Natural Product Research最新文献

The structural modification of madecassic acid focused on the contraction of the six-membered A-ring to a five-membered ring, combined with the dehydration of 6-OH to form a new double bond and formation of the esterification or amidation at C-28. The synthesised structures were identified based on the analysis of their NMR and EIS-MS data. Eighteen new madecassic acid analogues were tested in vitro for their cytotoxicity against three cancer cell lines, including human mouth carcinoma (KB), human hepatocellular carcinoma (HepG2), and human lung carcinoma (A549) using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. Among them, compounds 5 and 12 exhibited potent and selective cytotoxic activity in KB and HepG2 cell lines, with IC₅₀ values ranging from 3.57 to 6.32 µM. The results also indicated that analogues with a 5-membered A-ring containing an α,β-unsaturated aldehyde esterified at C-23 showed a decrease in their cytotoxic activity compared to precursors in the tested cancer cells.

Cassia nomame, an annual herb belonging to the Leguminosae family, is traditionally consumed as tea in the form of dried whole herbs or beans. To deepen our understanding of the chemical constituents of C. nomame, we isolated 16 compounds, categorised as flavone derivatives (1-4), including a novel compound nomameflavone A (4), a chalcone derivative (5), an aurone derivative (6), a chromone derivative (7), a juglone derivative (8), anthraquinone derivatives (9-11), phenolic compounds (12-14), and sterol derivatives (15, 16). The structure of each compound was elucidated using NMR and MS. Compounds 2, 6, 7, 8, 12, 13, and 14 were successfully isolated from C. nomame for the first time. Furthermore, compounds 1, 3, 5, and 6 exhibited DPPH radical scavenging activities, and the bioactivity of 3 was discovered. The elucidation of the diverse chemical constituents of C. nomame underscores its potential functional ingredients.

This study investigated the allelopathic and phytotoxic effects of Elaeagnus angustifolia flower essential oil (EO) and its major constituents. Forty-one compounds were identified by GC-MS, accounting for 96.93% of the total oil, with the main compounds being ethyl cinnamate and methyl cinnamate. The allelopathic assay of the EO completely suppressed the seed germination of Lolium perenne and Amaranthus retroflexus at 22.22 mg/mL air treatment. Phytotoxic activities of ethyl cinnamate and methyl cinnamate were much stronger than those of the EO against L. perenne, with IC₅₀ values of 0.386, 0.396, and 7.159 mg/mL, respectively. The strength of the phytotoxic activity of the major constituent ethyl cinnamate, and the mixture of ethyl cinnamate and methyl cinnamate was comparable to that of the commercial herbicide glyphosate in terms of suppressing root elongation in A. retroflexus, with IC₅₀ values of 0.049, 0.076, and 0.017 mg/mL, respectively, indicating a possible synergistic effect of the major compounds.

a new benzodioxole derivative 1,3-benzodioxole-2-one-4-N-methylcarboxylamide (1), two new natural products N-(aminocarbonyl)-2,3-dimethoxy-benzamide (2) and 2,3-dimethoxy-N-methylbenzamide (3), along with eight known compounds (4-11), were isolated from the marine-derived Streptomyces sp. SYPHU 0002. The structures of compounds 1-11 were determined through comprehensive spectroscopic analyses, including HRESIMS, 1D and 2D NMR. Compound 9 showed weak antibacterial activity against Bacillus pumilus with the MIC value of 64 μg mL^-1.

The study investigated the antidiabetic, antimicrobial, antioxidant, and genotoxic activities of extracts from Centaurea amanicola and C. antitauri (Asteraceae). Methanol extracts were analysed for phenolic and fatty oil contents. Major components of fatty oils were identified, including methyl hexadecanoate (48.30%) and heptacosane (22.13%) in C. antitauri, and methyl hexadecanoate (16.29%) and methyl linoleate (13.55%) in C. amanicola. The highest α-amylase inhibition was observed in hexane extracts of both species with 55.53% and 41.57% inhibition values, respectively. Antioxidant activity, measured by ABTS^•+ and DPPH^• scavenging, varied among extracts, with notable efficacy in C. antitauri dichloromethane extract and C. amanicola ethyl acetate extract. The dichloromethane extract of C. antitauri demonstrated effectiveness against Candida albicans with MIC= 156.25 µg/mL. Importantly, all extracts were found to be genotoxicity-safe. Overall, the findings highlight the potential of these extracts for various medicinal applications, particularly in managing diabetes and combating microbial infections.

In the course of our ongoing search for biologically active compounds from medicinal plant, the ethyl acetate extract from the leaves of Glycosmis parviflora (Rutaceae) was investigated. Six compounds including a new indole alkaloid, glycosparvine A (1), and five previously known metabolites (2-6) were identified. The structure of the new compound (1) was unambiguously elucidated by spectroscopic analyses, including 1D/2D NMR spectroscopy and HRESIMS. The absolute configuration of 1 was assigned by comparing its experimental ECD spectra with those reported for similar compound in the literature. Compounds 3 and 6 exhibited moderate inhibitory effects against acetylcholinesterase (AChE) with IC₅₀ values of 35.1 and 2.8 mM, respectively.

Sparassis latifolia often referred to as Cauliflower mushroom possess both medicinal and edibility values. In this research work, first time laccase purification and dye colourisation efficacy of Sparassis latifolia's purified laccase were assessed. Optimal laccase potential was noted after 12^th day of incubation with 4 pH of medium at 45 °C. As supplementary nutritional source, sucrose and ammonium sulphate were unveiled as most effective synthetic carbon and nitrogen sources while wheat straw found as proficient lignocellulosic biomass for enhanced laccase production. Following optimisation of laccase production parameters, laccase was purified to 14.2 fold by ammonium sulphate precipitation, dialysis and anion exchange chromatography. Laccase molecular weight determined through SDS PAGE was found to be of 65 KDa. This purified laccase was tested for its ability to decolourise the Congo red at definite pH and temperature. It was found that this fungus has capability to decolourise up to 98.6% of Congo-red dye.

Two new flavonoids, Alpinetin-7-O-[3''-O-galloyl-4'',6''-hexahydroxy-diphenoyl]-β-D-glucose (1), Pinocembrin-7-O-[4''-O-galloyl]-β-D-glucose (2), and three known compound (3-5) were isolated from Penthorum chinense Pursh (Saxifragaceae). The structures of all compounds were deduced from their comprehensive spectroscopic analysis including IR, HR-ESI-MS,¹H NMR,¹³C NMR, DEPT, COSY, HMBC and HMQC. Molecular docking model was used to test the anti-cholestatic liver activities of the isolated compounds, and compounds 1 and 2 showed higher docking scores (-9.90 and -11.27 kcal/mol, respectively) binding with FXR than 3, 4 and 5 (-8.00, -9.77, -9.10 kcal/mol, respectively), suggesting 1 and 2 exhibited potential anti-cholestatic activities. The present results show that P. chinense is a potential source of 2 new lead compounds that can be utilised to produce therapeutic drugs for liver diseases upon further studies.