Seasonal Changes in the Metabolic Profiles and Biological Activity in Leaves of Diospyros digyna and D. rekoi "Zapote" Trees

Triterpenoids from the Leaves of Diospyros digyna and Their PTP1B Inhibitory Activity

Six new 2α-hydroxy ursane triterpenoids, 3α-cis-p-coumaroyloxy-2α,19α-dihydroxy-12-ursen-28-oic acid (1), 3α-trans-p-coumaroyloxy-2α,19α-dihydroxy-12-ursen-28-oic acid (2), 3α-trans-p-coumaroyloxy-2α-hydroxy-12-ursen-28-oic acid (3), 3β-trans-p-coumaroyloxy-2α-hydroxy-12,20(30)-ursadien-28-oic acid (4), 3β-trans-feruloyloxy-2α-hydroxy-12,20(30)-ursadien-28-oic acid (5), and 3α-trans-feruloyloxy-2α-hydroxy-12,20(30)-ursadien-28-oic acid (6), along with eleven known triterpenoids (7-17), were isolated from the leaves of Diospyros digyna. Their chemical structures were elucidated by comprehensive analysis of UV, IR, HRESIMS, and NMR spectra. All the isolated compounds were evaluated for their PTP1B inhibitory activity. 3β-O-trans-feruloyl-2α-hydroxy-urs-12-en-28-oic acid (13) showed the best inhibition activity with an IC50 value of 10.32 ± 1.21 μM. The molecular docking study found that the binding affinity of compound 13 for PTP1B was comparable to that of oleanolic acid (positive control).

Larvicidal Activity against Spodoptera frugiperda of some Constituents from two Diospyros Species. In silico Pesticide-likeness Properties, Acetylcholinesterase Activity and Molecular Docking

This report informs for the first time the chemical constituents of Diospyros xolocotzii and Diospyros digyna, the pesticidal and the acetylcholinesterase (AChE) inhibition potential of some compounds calculated by in silico approaches, the larvicidal activity against Spodoptera frugiperda of available compounds, the AChE inhibition of selected compounds, and the results of the molecular docking of the most active ones with this receptor. From the aerial parts of D. xolocotzii were isolated pentacyclic triterpenes (1-4, 6, 10, 11-13), phytosterols (15-17), and isodiospyrin (18), whereas the analysis of aerial parts of D. digyna conducted to the isolation of pentacyclic triterpenes (4, 5, 7-9, 11-14), (4S)-shinanolone (19), and scopoletin (20). For comparison purposes, origanal (21) was chemically prepared from 11. The in silico analysis showed that the tested compounds have pesticide potential. The larvicidal activities of 11>13>12 indicated that the increase of the oxidation degree at C-28 increases their bioactivity. Compounds 11 and 21 presented the higher inhibition in the acetylcholinesterase assay, and the higher binding energies, and for the interactionswith AChE by molecular docking. Both Diospyros species are sources of triterpenes with pesticidal potential and the molecular changes in lupane triterpenes correlate with the observed bioactivity and molecular docking.

Plant Extracts Control In Vitro Growth of Disease-Causing Fungi in Chayote

The use of agrochemicals has caused environmental problems and toxicity to humans, so natural alternatives for disease control during harvest and postharvest have been evaluated. The aim of this study was to evaluate cinnamon essential oil, neem oil, and black sapote fruit extract for in vitro inhibition of fungi isolated from chayote fruit. The extracts were applied at 300, 350, and 400 ppm in Petri dishes and the mycelial growth of Fusarium oxysporum, Fusarium solani, Goetrichum sp., and Phytophthora capsici was evaluated for 7 days, and the percentage of mycelial growth inhibition per day was calculated. Cinnamon oil showed a fungicidal effect at all concentrations. Neem oil at 400 ppm showed a 42.3% reduction in the growth of F. solani and 27.8% reduction in the growth of F. oxysporum, while at 350 ppm it inhibited the mycelial growth of Phytophthora capsici by 53.3% and of Goetrichum sp. by 20.9%; finally, the black sapote extract at 400 ppm inhibited 21.9-28.6% of the growth of all fungi. The growth of postharvest fungi on chayote fruit could be prevented or reduced by applying the plant extracts evaluated at adequate concentrations.

Influence of seasonal and geographic variation on the anti-HSV-1 properties and chlorogenic acids content of Helichrysum aureonitens Sch. Bip

Pharmacological studies conducted in the past revealed the potential source of medicinal plants in the development of novel medicines. The phenolic contents of medicinal plants containing chlorogenic acids (CGA) have been linked to a variety of therapeutic effects, especially antiviral activity. Helichrysum aureonitens is a medicinal plant which has been reported to contain chlorogenic acids compounds and has also shown antiviral activities against a number of virus species including Herpes Simplex Virus-1 (HSV-1). In this study, the aim was to determine both the influence of seasonal variation and locality on the antiviral properties of H. aureonitens. Since chlorogenic acids have been reported as potent antiviral compounds, these compounds were targeted to determine the effects of locality and seasonal change on the chlorogenic acid profile, and subsequent antiviral activity. The ultra-performance liquid chromatography-quadrupole time-of-flight mass spectroscopy (UPLC-qTOF-MS) was employed to determine the metabolic profile variations of three derivatives of chlorogenic acids-caffeoylquinic acid (CQA), dicaffeoylquinic acid (DCQA) and tricaffeoylquinic acid (TCQA) in the harvested plants growing in two diverse geographical climates and two different seasons (spring and autumn). Using the cytopathic effect (CPE) reduction approach, twenty-six samples of the plants’ leaves and stems collected during spring and autumn at Telperion nature reserve in Mpumalanga and Wakefield farm, Midlands in KwaZulu-Natal region of South Africa were evaluated for anti-HSV activity. The MTT assay was used for the cytotoxicity evaluation of the extracts prior to antiviral determination. Seventeen (mostly spring collections) of the twenty-six extracts examined were found to have considerable anti-HSV activity as measured by a reduction in tissue culture infectious dose (TCID₅₀) of less than 10⁵. The UPLC-qTOF-MS result revealed that dicaffeoylquinic acid (DCQA) is the most abundant, with higher concentrations in both regions and seasons. 3-CQA was also shown to be the most abundant isomer of caffeoylquinic acid in this investigation.

Seasonal Variation in Selected Biochemical Traits in the Leaves of Co-Occurring Invasive and Native Plant Species under Mediterranean Conditions

The success of invasive alien species (IAS) is often linked to differences in functional traits in relation to other, either native or non-invasive, species. Two of the most problematic IAS in the Mediterranean area belong to Hakea and Acacia genera that often invade pine plantations. Therefore, the aim of this study was to assess the seasonal variations in photosynthetic pigments, total phenolics, and non-structural carbohydrates (NSC), including total soluble sugars (SS) and starch (St), and lipid peroxidation, in terms of malondialdehyde (MDA) in the leaves of evergreen species, two IAS (Hakea sericea and Acacia melanoxylon) and one native (Pinus pinaster), throughout 2019. All parameters showed a pronounced seasonal variability while also differing across species. Generally, the lowest contents of photosynthetic pigments, phenolics and SS were noted in early spring, along with the highest St and NSC values. On the other hand, higher photosynthetic pigment and lower NSC contents were measured in early autumn and early winter. When these parameters were compared across the three species, the IAS had significantly higher content of photosynthetic pigments, mainly chlorophyll b and total chlorophyll, and lower total phenolics and MDA concentrations in their leaves than Pinus pinaster. Differences in seasonal patterns were also observed. Hakea sericea and Acacia melanoxylon had considerably higher chlorophyll, SS and NSC contents in the early autumn, while Pinus pinaster had higher St and MDA contents in early summer. Overall, the biochemical characteristics of leaves of the studied IAS can explain their success in the Mediterranean area, in terms of tolerance to stressful environmental conditions.

Contrasting Metabolic Fingerprints and Seed Protein Profiles of Cucurbita foetidissima and C. radicans Fruits from Feral Plants Sampled in Central Mexico

Cucurbita foetidissima and C. radicans are scarcely studied wild pumpkin species that grow in arid and semi-arid areas of Mexico and the United States. This study describes the morphological, proximal composition, metabolic finger-prints and seed protein profiles of C. foetidissima and C. radicans fruits collected in the wild during a one-year period in different locations of central-western Mexico. The results obtained complement the limited information concerning the fruit composition of C. foetidissima and greatly expand information in this respect regarding C. radicans. Morphology and proximal composition of their fruits varied significantly. Different metabolic fingerprints and seed protein profiles were detected between them and also with the chemical composition of domesticated Cucurbita fruits. The neutral lipids in seed, pulp and peels were rich in wax content and in unsaturated compounds, probably carotenoids and tocopherols, in addition to tri-, di- and mono-acylglycerols. The tri- and diacylglycerol profiles of their seed oils were different from commercial seed oils and between each other. They also showed unusual fatty acid compositions. Evidence of a possible alkaloid in the pulp and peel of both species was obtained in addition to several putative cucurbitacins. An abundance of phenolic acids was found in all fruit parts, whereas flavonoids were only detected in the peels. Unlike most cucurbits, globulins were not the main protein fraction in the seeds of C. radicans, whereas the non-structural carbohydrate and raffinose oligosaccharide content in their fruit parts was lower than in other wild cucurbit species. These results emphasize the significantly different chemical composition of these two marginally studied Cucurbita species, which was more discrepant in C. radicans, despite the notion regarding C. foetidissima as an aberrant species with no affinity to any other Cucurbita species.

Unravelling the Anticancer Mechanisms of Traditional Herbal Medicines with Metabolomics

Metabolite profiling of cancer cells presents many opportunities for anticancer drug discovery. The Chinese, Indian, and African flora, in particular, offers a diverse source of anticancer therapeutics as documented in traditional folklores. In-depth scientific information relating to mechanisms of action, quality control, and safety profile will promote their extensive usage in cancer therapy. Metabolomics may be a more holistic strategy to gain valuable insights into the anticancer mechanisms of action of plants but this has remained largely unexplored. This review, therefore, presents the available metabolomics studies on the anticancer effects of herbal medicines commonly used in Africa and Asia. In addition, we present some scientifically understudied ‘candidate plants’ for cancer metabolomics studies and highlight the relevance of metabolomics in addressing other challenges facing the drug development of anticancer herbs. Finally, we discussed the challenges of using metabolomics to uncover the underlying mechanisms of potential anticancer herbs and the progress made in this regard.