A Rapid Nano-Liquid Chromatographic Method for the Analysis of Cannabinoids in Cannabis sativa L. Extracts

Cannabis sativa L. is an herbaceous plant belonging to the family of Cannabaceae. It is classified into three different chemotypes based on the different cannabinoids profile. In particular, fiber-type cannabis (hemp) is rich in cannabidiol (CBD) content. In the present work, a rapid nano liquid chromatographic method (nano-LC) was proposed for the determination of the main cannabinoids in Cannabis sativa L. (hemp) inflorescences belonging to different varieties. The nano-LC experiments were carried out in a 100 µm internal diameter capillary column packed with a C18 stationary phase for 15 cm with a mobile phase composed of ACN/H₂O/formic acid, 80/19/1% (v/v/v). The reverse-phase nano-LC method allowed the complete separation of four standard cannabinoids in less than 12 min under isocratic elution mode. The nano-LC method coupled to ultraviolet (UV) detection was validated and applied to the quantification of the target analytes in cannabis extracts. The nano-LC system was also coupled to an electrospray ionization–mass spectrometry (ESI-MS) detector to confirm the identity of the cannabinoids present in hemp samples. For the extraction of the cannabinoids, three different approaches, including dynamic maceration (DM), ultrasound-assisted extraction (UAE), and an extraction procedure adapted from the French Pharmacopeia’s protocol on medicinal plants, were carried out, and the results achieved were compared.     

The Dynamic Change in Fatty Acids during the Postharvest Process of Oolong Tea Production

As important factors to oolong tea quality, the accumulation and dynamic change in aroma substances attracts great attention. The volatile composition of oolong tea is closely related to the precursor contents. Fatty acids (FAs) and their derivatives are basic components of oolong tea fragrance during the postharvest process. However, information about the precursors of FAs during the postharvest process of oolong tea production is rare. To investigate the transformation of fatty acids during the process of oolong tea production, gas chromatograph–flame ionization detection (GC-FID) was conducted to analyze the composition of FAs. The results show that the content of total polyunsaturated FAs initially increased and then decreased. Specifically, the contents of α-linolenic acid, linoleic acid and other representative substances decreased after the turn-over process of oolong tea production. The results of partial least squares discrimination analysis (PLS-DA) showed that five types of FAs were obviously impacted by the processing methods of oolong tea (VIP > 1.0). LOX (Lipoxygenase, EC 1.13.11.12) is considered one of the key rate-limiting enzymes of long-chain unsaturated FAs in the LOX-HPL (hydroperoxide lyase) pathway, and the mechanical wounding occurring during the postharvest process of oolong tea production greatly elevated the activity of LOX.     

Variability in the Chemical Composition of Myrcia sylvatica (G. Mey) DC. Essential Oils Growing in the Brazilian Amazon

Myrcia sylvatica (G. Mey) DC. is known as “insulin plant” because local communities use the infusions of various organs empirically to treat diabetes. The leaves of seven specimens of Myrcia sylvatica (Msy-01 to Msy-07) were collected in the Brazilian Amazon. Furthermore, the essential oils were extracted by hydrodistillation and analyzed by gas chromatography coupled to mass spectrometry, and their chemical compositions were submitted to multivariate analysis (Principal Component Analysis and Hierarchical Cluster Analysis). The multivariate analysis displayed the formation of four chemical profiles (chemotypes), described for the first time as follows: chemotype I (specimen Msy-01) was characterized by germacrene B (24.5%), γ-elemene (12.5%), and β-caryophyllene (10.0%); chemotype II (specimens Msy-03, -06 and -07) by spathulenol (11.1–16.0%), germacrene B (7.8–20.7%), and γ-elemene (2.9–7.6%); chemotype III (Msy-04 and -05) by spathulenol (9.8–10.1%), β-caryophyllene (2.5–10.1%), and δ-cadinene (4.8-5.6%); and chemotype IV, (Msy-02) by spathulenol (13.4%), caryophyllene oxide (15.0%), and α-cadinol (8.9%). There is a chemical variability in the essential oils of Myrcia sylvatica occurring in the Amazon region.     

Phytochemical Compositions of Some Red Sea Halophyte Plants with Antioxidant and Anticancer Potentials

The aim of this study was to determine the compositions of carbohydrates, phenolic compounds, fatty acids (FAs), and amino acids (AAs) of four Rea Sea halophytes: Anabasis ehrenbergii, Suaeda aegyptiaca, Suaeda monoica, and Zygophyllum album. The results showed that S. aegyptiaca and S. monoica were rich in gallic acid with 41.72 and 47.48 mg/g, respectively, while A. ehrenbergii was rich in naringenin with 11.88 mg/g. The polysaccharides of the four species were mainly composed of galactose (54.74%) in A. ehrenbergii, mannose (44.15%) in S. aegyptiaca, glucose and ribose (33 and 26%, respectively) in S. monoica, and arabinose and glucose (36.67 and 31.52%, respectively) in Z. album. Glutamic acid and aspartic acid were the major AAs in all halophyte species with 50–63% and 10–22% of the total AAs, respectively. The proportion of unsaturated fatty acids (UFA) of the four species was 42.18–55.33%, comprised mainly of linolenic acid (15.54–28.63%) and oleic acid (5.68–22.05%), while palmitic acid (23.94–49.49%) was the most abundant saturated fatty acid (SFA). Phytol and 9,19-cyclolanost-24-en-3β–ol represented the major unsaponifiable matter (USM) constituents of S. monoica and A. ehrenbergii with proportions 42.44 and 44.11%, respectively. The phenolic fraction of S. aegyptiaca and S. monoica demonstrated noteworthy antioxidant activity with IC₅₀ values of 9.0 and 8.0 μg/mL, respectively, while the FAs fraction of Z. album exhibited potent cytotoxic activity against Huh-7, A-549, and Caco-2 cancer cell lines with IC₅₀ values of 7.4, 10.8, and 11.8 μg/mL, respectively. Our results indicate that these plants may be considered a source of naturally occurring compounds with antioxidant and anticancer effects that could be suitable for future applications.     

Gas Chromatography Combustion Isotope Ratio Mass Spectrometry to Detect Differences in Four Compartments of Simmental Cows Fed on C3 and C4 Diets

Fatty acids (FAs) metabolism in animals represents an important field of study since they influence the quality and the properties of the meat. The aim of this study is to assess the possibility to discriminate the diets of cows in different animal compartments and to study the fate of dietary FAs in the bovine organism, using carbon isotopic ratios. Five FAs, both essential (linoleic and linolenic) and non-essential (palmitic, stearic, and oleic) in four compartments (feed, rumen, liver, meat) of animals fed two different diets (based on either C3 or C4 plants) were considered. For all compartments, the carbon isotopic ratio (δ¹³C) of all FAs (with few exceptions) resulted significantly lower in cows fed on C3 than C4 plants, figuring as a powerful tool to discriminate between different diets. Moreover, chemical reactions taking place in each animal compartment result in fraction processes affecting the δ¹³C values. The δ¹³C_FAs tendentially increase from feed to meat in group C3. On the other hand, the δ¹³C_FAs generally increase from rumen to liver in group C4, while δ¹³C_FAs of rumen and meat are mostly not statistically different. Different trends in the δ¹³C_FAs of the two groups suggested different FAs fates depending on the diet.     

α-Linolenic Acid Suppresses Proliferation and Invasion in Osteosarcoma Cells via Inhibiting Fatty Acid Synthase

Fatty acid synthase (FASN) is highly expressed in multiple types of human cancers and is recognized as one of the targets for treating cancer metastasis. α-Linolenic acid is an omega-3 essential fatty acid and it possesses various biological activities. The present study was designed to reveal the effects of α-linolenic acid on osteosarcoma and to reveal whether the mechanism of α-linolenic acid in anticancer activity may be related to FASN inhibition. The cytotoxicity of α-linolenic acid was assessed in osteosarcoma MG63, 143B, and U2OS cells. Cell viability was detected by the MTT assay. The protein expression level was detected by western blotting. Flow cytometry, Annexin V/propidium iodide dual staining, and Hoechst 33258 staining were performed to assess the apoptotic effects. Wound healing assay was applied to detect the inhibitory effect of α-linolenic acid on osteosarcoma cells migration. The results showed that α-linolenic acid downregulated FASN expression. α-Linolenic acid inhibited osteosarcoma cell proliferation and migration in a dose-dependent manner. In addition, α-linolenic acid regulated endoplasmic reticulum transmembrane receptors and signal protein expression in osteosarcoma cells. The findings of the present study suggested that α-linolenic acid suppresses osteosarcoma cell proliferation and metastasis by inhibiting FASN expression, which provides a basis as a potential target for osteosarcoma treatment.     

Antioxidant,Antimicrobial Activities and Fatty Acid Compositions of Wild Berberis spp. by Different Techniques Combined with Chemometrics (PCA and HCA)

Interest in medicinal plants and fruits has increased in recent years due to people beginning to consume natural foods. This study aims to investigate the total phenolic flavonoid content, antioxidant activity, condensed tannin content, oil content, and fatty acid compositions of five local breeds of Berberis spp. from Bayburt, Turkey, and their antioxidant and antimicrobial activities. The fatty acid composition of samples was performed with gas chromatography-mass spectrometry (GC-MS), and the total fatty acid content of samples was between 6.12% and 8.60%. The main fatty acids in Berberis spp. samples were α-linolenic acid (32.85–37.88%) and linoleic acid (30.98–34.28%) followed by oleic acid (12.85–19.56%). Two antioxidant assays produced similar results, demonstrating that extracts of wild B. vulgaris L. had the highest ferric reducing antioxidant power (FRAP) (621.02 μmol FeSO₄.7H₂O/g) and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) (0.10 SC₅₀ mg/mL) values. According to principal component analysis (PCA), four components were determined. In addition, two main groups were determined according to hierarchical cluster analysis (HCA), and wild and culture of B. vulgaris L. were in different subgroups. This is the first original report about the fatty acid composition and oil content of Berberis spp. grown in Bayburt, Turkey. The obtained results indicate that B. integerrima Bunge and B. vulgaris, which have especially remarkable fatty acid content, antioxidant, and antimicrobial activity, could be potential sources for these properties in different areas of use.     

Profiling of Essential Oils from the Leaves of Pistacia lentiscus Collected in the Algerian Region of Tizi-Ouzou: Evidence of Chemical Variations Associated with Climatic Contrasts between Littoral and Mountain Samples

Leaves of Pistacia lentiscus were collected from two Algerian sites in the mountains and the littoral of the Tizi-Ouzou region. The harvest was conducted in four consecutive seasons on the same selected set of trees. Essential oils (EOs) were extracted by hydrodistillation; then, they were analyzed by gas chromatography coupled mass spectrometry (GC-MS). Forty-seven constituents could be detected and quantified, including α-pinene (2–13%), β-caryophyllene (8–25%), β-myrcene (0.3–19%), bornyl acetate (0.8–7%), δ-cadinene (3–8%), bisabolol (1–9%), β-pinene (0.9–7%), caryophyllene oxide (4–9%), and α-cadinol (3–11%). Antioxidant (AOx) activities of the EOs were assessed by ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2′-azino-bis (3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) assays. Significant differences in EO composition and AOx activities appeared dependent on the season and the site. Variations of AOx activities were significant for the FRAP and ABTS tests but not for DPPH. Characterization of the leaf fatty acyl (FA) profiles was performed by GC-MS. Variability appeared according to season and altitude. Polyunsaturated fatty acids levels were high (27–55%) at the coldest date and place. The levels of linolenic acyl in the leaves were significantly correlated with bisabolol levels in the EOs (Spearman’s correlation coefficient: 0.818). Such results will be useful for the sustainable local valorization of wild P. lentiscus. These data also open new routes for further studies on terpenoid biosynthesis using correlation networks and fluxomic approaches.     

Characterization and Identification of Bioactive Polyphenols in the Trapa bispinosa Roxb. Pericarp Extract

In this study, we present the isolation and characterization of the structure of six gallotannins (1–6), three ellagitannins (7–9), a neolignan glucoside (10), and three related polyphenolic compounds (gallic acid, 11 and 12) from Trapa bispinosa Roxb. pericarp extract (TBE). Among the isolates, the structure of compound 10 possessing a previously unclear absolute configuration was unambiguously determined through nuclear magnetic resonance and circular dichroism analyses. The α-glucosidase activity and glycation inhibitory effects of the isolates were evaluated. Decarboxylated rugosin A (8) showed an α-glucosidase inhibitory activity, while hydrolyzable tannins revealed stronger antiglycation activity than that of the positive control. Furthermore, the identification and quantification of the TBE polyphenols were investigated by high-performance liquid chromatography coupled to ultraviolet detection and electrospray ionization mass spectrometry analysis, indicating the predominance of gallic acid, ellagic acid, and galloyl glucoses showing marked antiglycation properties. These findings suggest that there is a potential food industry application of polyphenols in TBE as a functional food with antidiabetic and antiglycation activities.     

Gas Chromatographic Fingerprint Analysis for the Comparison of Seized Cannabis Samples

Cannabis sativa L. is widely used as recreational illegal drugs. Illicit Cannabis profiling, comparing seized samples, is challenging due to natural Cannabis heterogeneity. The aim of this study was to use GC–FID and GC–MS herbal fingerprints for intra (within)- and inter (between)-location variability evaluation. This study focused on finding an acceptable threshold to link seized samples. Through Pearson correlation-coefficient calculations between intra-location samples, ‘linked’ thresholds were derived using 95% and 99% confidence limits. False negative (FN) and false positive (FP) error rate calculations, aiming at obtaining the lowest possible FP value, were performed for different data pre-treatments. Fingerprint-alignment parameters were optimized using Automated Correlation-Optimized Warping (ACOW) or Design of Experiments (DoE), which presented similar results. Hence, ACOW data, as reference, showed 54% and 65% FP values (95 and 99% confidence, respectively). An additional fourth root normalization pre-treatment provided the best results for both the GC–FID and GC–MS datasets. For GC–FID, which showed the best improved FP error rate, 54 and 65% FP for the reference data decreased to 24 and 32%, respectively, after fourth root transformation. Cross-validation showed FP values similar as the entire calibration set, indicating the representativeness of the thresholds. A noteworthy improvement in discrimination between seized Cannabis samples could be concluded.     

Chemical Composition of Volatile Compounds in Apis mellifera Propolis from the Northeast Region of Pará State,Brazil

Propolis is a balsamic product obtained from vegetable resins by exotic Africanized bees Apis mellifera L., transported and processed by them, originating from the activity that explores and maintains these individuals. Because of its vegetable and natural origins, propolis is a complex mixture of different compound classes; among them are the volatile compounds present in the aroma. In this sense, in the present study we evaluated the volatile fraction of propolis present in the aroma obtained by distillation and simultaneous extraction, and its chemical composition was determined using coupled gas chromatography, mass spectrometry, and flame ionization detection. The majority of compounds were sesquiterpene and hydrocarbons, comprising 8.2–22.19% α-copaene and 6.2–21.7% β-caryophyllene, with additional compounds identified in greater concentrations. Multivariate analysis showed that samples collected from one region may have different chemical compositions, which may be related to the location of the resin’s production. This may be related to other bee products.     

Oat (Avena sativa) Extract against Oxidative Stress-Induced Apoptosis in Human Keratinocytes

Oat (Avena sativa) is well known for its various health benefits. The protective effect of oat extract against oxidative stress-induced apoptosis in human keratinocytes HaCaT was determined. First, extracts of two varieties of oat, Daeyang and Choyang, were analyzed for fat-soluble antioxidants such as α-tocotrienol, γ-oryzanols, lutein and zeaxanthin using an UPLC system and for antioxidant activity using a DPPH assay. Specifically, an 80% ethanol extract of Daeyang oat (Avena sativa cv. Daeyang), which had high amounts of antioxidants and potent radical scavenging activity, was further evaluated for protective effect against oxidative stress-induced cell death, intracellular reactive oxygen species levels, the phosphorylation of DNA damage mediating genes such as H2AX, checkpoint kinase 1 and 2, and p53 and the activation of apoptotic genes such as cleaved caspase-3 and 7 and poly (ADP-ribose) polymerase in HaCaT cells. The Daeyang and Choyang oat 80% ethanol extracts had 26.9 and 24.1 mg/100 g γ-oryzanols, 7.69 and 8.38 mg/100 g α-tocotrienol, 1.25 and 0.34 mg/100 g of lutein and 1.20 and 0.17 mg/100 g of zeaxanthin, respectively. The oat 80% ethanol extract treatment (Avena sativa cv. Daeyang) had a protective effect on oxidative stress-induced cell death in HaCaT cells. In addition, the oat 80% ethanol extracts led to a significant decrease in the intracellular ROS level at a concentration of 50–200 μg/mL, the attenuation of DNA damage mediating genes and the inhibition of apoptotic caspase activities in a dose dependent manner (50–200 μg/mL). Thus, the current study indicates that an oat (Avena sativa cv. Daeyang) extract rich in antioxidants, such as polyphenols, avenanthramides, γ-oryzanols, tocotrienols and carotenoids, has a protective role against oxidative stress-induced keratinocyte injuries and that oat may a useful source for oxidative stress-associated skin damage.     

Yield,Characterization, and Possible Exploitation of Cannabis Sativa L. Roots Grown under Aeroponics Cultivation

Cannabis sativa L. has been used for a long time to obtain food, fiber, and as a medicinal and psychoactive plant. Today, the nutraceutical potential of C. sativa is being increasingly reappraised; however, C. sativa roots remain poorly studied, despite citations in the scientific literature. In this direction, we identified and quantified the presence of valuable bioactives (namely, β-sitosterol, stigmasterol, campesterol, friedelin, and epi-friedelanol) in the root extracts of C. sativa, a finding which might pave the way to the exploitation of the therapeutic potential of all parts of the C. sativa plant. To facilitate root harvesting and processing, aeroponic (AP) and aeroponic-elicited cultures (AEP) were established and compared to soil-cultivated plants (SP). Interestingly, considerably increased plant growth—particularly of the roots—and a significant increase (up to 20-fold in the case of β-sitosterol) in the total content of the aforementioned roots’ bioactive molecules were observed in AP and AEP. In conclusion, aeroponics, an easy, standardized, contaminant-free cultivation technique, facilitates the harvesting/processing of roots along with a greater production of their secondary bioactive metabolites, which could be utilized in the formulation of health-promoting and health-care products.     

Biotechnological Approaches on Two High CBD and CBG Cannabis sativa L. (Cannabaceae) Varieties: In Vitro Regeneration and Phytochemical Consistency Evaluation of Micropropagated Plants Using Quantitative 1H-NMR

High cannabidiol (CBD) and cannabigerol (CBG) varieties of Cannabis sativa L., a species with medicinal properties, were regenerated in vitro. Explants of nodal segments including healthy axillary bud, after sterilization, were placed in Murashige-Skoog (MS) culture medium. The shoots formed after 30 days were subcultured in full- or half-strength MS medium supplemented with several concentrations of 6-benzyl-amino-purine (BA) or thidiazuron (TDZ). The highest average number and length of shoots was achieved when both full and half-strength MS media were supplemented with 4.0 μM BA. The presence of 4.0 μM TDZ showed also comparable results. BA and TDZ at concentrations of 4.0, 8.0 μM and 2.0, 4.0 μM respectively, displayed the maximum shooting frequency. The new shoots were transferred on the same media and were either self-rooted or after being enhanced with different concentrations of indole-3-butyric acid (IBA) or α-naphthalene acetic acid (NAA). Presence of 2.0 or 4.0 μM IBA or 4.0 μM NAA resulted to the optimum rooting rates. The maximum average number and length of roots per shoot was observed when the culture media was supplemented with 4.0 μM IBA or NAA. Approximately 92% of the plantlets were successfully established and acclimatized in field. The consistency of the chemical profile of the acclimatized in vitro propagated clones was assessed using quantitative ¹H-NMR high throughput screening. In each variety, analysis of the micropropagated plant in comparison with the mother plant showed no statistically significant differences (p ≤ 0.05) in CBD+ cannabidiolic acid (CBDA) and CBG+ cannabigerolic acid (CBGA) content respectively, thus indicating stability of their chemical profile.     

Chemical Composition and Biological Activities of Essential Oils from the Leaves,Stems, and Roots of Kadsura coccinea

The chemical composition and biological activities of the essential oils from the leaves, stems, and roots of Kadsura coccinea (K. coccinea) were investigated. The essential oils were extracted by hydro distillation and analyzed by gas chromatography mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID). Antioxidant activities of the essential oils were examined with DPPH radical scavenging assay, ABTS cation radical scavenging assay, and ferric reducing antioxidant power assay. Antimicrobial activities were evaluated by determining minimum inhibitory concentrations (MIC) and minimum microbiocidal concentrations (MMC). Acetylcholinesterase and butyrylcholinesterase inhibitory activity of the essential oils were also tested. A total of 46, 44, and 47 components were identified in the leaf, stem, and root oils, representing 95.66%, 97.35%, and 92.72% of total composition, respectively. The major compounds of three essential oils were α-pinene (16.60–42.02%), β-pinene (10.03–18.82%), camphene (1.56–10.95%), borneol (0.50–7.71%), δ-cadinene (1.52–7.06%), and β-elemene (1.86–4.45%). The essential oils were found to have weak antioxidant activities and cholinesterase inhibition activities. The essential oils showed more inhibitory effects against Staphylococcus aureus (S. aureus) than those of other strains. The highest antimicrobial activity was observed in the root oil against S. aureus, with MIC of 0.78 mg/mL. Therefore, K. coccinea essential oils might be considered as a natural antibacterial agent against S. aureus with potential application in food and pharmaceutical industries.     

A QuEChERS-HPLC-MS/MS Method with Matrix Matching Calibration Strategy for Determination of Imidacloprid and Its Metabolites in Procambarus clarkii (Crayfish) Tissues

We developed a method for determination of imidacloprid and its metabolites 5-hydroxy imidacloprid, olefin imidacloprid, imidacloprid urea and 6-chloronicotinic acid in Procambarus clarkii (crayfish) tissues using quick, easy, cheap, effective, rugged, and safe (QuEChERS) and high-performance liquid chromatography-triple quadrupole mass spectrometry. Samples (plasma, cephalothorax, hepatopancrea, gill, intestine, and muscle) were extracted with acetonitrile containing 0.1% acetic acid and cleaned up using a neutral alumina column containing a primary secondary amine. The prepared samples were separated using reverse phase chromatography and scanned in the positive and negative ion multiple reaction-monitoring modes. Under the optimum experimental conditions, spiked recoveries for these compounds in P. clarkii samples ranged from 80.6 to 112.7% with relative standard deviations of 4.2 to 12.6%. The limits of detection were 0.02–0.5 μg·L⁻¹, the limits of quantification were 0.05–2.0 μg·L⁻¹ and the method of quantification was 0.05–2.0 μg·kg⁻¹. The method is rapid, simple, sensitive and suitable for rapid determination and analysis of imidacloprid and its metabolites in P. clarkii tissues.     

VOCs Analysis of Three Different Cultivars of Watermelon (Citrullus lanatus L.) Whole Dietary Fiber

In this study, the trend of VOCs of dietary fiber samples, coming from three different watermelon cultivars Citrullus lanatus L. (variety Gavina^®®, Crimson Sweet, and Asahi Miyako) was investigated. This foodstuff, obtained as a by-product of residual agri-food production, has gained increasing attention because of its many bioactive components and high dietary fiber content. The result is a fibrous material for specific applications in food manufacturing, such as corrector for some functional and technological properties. In this study, a method based on headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC–MS) was used to characterize the aromatic profiles of the dried raw materials. Therefore, the VOCs of the samples of the three cultivars were investigated. Experimental results have shown that watermelon fibers generate VOCs, which can be grouped into six common classes of analytes. The different distributions of the identified compounds made it possible to effectively differentiate the three cultivars studied based on their peculiar aroma profiles. In particular, Gavina^®® fiber is distinguished by the high content of terpenes, Asahi Miyako by the presence of aldehydes generated as fatty acid metabolites, and Crimson Sweet by the higher content of acetyl esters.     

Chemotaxonomic Identification of Key Taste and Nutritional Components in ‘Shushanggan Apricot’ Fruits by Widely Targeted Metabolomics

The chemotypic and the content variation in taste substances and nutrients in ‘Shushanggan apricot’ fruits were detected by UPLC-MS/MS. A total of 592 compounds were identified, of which sucrose contributed mainly to the sweet taste and malic acid and citric acid were important organic acids affecting sweet–sour taste. γ-linolenic acid, α-linolenic acid and linoleic acid were the dominant free fatty acids, and neochlorogenic acid and chlorogenic acid were the predominant phenolic acids. Fruit taste was positively correlated with sucrose and negatively correlated with malic acid and citric acid. The differential metabolites were significantly enriched in the biosynthesis of amino acids and 2-oxocarboxylic acid metabolism pathways, regulating the sugar and organic acid biosynthesis. Taste and nutrient differences could be revealed by variations in composition and abundance of carbohydrates, organic acids and amino acids. The purpose of this study was to provide a comprehensive chemical characterization of taste and nutrient compounds in ‘Shushanggan apricot’ fruits.     

The Allelopathic Activity of Extracts and Isolated from Spirulina platensis

We determined the allelopathic effects of crude organic (hexane, ethyl acetate, and methanol) extracts of the cyanobacterial Spirulina platensis on barnyardgrass (Echinochloa crus-galli (L.) Beauv.) and Chinese amaranth (Amaranthus tricolor L.). The crude ethyl acetate extract showed the highest inhibitory activity and was subsequently fractionated by column chromatography into 23 fractions based on thin-layer chromatography band pattern similarities. Four concentrations (2000, 1000, 500, and 250 ppm) of each fraction were tested for their allelopathic activity. Fractions E6 and E13 exhibited the most significant inhibitory effects against Chinese amaranth. The constituents of the highly active E6F3-E6F5 fractions determined by GC-MS, chromatography, and spectroscopy included the fatty acids, γ-linolenic acid 15, oleic acid 12, and predominantly palmitic acid 7; minor constituents included 2-ethyl-3-methylmaleimide 9 and C₁₁ norisoprenoids (dihydroactinidiolide 10 and 4-oxo-β-ionone 13). Isolation of E13 fraction by column chromatography revealed four C₁₃ norisoprenoids: 3-hydroxy-β-ionone 17, 3-hydroxy-5α,6α-epoxy-β-ionone 18, 3-hydroxy-5β,6β-epoxy-β-ionone 19, and loliolide 20. Their structures were elucidated by NMR spectroscopy. All six isolated norisoprenoids inhibited seed germination and seedling growth of Chinese amaranth at concentrations of 250–1000 ppm. Allelochemicals from S. platensis could be utilized in the development of novel bioactive herbicides.