterial activity against Staphylococcus strains in vitro and in vivo. Among them, derivative c17 was the most promising antibacterial agent while compared with the positive control of norfloxacin, especially against methicillin-resistant Staphylococcus aureus (MRSA) in vitro. In addition, derivative c17 also showed remarkable efficacy against MRSA-infected murine skin model, leading to a significant reduction of bacterial counts during this in vivo study. Furthermore, some preliminary studies indicated that derivative c17 could effectively inhibit and eradicate the biofilm formation, disrupt the integrity of the bacterial cell membrane. Moreover, derivative c17 showed low hemolytic activity and low toxicity to mammalian cells of NIH 3T3 and HEK 293T. These aforementioned findings strongly support the potential of novel indole-benzosulfonamide OA derivatives as anti-MRSA agents.

Evaluating the moderating role of governance on the relationships between social inclusion, ICT infrastructure, and financial inclusion.

In this paper, we examine the Moderating Role of Governance on the Relationships between social inclusion (SI), Information and communication technology infrastructure (ICT), and financial inclusion (FI) in 46 countries representing a global sample span from 2010 to 2020. We collect the data from the IMF's financial access survey and construct a multidimensional FI index. Based on the FI index, we divide the sample into two sub-samples (med-high level and low-level FI countries). For the empirics, we employed panel-corrected standard errors, fully modified ordinary least squares and dynamic ordinary least squares techniques. We find that SI is negatively related to FI. ICT infrastructure positively influences FI. Further, we find that governance with sound ICT infrastructure and socially inclusive communities enhances FI. The findings of sub-samples are similar to the full sample results except for a promoting effect of SI and governance in the case of med-high financially inclusive economies. Moreover, the Interaction term of governance and ICT infrastructure is insignificant in med-high financially inclusive economies and negatively significant in low financially inclusive economies. Our study reports novel findings which have significant implications for policymakers and financial institutions to effectively develop and implement new policies which strengthen the institutional base, develop digital banking infrastructure, enhance SI to boost up FI and ensure sustainable economic growth.

Pyrgos[n]cages: Redefining antibacterial strategy against drug resistance.

Amid rising antibiotic resistance, the quest for advanced antibacterial agents to surpass microbial adaptation is paramount. This study introduces Pyrgos[n]cages (n = 1 to 4), pioneering multidecker cationic covalent organic cages engineered to combat drug-resistant bacteria via a dual-targeting approach. Synthesized through successive photocatalytic bromination and cage-forming reactions, these architectures stand out for their dense positive charge distribution, exceptional stability, and substantial rigidity. Pyrgos[n]cages exhibit potent bactericidal activity by disrupting bacterial membrane potential and binding to DNA. Notably, these structures show unparalleled success in eradicating both extracellular and intracellular drug-resistant pathogens in diverse infection scenarios, with antibacterial efficiency markedly increasing over 100-fold as the decker number rises from 1 to 3. This study provides an advance in antibacterial tactics and underscores the transformative potential of covalent organic cages in devising enduring countermeasures against antibiotic-resistant microbial threats.

Macrophage-engaging peptidic bispecific antibodies (pBsAbs) for immunotherapy via a facile bioconjugation strategy.

Bispecific antibodies are artificial molecules that fuse two different antigen-binding sites of monoclonal antibodies into one single entity. They have emerged as a promising next-generation anticancer treatment. Despite the fascinating applications of bispecific antibodies, the design and production of bispecific antibodies remain tedious and challenging, leading to a long R&D process and high production costs. We herein report an unprecedented strategy to cyclise and conjugate tumour-targeting peptides on the surface of a monoclonal antibody to form a novel type of bispecific antibody, namely the peptidic bispecific antibody (pBsAb). Such design combines the merits of highly specific monoclonal antibodies and serum-stable cyclic peptides that endows an additional tumour-targeting ability to the monoclonal antibody for binding with two different antigens. Our results show that the novel pBsAb, which comprises EGFR-binding cyclic peptides and an anti-SIRP-α monoclonal antibody, could serve as a macrophage-engaging bispecific antibody to initiate enhanced macrophage-cancer cell interaction and block the "don't eat me" signal between CD47-SIRP-α, as well as promoting antibody-dependent cellular phagocytosis and 3D cell spheroid infiltration. These findings give rise to a new type of bispecific antibody and a new platform for the rapid generation of new bispecific antibodies for research and potential therapeutic uses.

Doping control of estra-4,9-diene-3,17-dione in horses.

Estra-4,9-diene-3,17-dione (dienedione) is an anabolic-androgenic steroid (AAS) available on the market as a dietary supplement for bodybuilding. It is prohibited in both human and equine sports due to its potential performance-enhancing effect. With the rare presence of the 4,9-diene configuration in endogenous steroids, dienedione has been considered as a synthetic AAS. Nevertheless, the reoccurring detection of dienedione in entire male horse urine samples led to the investigation of its possible endogenous nature in horses, and its endogenous nature in entire male horses has been recently confirmed and reported by the authors' laboratory. While dienedione is not detected in castrated horses (geldings), it is essential to study its elimination and identify its metabolites for its effective control. To study the elimination and biotransformation of dienedione, administration experiments were performed by giving three castrated horses (geldings) each single oral dose of 1500 mg of dienedione powder for seven consecutive days. The postulated in vivo metabolites included 17-hydroxyestra-4,9-dien-3-one (M1a and M1b), hydroxylated dienedione (M2a, M2b, M3a, M3b, M4, M5) and hydroxylated M1 (M6a, M6b, M7a, M7b, M8a and M8b), formed from hydroxylation and reduction of dienedione. To control the misuse of dienedione in geldings, M3a and M3b are the potential targets that gave the longest detection time, which could be detected for up to 2-5 days in urine and 0.4-4 days in plasma.

Fluorodeschloroketamine found as a street drug in drug seizures and drug driving cases in Hong Kong.

BACKGROUND: With the decline of the use of ketamine, one of the common drugs of abuse in Hong Kong, detection of ketamine-related analogues in local laboratories has been encountered. AIM: A brief account of the occurrence of fluorodeschloroketamine (FDCK) in forensic cases is reported through a retrospective study of all drug seizures and driving under the influence of drugs (DUID) cases since its first appearance. METHODS: Identification of FDCK in drug seizures was achieved through gas chromatography - mass spectrometry (GC-MS) and/or liquid chromatography - diode array detection (LC-DAD) methods while its quantification was performed using gas chromatography - flame ionization detection (GC-FID). For the analysis of blood samples in DUID cases, identification and quantification were performed using LC-MS/MS by monitoring the respective transitions of FDCK and fluorodeschloronorketamine (FDCNK) using ketamine-d4 and norketamine-d4 respectively as internal standards. RESULTS: Since its first submission in November 2018, a total of 74 drug seizure cases (151 items) and 6 drug driving cases were encountered till December 2019. Drug seizures found with FDCK were physically similar to those of ketamine seizures. The majority of items were detected with FDCK only (103 items, ∼67%) or as a mixture of FDCK with ketamine (42 items, ∼28%). The drug purity detected with either FDCK only or FDCK mixed with ketamine was high which was similar to those purity found in ketamine seizures. The blood drug concentrations of FDCK of the 6 drug driving cases were in the range of <0.002-1.1 µg/mL and other psychoactive drug(s)/metabolite(s) were also identified. Except for one case where the analysis of the metabolite, fluorodeschloronorketamine (FDCNK), was not conducted due to insufficient sample, the FDCK (FDCNK) concentrations in blood found in the 6 cases were <0.002 (0.005), 0.002 (0.002), 0.002 (0.003), 0.02 (0.035), 0.87 (0.44) and 1.1 (not determined) µg/mL. CONCLUSIONS: With the drug seizures found with FDCK resembled in physical appearance with ketamine seizures, users might likely misuse it as ketamine. Though complicated by other drugs found, it is speculated that the two cases with higher concentration of FDCK found in blood (1.1 and 0.87 µg/mL) might have contributed to the impairment observed.