A new diaryl 1, 2-diketone from the heartwood of Dalbergia latifolia

Abstract

A new diaryl 1,2-diketone, named 1-(2,5-dihydroxy-4-methoxyphenyl)-2-phenylethane-1,2-dione (1), along with eight known compounds (2-9), were isolated from the heartwood of Dalbergia latifolia. They were identified on the basis of spectral data. Compounds 1-7 were obtained from the Dalbergia genus for the first time. Compounds 8 and 9 were firstly isolated from the plant. Compound 1 exhibited inactive against Staphylococcus aureus ATCC 6538 and Escherichia coli ATCC 21530 with the minimum inhibitory concentrations of 10.0 and 10.0 mg/mL, respectively.

Nature of the Nucleophilic Oxygenation Reagent Is Key to Acid-Free Gold-Catalyzed Conversion of Terminal and Internal Alkynes to 1,2-Dicarbonyls

“…Owing to the high prevalence in natural compounds and drug candidates, 2-hydroxybenzil motif is the desired target for synthesis. ,, To demonstrate the synthetic possibilities of the developed method for acid-free dicarbonylation of alkynes, we carried out a total synthesis of 2-hydroxybenzil 28 , isolated from the heartwood of Dalbergia latifolia, starting from vanillin 22 (Scheme ). The key step is the diketonization of acid-sensitive MOM-protected acetylene 26 , obtained by the gold-supported Sonogashira coupling from 25 .…”

“…Ph 3 PAuNTf 2 (22.2 mg, 50.0 μmol, 3 mol %) was added to a solution of 26 (328.4 mg, 1.0 mmol) and 2f (410.0 mg, 2.5 mmol) in PhCF 3 (5.0 mL). The resulting mixture was stirred at room temperature for 5 h. The solvent was then removed in vacuo, and the residue was purified by silica gel chromatography eluting with hexane/ethyl acetate (gradient from 4:1 to 1:1) to afford 27 as a yellow oil (201.8 mg, 56%); R f 0.40 (hexane/ethyl acetate 1:1); 72 Concentrated aqueous HCl (10.0 μL) was added to a solution of 27 (180.2 mg, 0.5 mmol) in THF (2.0 mL). The resulting mixture was stirred at room temperature for 12 h. The solvent was then removed in vacuo, and the residue was purified by silica gel chromatography eluting with hexane/ethyl acetate (gradient from 4:1 to 1:1) to afford 28 as a yellow solid (129.3 mg, 95%); R f 0.45 (hexane/ethyl acetate 1:1); (20 mL) was added dropwise to a stirred water bath-cooled (10 °C) mixture of substituted pyridine (10 mmol) and urea hydrogen peroxide (22 mmol) in dichloromethane (DCM, 50 mL).…”

Chemical characterization and therapeutics of Dalbergia latifolia Roxb: A review

“…Ether soluble fraction of heartwood yielded latifolin and neoflavonoid [25] . Along with known phthalic acid butyl isobutyl ester, dibutyl phthalate, methyl-4hydroxybenzoate, ethyl-4-hydroxybenzoate, phydroxybenzaldehyde, eucomic acid, 2-ethoxy-5-methoxy-1,4-benzoquinone and phenyl β-D-glucopyranoside compounds, a novel diaryl 1, 2-diketone compound named as1-(2,5-dihydroxy-4-methoxyphenyl)-2-phenylethane-1,2dione was also isolated from hydro-alcoholic extract of D. latifolia heartwood [26] . Seven triterpenoids identified as, 3-Oα-L-arabinopyranosyl-28-O-β-D-glucopyranosyl pomolic acid, β-sitostenone, β-sitosterol, stigmasterol, β-amyrin acetate, β-amyrin-3-palmitate and 3-acetoxy-oleanoic acid was successfully isolated from hydro-ethanolic extract of heartwood [27] .…”

“…Combination of leaves extract and antibiotics revealed better synergetic effect compared to individuals [8] . Compound, 1-(2,5dihydroxy-4-methoxyphenyl)-2-phenylethane-1,2-dione derived from D. latifolia heartwood revealed antibacterial action against S. aureus ATCC 6538 and E. coli ATCC21530 with MIC of 10 mg/mL respectively [26] . Methanol extract of D. latifolia leaves reported moderate activity against all tested urinary tract infection causing bacteria except Klebsiella pneumonia and least observed MIC and MBC were 3.41 and 4.27 mg/mL, respectively [9] .…”