• Corrosion Science and Technology
• /
• 제21권3호
• /
• pp.171-183
• /
• 2022

The performance and inhibitory action of the aqueous extract of Cyperus Conglomeratus's leaves against corrosion of XC70 steel in a 1M HCl acid medium are studied by the determination of the weight loss, the potentiodynamic polarization curves analysis, and electrochemical impedance measurements (electrochemical techniques). The corrosion inhibitory efficiency of XC70 steel increases with the increasing concentration of the green inhibitor, however, the corrosion rate of the steel decreases. Weight loss measurements show that the maximum percentage corrosion inhibition efficiency is approximately 61.86%, while the analysis of the mixed character polarization curves shows that the inhibitor could achieve an inhibition efficiency of 86.96%. The electrochemical impedance study confirmed that the value of the charge transfer resistance (R_ct) increases and the value of the double layer capacity (C_dl) decreases with increasing concentration of the aqueous extract of Cyperus Conglomeratus's leaves, thus increasing the inhibition efficiency. The study showed that this aqueous extract acts by adsorption on the metal surface; this adsorption follows the Langmuir isotherm. This research work showed that Cyperus Conglomeratus leaves extract acts as an effective and eco-friendly inhibitor on mild steel in an acid medium.

• Archives of Pharmacal Research
• /
• 제8권4호
• /
• pp.221-227
• /
• 1985

Acetyl-11-ketopomolic acid methyl ester (VI), mp 276-$278^{\circ}$ was synthesized from pomolic acid (III). The mild alkaline treatment of VI induced the opening of ring E on carbone skeleton to yield VII, and then VII was deacetylated to give VIII, mp 82-$84^{\circ}$ Compound VIII was established as 11, 19-diketo-18, 19-secoursolic acid methylester. The E-ring opening was believed to be due to regrograde aidol condensation.

• Animal cells and systems
• /
• 제16권6호
• /
• pp.462-468
• /
• 2012

Urodeles including newt and salamander have remarkable regenerative capacity during the postembryonic life span. Some of the unique features are the formation of the well-developed wound epidermis and the active dedifferentiation process in the early phase of regeneration. These are regarded as key events for the successful regeneration since no further regenerative activity is possible without them. In this study, we investigated the role of retinoic acid (RA) in salamander limb regeneration by blocking RA synthesis using disulfiram, an inhibitor of aldehyde dehydrogenase that oxidizes retinal to RA. Disulfiram treatment resulted in delaying the limb regeneration processes via inhibition of wound epidermis formation and dedifferentiation process. When RA was administered after disulfiram treatment, the inhibitory effect of disulfiram was rescued. In addition, disulfiram treatment after the dedifferentiation stage resulted in the mild retardation of limb regeneration, suggesting that RA might also be involved in the blastema outgrowth. Furthermore, salamander MMP-9 gene expression was also inhibited by disulfiram treatment. Collectively, our findings indicate that endogenous RA may play an important role(s) in the early phase of limb regeneration by regulating the expression of molecules responsible for the modification of intracellular and extracellular environment during salamander limb regeneration.

• 생약학회지
• /
• 제31권2호
• /
• pp.235-239
• /
• 2000

The effects of several compounds related to signal transduction cascade were determined to induce the production of alizarin and purpurin in the hairy root culture system of Rubia cordifolia var. pratensis. It was found that out of five tested compounds jasmonic acid(1 mg/l) and methyl jasmonate(1 mg/l) stimulated strongly the biosynthesis of the pigments while linolenic acid(1 mg/l) induced no significant increase of the product. Yeast extract(600 mg/l) and arachidonic acid(1 mg/l) showed relatively mild inducing effects on production of alizarin. The effects of jasmonic acid and methyl jasmonate were reduced by treatment with cycloheximide(2.8 mg/l).

• 약학회지
• /
• 제43권4호
• /
• pp.516-525
• /
• 1999

Hedera rhombea (HR) has been used for treatments of hemorrage, chronic catarrh, jaundice, lithisis and convulsion. This study was done to isolate active compounds that have protective effect on liver damage. BuOH and EtOAc fractions of HR recovered serum glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT) and ${\gamma}-glutamyltranspeptidase$ (${\gamma}-GTP$) activities in CCl4 treated rats. We isolated 7 phenolic compounds from BuOH and EtOAc fractions, which were identified as 3-caffeoyl quinic acid, 3,4-di-O-caffeoyl quinic acid, 3,5-di-O-caffeoyl quinic acid, 4,5-di-O-caffeoyl quinic acid, caffeic acid, methyl 3,4-di-O-caffeoyl quinic acid and methyl 3,5-di-O-caffeoyl quinic acid by chemical and spectral analysis. These compounds reduced significantly serum GOT and GPT elevated by CCl4 treatment in rats, and 3-caffeoyl quinic acid, 3,5-di-O-caffeoyl quinic acid and caffeic acid also showed mild inhibitory activity against human immunodeficiency virus.

• Biomolecules & Therapeutics
• /
• 제29권5호
• /
• pp.536-544
• /
• 2021

5-amino salicylic acid (5-ASA) is a standard therapy for the treatment of mild to moderate forms of inflammatory bowel diseases (IBD) whereas more severe forms involve the use of steroids and immunosuppressive drugs. Hyaluronic acid (HA) is a naturally occurring non-sulfated glycosaminoglycan that has shown epithelium protective effects in experimental colitis recently. In this study, both 5-ASA (30 mg/kg) and HA (15 mg/kg or 30 mg/kg) were administered rectally and investigated for their potential complementary therapeutic effects in moderate or severe murine colitis models. Intrarectal treatment of moderate and severe colitis with 5-ASA alone or HA alone at a dose of 30 mg/kg led to a significant decrease in clinical activity and histology scores, myeloperoxidase activity (MPO), TNF-α, IL-6 and IL-1β in colitis mice compared to untreated animals. The combination of HA (30 mg/kg) and 5-ASA in severe colitis led to a significant improvement of colitis compared to 5-ASA alone. Combined rectal therapy with HA and 5-ASA could be a treatment alternative for severe cases of IBD as it was the only treatment tested that was not significantly different from the healthy control group. This study further underlines the benefit of searching for yet unexplored drug combinations that show therapeutic potential in IBD without the need of designing completely new drug entities.

• Toxicological Research
• /
• 제16권1호
• /
• pp.89-94
• /
• 2000

Alpha-hydroxy acid(AHA) are used in cosmetic products as a pH adjuster, mild exfoliant and humectant-skin conditioner. Cosmetics containing higher concentration (30%) and lower pH (3.0) of AHA can cause side effects if it is applied without the prescription. For providing information on the safety of AHA and on human risk assessments we studied skin irritation effect of glycolic acid, one of the most commonly used AHA in guinea pigs. The skin irritation by glycolic acid was increased in a dose(10% to 70%), acidity (pH 2.5 to 5.5.) and length of exposure dependent manner (for up to 14 days), respectively. The combination treatment with UVB (0.4 or 3.0 J/$cm^2$) increased glycolic acid-induced skin irritation. Histological examination showed that hyperplasia of non-inflammatory cells in the epidermis of skin treated with high dose of glycolic acid (pH 3.0). There results show that glycolic acid increased skin irritation in a dose, length of exposure and pH dependent manner, respectively, in guinea pig, and the combination with UVB increased glycolic acid-induced skin irritation. The cell proliferation of non-inflammatory cell may be involved in high doses of glycolic acid-induced skin irritation. Long-term application of more than 30% of glycolic acid (pH 3.0) may cause skin irritation.

• Biomolecules & Therapeutics
• /
• 제9권1호
• /
• pp.63-68
• /
• 2001

General pharmacological properties of (R)-JG-381 were examined in laboratory animals to investigate its safety profile. Administration of (R)-JG-381 (50 and 100 mg/kg) in mice and rats had no effects of general behaviors, central nervous system of the animals in test systems of pentobarbital-induced sleeping time, writhing syndromes induced by 0.7% acetic acid, chemo-shock produced by pentylenetetrazole, and, however, had mild effects on motor coordination. Heart rate and blood pressure were not changed by (R)-JG-381 treatment. (R)-JG-381 also showed mild effects on intestinal propulsion and gastric secretion. These results suggest that (R)-JG-381 dose not exert serious pharmacological effects.

• Journal of Ginseng Research
• /
• 제15권3호
• /
• pp.188-191
• /
• 1991

The mild hydrolysis of ginsenosie Re with 50% acetic acid gave a prosapogenin mixture, 20(R)- and 20(S)-ginsenoside Rg2. The products were acetylated to give the peracetates, which were further converted into 20(R)- and 20(S)-ginsenoside Rh1 by the alcoholic alkaline treatment.

• 생약학회지
• /
• 제21권2호
• /
• pp.186-192
• /
• 1990

This study was conducted to further purify and characterize a polysaccharide fraction from whole parts of Duchesnea indica (Andr.) Focke, which was previously reported to show an antitumor activity by us. Mild acid-treatment of the fraction by 5% acetic acid yielded three subtractions (Fr. A,B and C) on a Sephadex G-25. Fr. A was composed of uronic acid, hexose, pentose and phenolic substance, Fr. C mainly phenolic substance, and Fr. B contained hexose. All three fractions exhibited colony stimulating factor activity.