Synthesis, Evaluation, and Molecular Docking Study of 4-Monoacyl Resorcinol Against Tyrosinase Enzyme

Tyrosinase is a crucial enzyme in melanin production to protect the skin from ultraviolet, leading to skin cancers. This study synthesized eight compounds of acyl resorcinol with long-chain carbon (1-8) and structurally elucidated by 1H and 13C NMR. The in vitro evaluation of eight synthesized compounds against tyrosinase enzyme showed that 4-heptanoyl resorcinol (6) exhibited high inhibitory activity compared with the kojic acid as standard. In addition, the molecular docking study demonstrated that 6 showed lower binding energy (-7.3 kcal/mol) than kojic acid (-6.9 kcal/mol) and possessed interaction with crucial residues in the active site

Structure-Activity Relationships of 3,3′-Phenylmethylene-bis-4-hydroxycoumarins: Selective and Potent Inhibitors of Gram-Positive Bacteria

Dicoumarols and coumarin derivatives have shown a variety of pharmaceutical activities and have been found to be potent inhibitor for the NAD(P)H-dependent flavoproteins. In this report, dicoumarol and its derivatives containing the substituted benzene ring at the methylenebis position were synthesized and evaluated for their antibacterial activity against gram-positive bacteria: Staphylococcus aureus and Bacillus subtilis, and gram-negative bacteria: Escherichia coli and Klebsiella sp. The results showed that the synthesized dicoumarols affect cell growth but are selective against gram-positive over gram-negative bacterial cells. However, for most derivatives, the substitution of steric bulky benzene group on the methylenebis position appears to decrease in the efficacy of antibacterial effect. This finding is roughly described by the predicted poorer docked structure of the derivatives to a homology model of S. aureus flavoprotein. 3D-QSAR study highlighted structural features around the substituted benzene ring of dicoumarols as the antibacterial activity. CoMFA and CoMSIA contour maps support the idea that steric repulsion at the para position could diminish the antibacterial activity. The results of this study provide a better understanding of the molecular basis for the antibacterial activity of dicoumarols

9-Meth­oxy-6a,11a-dimethyl-6a,11a-dihydro-6H-1-benzofuro[3,2-c]chromen-3-ol from Dalbergia oliveri

The title compound, commonly known as (+)-(6aS,11aS)-medicarpin, C16H14O4, was isolated from Dalbergia oliveri and displays a rigid mol­ecule consisting of four fused rings. The benzofuran system is inclined at an angle of 76.49 (2)° with respect to the chroman unit. The compound exists as a polymeric chain arising from inter­molecular O—H⋯O bonding

Synthesis, Evaluation, and Molecular Docking Study of 4-Monoacyl Resorcinol Against Tyrosinase Enzyme

Tyrosinase is a crucial enzyme in melanin production to protect the skin from ultraviolet, leading to skin cancers. This study synthesized eight compounds of acyl resorcinol with long-chain carbon (1-8) and structurally elucidated by 1H and 13C NMR. The in vitro evaluation of eight synthesized compounds against tyrosinase enzyme showed that 4-heptanoyl resorcinol (6) exhibited high inhibitory activity compared with the kojic acid as standard. In addition, the molecular docking study demonstrated that 6 showed lower binding energy (-7.3 kcal/mol) than kojic acid (-6.9 kcal/mol) and possessed interaction with crucial residues in the active site

Phenolic contents and antioxidant activities of leaf extracts from Elaeocarpus submonoceras Miq.

The phenolic contents and antioxidant activities of leaf extracts from Elaeocarpus submonoceras Miq. were determined for two alternative extractions, namely maceration with ethanol and successive extraction by Soxhlet, with various solvents. Ethanol extract showed the highest phenolic content and strong antioxidant activities against DPPH and ABTS, followed in rank order by methanol and ethyl acetate extracts. The ethyl acetate extract showed no cytotoxic effect towards HaCaT, a human skin non-carcinoma cell. Based on thin layer chromatography, cytotoxic and antioxidant activities, ethyl acetate extract was chosen for isolation. The structure of an isolated compound was identified as gallic acid from 1H-NMR. This study provides the first scientific information regarding the phenolic content and antioxidant activities of E. submonoceras Miq

Taraxeryl Cis-P-Hydroxycinnamate, A Novel Taraxeryl From Rhizophora Apiculata

Taraxerol, careaborin (taraxeryl trans-p-hydroxycinnamate), and the novel triterpenoid taraxeryl cis-p-hydroxycinnamate were isolated from the leaves of Rhizophora apiculata. © 1990, American Chemical Society. All rights reserved

Thioacetalization of aldehydes and ketones catalyzed by hexabromoacetone

<p></p> <p>Protection of <i>p</i>-anisaldehyde with 1,3-propanedithiol under UV irradiation without a catalyst resulted in 87% yield of 1,3-dithiane in 20 min. Addition of hexabromoacetone further reduced the reaction time and UV irradiation also accelerated the formation of dithianes, yielding 95% of 1,3-dithiane in only 1 min. Aromatic aldehydes or ketones with electron-donating substituents at the <i>ortho</i> or <i>para</i> position increased the yield of the corresponding dithianes, while electron-withdrawing group decelerated the reaction. Aldehydes were easier to protect than ketones, and aliphatic ketones were also more readily protected than aromatic ketones. The protection was highly selective towards an aldehyde compared to a ketone.</p

Long Chain Aliphatic Alcohols And Saturated Carboxylic Acids From Heartwood Of Rhizophora Apiculata

Five long chain aliphatic alcohols, 11 long chain aliphatic saturated carboxylic acids, three steroids, 2,6-dimethoxy-p-benzoquinone, syringaldehyde and sitosteryl 3-glucoside were isolated from the heartwood of Rhizophora apiculata and subsequently bioassayed for boll weevil antifeedant, antifungal and antimicrobial activity. While 2,6-dimethoxy-p-benzoquinone is the only constituent which exhibited activity, it is significant that this compound was active against fungi, bacteria and boll weevils. © 1993

Synthesis and Biological Evaluation of N'-Arylidene-4-Hydroxybenzohydrazides against α-Glucosidase Enzyme

Hydrazides have been reported to have a broad spectrum of bioactivities, such as anticancer, antifungal, antibacterial, and antidiabetic. Thus, our work aimed to synthesize N'-arylidene-4-hydroxybenzohydrazides and investigate their α-glucosidase inhibition. Three compounds (AD-H1-3) were synthesized with a yield of product from 33 to 65% and then characterized using 1H-and 13C-NMR spectroscopy. The in vitro α-glucosidase inhibition demonstrated that AD-H2 possessing two hydroxy groups on arylidene moiety showed the best inhibitory activity against α-glucosidase enzyme with an IC50 value of 14.4 µM compared with acarbose as a positive control with IC50 value of 93.6 µM. Thus, AD-H2 could be a candidate as a lead compound for antidiabetics

Convenient method for the transformation of epoxide to aldehyde and acetonide mediated by Cr-PLM

<p>Chromium-pillared montmorillonite (Cr-PLM) could be synthesized and efficiently utilized for styrene oxide transformations. The target aldehyde product could be quantitatively achieved from the isomerization of styrene oxide by using 10 wt% of Cr-PLM under reflux temperature for 15 min. The acetonide product could be achieved in excellent yield from the reaction of styrene oxide and acetone by using 10 wt% of Cr-PLM under room temperature for 20 min. The catalyst could be recovered and reused at least five times without loss of activity.</p