DNA Barcoding of Crude Herbal Drugs: A Molecular Defense strategy to Detect Adulteration in Ayurvedic and Herbal Markets

Abstract

The rapid growth of the herbal and ayurvedic drug industry has necessitated increasing interest in dependable identification methods that guarantee authenticity, purity, and safety of the crude drug materials. Traditional approaches involving morphology, microscopy, or phytochemical profiling very often prove to be inadequate in cases of powdered, processed, or intentionally adulterated samples with visually similar materials. DNA barcoding has emerged as an exact, reproducible, and universally applicable method at a molecular level for species authentication. The method of DNA barcoding, through the analysis of short, standardized genetic loci such as ITS2, rbcL, and psbA-trnH, can correctly identify even closely related taxa and reveal intentional or unintentional substitution in commercial herbal raw materials. The review consolidates major advances in DNA barcoding applications for crude drug verification, summarizes successful case studies for detection of adulteration, evaluates marker performances in complex matrices, and also shows integrated workflows combining barcoding with chemo profiling for enhanced quality assurance. The status of current gaps in research, including limited availability of reference sequences, challenges posed by degraded DNA, and a lack of sufficient validation for polyherbal formulations, is also presented. Addressing these gaps is bound to establish DNA barcoding as a routine component of regulatory quality-control frameworks and ensure global confidence in herbal medicine supply chains.

Keywords

Introduction

The increasing preference for natural therapies, expanding research into plant-based treatments, and growing awareness of wellness all make the world more eager for herbal medicines and Ayurvedic raw materials. Certainly, with growing demand, the need to have reliable methods for identification that guarantee authenticity and safety becomes increasingly critical.

Adulteration and substitution of crude herbal drugs are critical quality-control challenges that substantially compromise therapeutic efficacy, patient safety, and overall market credibility. Due to the replacement or admixture with incorrect species of botanical ingredients expected pharmacological activity declines, leading to inconsistent or ineffective clinical outcomes. Contaminants or toxic substitutes may introduce unexpected adverse effects, placing patients at significant risk.

DNA barcoding has emerged as a powerful and contemporary tool for authentication of herbal raw materials. Analysis of the short, species-specific DNA regions such as rbcL, matK, or ITS2 allows verification of the botanical origin even when the material has been dried, pulverized, or otherwise processed beyond recognition by gross morphological and microscopic features. Since physical degradation often leaves the genetic signature intact, DNA barcoding provides a degree of accuracy and reliability not possible from the traditional morphological and microscopic examination in powdered drugs.[1]

Traditional morphological and microscopic identification only works when the herbal materials retain visible structures such as leaves, roots, trichomes, vessels, or cell patterns. However, in powdered, dried, or processed herbal drugs, these diagnostic characters are destroyed and, as such, species identification becomes unreliable or impossible.

Principle of DNA Barcoding

DNA barcoding is a molecular approach for which a small, standardized segment of DNA is used to identify a species with high accuracy. Even fragmented or processed herbal materials can be reliably authenticated by comparing the amplified sequence to reference databases. This overcomes the limitations of morphological and chemical analyses and represents a rapid, objective method for detecting adulteration in crude herbal drugs.

All the DNA barcodes proposed for plants comprise a few loci which are well-established and provide reliable species-level resolution. rbcL, a chloroplast gene, is considered to have universal amplification and wide taxonomic coverage, though it provides only moderate discrimination. matK is another chloroplast gene that is more variable and hence provides strong species-level resolution. Thirdly, the nuclear ribosomal ITS/ITS2 region is highly informative because of its rapid evolution and hence it finds useful application to closely related species. The chloroplast intergenic spacer psbA–trnH is also widely used because it is highly variable and easy to amplify. Overall, all these loci provide a robust multilocus framework for the authentication of crude herbal drugs.

DNA barcoding could particularly offer advantages regarding authentication of herbal drugs, since it allows species identification even in dried, powdered, or highly fragmented biological materials in which morphological features are lost. Failures in PCR amplification due to degraded DNA and incomplete or poorly curated reference databases, however, may impede correct species matching and thus in general reduce reliability.

DNA Barcoding of crude herbal drugs

Crude raw drugs are frequently adulterated because of strong market demand combined with very limited availability of genuine medicinal plants and economic motives to substitute with cheaper or more accessible species. Similarity in appearance among plant parts, particularly in the dried or powdered state, further facilitates deliberate or accidental substitution. Poor authentication practices at almost all levels, complex supply chains, and regulatory oversight further contribute to adulteration. These factors collectively compromise quality, safety, and therapeutic dependability of Ayurvedic and herbal formulations.

DNA-based surveys of herbal products in India have reported alarmingly high rates of adulteration and substitution. One study of commercially sold Ayurvedic raw-drug samples revealed that only 40% matched the labeled species and 60% were adulterated. Another market-level study of 203 raw drug samples from South India showed substitution rates of 20% to 100%, indicating that a considerable fraction of market specimens are not genuine. DNA barcoding has been effectively used for the identification of various forms of adulteration in crude herbal drugs.

It detects the substitution of species by comparing the barcode sequence of the sample with authenticated reference databases, showing when a cheaper or unrelated plant replaces the labeled species.

It identifies contamination when trace sequences from unintended species appear along with the primary barcode. DNA barcoding also uncovers mixing of multiple species through amplifying and sequencing heterogeneous DNA, showing the presence of more than one plant source in a single raw-drug sample.

ITS2 and psbA–trnH have been very successful in the authentication of crude herbal drugs due to their high discriminatory power and reliable amplification.

ITS2 is a fast-evolving nuclear locus that provides an excellent resolution among closely related species and works well even on processed or degraded material.

The chloroplast spacer psbA-trnH possesses a high variability in sequence and compatibility of universal primer, thus allowing efficient amplification across diverse taxa. Collectively, these markers continue to consistently deliver correct species identification and therefore hold a special value with regard to adulterant detection in crude raw-drug samples.

DNA barcoding gives a genetic snapshot of the plant material that helps in its identification even when the drug is processed or powdered. It may reveal species substitution, whereby a different plant is supplied instead of the genuine one, through comparing barcode regions to reference databases. The technique also detects contamination, showing undeclared or accidental plant material introduced during harvest or manufacture. When more than one plant is involved, more advanced methods such as DNA metabarcoding can produce a map of the whole mixture, identifying all constituent species present in polyherbal formulations. [2]

DNA Barcoding of Powdered Herbal Drugs

Among all the challenging herbal materials for authentication, powdered herbal materials are on top because grinding annihilates all the diagnostic morphological and microscopic features. In such situations, DNA barcoding becomes imperative because it identifies species through genetic sequences that remain detectable even when visible structures are lost. In this way, one could verify powdered crude drugs reliably and, as an added advantage, detect substitution or adulteration in the herbal market effectively. [3]

Such processes as drying, heating, and mechanical grinding during the preparation of crude herbal drugs progressively damage plant DNA. Dehydration and extended thermal exposure activate various chemical reactions that nick, oxidize, or break strands, while pulverization mechanically shears the molecules into very small fragments. These combined stresses leave DNA highly degraded, reducing the success of amplifying longer genetic regions. Thus, only short and stable barcode loci have any chance to survive the harsh treatment associated with the production of drugs from such materials.[4][5]

Optimization Strategies for DNA Barcoding of Herbal Drugs

Modified CTAB Extraction

The most widely used method for plant DNA isolation is the CTAB method, which efficiently removes polysaccharides and polyphenols that may inhibit PCR. However, when plant material is in powdered, dried, or otherwise processed herbal form, the standard protocol usually requires modification. A higher concentration of CTAB or longer incubation time generally enhances DNA yield from challenging or fibrous tissues. Addition of antioxidants such as β-mercaptoethanol prevents oxidation damage, while additional purification steps, including chloroform:isoamyl alcohol extraction or silica-based cleanup, remove any remaining inhibitors. These modifications help obtain higher-quality DNA suitable for amplification, even from degraded samples.[6]

ITS2 + psbA-trnH Barcode Combination

The identification of the species is improved using two complementary barcode regions. ITS2 is effective for distinguishing closely related species due to its high interspecific variability, whereas psbA-trnH is broadly amplifiable and works well with degraded DNA from processed samples. Both the markers together increase the identification accuracy, reduce false negatives, and are useful when herbal products are mixed or processed. This dual strategy strengthens the molecular authentication of crude and processed herbal drugs.[7]

Multi-Ingredient Products & Polyherbal Formulations

The presence of multiple plant species, usually as powders or extracts in polyherbal products, makes the task of molecular authentication very challenging. DNA from constituent ingredients can be diluted or degraded, and hence, recovery of complete sequences is difficult. Identification based on a single DNA barcode may therefore fail to provide the suite of constituent species that comprises the product and thus let substitutions or contaminants go undetected. For that, multi-locus barcoding or metabarcoding approaches will always be preferred because they can simultaneously detect multiple species in complex formulations with much higher accuracy.[8]

DNA metabarcoding couples traditional DNA barcoding with NGS, enabling identification of multiple species present within a single sample. This approach is invaluable in the cases of polyherbal formulations, powdered herbs, or complex extracts, where several plants' DNA can be present in one sample and may also be degraded. Short barcode regions from all the species are thereby amplified, sequenced in parallel, and matched against reference databases for a comprehensive species profile. The metabarcoding approach overcomes the limitations of single-locus barcoding in enabling accurate detection of substitutions, contaminations, and undeclared ingredients in complex herbal products.[9]

Identification of Undeclared Species in Herbal Products

Undeclared plant species not mentioned on the product labels can be revealed by molecular approaches such as DNA barcoding and metabarcoding. Undeclared ingredients are commonly the result of accidental contamination during the collection or processing steps or from the intentional substitution by other ingredients that are cheaper. The detection of such hidden components is important, since such can affect safety, cause allergic reactions, or affect the intended therapeutic activities. Multi-locus barcoding or NGS-based metabarcoding permits the thorough and unbiased assessment of complex herbal formulations for more reliable quality control. [10]

Advanced Approaches: DNA Metabarcoding & NGS

Metabarcoding is a technique used to identify multiple species from mixed DNA samples on a large scale by next-generation sequencing. It involves DNA extraction from complex samples such as soil, water, or bulk organisms followed by target amplification using universal primers that can bind to the genetic marker regions of several species at once. The amplified fragments are then sequenced with high-throughput NGS technology, enabling the identification of various taxa present within the sample through comparison with reference databases. Thus, community composition or biodiversity estimation can be determined without the need for isolation and direct observation of single organisms.

Major characteristics of metabarcoding are:

• Using environmental or bulk samples that contain DNA from many species.
• Application of PCR using universal primers to target homologous barcode genes across taxa.
• Performing massive parallel sequencing of these barcode regions.
• Employing bioinformatics tools for analyzing sequence data and assigning taxonomic identities.
• Providing a faster, more economical alternative to traditional species-by-species barcoding.

While conventional DNA barcoding involves processing one specimen at a time, the technique of metabarcoding offers the ability to profile biodiversity across many organisms simultaneously, including even the rare and cryptic species. Applications are numerous: from ecological monitoring and environmental DNA assessment to dietary analysis and conservation biology.

Integrated Approaches (DNA + Chemical Methods)

Ensuring the authenticity and quality of herbal medicines normally requires a combination of molecular techniques with chemical analysis. Different types of information are provided by DNA-based identification and chemical profiling, and when put together, a sample's true nature is better understood.

Integrated Approaches (DNA + Chemical Methods)

Ensuring the authenticity and quality of herbal medicines normally requires a combination of molecular techniques with chemical analysis. Different types of information are provided by DNA-based identification and chemical profiling, and when put together, a sample's true nature is better understood.

1. Limitations of Using Only DNA Barcoding

DNA barcoding remains one of the most reliable means to authenticate the botanical identity of plant materials, crude drugs, and herbal products of pharmaceutical importance. However, its capacity extends only to biological authentication. Once the species identity is established, DNA analysis alone cannot provide any further information on the chemical profile of the sample. In particular, DNA techniques cannot:

• • Quantify bioactive compounds

DNA can tell you what plant the material came from, but it is not a reflection of how much medicinal constituent is contained within. Levels of key phytochemicals can vary due to environmental conditions, harvesting stage, or extraction methods—information that DNA cannot capture.

• • Determine extract purity

Sequencing DNA cannot show whether the final extract has been diluted, contaminated, or mixed with non-plant substances. Chemical data is needed to assess purity.

• • Evaluate medicinal strength or potency

The therapeutic effect of a herbal product depends on the concentration of active molecules. DNA sequences do not provide any measure of these chemical concentrations.[12]

2. Contribution of Chemical Analytical Techniques

Chemical methods, such as HPLC, LC–MS, GC–MS, FTIR, Raman spectroscopy, and NMR, focus on the chemical composition of a sample. They help in determining:

• The amount of bioactive or marker compounds
• Presence of contaminants or synthetic adulterants
• Chemical fingerprints of the plant extract
• Overall potency and quality of the formulation.

These techniques, however, cannot confirm which species a sample is derived from, particularly in highly processed or powdered materials.[12]

Importance of Combining DNA and Chemical Methods

By integrating both approaches, researchers can ensure species-level correctness as well as chemical quality, covering all major aspects of herbal drug authentication.

Integrated Workflow for DNA Barcoding and Chemoprofiling in Herbal Quality Control

In my experience the combined approaches that join DNA-based identification, with chemical profiling techniques such as HPTLC or LC–MS work in a step by step process. I see this every day. The orthogonal approach makes sure that the batch is examined from the side and the chemical side. The orthogonal approach gives a quality?control path from the sampling, to the final decision?making.

Overall Workflow Structure

Step 1: Define the Objective and Plan the Sampling

The first step is to define the reason, for analysis. The reason for analysis can be to authenticate raw plant material to authenticate a plant extract or to authenticate a finished dosage form. I then select batches for raw plant material for plant extract and for dosage form. I gather authenticated reference samples, voucher specimens and verified chemical standards. The reference samples, voucher specimens and chemical standards become the benchmarks for DNA authentication and, for chemical comparison.

Step 2: Performing DNA and Chemical Analyses Simultaneously

The DNA barcoding/metabarcoding and chemoprofiling happen together. Each sample gets the identity check and the phytochemical quality assessment.

A. DNA Barcoding Component

a) Sample Preparation and DNA Extraction

I take an amount of the material. Homogenize it. The material may be powder, raw drug or formulated product. Then I isolate DNA. I isolate DNA, with CTAB?based extraction. I also isolate DNA, with plant DNA kits that are adapted for processed matrices where DNA may be degraded.

b) PCR Amplification and Sequencing

I target the plant barcode regions, such, as the region, the matK region and the ITS or ITS2 region. I amplify the mini-barcodes when the DNA damage is expected. I use the Sanger sequencing for the single?species material. I use the NGS or the metabarcoding, for the complex mixtures.

c) Species Identification and Data Interpretation

We compare the generated sequences with the selected reference databases, such, as BOLD and GenBank and, with the in?house checked libraries. The comparison confirms the declared species. The comparison flags the substitutions, the undeclared species or the botanical adulteration.

B. Chemoprofiling Component: HPTLC / LC–MS

a) Extracts preparation

I make the extracts, from the batch using solvents, usually methanol or hydroalcoholic mixtures. I keep the extraction conditions the same so that the chromatographic results stay reproducible.

b) Chromatographic Analysis and Detection

For HPTLC I spot the samples and standards on plates. I develop the samples and standards, in optimized solvent systems. I visualize the samples and standards to create fingerprint patterns and measurable marker bands.

In LC–MS, high-resolution chromatograms and mass spectra are generated in order to identify and quantify key phytochemicals.

c) Chemometric Assessment and Specification Matching

I compare fingerprints, constituent profiles and marker compound levels with reference standards or pharmacopoeia requirements. I check if chemical fingerprints match the pattern if constituent profiles stay within concentration ranges and if marker compound levels contain no toxic compounds. When all those checks pass I see that the chemical quality is satisfactory.

Integration and Final Decision

Orthogonal Analysis of Outcomes

I look at the datasets and the chemical datasets together:

• DNA and chemical profiles match the references. The batch is authentic. The batch has quality.
• I have seen the DNA identity be correct while the chemo-profile is abnormal. Poor processing, breakdown, dilution or low?quality material cause the chemo-profile even when the DNA identity is correct and the species origin is correct.
• Chemo-profile but wrong DNA result: The chemo-profile looks acceptable. The DNA result is wrong. The wrong DNA result shows that there was a substitution or an adulteration, with another species even though the chemical profile looked similar. [13]

Liquid Chromatography–Mass Spectrometry (LC–MS) Technique

Liquid Chromatography–Mass Spectrometry (LC–MS) is now an reliable tool. Liquid Chromatography–Mass Spectrometry (LC–MS) is used for checking the quality of the materials and the phytopharmaceutical products. Liquid Chromatography–Mass Spectrometry (LC–MS) helps scientists make sure the herbal materials and the phytopharmaceutical products meet the standards.

LC-MS combines the separation power of chromatography with the detection power of spectrometry. LC-MS can. Measure plant chemicals such, as alkaloids, flavonoids, terpenoids and glycosides. The sensitivity of LC-MS is so high that LC-MS can detect amounts of chemicals. LC-MS can tell apart molecules that're very similar when traditional chromatography does not separate them. I have found that these strengths let LC?MS work well for confirming the authenticity of materials for checking the presence of marker compounds for keeping the production batches uniform and, for spotting any adulterants or contaminants. LC?MS also creates chemical profiles. Those chemical profiles feed chemoprofiling. They make the quality control procedures more reliable and stronger.[14]

Study showing Curcuma longa adulterated with Curcuma zedoaria

We used psbA–trnH and ITS barcoding markers to test powders. The molecular data showed that some products were partly or fully swapped with Curcuma zedoaria. The barcode made the difference, between C. Longa and the adulterant species clear. In a samples we saw Curcuma zedoaria sequences, which means the product was fully swapped.

Chromatographic Confirmation (HPTLC)

The authors did the HPTLC-based chemical profiling to back up the barcoding findings. 

The chromatograms of the samples showed:

• Significantly reduced levels of curcumin,
• Appearance of sesquiterpene markers specific to C. zedoaria such as germacrone and curdione, and
• Distinctly different banding patterns from the authenticated C. longa material.

I saw that these differences showed a result. The chemical makeup of the samples was not the same, as the chemical makeup of turmeric.[15]

Conclusion of the Study

DNA barcoding and HPTLC analysis showed that the market turmeric products contain C. Zedoaria. DNA barcoding and HPTLC analysis together demonstrate that using the tools and the chemical tools can provide authentication and quality assessment, for the raw materials.[15]

Challenges and Limitations of DNA Barcoding in Herbal Drug Authentication

Scientists use DNA barcoding more to check the drugs. Yet researchers still find research gaps that block DNA barcoding from protecting the products and the other herbal products. When we find those research gaps and when we fix those research gaps we make the quality control frameworks stronger. We meet the compliance.

1. Inadequate India-Specific DNA Barcode Reference Libraries       

I notice that most studies depend on the databases GenBank and BOLD. The global databases have sequences, for medicinal plants. A identified reference sequence or a missing reference sequence reduces the reliability of species identification. The reduced reliability of species identification shows up most for related species groups and, for variants.

Strategy to address: I think we need to build a curated, voucher?linked India?focused DNA barcode library for plants. The DNA barcode library will contain metadata that is well documented. The DNA barcode library will contain identification that is verified. The DNA barcode library will contain sequences that are validated. The DNA barcode library will serve as a reference, for authentication.

2. Lack of Standardized Protocols for Powdered Herbal Samples     

Most of the powdered and processed drugs that are sold cause problems because the DNA breaks down because PCR inhibitors are, in the drugs and because the herbal drugs receive different chemical treatments. The extraction steps and the amplification steps that researchers use are not consistent, across studies. I have seen this problem in labs.

Strategy to address the problem: I think we should create and follow protocols, for DNA extraction, marker selection and amplification when working with drugs. I have used protocols for DNA extraction, marker selection and amplification before. The combination of markers, like ITS2 and psbA?trnH and better extraction methods raises the success rate. Improves reproducibility.

3. Limited Comparative DNA Barcode Markers Evaluation

Researchers have used rbcL, matK, ITS2 and psbA–trnH a lot. Researchers have not compared rbcL, matK, ITS2 and psbA– side, by side. Researchers have not tested rbcL, matK, ITS2 and psbA–trnH in the plants or, in the processed or degraded samples.

Strategy to address: I will do meta-analyses. I will gather the performance data of the markers, for the plant groups and the sample types. The guidelines will help you choose the barcode combinations, for a particular herbal product.

4. Underexplored Authentication of Polyherbal Formulations

I see that most DNA barcoding studies look at single?ingredient drugs. I see that polyherbal formulations stay largely untested. Traditional barcoding methods run into trouble with the mixtures because the complex mixtures bring DNA templates and the low?abundance species.

Strategy to address: Use high?throughput DNA metabarcoding, for formulations. High?throughput DNA metabarcoding can identify plant species at the time. High?throughput DNA metabarcoding gives a view of the composition and any adulteration, in the products.

5. Insufficient Integration with Chemical Profiling

DNA barcoding tells the species. Dna barcoding does not give any information, about the chemical composition, the potency or the purity. Current quality control uses methods or only chemical methods. Current quality control limits the assessment of the product quality.

I think the integrated quality control workflow should use the DNA barcoding for the species authentication and should also use the HPTLC, the other chemical profiling techniques, for the potency and the purity assessment. The integrated quality control workflow then provides the verification and the chemical verification.

6. Regulatory and Policy Gaps

In developing countries there is no rule that forces DNA-based authentication of raw or finished herbal products. I notice that the lack of frameworks lowers the incentive to adopt DNA-based authentication. The lack of frameworks also lowers the incentive to adopt molecular authentication.

Strategy: In my view the government should push for the adding of DNA barcoding guidelines, in the AYUSH pharmacopoeias and the GMP standards. I think the policy makers should adopt rules, for market monitoring. Routine market monitoring will increase consumer safety. Routine market monitoring will also improve the trustworthiness of the products.

CONCLUSION

DNA barcoding has emerged as a highly reliable molecular tool for authenticating herbal drugs, particularly in processed, dried, or powdered forms where traditional morphological and microscopic methods fail. By targeting specific DNA regions such as rbcL, matK, ITS2, and psbA–trnH, this approach enables precise species identification, detects substitution, contamination, and multi-species mixtures, and ensures the authenticity of both single-ingredient and polyherbal formulations. Among these markers, ITS2 and psbA–trnH are especially effective due to their high amplification success and strong discriminatory power, making them ideal for complex herbal products.

Despite its advantages, DNA barcoding faces challenges including degraded DNA in processed samples, PCR inhibitors, low template concentrations, and limited resolution of certain markers. Incomplete or poorly curated reference libraries, particularly for Indian medicinal plants, misidentifications in global databases, and lack of standardized protocols for powdered materials reduce overall reliability. Additionally, polyherbal formulations complicate authentication due to multiple DNA templates and uneven species representation. Regulatory gaps and resource limitations in small-scale industries further restrict widespread application.

To address these limitations, establishing curated, voucher-linked DNA databases for Indian medicinal plants is critical. Optimized extraction methods, short and high-resolution barcode regions, and multi-locus or metabarcoding strategies can enhance identification accuracy. Integration with chemical profiling techniques such as HPTLC or LC–MS allows simultaneous verification of botanical origin, chemical composition, and potency. Incorporating these molecular and chemical tools into regulatory frameworks will strengthen quality control, improve consumer safety, and ensure more trustworthy herbal products in the market.

CONFLICT OF INTEREST

The authors have no conflicts of interest.

REFERENCES

1. Ichim MC. The DNA-based authentication of commercial herbal products. Frontiers in Pharmacology, 2019 https://www.frontiersin.org/articles/10.3389/fphar.2019.01227/full
2. Raclariu-Manolic? AC, Mauvisseau Q, de Boer HJ. Horizon scan of DNA-based methods for quality control and monitoring of herbal preparations. Front Pharmacol. 2023;14:1179099. https://www.frontiersin.org/articles/10.3389/fphar.2023.1179099/full
3. Techen N, Parveen I, Pan Z, Khan IA. DNA barcoding of medicinal plant material for identification. Curr OpinBiotechnol. 2014;25:103-110. https://doi.org/10.1016/j.copbio.2013.09.010 ScienceDirect
4. Xin T, Yao H, Gao H, Zhou X, Ma X, Xu C, et al. Super food Lyciumbarbarum (Solanaceae) traceability via an internal transcribed spacer 2 (ITS2) barcode. J Agric Food Chem. 2013;61(50):11841–11848.
5. Srirama R, Kokate S, Khanuja SP, Shasany AK (2015) — “Optimized DNA isolation from medicinal plants for barcoding applications.” Journal of Medicinal Plants Research. 2015;9(27): 876 883.
6. Ivanova NV, DeWaard JR, Hebert PD. An inexpensive, automation friendly protocol for recovering high quality DNA. Molecular Ecology Notes. 2006;6(4):998–1002..
7. Kress WJ, Erickson DL. A two-locus global DNA barcode for land plants: the coding rbcL gene complements the non coding trnH–psbA spacer region. https://pubmed.ncbi.nlm.nih.gov/17551588/.
8. Newmaster SG, Grguric M, Shanmughanandhan D, Ramalingam S, Ragupathy S. DNA barcoding detects contamination and substitution in North American herbal products. BMC Med. 2013;11:222. doi:10.1186/1741-7015-11-222. https://pubmed.ncbi.nlm.nih.gov/24120035/
9. Seethapathy GS, Raclariu AC, Tadesse M, Parducci L, de Boer HJ, Wangensteen H, et al. DNA metabarcoding authentication of Ayurvedic herbal products on the European market raises concerns of quality and fidelity. https://www.frontiersin.org/articles/10.3389/fpls.2019.00068/full
10. Urumarudappa SKJ, Jo H, Lee GJ, Kim YD, Han K, et al. DNA metabarcoding to unravel plant species composition in herbal teas and medicinal plant mixtures. Sci Rep. 2020;10:1467.
11. Taberlet, P., Coissac, E., Pompanon, F., Brochmann, C., & Willerslev, E. (2012). Towards next?generation biodiversity assessment using DNA metabarcoding. Molecular Ecology, 21(8), 2045–2050. https://pubmed.ncbi.nlm.nih.gov/22486824/
12. Nazar N. et al., “Integrating DNA Barcoding Within an Orthogonal Approach for the Quality Assurance of Plant Materials.” Phytochemical Analysis, 2024/2025. This review discusses DNA barcoding together with chromatographic and spectrometric tests (HPTLC, HPLC, LC MS, NMR, etc.) for authentication of plant materials and herbal products.
13. Chen S. et al., “DNA Barcoding and Chromatography Fingerprints for the Authentication of Herbal Medicinal Products.” Frontiers in Pharmacology, 2017. Focuses on combining DNA barcoding with chromatographic fingerprints (mainly HPLC/HPTLC) as a dual marker strategy for quality control of herbal medicinal products.
14. Mahgoub Y.A. et al., “Plant DNA Barcoding and Metabolomics for Herbal Medicine Authentication.” Journal of Pharmaceutical and Biomedical Analysis, 2022. Reviews the joint use of DNA barcoding with metabolomics methods (including LCMSbased profiling) to overcome limitations of each method alone in plant authentication.
15. Mishra P., Shukla A.K., Sundaresan V. (2016). DNA barcoding combined with HPTLC chemoprofiling identifies adulteration in Curcuma longa products. Food Chemistry, 194: 463–470.