Isoprenylated phenolic compounds with tyrosinase inhibition from Morus nigra

A new isoprenylated sanggenon-type flavanone, nigrasin K (1), together with three known analogs (2–4) and five known Diels–Alder adducts (5–9), were isolated from the twigs of Morus nigra. Their structures were elucidated by spectroscopic methods. Sanggenon M (2), chalcomoracin (5), sorocein H (6), kuwanon J (7), sanggenon C (8), and sanggenon O (9) showed significant inhibitory effects on mushroom tyrosinase.     

无花果果实中化学成分研究

目的研究桑科榕属植物无花果Ficus carica果实的化学成分。方法综合运用硅胶柱色谱、ODS柱色谱、Sephadex LH-20凝胶柱色谱以及制备型高效液相色谱等技术进行系统分离,根据化合物的理化性质及波谱数据鉴定化合物的化学结构。结果从无花果果实的90%乙醇提取物中分离得到了16个化合物,分别鉴定为怀特酮(1)、甘草宁G(2)、4′-羟基-5,7-二甲氧基-6-(3-甲基-丁烯基)-异黄酮(3)、猫尾草异黄酮(4)、indicanine C(5)、木豆素(6)、美迪紫檀素(7)、高丽槐素(8)、4-羟基-3-甲氧基-8,9-亚甲二氧基紫檀烷(9)、3-羟基-9,10-二甲氧基紫檀烷(10)、松脂素(11)、杜仲树脂酚(12)、丁香树脂醇(13)、8-羟基松脂醇(14)、3-羟基-1-(4-羟基-3-甲氧基苯)-1-丙酮(15)和4-羟基-3-甲氧基苯乙醇(16)。结论所有化合物均为首次从无花果中分离得到。     

Antibacterial and Anti-Biofilm Activity of Flavonoids and Triterpenes Isolated from the Extracts of Ficus Sansibarica Warb. Subsp. Sansibarica (Moraceae) Extracts

Background

Ficus species are used in African traditional medicine in the treatment of a wide variety of ailments and diseases such as convulsive disorder, wound healing, gonorrhea, tuberculosis, diabetes, diarrhoeal infections, dysentery, malaria and HIV. The aim of this study was to isolate the phytochemical constituents in the plant and test them for their antibacterial activity.

Materials and methods

The fruits, leaves and stem bark were extracted with organic solvents and the compounds in the extracts separated and purified by column chromatography before being identified by NMR spectroscopy and by comparison of the NMR data against values reported in the literature. The antibacterial activity of the pure compounds and extracts were tested using the disk diffusion method.

Results

Three triterpenes and three flavonoids: lupeol acetate (1); cycloart-23-ene-3,25-diol (2); β-sitosterol (3); 5,7,4′-trihydroxyflavan-3-ol (4); epicatechin (5); and isovitexin (6) were isolated in this study. Antimicrobial activity was observed at 8 mg mL⁻¹ for Staphylococcus aureus ATCC 29213 with four of the six isolated compounds, with no activity being observed at 1 – 4 mg mL⁻¹ against Escherichia coli ATCC 25922, E. coli ATCC 35218 and S. aureus ATCC 43300. Epicatechin (5) was found to decrease adhesion of E. coli ATCC 25922 and S. aureus ATCC 29213. Decreased adhesion of S. aureus ATCC 29213 was also observed with 5,7,4′-trihydroxyflavan-3-ol (4) and isovitexin (6).

Conclusions

The results of this study provide baseline information on F. sansibarica''s potential validity in the treatment of infections associated with Gram-positive microorganisms.     

Xanthones from the roots of Cudrania fruticosa Wight

Chemical investigation on the roots of Cudrania fruticosa resulted in the isolation of two new xanthones, 1,6,7-trihydroxy-2-(1,1-dimethyl-2-propenyl)-3-methoxyxanthone (1) and 3,6,7-trihydroxy-1-methoxyxanthone (2), together with three known ones, 1,3,5-trihydroxy-4-(3-hydroxy-3-methylbutyl)xanthone (3), 1,3-dihydroxy-6,7-dimethoxyxanthone (4) and 3,5,6-trihydroxy-1-methoxyxanthone (5), respectively. Their structures were elucidated on the basis of spectral and chemical techniques.     

New prenylated flavones from <Emphasis Type="Italic">Artocarpus champeden</Emphasis>, and their antimalarial activity in vitro

Two new prenylated flavones, artocarpones A and B (1 and 2), and seven known isoprenylated flavonoids, artonin A (3), cycloheterophyllin (4), artoindonesianin E (5), artoindonesianin R (6), heterophyllin (7), heteroflavanone C (8), and artoindonesianin A-2 (9), have been isolated from the stem bark of Artocarpus champeden. Their structures were determined by spectroscopic analysis. Among the compounds isolated, 8 had the most potent inhibitory activity against the growth of Plasmodium falciparum 3D7 clone, with an IC₅₀ value of 1 nmol L⁻¹.     

桑白皮各化学拆分组分化学成分研究

目的：研究桑白皮各化学拆分组分的化学成分。方法：利用Diaion HP-20、Toyopearl HW-40、Sephadex LH-20、MCI Gel CHP-20、硅胶柱等柱色谱技术以及制备液相技术,对桑白皮化学拆分组分进行分离纯化,并根据其理化性质和光谱数据鉴定化合物的结构。结果：从桑白皮各拆分组分中共分离并鉴定了23个化合物的结构,其中从30%乙醇组分中分离得到16个单体化合物,分别为：香草酸（1）,3,4-二甲氧基苯酚（2）,苯甲酸（3）,丁香酸（4）,kelampayoside A（5）,对羟基苯丙酸（6）,咖啡酸（7）,氢化阿魏酸（8）,6,7-二羟基香豆素（9）,5,7-二羟基香豆素（10）,桑色素-7-O-β-D-葡萄糖苷（11）,liriodendrin（12）,2,3-反式二氢桑色素（13）,2,3-顺式二氢桑色素（14）,2,3-反式二氢槲皮素（15）,2,3-顺式二氢槲皮素（16）;从50%乙醇组分中分离得到4个单体化合物,分别为：东莨菪亭（17）,桑色素（18）,山奈酚-7-O-β-D-葡萄糖苷（19）,伞形花内酯（20）;从80%乙醇组分中分离得到3个单体化合物,分别为：桑根酮R（21）,cis-mulberroside A（22）,白藜芦醇（23）。结论：化合物2,4-6,11,16,19为首次从该植物中分离得到。     

Inhibitory Effects of (2′R)‐2′,3′‐dihydro‐2′‐(1‐hydroxy‐1‐methylethyl)‐2,6′‐bibenzofuran‐6,4′‐diol on Mushroom Tyrosinase and Melanogenesis in B16‐F10 Melanoma Cells

(2′R)‐2′,3′‐Dihydro‐2′‐(1‐hydroxy‐1‐methylethyl)‐2,6′‐bibenzofuran‐6,4′‐diol (DHMB) is a natural compound extracted from Morus notabilis. It was found that DHMB acts as a competitive inhibitor against mushroom tyrosinase with a Ki value of 14.77 μM. Docking results further indicated that it could form strong interactions with one copper ion with a distance of 2.7 Å, suggesting the mechanism of inhibition might be due to chelating copper ions in the active site. Furthermore, melanin production in B16‐F10 murine melanoma cells was significantly inhibited by DHMB in a concentration‐dependent manner without cytotoxicity. The results of western blotting also showed that DHMB decreased 3‐isobuty‐1‐methxlzanthine‐induced mature tyrosinase expression. Taken together, these findings indicated that DHMB may be a new promising pigmentation‐altering agent for agriculture, cosmetic, and therapeutic applications. Copyright © 2015 John Wiley & Sons, Ltd.     

Evaluation of Antiaris africana methanol extract and compounds for antioxidant and antitumor activities

A methanol extract from the stem bark of Antiaris africana Engler (Moraceae), as well as compounds isolated and identified as betulinic acid (1), 3β-acetoxy-1β,11α-dihydroxy-olean-12-ene (2), ursolic acid (3), oleanolic acid (4), strophanthidol (5), periplogenin (6), convallatoxin (7), strophanthidinic acid (8), methyl strophanthinate (9), and 3,3′-dimethoxy-4′-O-β-d-xylopyronosylellagic acid (10), were tested for their antioxidant and anticancer activities. The DPPH radical scavenging assay was used for the antioxidant test while the potato disk tumor induction and XTT assays were used to detect antitumor activities. The antioxidant test showed that the methanol extract and compounds 1, 9, and 10, as well as vitamin C, used as reference antioxidant drug, were able to interact with more than 50% DPPH. The results of the potato disk tumor induction assay also indicated a pronounced tumor reducing activity of the methanol extract (83.12%) and compound 10 (96.64%). Samples showing more than 20% inhibition of Crown gall tumors were then tested against human DU-145 and hepatocarcinoma Hep G2 cells. The results showed inhibitory activities of 64.12% and 73.62%, respectively, on DU-145 and Hep G2 cells for the methanol extract. Compound 10 showed the highest inhibition potency on both cell lines with more than 70% inhibition at 50?μg/mL. The methanol extract showed an IC₅₀ value lower than this at 30?μg/mL, a threshold value for potential antineoplastic extracts. The results of the present study provide supportive data for the traditional anticancer use of A. africana and indicate that the methanol extract as well as compound 10 represent a potential source of medicine for the treatment of cancer, having also interesting antioxidant properties.     

Antioxidant and hepatoprotective activities of Egyptian moraceous plants against carbon tetrachloride-induced oxidative stress and liver damage in rats

Context: In the absence of reliable liver-protective drugs in modern medicine, a large number of medicinal preparations are recommended for treatment of liver disorders.

Objective: The antioxidant, hepatoprotective and kidney protective activities of methanol extracts of Ficus carica Linn. (Moraceae) leaves and fruits and Morus alba Linn. root barks (Moraceae) are evaluated here.

Materials and methods: Liver and kidney damage were induced in rats by carbon tetrachloride in a subcutaneous dose of 1?mL (40% v/v in corn oil)/kg. The extract was given intraperitoneally at doses of 50?mg/kg (F. carica leaf and M. alba root bark) and 150?mg/kg (F. carica fruit). The activity of the extracts was comparable to that of silymarin, a known hepatoprotective agent. Antioxidant activity was evaluated by measuring blood glutathione (GSH) content, superoxide dismutase (SOD), catalase (CAT) activities, and malondialdehyde equivalent (MDA). Hepatoprotective activity was evaluated by measuring serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total bilirubin, and total protein. These biochemical observations were supported by histopathological examination of liver sections. Kidney function was evaluated by measuring plasma urea and creatinine.

Results: Methanol extracts of Ficus carica and Morus alba showed potent antioxidant and hepatoprotective activities; in-depth chromatographic investigation of the most active extract (Ficus carica leaf extract) resulted in identification of umbelliferone, caffeic acid, quercetin-3-O-β-d-glucopyranoside, quercetin-3-O-α-l-rhamnopyranoside, and kaempferol-3-O-α-l-rhamnopyranoside.

Discussion and conclusion: These findings demonstrate that the phenolic constituents of Ficus carica leaf and Morus alba root bark are responsible at least in part for the observed protective effects.