Month: May 2025

Origin and properties of Desmodium adscendens (Swartz) DC.

A plant from the Fabaceae family, Desmodium adscendens (Swartz) DC. is native to the humid equatorial region of Africa, where it grows by climbing tree trunks. This species has long been used in traditional medicine, primarily to support the proper functioning and drainage of the liver. The aerial parts of Desmodium adscendens (Swartz) DC., including its leaves, are used. These leaves protect liver cells from damage caused by hepatotoxic substances, including certain medications.

Shortage and counterfeiting of Desmodium adscendens (Swartz) DC.

Due to its extensive use, shortages of Desmodium adscendens (Swartz) DC. frequently occur, leading to the sale of quantities greater than those actually produced. To meet the high demand, some sellers offer other species (often from the Desmodium sp.) as substitutes for the target species, Desmodium adscendens (Swartz) DC. The compositions, including any counterfeit additives, can therefore be quite similar. Furthermore, limited data is available in the literature, making quality controls even more complex.

Issue: a chemical composition difficult to authenticate

Knowledge of the phytochemical composition of Desmodium adscendens (Swartz) DC. is relatively limited. A few secondary metabolites have been described, including flavones (2″-O-pentosyl-C-hexosyl-apigenin derivative, vitexin, and isovitexin), saponins (soyasaponin I), salicylic acid, and alkaloids (indolic types and phenylethylamine derivatives).

It appears that the chemical composition varies significantly depending on geographic origin (Ghana, Nigeria, Sierra Leone, Togo, Madagascar), making authentication even more complex. Given this level of complexity, an appropriate analysis is necessary to obtain as much information as possible. For instance, a TLC or HPTLC analysis will typically focus on only one family of compounds (such as flavones, alkaloids, or saponins) thereby overlooking a large portion of the overall composition.

Detecting the counterfeiting of Desmodium adscendens (Swartz) DC.

Client sample analysis

As part of an annual testing campaign, 43 commercial dry extracts were analysed. Of these samples, 28 were found to be non-compliant. Among the 28 non-compliant samples, 12 contained secondary metabolite levels too low to verify the plant species, and 16 were confirmed to have been obtained from a different species (representing 37% of all samples).

Among the various cases, some samples showed significantly different compositions while still sharing many chemical family correlations.

This is the case with Sample A, for example, which does not match the expected composition for Desmodium adscendens (Swartz) DC. leaves, but still appears to belong to the Desmodium sp.

In sample B, we also observe significantly different profiles, this time with almost no correlation. The presence of such pronounced differences points to species that are very different and not Desmodium sp., clearly indicating the counterfeiting of Desmodium adscendens (Swartz) DC. with other plant species.

Finally, among the 43 samples analysed, 15 of them (35%) showed profiles fully consistent with Desmodium adscendens (Swartz) DC. leaves, as seen in Sample C.

Authenticate your botanical reference with BotaniCERT controls

Conducting an inadequate control (especially when the plant is poorly documented in the literature) can prove to be more detrimental than performing no control at all, since fraud is often subtle and difficult to detect.

How can you ensure the quality of your Desmodium samples?

By confirming the presence of Desmodium, the absence of other plant species, the absence of enrichment, and by verifying the claimed levels of active compounds.

Contact us to know more

Origin and properties of Curcuma longa L.

Turmeric is a plant from the Zingiberaceae family that has been used for centuries throughout Asia. Based on its antioxidant properties, turmeric has long been used as a natural food preservative. In traditional use, the rhizome is employed cut into small pieces, heated, and dried before being ground into powder. In this context, it is used to promote bile production and secretion, support digestion in cases of discomfort, and stimulate appetite. More recent research shows that it may help reduce blood cholesterol levels and act as an anti-inflammatory in chronic diseases such as rheumatoid arthritis, osteoarthritis, and inflammatory colitis.

Its main active compound: curcumin

The substances primarily responsible for these actions are curcuminoids, particularly curcumin, the dominant compound that also gives the rhizome its intense yellow colour. Curcumin can be synthesised relatively easily. Two main methods are described: chemical synthesis according to Pabon (a multi-step process involving several washing steps), and the Pavolini method, which is a single-step process with a 10% yield and a reaction time of just 30 minutes. This reaction involves one equivalent of acetylacetone and two equivalents of vanillin, in the presence of boron trioxide.

Study of Curcuma longa L.

Adulteration of Curcuma longa L. through enrichment with synthetic curcumin

Since the major compound of interest can be synthesised relatively easily, it is reasonable to assume that adulteration is widespread in market products. In 2019, Italian health authorities linked 27 cases of liver damage to the consumption of turmeric-based dietary supplements in capsule form (containing dry turmeric extract). The exact cause was not determined. However, it is known that turmeric extracts sold on the market are often highly concentrated in active compounds (>95% curcuminoid derivatives), and that what is labelled as turmeric may in fact be solely synthetic curcumin.
It is therefore essential to distinguish between a dry extract obtained solely from Curcuma longa L. rhizomes, an extract enriched with synthetic curcumin, and a sample composed entirely of synthetic curcumin.

How to detect the presence of synthetic curcumin

There is a monograph of the European Pharmacopoeia (01/2015:2543) that seems to allow for the separation of curcuminoids (see Figure 2), but the interpretation described in it (see below) is very brief and makes no mention whatsoever of the possibility of synthetic curcumin being present and therefore does not allow for its verification.

Interpretation of the TCL / HPTLC plate according to monograph 01/2015:2543: The chromatograms obtained with the control solution (curcuminoid standard) and the solution to be examined.

Additionally, other low-intensity bands may be present in the chromatogram obtained with the solution to be examined.

Client sample analysis

The addition of synthetic curcumin alone can be detected by HPTLC (Figure 3) or by HPLC (Figures 4 and 5).

However, when a quantity of synthetic curcumin is added to the dry extract, detecting the adulteration is much more challenging by HPTLC (because the verification is purely visual) than by HPLC (where the ratios between the three curcuminoids can be precise and compared to databases).

Proving the quality of Curcuma longa L. through HPLC analysis by BotaniCERT

Furthermore, the disadvantage of the HPTLC method is that the analysis will only detect curcuminoid derivatives. If other compounds are present in the dry extract, they will not be detected. Contamination by another species cannot be detected using this method, unlike HPLC analysis, which can detect it, provided that a proper database is established.

Performing an appropriate control is important for your plant-based products, as frauds are often subtle and difficult to detect.

How can you ensure the quality of your Curcuma samples?

By proving the presence of curcuma, the absence of other plant species, the absence of enrichment with synthetic curcumin, and by verifying the quantities of active compounds claimed.

Contact us to know more

Originally from the Amazon, Guarana is best known for its high caffeine content. Its seeds contain one of the highest natural concentrations of caffeine. This characteristic makes the species particularly interesting worldwide, having first been traditionally used in beverage form.

Properties of guarana

Today, Guarana is recognised for its stimulating effects, mainly due to its high caffeine content. It is also known to enhance concentration and memory, and has antibacterial and antifungal properties which are linked to the presence of condensed tannins and certain well-known monomers such as catechin and epicatechin.

Fraudulent caffeine enrichment

However, as is often the case when commercial use is widespread and significant financial stakes are involved, fraud can occur. This is true for this species, whose dry seed extracts are frequently enriched with caffeine (either synthetic or natural) without any disclosure of such enrichment.

Chemical composition of caffeine-enriched guarana dry extract

Guarana dry extracts are very often significantly enriched with caffeine, resulting in a chemical composition where only caffeine is present (Figure 1). However, Guarana seeds naturally contain more than just caffeine. It is therefore obvious that a caffeine-enriched Guarana dry extract will not display the traditional action typically associated with Guarana. The benefits provided will be solely based on the presence of caffeine. In such cases, it should no longer be referred to as Guarana dry extract, but rather as caffeine on a carrier such as maltodextrin.

Inability to differentiate between guarana dry extract and caffeine on a carrier using traditional analytical methods

Moreover, to carry out quality controls on dry extracts, laboratories often rely on the detection of caffeine using methods such as TLC or HPTLC analysis (Figure 2). Since these analyses focus solely on detecting caffeine, it is easy to understand that such tests will never be able to distinguish between a high-quality Guarana dry extract and a sample containing only caffeine on a carrier. This is because compounds other than caffeine will not be detected.

Detecting caffeine enrichment in guarana

But what methods can be used to detect caffeine enrichment?

Isotope ratio mass spectometry: a limited technique

One technique known for addressing this type of issue is IRMS (Isotope Ratio Mass Spectrometry), which measures the relative abundance of different isotopes of a given chemical element in a sample (13C). Isotopic ratios differentiate between a synthetically produced molecule and a naturally occurring one. The drawback of this method is that while it can detect fraud when a sample contains only synthetic caffeine, it becomes much more difficult to interpret the results when smaller amounts of synthetic caffeine are added. The complexity increases even further if natural caffeine has been added.

BotaniCERT’s comprehensive monitoring: proving the quality and authenticity of guarana

At BotaniCERT, we believe that if caffeine (natural or synthetic) has been added, the ratio between caffeine and the minority compounds will change. Therefore, a database is necessary to determine when it can be unequivocally considered as an enrichment.

Client sample analysis: how to prove guarana compliance

Out of 58 samples analysed during a campaign, 36 samples were identified as being significantly enriched with caffeine, representing 62% non-compliance (Sample A).

It might be easy to assume that highly concentrated in caffeine dry extracts show a decrease in the concentration of minority compounds in favour of caffeine. However, many dry extracts standardised to 10% exist and present a perfectly expected chemical composition (Sample B). Therefore, high-quality samples do exist.

Carrying out an inadequate inspection (based solely on criteria such as caffeine) can prove to be far more detrimental than not conducting any controls at all, as frauds are often subtle and difficult to detect.

How can you ensure the quality of your guarana samples?

By proving its presence, the absence of other plant species, the absence of caffeine enrichment, and verifying the quantity of claimed active ingredients.

Contact us to know more