Toonanoronoids A-E, five new limonoids from Toona ciliata var. yunnanensis.

Five new B-seco-limonoids, namely toonanoronoids A-E (1-5), in conjunction with three previously reported compounds, were isolated from the EtOAc extract of the twigs and leaves of Toona ciliata var. yunnanensis. Their structures were elucidated through comprehensive spectroscopic and X-ray crystallographic analysis. The cytotoxic activities of new compounds against five human tumor cell lines (HL-60, SMMC-7721, A549, MCF-7, and SW480) were screened, Compounds 4 and 5 exerted inhibition toward two tumor cell lines (HL-60, SW-480) with IC50 values between 1.7 and 5.9 µM.

6'-O-Caffeoylarbutin from Quezui Tea: A Highly Effective and Safe Tyrosinase Inhibitor.

Tyrosinase is vital in fruit and vegetable browning and melanin synthesis, crucial for food preservation and pharmaceuticals. We investigated 6'-O-caffeoylarbutin's inhibition, safety, and preservation on tyrosinase. Using HPLC, we analyzed its effect on mushroom tyrosinase and confirmed reversible competitive inhibition. UV_vis and fluorescence spectroscopy revealed a stable complex formation with specific binding, causing enzyme conformational changes. Molecular docking and simulations highlighted strong binding, enabled by hydrogen bonds and hydrophobic interactions. Cellular tests showed growth reduction of A375 cells with mild HaCaT cell toxicity, indicating favorable safety. Animal experiments demonstrated slight toxicity within safe doses. Preservation trials on apple juice showcased 6'-O-caffeoylarbutin's potential in reducing browning. In essence, this study reveals intricate mechanisms and applications of 6'-O-caffeoylarbutin as an effective tyrosinase inhibitor, emphasizing its importance in food preservation and pharmaceuticals. Our research enhances understanding in this field, laying a solid foundation for future exploration.

Subcritical Water Extraction of Phenolic Compounds from Vaccinium Dunalianum Wight Leaves and Their Antioxidant and Tyrosinase Inhibitory Activities in Vitro.

Subcritical water extraction was used to extract bioactive phenolic compounds from Vaccinium dunalianum Wight leaves. The optimal extraction conditions were determined as an extraction temperature of 150 °C, an extraction time of 40 min, and a liquid-solid ratio of 35 : 1 mL/g. The total phenolic content reached 21.35 mg gallic acid /g, which was 16 % higher than that by hot water extraction. The subcritical water extraction extract exhibited strong scavenging activity of DPPH free radical and ABTS+ free radical, as well as significant tyrosinase inhibitory activity. The study suggests that subcritical water extraction can alter the composition of the extracts, leading to the production of various phenolic compounds, effective antioxidants, and tyrosinase inhibitors from Vaccinium dulciana Wight leaves. These findings confirm the potential of Vaccinium dunalianum Wight as a natural antioxidant molecule source for the medicine and food industries, and for the therapy of skin pigmentation disorders.

C21, C22 pregnane glycosides and cytotoxic C27 spriostanol steroids from Asparagus cochinchinesis.

A preliminary chemical investigation on 70% MeOH extract of the roots of Asparagus cochinchinensis resulted in the isolation of nine steroids. These isolates comprised of four new C21 (1-4) and one new pregnane (5) glycosides, and four known C27 (6-9) spirostanol steroids. Their structures were identified via analysis of the spectroscopic data and the results of hydrolytic cleavage. The cytotoxic activities of the compounds were tested toward the human tumor cell line Hela (cervical cancer), and compounds 7 and 8 displayed moderate activity with IC50 values of 35.5 and 39.6 µM, respectively.

Pepluane and Paraliane Diterpenoids from Euphorbia peplus with Potential Anti-inflammatory Activity.

Twelve new diterpenoids based on two rare skeletal types, namely, paralianones A-D (1-4) and pepluanols A-H (5-12), along with five known compounds, were isolated from an acetone extract of Euphorbia peplus. Their structures were proposed based on 1D and 2D NMR spectroscopic data analysis. These diterpenoids were evaluated for potential anti-inflammatory activity in a lipopolysaccharide-stimulated mouse macrophage cellular model. Compounds 3, 4, 11, 13, and 16 displayed moderate inhibitory effects on NO inhibition, with IC50 values ranging from 29.9 to 38.3 µM.

Antioxidant farnesylated hydroquinones from Ganoderma capense.

Phytochemical investigation of the fruiting bodies of Ganoderma capense led to isolation of eight aromatic meroterpenoids (1-8). Ganocapensins A and B (1, 2) possessed a thirteen-membered and a fourteen-membered ether rings, respectively. The structures of new isolates including absolute configuration were elucidated on the basis of extensive spectroscopic technologies and Mosher's method. All isolated compounds showed significant antioxidant effects with IC50 values ranging from 6.00±0.11 to 8.20±0.30µg/ml in the DPPH radical scavenging assay.

Cytotoxic 9,19-cycloartane triterpenes from the aerial parts of Cimicifuga yunnanensis.

Six new 9,19-cycloartane triterpenes (1-6) were isolated from the aerial parts of Cimicifuga yunnanensis. The new chemical structures were determined by extensive analyses of 1D and 2D NMR spectroscopy. Compounds 1 and 2 are the first 9,19-cycloartane triterpenes characterized by CH3-18 shifting from C-13 to C-12 in the Cimicifuga spp. The evaluation of inhibition activity against human HL-60, SMMC-7721, A-549, MCF-7, and SW480 cell lines indicated that compounds 1-6 showed different levels of cytotoxic activities with IC50 values ranging from 1.2 to 27.8 µm.

Steroidal saponins from the roots of Asparagus cochinchinensis.

AIM: To study the chemical constituents of the roots of Asparagus cochinchinensis (Asparagaceae). METHODS: The compounds were isolated with Diaion HP20, silica gel, and ODS chromatography, and their structures were determined on the basis of chemical methods, HR-ESI-MS, and 1D- and 2D-NMR techniques. RESULTS: Seven compounds were isolated from the n-butanol fraction of the roots of A. cochinchinensis, and their structures were elucidated as (25S)-26-O-ß-D-glucopyranosyl-5ß-furostan-3ß, 22α, 26-triol-12-one-3-O-ß-D-glucopyranoside (1), (25S)-26-O-ß-D-glucopyranosyl-22α-methoxy-5ß-furostan-3ß, 26-diol-12-one-3-O-ß-D-glucopyranoside (2), (25S)-26-O-ß-D-glucopyranosyl-5ß-furostan-3ß, 22α, 26-triol (3), (25S)-26-O-ß-D-glucopyranosyl-5ß-furstan-3ß, 22α, 26-triol-3-O-ß-D-glucopyranoside (4), (25S)-26-O-ß-D-glucopyranosyl-5ß-furostan-3ß, 22α, 26-triol-3-O-α-L-rhamnopyranosyl-(1, 4)-ß-D-glucopyranoside (5), (25S)-5ß-spirostan-3ß-ol-3-O-α-L-rhamnopyranoside (6), and (25S)-5ß-spirostan-3ß-ol-3-O-ß-D-glucopyranoside (7). CONCLUSION: Compounds 1 and 2 were two new furostanol saponins.