Profiling the Lipophilic Fractions of Pithecellobium dulce Bark and Leaves Using GC/MS and Evaluation of Their Antioxidant, Antimicrobial and Cytotoxic Activities

Valorization of Citrus peels: GC/MS-based metabolites profiling, multivariate analysis, and antiaging potential

Aging and agro-waste are major challenges. Natural ingredients are preferred in skincare. This study intended to isolate the essential oils (EO) from the leftover peels obtained from three commonly edible Citrus species fruit peels, namely Citrus paradisi (grapefruit), Citrus sinensis (sweet orange), and Citrus deliciosa (mandarin). Gas chromatography/mass spectrometry analysis identified volatile constituents in EO and headspace aroma. Multivariate analysis distinguished between the three species. The antiaging effects of Citrus EO were assessed in vitro and in silico, studying volatile interactions with target enzymes. C. sinensis peels had the highest oil yield, rich in monoterpenes. C. paradisi and C. deliciosa contained sesquiterpenes. Limonene dominated the hydrodistilled EO: 94.50% in C. paradisi, 96.80% in C. sinensis, and 80.66% in C. deliciosa. Unsupervised multivariate analysis of Citrus species revealed that  d-limonene, γ-terpinene, and β-pinene are the key phytochemical markers contributing to their diverse chemical composition. C. paradisi exhibited the highest enzyme inhibitory activity, with IC50 values of 12.82, 27.58, and 18.16 µg/mL for tyrosinase, elastase, and collagenase, respectively. In silico studies showed that the volatiles can inhibit the tested antiaging enzymes. According to these findings, the investigated agro-waste might slow aging in skin care.

The impact of seasonal variation on the composition of the volatile oil of Polyalthia suberosa (Roxb.) Thwaites leaves and evaluation of its acetylcholinesterase inhibitory activity

BACKGROUND

Polyalthia suberosa (Roxb.) Thwaites (Annonaceae) is a medicinal plant that has been reported for its various pharmacological potentials, such as its anti-inflammatory, analgesic, antioxidant, and neuropharmacological activities. This study aimed to analyze the leaf essential oils of P. suberosa (PSLO) collected in different seasons, to evaluate the acetylcholinesterase inhibitory activity, and to corroborate the obtained results via in-silico molecular docking studies.

METHODS

The leaf essential oils of P. suberosa collected in different seasons were analyzed separately by GC/MS. The acetylcholinesterase inhibitory activity of the leaves oil was assessed via colorimetric assay. In-silico molecular docking studies were elucidated by virtual docking of the main compounds identified in P. suberosa leaf essential oil to the active sites in human acetylcholinesterase crystal structure.

RESULTS

A total of 125 compounds were identified where D-limonene (0.07 - 24.7%), α-copaene (2.25 - 15.49%), E-β-caryophyllene (5.17 - 14.42%), 24-noroleana-3,12-diene (12.92%), β-pinene (0.14 - 8.59%), and α-humulene (2.49-6.9%) were the most abundant components. Results showed a noteworthy influence of the collection season on the chemical composition and yield of the volatile oils. The tested oil adequately inhibited acetylcholinesterase enzyme with an IC50 value of 91.94 µg/mL. Additionally, in-silico molecular docking unveiled that palmitic acid, phytol, p-cymene, and caryophyllene oxide demonstrated the highest fitting scores within the active sites of human acetylcholinesterase enzyme.

CONCLUSIONS

From these findings, it is concluded that P. suberosa leaf oil should be evaluated as a food supplement for enhancing memory.

Phytochemical analysis of Pithecellobium dulce (Roxb) Benth Bark via UPLC-ESI-MS/MS and evaluation of its biological activity

The metabolites profile of Egyptian P. dulce bark was investigated using UPLC-ESI-MS/MS analysis with subsequent analysis of its cytotoxicity, antimicrobial, and antioxidant activities. Asides, in silico molecular docking study was performed for validation of cytotoxicity. P. dulce bark showed richness in polyphenolics and flavonoids, displaying 575.5 mg GAE/g extract (total phenolic content) and 310.82 mg CE/g extract (flavonoid content). A total of 29 compounds were tentatively identified. Proanthocyanidins and phenolic acids were the major classes observed. P. dulce bark possessed promising antioxidant and cytotoxic activities, however, it exhibited a weak antimicrobial activity. No antifungal activity was observed. In silico molecular docking revealed that daidzein compound achieved the best interaction energy score on the 5II2 of Gibbs free energy of -6.911 kcal/mol. This study revealed that P. dulce bark can be introduced as a potential source for valuable bioactive compounds that supporting its usage in food and pharmaceutical industries.

Analysis of Marrubiin in Marrubium alysson L. Extract Using Advanced HPTLC: Chemical Profiling, Acetylcholinesterase Inhibitory Activity, and Molecular Docking

The main purpose of this work is to investigate the phytochemical composition of Marrubium alysson L. non-polar fraction. GC/MS analysis was used to evaluate the plant extract's saponifiable and unsaponifiable matter. Although M. alysson L. lipoidal matter saponification produced 30.3% of fatty acid methyl esters and 69.7% of unsaponifiable matter. Phytol was the most dominant substance in the unsaponifiable materials. Notably, marrubiin which is one of the most prominent metabolites of Marrubium alysson L. was not detected through our adopted GC/MS technique. Thus, further characterization was proceeded through simple and rapid HPTLC analysis which successfully managed to identify marrubiin. Based on the regression equation, the concentration of marrubiin in M. alysson L. extract was 14.09 mg/g of dry extract. Concerning acetylcholinesterase inhibitory activity, both the crude M. alysson L. total methanolic extract and the non-polar fraction displayed reasonable inhibitory activity against acetylcholinesterase (AChE), whereas the pure compound marrubiin was considered to be the most effective and potent AChE inhibitor, with an IC50 value of 52.66 (µM). According to the molecular docking studies, potential sites of interaction between the pure chemical marrubiin and AChE were examined. The results show that Tyr124 on AChE residue was critical to the activity of the aforementioned drug. Based on the depicted marrubin AChE inhibition activity and reported safety profile, this chemical metabolite is considered as a promising lead compound for further pre-clinical investigation as well as drug development and optimization.

Valorization of Pimenta racemosa Essential Oils and Extracts: GC-MS and LC-MS Phytochemical Profiling and Evaluation of Helicobacter pylori Inhibitory Activity

Pimenta racemosa is a commonly known spice used in traditional medicine to treat several ailments. In this study, comprehensive phytochemical profiling of the essential oils and methanol extracts of P. racemosa leaves and stems was performed, alongside assessing their potential Helicobacter pylori inhibitory activity in vitro and in silico. The essential oils were chemically profiled via GC-MS. Moreover, the methanol extracts were profiled using HPLC-PDA-ESI-MS/MS. The antibacterial activity of the essential oils and methanol extracts against H. pylori was determined by adopting the micro-well dilution method. GC-MS analysis unveiled the presence of 21 constituents, where eugenol represented the major component (57.84%) and (59.76%) in both leaves and stems of essential oils, respectively. A total of 61 compounds were annotated in both leaves and stems of P. racemosa methanolic extracts displaying richness in phenolic compounds identified as (epi)catechin and (epi)gallocatechin monomers and proanthocyanidins, hydrolyzable tannin derivatives (gallotannins), flavonoids, and phenolic acids. The stem essential oil showed the most promising inhibitory effects on H. pylori, exhibiting an MIC value of 3.9 µg/mL, comparable to clarithromycin with an MIC value of 1.95 µg/mL. Additionally, in silico molecular modeling studies revealed that decanal, eugenol, terpineol, delta-cadinene, and amyl vinyl showed potential inhibitory activity on H. pylori urease as demonstrated by high-fitting scores indicating good binding to the active sites. These findings indicate that P. racemosa comprises valuable phytochemical constituents with promising therapeutic effects, particularly the stem, an economic agro-industrial waste.

GC-MS profiling of Vitex pinnata bark lipophilic extract and screening of its anti-TB and cytotoxic activities

Tuberculosis is a highly infectious ailment worldwide. The emergence of multi-drug resistance and serious adverse effects of anti-TB drugs have led to the continuous search of natural candidates. This study aimed to analyse the chemical profile of Vitex pinnata (VP) bark lipophilic extract using GC-MS also evaluating its anti-TB and cytotoxic activities. GC-MS revealed a total of 81 compounds which representing 86% identified compounds. In vitro anti-TB of VP lipophilic extract was evaluated using the Microplate Alamar Blue Assay which exhibited MIC value of 62.5 µg/mL. In vitro cytotoxicity was evaluated using Water Soluble formazan assay recording IC₅₀ > 100 and 200 µg/mL using Vero and A-549 cell lines, respectively. In silico docking study was performed on the major identified compounds, n-nonane showed the most favourable binding affinity (ΔG) equals to -33.34 Kcal/mol. The results obtained herein unravelled the potential use of VP n-hexane extract as a natural anti-TB.

Phytochemical discrimination of Pinus species based on GC-MS and ATR-IR analyses and their impact on Helicobacter pylori

INTRODUCTION

The leaves and cones of Pinus plants as well as their essential oils have been used in traditional medicine for the treatment of several ailments.

OBJECTIVES

Phytochemical discrimination of Pinus species and investigation of their anti-Helicobacter pylori activity in vitro and in silico.

MATERIALS AND METHODS

Gas chromatography-mass spectrometry (GC-MS) and attenuated total reflectance infrared (ATR-IR) metabolic profiling of the essential oils of Pinus species. Principal component analysis (PCA) and hierarchal cluster analysis (HCA) were applied for discrimination and segregation of Pinus species.

RESULTS

GC-MS revealed the presence of 76 constituents, where monoterpenes represented the major class with the dominance of α-pinene (72%) followed by β-pinene (16%) for P. canariensis. β-Pinene was the dominant component in P. pinea (24%) followed by terpinolene (11%). α-Pinene (17%) and caryophyllene (12%) were the major components in P. halepensis, while, 3-carene (33%) and α-pinene (17%) represented the major constituents of P. roxburghii oil. By applying PCA and HCA on GC-MS and ATR-IR data analysis, ATR-IR displayed much better discrimination for Pinus species. The pine oils showed promising inhibitory effects on Helicobacter pylori. Furthermore, in silico molecular modelling was carried out where the calculated free binding energies of phytochemicals identified ranged from -33.71 to -19.67 kcal/mol for urease and -41.18 to -16.57 kcal/mol for shikimate kinase. This suggests favourable binding of pine essential oil components to both enzymes, thus explaining their potential inhibitory activity on H. pylori.

CONCLUSION

GC-MS and ATR-IR based metabolic analyses could discriminate between Pinus species. Pine essential oils can be used as promising therapeutic drugs to protect against H. pylori infection.

Anti-Allergic, Anti-Inflammatory and Anti-Hyperglycemic Activity of Chasmanthe aethiopica Leaf Extract and Its Profiling Using LC/MS and GLC/MS

This study aims to comprehensively explore the phytoconstituents as well as investigate the different biological activities of Chasmanthe aethiopica (Iridaceae) for the first time. Metabolic profiling of the leaf methanol extract of C. aethiopica (CAL) was carried out using HPLC-PDA-ESI-MS/MS. Twenty-nine compounds were annotated belonging to various phytochemical classes including organic acids, cinnamic acid derivatives, flavonoids, isoflavonoids, and fatty acids. Myricetin-3-O-rhamnoside was the major compound identified. GLC/MS analysis of the n-hexane fraction (CAL-A) resulted in the identification of 45 compounds with palmitic acid (16.08%) and methyl hexadecanoic acid ester (11.91%) representing the major constituents. CAL-A exhibited a potent anti-allergic activity as evidenced by its potent inhibition of β-hexosaminidase release triggered by A23187 and IgE by 72.7% and 48.7%, respectively. Results were comparable to that of dexamethasone (10 nM) in the A23187 degranulation assay showing 80.7% inhibition for β-hexosaminidase release. Both the n-hexane (CAL-A) and dichloromethane (CAL-B) fractions exhibited potent anti-inflammatory activity manifested by the significant inhibition of superoxide anion generation and prohibition of elastase release. CAL showed anti-hyperglycemic activity in vivo using streptozotocin-induced diabetic rat model by reducing fasting blood glucose levels (FBG) by 53.44% as compared with STZ-treated rats along with a substantial increase in serum insulin by 22.22%. Molecular modeling studies indicated that dicaffeoylquinic acid showed the highest fitting with free binding energies (∆G) of -47.24 and -60.50 Kcal/mol for human α-amylase and α-glucosidase, respectively confirming its anti-hyperglycemic activity. Thus, C. aethiopica leaf extract could serve as an effective antioxidant natural remedy combating inflammation, allergy, and hyperglycemia.