Natural Product Research最新文献

Leishmaniasis affects millions of people in tropical and subtropical regions. Currently, only a few medications are available for its treatment, many of which cause adverse effects. Therefore, the development of effective, and safer drugs is urgently needed. Leishmania major Pteridine reductase-1 (LmPTR-1) is a vital enzyme for parasite survival, and thus serves as a valid drug target. Our investigation on the ethanolic extract of Tussilago farfara L. resulted in the isolation of twenty known phenolic compounds 1-20. Among them, vanillic acid (1), 1S,3R,4R,5R)-3,5-di-O-caffeoylquinic acid (14), and 3,4,5-tri-O-caffeoylquinic acid methyl ester (20) are first time reported here. Compounds (1S,3R,4S,5R)-3,5-di-O-caffeoylquinic acid (15), 3,4-di-O-caffeoylquinic acid (16), 4,5-di-O-caffeoylquinic acid (17), and 3,4-di-O-caffeoylquinic acid methyl ester (18) exhibited LmPTR-1 inhibition with IC₅₀ between 81.9-189.7 μΜ. In silico studies further revealed strong interactions between compounds 15-18, and LmPTR-1 enzyme. In summary, quinic acid derivatives, containing caffeoyl moieties can serve as potential as anti-leishmanial agents.

Sporothrix brasiliensis is the primary cause of sporotrichosis in Brazil. Reports of therapeutic failures with itraconazole treatment exist. We evaluated the antifungal activity of the hydroacetone extract of Psidium guajava in planktonic cells and biofilms of S. brasiliensis. The extract was obtained from the leaves, and high-performance liquid chromatography was performed. Broth microdilution tests were performed according to the CLSI M38. The strains were subjected to biofilm formation, and the antifungal activity of the extract against a strong producer strain was determined. The extract inhibited planktonic cells with minimum inhibitory concentrations (MICs) of ≤ 2 to 8 µg/mL. The metabolic activity of the strain with strong biofilm formation was inhibited with MICs of 16 and 32 µg/mL. The anti-Sporothrix activity of the hydroacetone extract of P. guajava serves as a basis for future studies for developing new drugs for the treatment of sporotrichosis.

Although mangroves have been utilised for traditional and natural remedies, their pharmacological and medicinal benefits have yet to be fully elucidated. As mangroves are exposed to challenging growing conditions, they are endowed with a profusion of phytochemicals that offer a range of therapeutic benefits. Mangroves possess an abundance of alkaloids, flavonoids, phenolics, terpenoids, and numerous other active secondary metabolites, contributing to a wide array of medicinal attributes, including anti-inflammatory, antibacterial, anti-tumour, and anticancer effects. Therefore, mangroves may represent a promising source of natural chemotherapeutic agents for cancer therapy. This review highlights the relationships between mangroves' bioactivity and geographical, environmental, and extraction factors, as well as the challenges that hinder their clinical translation as a potential source of pharmaceutically significant drugs.

One new caffeoylquinic acid derivative, daphnequinic acid (1), along with six known analogues (2-7), were isolated from Daphne gemmata. The new caffeoylquinic acid was elucidated through interpretation of comprehensive NMR spectral data, in combination with a quantum chemical calculations ECD analysis. Compounds 1-7 were evaluated for their antimicrobial activities against E. coli, S. aureus, S. enterica, and P. aeruginosa. The antibacterial activity assay demonstrated that compounds 3, 6, and 7 exhibited moderate antibacterial activity against S. aureus, with minimum inhibitory concentration (IC₅₀) values of (41.97 ± 0.16) μM, (23.35 ± 0.32) μM, and (18.91 ± 1.55) μM, respectively.

Two undescribed biphenyl cyclooctene lignans, Schisandrin H (1) and Schisandrin S (2), and two known compounds (3) and (4), were extracted from fruits of Schisandra grandiflora. Structural elucidation was achieved through integrated UV, HRESIMS, NMR, ECD and ORD data analysis. At 1 μmol/L, inhibition of LPS-induced NO production in RAW264.7 macrophages was 28.85 ± 4.60% (compound 2), 8.36 ± 5.33% (3), 16.72 ± 4.42% (4) and 38.25 ± 2.54% for dexamethasone (positive control), relative to the model group. Additionally, all compounds were evaluated for in vitro anti-oxidant activity using DPPH and ABTS⁺ radical scavenging methods. Compounds 2 and 4 showed appreciable ABTS⁺ scavenging activity, with activity levels comparable to VC at higher concentrations.

Depression is a prevalent and debilitating mental illness with a persistent sense of hopelessness and a lack of enthusiasm for day-to-day activities. Curcumin has garnered attention due to its putative antidepressant properties as well as its neuroprotective, anti-inflammatory, and antioxidant properties. Pro-inflammatory cytokines have been found to increase the intensity of depressed symptoms, and recent investigations have demonstrated the important role that neuroinflammation plays in the development and maintenance of depression. This review explored the neuroinflammatory mechanisms associated with depression. It elucidated the multifaceted actions of curcumin, including inhibition of the NLRP3 inflammasome, modulation of the kynurenine pathway, and reduction of inflammatory markers in the brain. Evidence from clinical trials and meta-analyses suggests that curcumin can significantly alleviate depressive symptoms, making it a promising adjunctive treatment for major depressive disorder. By addressing the underlying neuroinflammatory processes, curcumin offers a novel approach that could improve patient outcomes in managing depression.

Chemical investigation of Cannabis sativa roots led us to the isolation of three phenolic compounds, namely p-coumaric acid methyl ester (1), N-p-coumaroyltyramine (2) and N-p-coumaroyloctopamine (3). Among the isolated phenolics, 3 was the first report from cannabis roots. To perform a structure-activity relationship study a series of cinnamide analogs were synthesised and tested using the zebrafish larval behavioural model. Increased locomotor activities were observed for 3 and some synthetic cinnamide analogues during the first 50 min following exposures at a 30 µM concentration. The zebrafish larval behaviour effects of these cinnamides differ from those of the two principal cannabinoids of C. sativa, cannabidiol and Δ⁹-tetrahydrocannabinol, which were well studied for their medicinal applications. The structure-activity relationship study clearly demonstrates the amide or ester bond is essential for such activity, as none of the free cinnamic acid derivatives tested showed zebrafish behaviour activity as compared to the control group.

Tuberculosis (TB) remains a leading global cause of infectious disease-related mortality, further complicated by the emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains.This study investigates the therapeutic potential of Orobanche ramosa L. (broomrape), a parasitic plant traditionally used in ethnomedicine for respiratory disorders, marking the first evaluation of its antimycobacterial activity. Various extracts were prepared using solvents such as hexane, methanol, and dichloromethane, and tested against M. tuberculosis H37Rv using the Microplate Alamar Blue Assay (MABA).Complementary analyses included ABTS radical scavenging assays for antioxidant capacity and LC-MS/MS for identifying bioactive phenolic profiles. The results demonstrated that ethanol, methanol, and dichloromethane extracts possessed the strongest antimycobacterial activity, each yielding MIC values of 125 µg/mL. Furthermore, methanol and DMSO extracts exhibited the highest antioxidant potency (IC50 values of 5.6 and 5.4 µg/mL) and total phenolic content. LC-MS/MS analysis identified several key bioactive compounds, including luteolin, kaempferol, resveratrol, and protocatechuic acid.These findings provide scientific evidence supporting the traditional medicinal use of O. ramosa and highlight its potential as a significant natural source for developing novel agents to combat tuberculosis.

Phytochemical investigation of the flowers of Sphaerocoryne lefevrei (Baill.) D.M.Johnson & N.A.Murray led to the isolation of thirteen compounds. They consist of one previously undescribed heptenoid, namely 7-benzoyloxy-4-hydroxy-1-ethoxy-(2E,4Z)-heptadiene-1,6-dione (1), one simple benzenoid isolated for the first time from a natural source, namely 2-oxopropyl benzoate (2), and eleven known compounds. The isolated compounds were identified by thorough analysis of spectroscopic (UV, IR and NMR) and spectrometric (HRESIMS) data. The previously undescribed compound 1 and four known compounds were tested in vitro for anti-proliferative and anti-inflammatory activities. Compound 7 showed potent activity against the HeLa cell line (IC₅₀ = 4.7 µM), while compound 8 displayed moderate activity against the KB cell line (IC₅₀ = 30.7 µM). The latter also showed a moderate NO inhibitory effect in LPS-induced macrophage RAW 264.7 (IC₅₀ = 51.3 µM). This work is the first phytochemical investigation of S. lefevrei.

Two undescribed dihydro-β-agarofuran sesquiterpene polyesters, named tripterysines H (1) and I (2), were obtained from Tripterygium wilfordii roots, alongside five reported analogues (3-7). The chemical structures of two undescribed compounds were unambiguously assigned by comprehensive analysis of their NMR data in combination with HRESIMS results, and the absolute configurations of them were established via electronic circular dichroism (ECD) calculations. In addition, compounds 1 and 3 demonstrated potent cytotoxicity against SK-MEL-2 and HCC1806 cell lines (IC₅₀ 4.59-8.14 μM), with potency comparable to the positive control.