Analysis of cannabinoids in fiber hemp plant varieties (Cannabis sativa L.) by high-performance liquid chromatography

Modeling a pesticide remediation strategy for preparative liquid chromatography using high-performance liquid chromatography

BACKGROUND

Cannabis sativa L. also known as industrial hemp, is primarily cultivated as source material for cannabinoids cannabidiol (CBD) and ∆9-tetrahydrocannabinol (∆9-THC). Pesticide contamination during plant growth is a common issue in the cannabis industry which can render plant biomass and products made from contaminated material unusable. Remediation strategies to ensure safety compliance are vital to the industry, and special consideration should be given to methods that are non-destructive to concomitant cannabinoids. Preparative liquid chromatography (PLC) is an attractive strategy for remediating pesticide contaminants while also facilitating targeted isolation cannabinoids in cannabis biomass.

METHODS

The present study evaluated the benchtop-scale suitability of pesticide remediation by liquid chromatographic eluent fractionation, by comparing retention times of 11 pesticides relative to 26 cannabinoids. The ten pesticides evaluated for retention times are clothianidin, imidacloprid, piperonyl butoxide, pyrethrins (I/II mixture), diuron, permethrin, boscalid, carbaryl, spinosyn A, and myclobutanil. Analytes were separated prior to quantification on an Agilent Infinity II 1260 high performance liquid chromatography with diode array detection (HPLC-DAD). The detection wavelengths used were 208, 220, 230, and 240 nm. Primary studies were performed using an Agilent InfinityLab Poroshell 120 EC-C18 3.0 × 50 mm column with 2.7 μm particle diameter, using a binary gradient. Preliminary studies on Phenomenex Luna 10 μm C18 PREP stationary phase were performed using a 150 × 4.6 mm column.

RESULTS

The retention times of standards and cannabis matrices were evaluated. The matrices used were raw cannabis flower, ethanol crude extract, CO₂ crude extract, distillate, distillation mother liquors, and distillation bottoms. The pesticides clothianidin, imidacloprid, carbaryl, diuron, spinosyn A, and myclobutanil eluted in the first 3.6 min, and all cannabinoids (except for 7-OH-CBD) eluted in the final 12.6 min of the 19-minute gradient for all matrices evaluated. The elution times of 7-OH-CBD and boscalid were 3.44 and 3.55 min, respectively.

DISCUSSION

7-OH-CBD is a metabolite of CBD and was not observed in the cannabis matrices evaluated. Thus, the present method is suitable for separating 7/11 pesticides and 25/26 cannabinoids tested in the six cannabis matrices tested. 7-OH-CBD, pyrethrins I and II (RT_A: 6.8 min, RT_B: 10.5 min), permethrin (RT_A: 11.9 min, RT_B: 12.2 min), and piperonyl butoxide (RT_A: 8.3 min, RT_B: 11.7 min), will require additional fractionation or purification steps.

CONCLUSIONS

The benchtop method was demonstrated have congruent elution profiles using preparative-scale stationary phase. The resolution of pesticides from cannabinoids in this method indicates that eluent fractionation is a highly attractive industrial solution for pesticide remediation of contaminated cannabis materials and targeted isolation of cannabinoids.

Evaluation of the Adsorption-Accessible Surface Area of MIL-53(Al) using Cannabinoids in a Closed System

Cannabinoids are important industrial analytes commonly assayed with high-pressure liquid chromatography (HPLC). In this study, we evaluate the suitability of MIL-53(Al), a commercially available metal-organic framework (MOF), as a stationary phase for cannabinoid separations. The suitability of an MOF for a given separation is hypothesized to be limited by the ability of a given molecule to enter the pore of the MOF. To evaluate the extent of possible adsorptive interactions between cannabinoids and the interior surface area of MIL-53(Al), the radii of gyration (R_g) and solvent-accessible surface areas were calculated for three cannabinoids, namely, cannabidiol, cannabinol, and Δ9-tetrahydrocannabinol, as well as the MOF. These values were used to calculate the theoretical adsorption capacity of the MOF, using four competing adsorption models. The R_g of cannabinoids (4.1 Å) is larger than one MOF pore aperture dimension (4.0 × 5.0 Å). The adsorption capacity was measured by relating a decrease in the cannabinoid concentration in acetonitrile when exposed to 100 mg of MOF. The cannabinoid uptake by the MOF was estimated using the relative standard deviation (RSD) of the soaking solution assay, as the decomposition-corrected RSD as uptake (DCRU). The DCRU was calculated as 0.007 ± 0.004 μg_cannabinoids/mg_MOF. These findings indicate that most of the MOF surface area was inaccessible for adsorption by cannabinoids due to size-exclusion effects. The implication of this work is that the suitability of an MOF for adsorptive separations, such as liquid chromatography, must have an upper limit for the size of the analyte. Additionally, MOFs may generally be more suitable for separations in the gas phase, where adsorbates are not hindered by the presence of a solvation shell.

THC and CBD Fingerprinting of an Elite Cannabis Collection from Iran: Quantifying Diversity to Underpin Future Cannabis Breeding

Cannabis (Cannabis sativa L.) has a rich history of human use, and the therapeutic importance of compounds produced by this species is recognized by the medical community. The active constituents of cannabis, collectively called cannabinoids, encompass hundreds of distinct molecules, the most well-characterized of which are tetrahydrocannabinol (THC) and cannabidiol (CBD), which have been used for centuries as recreational drugs and medicinal agents. As a first step to establish a cannabis breeding program, we initiated this study to describe the HPLC-measured quantity of THC and CBD biochemistry profiles of 161 feral pistillate cannabis plants from 20 geographical regions of Iran. Our data showed that Iran can be considered a new region of high potential for distribution of cannabis landraces with diverse THC and CBD content, predominantly falling into three groups, as Type I = THC-predominant, Type II = approximately equal proportions of THC and CBD (both CBD and THC in a ratio close to the unity), and Type III = CBD-predominant. Correlation analysis among two target cannabinoids and environmental and geographical variables indicated that both THC and CBD contents were strongly influenced by several environmental-geographical factors, such that THC and CBD contents were positively correlated with mean, min and max annual temperature and negatively correlated with latitude, elevation, and humidity. Additionally, a negative correlation was observed between THC and CBD concentrations, suggesting that further studies to unravel these genotype × environment interactions (G × E interactions) are warranted. The results of this study provide important pre-breeding information on a collection of cannabis that will underpin future breeding programs.

Contents of Cannabinoids in Hemp Varieties Grown in Maryland

Coincident with the cannabis legalization and the increased interest in the medicinal use of the plant, the cannabis marketplace and farming have seen tremendous growth. It is reported that there are more than 2000 cannabis varieties available to customers. However, the data that is available to the growers and breeders regarding the cannabinoid contents of various varieties remains low. Here, a high-performance liquid chromatography (HPLC) method was developed and validated for the simultaneous separation and determination of 11 cannabinoids. A total of 104 hemp bud materials belonging to 20 varieties were collected from farms in the state of Maryland and analyzed with the HPLC method. The contents of the 11 cannabinoids in various varieties were compared and discussed, highlighting the varieties that showed a high yield of cannabinoids and good consistency that are more appropriate for cannabinoid production.

Assessment of the Cannabinoid Content from Different Varieties of Cannabis sativa L. during the Growth Stages in Three Regions

Hemp (Cannabis sativa L.) belongs to the Cannabaceae family. It is very rich in chemical constituents, especially the cannabinoids which has not been reported in any other plant, and has broad pharmacological properties. Hemp as a multi-purpose crop is a good source of fibers, seed, fixed and volatile oil. It is known that the cannabinoid content of hemp is related to genetic factors, as well as plant's growth stages and environmental factors such as latitude, altitude, weather, particularly moisture availability and nutrient supply during the growing season. The present study was designed to produce hemp that contains allowable concentration of THC (<3 %) by comparing different varieties of hemp, different stages of plant growth, and different geographical locations where it was planted. To achieve this, seeds of two native populations from Iran (Fars and Yazd Provinces) and one foreign variety from France (Fedora17, as an industrial hemp cultivar) with its progenies (Fedora17-2) were cultivated in 3 research fields (Gilan, Golestan and Alborz provinces) in Iran. The following plant materials were extracted with methanol/chloroform and analyzed by HPLC: foliage in the vegetative stage, inflorescent in the flowering stage, inflorescent of seeds in the seeding stage and the mature seed. The THC concentration of Fedora17 (Fed17) in all three geographical locations was found to be under 0.03 % or even non-detectable. Same result was also observed in its progenies (Fed17-2), indicating stability of the trait in this cultivar. The THC concentration of the Yazd variety that was planted in Alborz and Gilan regions was less than 0.080 % in all growth stages. The female flowers planted in Golestan, showed a THC concentration of 1.029 % which was more than the allowed THC concentration of <3 %. The THC concentration in all growth stages of all of the different varieties planted varied from 0 to 1.392 %. The above results indicates that the type of cannabinoid produced depends on the difference in genetic prosperities of the different seed types as well as the growth stage in which the plant material was extracted. On the other hand, the climate and the region in which the seeds were planted had little influence on the THC concentration.

Origin and Evolution of the Cannabinoid Oxidocyclase Gene Family

Cannabis is an ancient crop representing a rapidly increasing legal market, especially for medicinal purposes. Medicinal and psychoactive effects of Cannabis rely on specific terpenophenolic ligands named cannabinoids. Recent whole-genome sequencing efforts have uncovered variation in multiple genes encoding the final steps in cannabinoid biosynthesis. However, the origin, evolution, and phylogenetic relationships of these cannabinoid oxidocyclase genes remain unclear. To elucidate these aspects, we performed comparative genomic analyses of Cannabis, related genera within the Cannabaceae family, and selected outgroup species. Results show that cannabinoid oxidocyclase genes originated in the Cannabis lineage from within a larger gene expansion in the Cannabaceae family. Localization and divergence of oxidocyclase genes in the Cannabis genome revealed two main syntenic blocks, each comprising tandemly repeated cannabinoid oxidocyclase genes. By comparing these blocks with those in genomes from closely related species, we propose an evolutionary model for the origin, neofunctionalization, duplication, and diversification of cannabinoid oxidocycloase genes. Based on phylogenetic analyses, we propose a comprehensive classification of three main clades and seven subclades that are intended to aid unequivocal referencing and identification of cannabinoid oxidocyclase genes. Our data suggest that cannabinoid phenotype is primarily determined by the presence/absence of single-copy genes. Although wild populations of Cannabis are still unknown, increased sampling of landraces and wild/feral populations across its native geographic range is likely to uncover additional cannabinoid oxidocyclase sequence variants.

Influence of Technological Maturity on the Secondary Metabolites of Hemp Concentrate (Cannabis sativa L.)

During the last decade, the popularity of hemp products has been rising rapidly. Products containing cannabidiol (CBD) are of predominant interest. Traditional hemp products are frequently enriched by CBD due to their potential therapeutic effects. Cannabidiol occurs naturally in hemp juice together with other biologically active substances, such as terpenes, flavonoids, and stilbenoids. These constituents act synergistically. This study aimed to observe the influence of the hemp plant developmental stage on its chemical composition and antioxidant activity. The hemp plants were analyzed during three vegetative stages, i.e., before, during, and after flowering. The collected samples were evaluated using the following analyses: total polyphenolic content and profile, terpenoid and cannabinoid contents, and ferric reducing antioxidant power. The results revealed statistically significant differences between the samples in almost all set parameters. The optimal period for hemp harvest depends on desirable compounds, i.e., phenolic content is the highest before flowering, while the levels of cannabinoids and terpenoids are the highest during the flowering period.

Gene copy number is associated with phytochemistry in Cannabis sativa

Gene copy number (CN) variation is known to be important in nearly every species where it has been examined. Alterations in gene CN may provide a fast way of acquiring diversity, allowing rapid adaptation under strong selective pressures, and may also be a key component of standing genetic variation within species. Cannabis sativa plants produce a distinguishing set of secondary metabolites, the cannabinoids, many of which have medicinal utility. Two major cannabinoids-THCA (delta-9-tetrahydrocannabinolic acid) and CBDA (cannabidiolic acid)-are products of a three-step biochemical pathway. Using whole-genome shotgun sequence data for 69 Cannabis cultivars from diverse lineages within the species, we found that genes encoding the synthases in this pathway vary in CN. Transcriptome sequence data show that the cannabinoid paralogs are differentially expressed among lineages within the species. We also found that CN partially explains variation in cannabinoid content levels among Cannabis plants. Our results demonstrate that biosynthetic genes found at multiple points in the pathway could be useful for breeding purposes, and suggest that natural and artificial selection have shaped CN variation. Truncations in specific paralogs are associated with lack of production of particular cannabinoids, showing how phytochemical diversity can evolve through a complex combination of processes.

Chemical fingerprinting of single glandular trichomes of Cannabis sativa by Coherent anti-Stokes Raman scattering (CARS) microscopy

BACKGROUND

Cannabis possesses a rich spectrum of phytochemicals i.e. cannabinoids, terpenes and phenolic compounds of industrial and medicinal interests. Most of these high-value plant products are synthesised in the disk cells and stored in the secretory cavity in glandular trichomes. Conventional trichome analysis was so far based on optical microscopy, electron microscopy or extraction based methods that are either limited to spatial or chemical information. Here we combine both information to obtain the spatial distribution of distinct secondary metabolites on a single-trichome level by applying Coherent anti-Stokes Raman scattering (CARS), a microspectroscopic technique, to trichomes derived from sepals of a drug- and a fibre-type.

RESULTS

Hyperspectral CARS imaging in combination with a nonlinear unmixing method allows to identify and localise Δ⁹-tetrahydrocannabinolic acid (THCA) in the secretory cavity of drug-type trichomes and cannabidiolic acid (CBDA)/myrcene in the secretory cavity of fibre-type trichomes, thus enabling an easy discrimination between high-THCA and high-CBDA producers. A unique spectral fingerprint is found in the disk cells of drug-type trichomes, which is most similar to cannabigerolic acid (CBGA) and is not found in fibre-type trichomes. Furthermore, we differentiate between different cell types by a combination of CARS with simultaneously acquired two-photon fluorescence (TPF) of chlorophyll a from chloroplasts and organic fluorescence mainly arising from cell walls enabling 3D visualisation of the essential oil distribution and cellular structures.

CONCLUSION

Here we demonstrate a label-free and non-destructive method to analyse the distribution of secondary metabolites and distinguish between different cell and chemo-types with high spatial resolution on a single trichome. The record of chemical fingerprints of single trichomes offers the possibility to optimise growth conditions as well as guarantee a direct process control for industrially cultivated medicinal Cannabis plants. Moreover, this method is not limited to Cannabis related issues but can be widely implemented for optimising and monitoring all kinds of natural or biotechnological production processes with simultaneous spatial and chemical information.

¹H NMR and HPLC/DAD for Cannabis sativa L. chemotype distinction, extract profiling and specification

The medicinal use of different chemovars and extracts of Cannabis sativa L. requires standardization beyond ∆9-tetrahydrocannabinol (THC) with complementing methods. We investigated the suitability of (1)H NMR key signals for distinction of four chemotypes measured in deuterated dimethylsulfoxide together with two new validated HPLC/DAD methods used for identification and extract profiling based on the main pattern of cannabinoids and other phenolics alongside the assayed content of THC, cannabidiol (CBD), cannabigerol (CBG) their acidic counterparts (THCA, CBDA, CBGA), cannabinol (CBN) and cannflavin A and B. Effects on cell viability (MTT assay, HeLa) were tested. The dominant cannabinoid pairs allowed chemotype recognition via assignment of selective proton signals and via HPLC even in cannabinoid-low extracts from the THC, CBD and CBG type. Substantial concentrations of cannabinoid acids in non-heated extracts suggest their consideration for total values in chemotype distinction and specifications of herbal drugs and extracts. Cannflavin A/B are extracted and detected together with cannabinoids but always subordinated, while other phenolics can be accumulated via fractionation and detected in a wide fingerprint but may equally serve as qualitative marker only. Cell viability reduction in HeLa was more determined by the total cannabinoid content than by the specific cannabinoid profile. Therefore the analysis and labeling of total cannabinoids together with the content of THC and 2-4 lead cannabinoids are considered essential. The suitability of analytical methods and the range of compound groups summarized in group and ratio markers are discussed regarding plant classification and pharmaceutical specification.

Effect of induced polyploidy on some biochemical parameters in Cannabis sativa L

This study is aimed at testing the efficiency of colchicine on inducing polyploidy in Cannabis sativa L. and investigation of effects of polyploidy induction on some primary and secondary metabolites. Shoot tips were treated with three different concentrations of colchicine (0, 0.1, 0.2 % w/v) for 24 or 48 h. The biggest proportion of the almost coplanar tetraploids (43.33 %) and mixoploids (13.33 %) was obtained from the 24-h treatment in 0.2 and 0.1 % w/v, respectively. Colchicine with 0.2 % concentration and 48 h duration was more destructive than 24 h. The ploidy levels were screened with flow cytometry. The biochemical analyses showed that reducing sugars, soluble sugars, total protein, and total flavonoids increased significantly in mixoploid plants compared with tetraploid and diploid plants. Tetraploid plants had a higher amount of total proteins, total flavonoids, and starch in comparison with control plants. The results showed that polyploidization could increase the contents of tetrahydrocannabinol in mixoploid plants only, but tetraploid plants had lower amounts of this substance in comparison with diploids. Also, we found such changes in protein concentration in electrophoresis analysis. In overall, our study suggests that tetraploidization could not be useful to produce tetrahydrocannabinol for commercial use, and in this case, mixoploids are more suitable.

Influence of mevinolin on chloroplast terpenoids in Cannabis sativa

Plants synthesize a myriad of isoprenoid products that are required both for essential constitutive processes and for adaptive responses to the environment. Two independent pathways for the biosynthesis of isoprenoid precursors coexist within the plant cell: the cytosolic mevalonic acid (MVA) pathway and the plastidial methylerythritol phosphate (MEP) pathway. In this study, we investigated the inhibitory effect of the MVA pathway on isoprenoid biosynthesized by the MEP pathway in Cannabis sativa by treatment with mevinolin. The amount of chlorophyll a, b, and total showed to be significantly enhanced in treated plants in comparison with control plants. Also, mevinolin induced the accumulation of carotenoids and α-tocopherol in treated plants. Mevinolin caused a significant decrease in tetrahydrocannabinol (THC) content. This result show that the inhibition of the MVA pathway stimulates MEP pathway but none for all metabolites.

First systematic evaluation of the potency of Cannabis sativa plants grown in Albania

Cannabis products (marijuana, hashish, cannabis oil) are the most frequently abused illegal substances worldwide. Delta-9-tetrahydrocannabinol (THC) is the main psychoactive component of Cannabis sativa plant, whereas cannabidiol (CBD) and cannabinol (CBN) are other major but no psychoactive constituents. Many studies have already been carried out on these compounds and chemical research was encouraged due to the legal implications concerning the misuse of marijuana. The aim of this study was to determine THC, CBD and CBN in a significant number of cannabis samples of Albanian origin, where cannabis is the most frequently used drug of abuse, in order to evaluate and classify them according to their cannabinoid composition. A GC-MS method was used, in order to assay cannabinoid content of hemp samples harvested at different maturation degree levels during the summer months and grown in different areas of Albania. This method can also be used for the determination of plant phenotype, the evaluation of psychoactive potency and the control of material quality. The highest cannabinoid concentrations were found in the flowers of cannabis. The THC concentrations in different locations of Albania ranged from 1.07 to 12.13%. The influence of environmental conditions on cannabinoid content is discussed. The cannabinoid content of cannabis plants were used for their profiling, and it was used for their classification, according to their geographical origin. The determined concentrations justify the fact that Albania is an area where cannabis is extensively cultivated for illegal purposes.

Cannabis - from cultivar to chemovar

The medicinal use of Cannabis is increasing as countries worldwide are setting up official programs to provide patients with access to safe sources of medicinal-grade Cannabis. An important question that remains to be answered is which of the many varieties of Cannabis should be made available for medicinal use. Drug varieties of Cannabis are commonly distinguished through the use of popular names, with a major distinction being made between Indica and Sativa types. Although more than 700 different cultivars have already been described, it is unclear whether such classification reflects any relevant differences in chemical composition. Some attempts have been made to classify Cannabis varieties based on chemical composition, but they have mainly been useful for forensic applications, distinguishing drug varieties, with high THC content, from the non-drug hemp varieties. The biologically active terpenoids have not been included in these approaches. For a clearer understanding of the medicinal properties of the Cannabis plant, a better classification system, based on a range of potentially active constituents, is needed. The cannabinoids and terpenoids, present in high concentrations in Cannabis flowers, are the main candidates. In this study, we compared cultivars obtained from multiple sources. Based on the analysis of 28 major compounds present in these samples, followed by principal component analysis (PCA) of the quantitative data, we were able to identify the Cannabis constituents that defined the samples into distinct chemovar groups. The study indicates the usefulness of a PCA approach for chemotaxonomic classification of Cannabis varieties.

Characteristics of cannabinoids composition of Cannabis plants grown in Northern Thailand and its forensic application

The Thai government has recognized the possibility for legitimate cultivation of hemp. Further study of certain cannabinoid characteristics is necessary in establishing criteria for regulation of cannabis cultivation in Thailand. For this purpose, factors affecting characteristics of cannabinoids composition of Thai-grown cannabis were investigated. Plants were cultivated from seeds derived from the previous studies under the same conditions. 372 cannabis samples from landraces, three different trial fields and seized marijuana were collected. 100g of each sample was dried, ground and quantitatively analyzed for THC, CBD and CBN contents by GC-FID. The results showed that cannabis grown during March-June which had longer vegetative stages and longer photoperiod exposure, had higher cannabinoids contents than those grown in August. The male plants grown in trial fields had the range of THC contents from 0.722% to 0.848% d.w. and average THC/CBD ratio of 1.9. Cannabis in landraces at traditional harvest time of 75 days had a range of THC contents from 0.874% to 1.480% d.w. and an average THC/CBD ratio of 2.6. The THC contents and THC/CBD ratios of cannabis in second generation crops grown in the same growing season were found to be lower than those grown in the first generation, unless fairly high temperatures and a lesser amount of rainfall were present. The average THC content in seized fresh marijuana was 2.068% d.w. while THC/CBD ratios were between 12.6 and 84.09, which is 10-45 times greater than those of similar studied cannabis samples from the previous study. However, most Thai cannabis in landraces and in trial fields giving a low log(10) value of THC/CBD ratio at below 1 may be classified as intermediate type, whereas seized marijuana giving a higher log(10) value at above 1 could be classified as drug type. Therefore, the expanded information provided by the current study will assist in the development of criteria for regulation of hemp cultivation in Thailand.

Risk factors for bango abuse in upper Egypt

Cannabis is the most commonly abused drug in the world. In Egypt, the Anti Narcotic General Administration, showed that the narcotics problem costs the Egyptian economy approximately 800 million dollars annually. The present study was designed to determine the risk factors that lead to bango abuse among secondary school students and drivers in Assiut province. Urine samples were taken from 1000 volunteers after filling questionnaires and the risk factors were determined. Ethical consideration and informed consent was taken on. In drivers, the study found that bango abuse was concentrated in age group (21 to <31 years) and in those driving microbus, van and half van. In students, abuse concentrated in male students by 100%, and in those with high daily fund. The abused students tend to be more aggressive. Also, tend to be lazy to share in school activities. Abused students present in large family (8-11 persons) and families with troubles between parents (81% in divorced parents). In conclusion, bango abuse leads to deterioration of the academic achievement, and may be associated with antisocial and violent behavior.