A validated high-performance liquid chromatography method for detecting geniposide, ellagic acid, piperine, costunolide and dehydrocostus lactone in Liuwei Muxiang capsules.

In this study, a sensitive high-performance liquid chromatography detector was established and validated for the simultaneous determination of geniposide, ellagic acid, piperine, costunolide and dehydrocostuslactone in Liuwei Muxiang Capsules. The analysis was achieved on CHANIN 100-5-C18-H column (5µm, 250 mm×4.6 mm) with the temperature of 30oC. Gradient elution was applied using 0.1% phosphoric acid solution-methanol-acetonitrile (50:50) as mobile phase at the flow rate of 1.0 mL/min. The determination was performed at the wavelength of 225 nm (detecting geniposide), 254 nm (detecting ellagic acid), 343 nm (detecting piperine) and 225 nm (detecting costunolide and dehydrocostuslactone) along with the sample volume of 10µL. The linear ranges of geniposide, ellagic acid, piperine, costunolide and dehydrocostuslactone demonstrated good linear relationships within their respective determination ranges. The average recoveries were 100.04%, 99.86%, 99.79%, 100.17% and 100.41%, respectively. RSD% was 1.3%, 1.2%, 1.2%, 1.2%, 1.5%, respectively. The developed method was proved to be simple, accurate and sensitive, which can provide a quantitative analysis method for the content determination of geniposide, ellagic acid, piperine, costunolide and dehydrocostuslactone in Liuwei Muxiang capsules.

Identification of the metabolites of methylophiopogonanone A by ultra-high-performance liquid chromatography combined with high-resolution mass spectrometry.

RATIONALE: Methylophiopogonanone A (MOA) is a naturally occurring homoisoflavonoid from the Chinese herb Ophiopogon japonicus, which has been demonstrated to attenuate myocardial apoptosis. However, the metabolism of MOA remains unknown. The goal of the present work was to investigate the in vitro metabolism of MOA using liver microsomes and hepatocytes. METHODS: The metabolites were generated by incubating MOA with rat, monkey and human liver microsomes or hepatocytes. The resulting samples were analyzed by using a quadrupole-orbitrap high-resolution mass spectrometer. The metabolites were identified through the measurements of the exact mass, elemental composition and product ions. RESULTS: A total of 15 metabolites were detected and identified. Among these metabolites, M7 (demethylenation) was the most abundant metabolite in liver microsomes, while M6 (hydroxylation) was the predominant metabolite in hepatocytes, and glucuronidation metabolites (M9 and M10) were also the main metabolites in hepatocytes. The metabolic pathways of MOA included hydroxylation, demethylenation, glucuronidation, methylation, sulfation and glutathione conjugation. CONCLUSIONS: This study for the first time provides valuable data on the metabolites of MOA, which will be of great importance for a better understanding of its disposition and to predict human pharmacokinetics.

Development and validation of a rapid high-performance thin-layer chromatographic method for quantification of gallic acid, cinnamic acid, piperine, eugenol, and glycyrrhizin in Divya-Swasari-Vati, an ayurvedic medicine for respiratory ailments.

Divya-Swasari-Vati is a calcium containing polyherbal ayurvedic medicine prescribed for the lung-related ailments observed in the current pandemic of Severe Acute Respiratory Syndrome Coronavirus 2 infections. The formulation is a unique quintessential blend of nine herbs cited in Ayurvedic texts for chronic cough and lung infection. Analytical standardization of herbal medicines is the pressing need of the hour to ascertain the quality compliance. This persuaded us to develop a simple, rapid, and selective high-performance thin-layer chromatographic method for Divya-Swasari-Vati quality standardization. The developed method was validated for the quantification of marker components, gallic acid, cinnamic acid, piperine, eugenol and glycyrrhizin, against reference standards in five different batches of Divya-Swasari-Vati. The analytes were identified by visualization at 254 nm, and by matching their retention factor with authentic standards. The developed method was validated as per the guidelines recommended by the International Council for Harmonization for parameters like, linearity, limit of detection, limit of quantification, accuracy, and precision. Therefore, the developed novel high-performance thin-layer chromatographic process could be employed for rapid standardization of Divya-Swasari-Vati and other related herbal formulation, which would aid in quality manufacturing and product development.

The inhibitory effects of sesamol and sesamolin on the glycidyl esters formation during deodorization of vegetables oils.

BACKGROUND: Glycidyl esters (GEs) have attracted worldwide attention for their potential harm to human health. The GEs in edible oils mainly form during the deodorization of the oil refining processes. We used sesamol and sesamolin to inhibit the formation of GEs in model corn oil (MCO), model palm oil (MPO) and model rice bran oil (MRO) during a deodorization process. RESULTS: The results showed that, in the three model oils, the total GE content was in the following order from highest to lowest: MRO (1437.98 µg kg-1 ) > MPO (388.64 µg kg-1 ) > MCO (314.81 µg kg-1 ). The inhibitory effect of the three antioxidants on the formation of GEs in the MCO was in the following order from strongest to weakest: tert-butylhydroquinone (TBHQ) > sesamol > sesamolin. CONCLUSION: When the mass percentage of sesamol was 0.05%, its inhibition percentage on GEs was close to the inhibition percentage of 0.02% added TBHQ. The present study provides a foundation for understanding how to inhibit the formation of GEs in oils by adding sesamol during the deodorization process.

Identification of the metabolites of piperine via hepatocyte incubation and liquid chromatography combined with diode-array detection and high-resolution mass spectrometry.

RATIONALE: Piperine, an alkaloid isolated from Piper nigrum L., has been demonstrated to have many pharmacological effects and several health benefits. The aim of this work was to study the metabolic profiles of piperine in mouse, rat, dog and human hepatocytes. METHODS: The biotransformation was carried out by incubating piperine with hepatocytes at 37°C. After incubation for 2 h, the samples were pretreated and analyzed using liquid chromatography combined with diode-array detection and high-resolution mass spectrometry (LC/DAD-HRMS). The structures of the metabolites were assigned through a comparison of their accurate masses and product ions with those of the parent compound. RESULTS: A total of 20 metabolites were detected, and the structures were proposed. Piperine was metabolized through the following pathways: (a) oxidation to form a catechol derivative, which further underwent methylation, glucuronidation, glutathione (GSH) conjugation, and hydroxylation followed by opening of the piperidine ring; (b) hydroxylation to form a carbinolamine intermediate followed by opening of the piperidine ring and the formation of alcohol and acid derivatives; and (c) hydroxylation to form stable hydroxylated metabolites. In mouse, the formation of the catechol derivative (M12) and hydroxylation (M11) were the major metabolic pathways; in rat, the formation of the catechol derivative (M12) and glucuronidation (M9) were the main pathways; and in dog and human, the formation of the catechol derivative (M12) was the predominant pathway. No human-specific metabolite was observed. CONCLUSIONS: This study provided some new information on the metabolic profiles of piperine, which should be of great importance in the study of the pharmacology and toxicity of this compound.

Switchable-hydrophilicity solvent liquid-liquid microextraction versus dispersive liquid-liquid microextraction prior to HPLC-UV for the determination and isolation of piperine from Piper nigrum L.

Switchable-hydrophilicity solvent liquid-liquid microextraction and dispersive liquid-liquid microextraction were compared for the extraction of piperine from Piper nigrum L. prior to its analysis by using high-performance liquid chromatography with UV detection. Under optimum conditions, limits of detection and quantitation were found as 0.2-0.6 and 0.7-2.0 µg/mg with the two methods, respectively. Calibration graphs showed good linearity with coefficients of determination (R2 ) higher than 0.9962 and percentage relative standard deviations lower than 6.8%. Both methods were efficiently used for the extraction of piperine from black and white pepper samples from different origins and percentage relative recoveries ranged between 90.0 and 106.0%. The results showed that switchable-hydrophilicity solvent liquid-liquid microextraction is a better alternative to dispersive liquid-liquid microextraction for the routine analysis of piperine in food samples. A novel scaled-up dispersive liquid-liquid microextraction method was also proposed for the isolation of piperine providing a yield of 102.9 ± 4.9% and purity higher than 98.0% as revealed by NMR spectroscopy.

Analytical method development and validation of reverse-phase high-performance liquid chromatography (RP-HPLC) method for simultaneous quantifications of quercetin and piperine in dual-drug loaded nanostructured lipid carriers.

Quercetin and piperine are often used as an add-on therapy for various diseases, however both drug exhibits poor aqueous solubility and photosensitivity issue. Therefore, the aim of the present study is to improve the pharmaceutical challenges by incorporating both the drugs in nanostructured lipid carriers (NLCs) and to develop a sensitive, selective, accurate and precise reverse-phase high performance liquid chromatography (RP-HPLC) method for the simultaneous analysis of both drugs in NLCs. Effective chromatographic separation of quercetin and piperine was achieved on Hypersil gold C-18 column and mobile phase consisting of a mixture of acetonitrile and HPLC grade water (pH 2.6, adjusted with 2%v/v glacial acetic acid) in an isocratic elution mode. The flow rate of the mobile phase was 1 mL/min, column temperature at 35 ± 0.2 °C and the injection volume was 20 µL. The retention time for quercetin and piperine were found to be at 2.80 min and 10.36 min, respectively and detected at an isobestic wavelength of 346 nm using a photodiode array (PDA) detector. The method was found to be specific for the simultaneous analysis of quercetin and piperine in presence of NLCs matrix, accurate (>90%) and precise (%RSD < 2%). The validated RP-HPLC method effectively utilised to determine the percentage drug entrapment efficiency cum percentage drug loading of quercetin and piperine in NLCs enriched formulations along with the secondary estimation of in vitro cumulative percentage drug release study. The results were found to be reliable, hence the validated RP-HPLC method could be further used for the simultaneous detection and quantification of both these drugs in other lipid-based nano-formulations such as solid-lipid nanoparticles, polymer-lipid hybrid nanoparticles, lipid drug conjugates, etc. in in vitro and in vivo.

Effect of roasting and in vitro digestion on phenolic profiles and antioxidant activity of water-soluble extracts from sesame.

The effects of roasting and in vitro digestion on total phenolic content (TPC), total flavonoid content (TFC), phenolic profiles, and antioxidant activity of water-soluble extracts from six varieties of sesame were investigated in this study. Our results showed that the major phenolic compounds in raw, roasted and digested sesame were gallic acid (GA), protocatechuic acid (PA), 4-hydroxybenzoic acid (4 HBA), ferulic acid (FA) and quercetin (Quer). Roasting significantly increased the TPC, pinoresinol diglucoside (PD), sesamol, as well as the content of phenolic compounds (especially GA, PA, 4 HBA and Quer) in sesame, but kept or reduced the TFC, sesamin and sesamolin. After roasting, the antioxidant potency composite index (ACI) of six varieties of sesame was significantly increased by 29.8%-216.6%. Additionally, the ACI of gastric digestion was significantly higher than that of oral and intestinal digestion during the in vitro digestion of the roasted-sesame, except for the varieties of Ganzhi 9 and Ganzhi 17. This study showed that five phenolic compounds (GA, PA, 4 HBA, p-coumaric acid, Quer) and sesamol of the water-soluble extracts contributed to the antioxidant activities of the digestive products of sesame.

Selective in vivo molecular and cellular biocompatibility of black peppercorns by piperine-protein intrinsic atomic interaction with elicited oxidative stress and apoptosis in zebrafish eleuthero embryos.

Day to day consumption of black pepper raise concern about the detailed information about their medicinal, pharmaceutical values and knowledge about the biocompatibility with respect to ecosystem. This study investigates the in vivo selective molecular biocompatibility of its seed cover (SC) and seed core (SP) powder extract using embryonic zebrafish model. Gas chromatography mass spectrometry (GCMS) analysis of the extract prepared by grinding showed presence of different components with "piperine" as principle component. Biocompatibility analysis showed dose and time dependent selective effect of SC and SP with LC50 of 30.4 µg/ml and 35.6 µg/ml, respectively on survivability, hatching and heartbeat rate in embryonic zebrafish. Mechanistic investigation elucidated it as effect of accumulation and internalization of black pepper leading to their influence on structure and function of cellular proteins hatching enzyme (he1a), superoxide dismutase (sod1) and tumor protein (tp53) responsible for delayed hatching, oxidative stress induction and apoptosis. The study provided insight to selective biocompatibility of black pepper expedient to produce higher quality spices with respect to pharmaceutical, clinical and environmental aspects.

Development and Validation of a Novel Stability-Indicating RP-HPLC Method for Simultaneous Determination of Tezacaftor and Ivacaftor in Fixed Dose Combination.

A simple and precise novel stability-indicating method for the simultaneous estimation of tezacaftor and ivacaftor in combined tablet dosage form was developed and validated using reversed-phase high-performance liquid chromatography (RP-HPLC). The method is being reported for the first time and includes an estimation of degradation products produced post-stress conditions without any extraction or derivatization. The chromatographic separation of the drugs was achieved with a Symmetry Shield RP18 Column (100 Å, 5 µm, 4.6 mm × 250 mm) using a mixture of buffer, methanol and acetonitrile (42:27:31 v/v/v) as mobile phase. The buffer used in mobile phase contained 35 mM potassium dihydrogen phosphate, and its pH was adjusted to 7.0 ± 0.02 with 20% orthophosphoric acid. The instrument was set at flow rate of 1.2 mL min-1 at ambient temperature and the wavelength of UV-visible detector at 275 nm. The developed method could be suitable for the quantitative determination of these drugs in pharmaceutical preparations and also for quality control in bulk manufacturing. Stress testing was performed to prove the specificity. No interference was observed from its stress degradation products. The statistical analysis was done by using F-test and t-test at 95% confidence level.

Characteristics, Biological Properties and Analytical Methods of Piperine: A Review.

Piperine (PIP) is a natural alkaloid isolated from Piper longum L. that presents antioxidant, anticonvulsant, antimicrobial, neuroprotective, larvicidal, antiparasitic, anticancer effect and other pharmacological properties. However, the low aqueous solubility is the main barrier to its development from the laboratory to the clinic as a drug. Several strategies have been used to overcome this obstacle, like the incorporation of PIP into different drug delivery systems turned out to be highly efficient. In addition, several methods for the quantitative and qualitative analysis of PIP in various raw materials, including biological fluids (plasma, urine, metabolites, brain), plants and drug delivery systems, were investigated. Most recently high-performance liquid chromatography was used together with several detectors for this purpose. Therefore, this review presents a summary of characteristics chemical and biological properties of PIP as well as several techniques and analytical methods to optimize the analytical signal, increase sensitivity, selectivity and reduce the effects of interference for this drug.

Quantitative Estimation of 38 Illicit Psychostimulants in Blood by GC-APCI-QTOFMS with Nitrogen Chemiluminescence Detection Based on Three External Calibrators.

A method was developed for quantitative estimation of illicit psychostimulants in blood, with an emphasis on new psychoactive substances, based on gas chromatography nitrogen chemiluminescence detection coupled with atmospheric pressure chemical ionization quadrupole time-of-flight mass spectrometry (GC-NCD-APCI-QTOFMS). Quantitative estimation relied on the NCD's N-equimolar response to nitrogen, using amphetamine, 3,4-methylenedioxymethamphetamine (MDMA) and methylenedioxypyrovalerone as external calibrators for prim-, sec- and tert- amines, respectively. After spiking with 38 stimulants at 3 concentration levels, the donor blood samples were submitted to liquid-liquid extraction at a basic pH followed by acylation with trifluoroacetic anhydride. All but 3 psychostimulants could be analyzed with a limit of quantification (LOQ) of 0.05 mg/L. At LOQ, the coefficient of variation (CV) values for between-day accuracy was 62.3-143.3% (mean, 93.5%; median, 88.5%) and precision 6.6-22.4% (mean, 15.8%; median, 16.1%). In addition, 11 post-mortem blood samples, containing 0.08-2.4 mg/L of amphetamine (n = 5), methamphetamine (n = 4) or MDMA (n = 4), were analyzed by the GC-NCD-APCI-QTOFMS method, and the results were compared with an established electron ionization GC-MS method with appropriate calibration. The agreement between the 2 methods was 62.5-117.3%. Regarding identification, the APCI source permitted detection of the intact precursor ion, or the respective acylation product, for all of the measured compounds. The GC-NCD-APCI-QTOFMS method developed here enables instant quantitative estimation of illicit psychostimulants in blood at reasonable accuracy, without the necessity of possessing the true reference standards for each analyte.

Electrochemical quantification of piperine in black pepper.

A simple, rapid method of the detection of piperine in black pepper is reported using a voltammetric sensor based on a glassy carbon (GC) electrode with analysis following a short one-step extraction using ethanol. The method is based on a novel potential sweep designed to maximise signal sizes and shown with context of the present analytical challenge to be essential for gathering data allowing the construction of a linear calibration curve for the analysis in the relevant range namely 0.25-5.0 mM.

Rapid electroanalytical procedure for sesamol determination in real samples.

In this study, the development of an electroanalytical assay based on square wave voltammetry technique for determining sesamol (Ses) in sesame oil samples is described. The influence of various factors such as pH of the supporting electrolyte, its composition, and SW (square wave) parameters was studied. Linearity of the peak current depended on the concentration of Ses in the range from 3.0 to 140.0 µmol L-1 with a limit of detection of 0.71 µmol L-1. Furthermore, the cyclic voltammetric behavior of Ses and the effects of scan rate and pH on the peak current and peak potential of Ses were determined. Moreover, the electrode process was found to be diffusion-controlled. The proposed methodology was successfully applied for determining Ses in commercial sesame oil samples. The obtained results were in good agreement with the results from the HPLC-UV reference method.

Validation of Cell-Based Assay for Quantification of Sesamol Uptake and Its Application for Measuring Target Exposure.

The intracellular drug concentration is needed for determined target exposure at the site of action regarding its pharmacological action and adverse effects. Sesamol is an antiproliferative molecule from Sesamum indicum with promising health benefits. We present a method for measuring the intracellular sesamol content using reverse-phase HPLC with a UV diode array in melanoma cells. Sesamol was completely resolved by isocratic elution (4.152 ± 0.008 min) with methanol/water (70%, v/v) through a 30 °C, 5-µm C-18 column and detection at 297 nm. The present assay offers high sensitivity, fast elution, and an accurate and linear nominal concentration range of 10-1000 ng/mL (R2 = 0.9972). The % accuracy of the sesamol quality control sample was -3.36% to 1.50% (bias) with a 0.84% to 5.28% relative standard deviation (RSD), representing high repeatability and high reproducibility. The % recovery was 94.80% to 99.29%, which determined that there was no loss of sesamol content during the sample preparation. The validated method was applied to monitor intracellular sesamol concentration after treatment from 5 min to 24 h. The remaining intracellular sesamol content was correlated with its antiproliferative effect (R2 = 0.9483). In conclusion, this assay demonstrated low manipulation, quick elution, and high sensitivity, precision, accuracy, and recovery, and it was successfully applied to the quantification of sesamol in target cells.

Simultaneous determination of six components in commercial Roukou Wuwei pills using ultra-high-performance liquid chromatography with diode-array detector.

An efficient ultra-performance liquid chromatography with diode-array detector method was established for simultaneous determination of six active components in Roukou Wuwei pills, namely gallic acid, piperine, costundide, dehydrocostus lactone, isoalantolactone and alantolactone. Chromatographic separation of six components was successfully achieved on an Waters BEH C18 column (50 × 2.1 mm, 1.7 µm) with a mobile phase composed of acetonitrile and water using a gradient elution. Gallic acid and piperine were detected at 270 nm and 343 nm, respectively; while costundide, dehydrocostus lactone, isoalantolactone and alantolactone were simultaneously measured at 225 nm. All six calibration curves showed good linearity (R2 ≥ 0.9994) between the peak area of each component and corresponding concentration. Relative standard deviations for inter- and intra-day precisions were <0.45 and 0.77%, respectively. The mean recovery rates ranged from 96.72 to 102.2% with relative standard deviations <2.07%. The developed method was validated in terms of linearity, precision and accuracy and then successfully applied for the quality control of commercial Roukou Wuwei samples.

Characterization of stable and reactive metabolites of piperine formed on incubation with human liver microsomes.

Black pepper, though commonly employed as a spice, has many medicinal properties. It consists of volatile oils, alkaloids, pungent resins, etc., of which piperine is a major constituent. Though safe at low doses, piperine causes alteration in the activity of drug metabolising enzymes and transporters at high dose and is known to precipitate liver toxicity. It has a potential to form reactive metabolite(s) (RM) owing to the presence of structural alerts, such as methylenedioxyphenyl (MDP), α, ß-unsaturated carbonyl group (Michael acceptor), and piperidine. The present study was designed to detect and characterize stable and RM(s) of piperine formed on in vitro incubation with human liver microsomes. The investigation of RMs was done with the aid of trapping agents, viz, glutathione (GSH) and N-acetylcysteine (NAC). The samples were analysed by ultra-high performance liquid chromatography coupled with high resolution mass spectrometry (UHPLC-HRMS) using Thermo Scientific Q Exactive Plus Orbitrap. Full scan MS followed by data-dependent MS2 (Full MS-ddMS2 ) mode was used to establish mass spectrometric fragmentation pathways of protonated piperine and its metabolites. In total, four stable metabolites and their isomers (M1a-c, M2a-b, M3a-c, and M4a-b) were detected. Their formation involved removal of carbon (3, M1a-c), hydroxylation (2, M2a-b), hydroxylation with hydrogenation (3, M3a-c), and dehydrogenation (2, M4a-b). Out of these metabolites, M1, M2, and M3 are reported earlier in the literature, but their isomers and two M4 variants are novel. In addition, six novel conjugates of RMs, including three GSH conjugates of m/z 579 and three NAC conjugates of m/z 435, were also observed.

Simultaneous determination of N-ethylpentylone, dopamine, 5-hydroxytryptamine and their metabolites in rat brain microdialysis by liquid chromatography tandem mass spectrometry.

N-Ethylpentylone (NEP) is a popular synthetic cathinone abused worldwide. To obtain more information about its pharmacokinetics and pharmacodynamics, a rapid, simple and sensitive liquid chromatography-tandem mass spectrometry method was developed for the determination of NEP, two important neurotransmitters, dopamine and serotonin, and their metabolites, including 3,4-dihydroxyphenylacetic acid, 3-methoxytyramine and 5-hydroxyindole-3-acetic acid, in rat brain microdialysate. The analytes were separated on a Phnomenex Polar C18 column, with a mobile phase of 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile (B) under gradient elution to shorten the total chromatographic run time. A triple quadruple mass spectrometer coupled with an electrospray ionization source in both positive and negative ion mode was used to detect the analytes. This method showed excellent accuracy (87.4-113.5%) and precision (relative standard deviation <15%) at three quality control levels. The limits of detection were 0.2 ng/mL for NEP and 0.2-50 nm for the others and good linearity was obtained. This study pioneered a method to integrate exogenous drugs and endogenous neurotransmitters as the drugs act on the same determination system, which means that this innovation can provide support for further study of the addictive effects of NEP or other synthetic cathinones on extracellular levels of dopamine and 5-hydroxytryptamine.

Enantioselective determination of cathinones in urine by high pressure in-line SPE-CE.

This work presents a strategy based on the in-line coupling of SPE and CE for the chiral determination of cathinones (R,S-mephedrone, R,S-4-methylephedrine, and R,S- methylenedioxypyrovalerone) in urine samples, using a sample pretreatment based on liquid-liquid extraction. The chiral separation of the compounds is achieved by adding a mixture of 8 mM 2-hydroxypropil ß-CD and 5 mM ß-CD to the BGE, which consists of 70 mM of monosodium phosphate aqueous solution at pH 2.5. Oasis HLB was the selected sorbent for the in-line SPE device, and to reduce analysis time and LODs, several parameters affecting the in-line SPE system were evaluated, such as pressure and time of sample injection and dimensions of the SPE device. The highest preconcentration factors were achieved by using 3 bar of injection pressure for 20 min with an in-line SPE device of 2 mm length and 150 µm of i.d. The developed method was applied to determine the presence of the compounds in spiked urine samples. The LODs obtained were between 3 and 8 ng/mL, and these levels were below the usual concentrations at which these drugs are present in urine from cathinone abusers. Thus, the optimized method has the potential to be applied for toxicological and forensic purposes.

Label-Free, Visual Detection of Small Molecules Using Highly Target-Responsive Multimodule Split Aptamer Constructs.

Colorimetric aptamer-based sensors offer a simple means of on-site or point-of-care analyte detection. However, these sensors are largely incapable of achieving naked-eye detection, because of the poor performance of the target-recognition and signal-reporting elements employed. To address this problem, we report a generalizable strategy for engineering novel multimodule split DNA constructs termed "CBSAzymes" that utilize a cooperative binding split aptamer (CBSA) as a highly target-responsive bioreceptor and a new, highly active split DNAzyme as an efficient signal reporter. CBSAzymes consist of two fragments that remain separate in the absence of target, but effectively assemble in the presence of the target to form a complex that catalyzes the oxidation of 2,2'-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid, developing a dark green color within 5 min. Such assay enables rapid, sensitive, and visual detection of small molecules, which has not been achieved with any previously reported split-aptamer-DNAzyme conjugates. In an initial demonstration, we generate a cocaine-binding CBSAzyme that enables naked-eye detection of cocaine at concentrations as low as 10 µM. Notably, CBSAzyme engineering is straightforward and generalizable. We demonstrate this by developing a methylenedioxypyrovalerone (MDPV)-binding CBSAzyme for visual detection of MDPV and 10 other synthetic cathinones at low micromolar concentrations, even in biological samples. Given that CBSAzyme-based assays are simple, label-free, rapid, robust, and instrument-free, we believe that such assays should be readily applicable for on-site visual detection of various important small molecules such as illicit drugs, medical biomarkers, and toxins in various sample matrices.