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A Journal Critique on the Synthesis of New Derivatives of Resveratrol and to Explore its Potential Health Benefits
Summary
The goal of the study is to extract and purify resveratrol from fresh skin of black grapevine. Resveratrol is a member of a group of plant compounds called polyphenols and belongs to the class called stilbene. Resveratrol is produced by grapes and some plants in response to stress, injury, fungal or bacterial attack and ultraviolet radiation. Studies show that it makes chemotherapy more effective, weaken viruses including influenza and HIV (Adams, 2011). It could also counter the effects of a high-fat diet and increase physical endurance, which some scientists believes that it is one of the factors behind the French Paradox or the concept that despite of the high intake of dietary cholesterol and saturated fat, there is a low percentage of coronary heart disease mortality in France (Ferrières, 2004). In rodent studies, a mice fed with a high-calorie diet lived longer than similarly fed mice not given resveratrol. Resveratrol protected mice fed a high-calorie diet from obesity-related health problems by imitating the effects of caloric restriction (Maddox, 2012). Resveratrol also incredibly lengthen the lifespan of worms, yeast, and some fishes (Adams, 2011). In the experiment, local black grapes were gathered and were classified as Vitis vinifera. The skin was separated from the fruit and was placed in dark, cool area. To avoid oxidation of the plant extract, the steps were done away from direct light. The skin was shaken with ethyl acetate and was kept for 72 hours and was filtered. The filtrate was dried using a rotary evaporator to get one-tenth of its original amount. The functional and phenolic groups present in the resveratrol were tested using standard methods. Aromaticity and the melting point were also determined. In the preparation of the resveratrol derivatives, the first two resveratrol extracts were dissolved in dry benzene. To each resveratrol, different substances were added and were refluxed for 2 and 6 hours, respectively. The precipitate was filtrated and dried. The other two derivatives to be prepared were dissolved in absolute ethanol. Different substances were added to each resveratrol and were refluxed for 7 and 8 hours, respectively. The solvent was removed, and the precipitate was filtrated and dried. The results of the general phenolic compound tests after resveratrol was extracted and purified were shown using a table. It was soluble in 5% NaOH solution, insoluble in 5% Sodium carbonate solution, and it gave off a green colored solution in 1% Ferric chloride solution. It was positive in the following tests; Liebermann reaction, Phthalein reaction, Friedle craft test, Bromine decolourisation test and the Baeyer test. The infrared frequencies region for the functional groups was shown, comparing the standard resveratrol and the extracted pure resveratrol. The IR frequency of the pure resveratrol was higher than the standard resveratrol in most functional groups except for the Aromatic C-H group. The infrared spectra for the four derivatives were also presented. All of the four derivatives has a lot of functional groups, but has different wavelengths for each functional group. The first derivative is (E)-2,2’-(5-(4-(Carboxymethoxy)styryl)-1,3-phenylene)bis (oxy) diacetic acid. It has phenolic-OH, aromatic C-H, aliphatic C-H, aromatic C=C, aliphatic C=C and a C-O group. Each of the functional groups has different wavelengths as shown in the infrared spectra figure. The second derivative is (E)-(5-(4-(3-Chloropropanyloxy)styryl)-1,3-phenylene)bis(3-chloropropanoate). There is the absence of OH group in this derivative as shown in the IR spectra, but it still has aromatic C-H, aliphatic C-H, aliphatic C=C, C=O group, and the appearance of a C-Cl group. The third derivative is 5-(4-(4-Hydrazinylbutanoyloxy)styryl)-1,3,-phenylene bis(4-hydrazinylbutanoate). An appearance of H-N-H group and the absence of the C-Cl group were shown in the IR spectra. Still the aromatic C-H, aliphatic C-H, aliphatic C=C, and C=O group are present in the third derivative. The last derivative is 5-(4-(4-(2-Benzo[d]thiazol-2-yl)hydrazinyl) butanoyloxy)styryl)-1,3-phenylene bis(4-(2-(benzo[d]thiazol-2-yl)hydrazinyl)butanoate) which has aromatic C-H, aliphatic C-H, aliphatic C=C, and C=O group. The H-N-H group disappeared in this derivative, but three functional groups appeared, C-S group, C=N group and the C-N group. Each of the derivatives has different functional groups present, this is the indicator that each of the derivatives might have different effects on our health which may be unravel by exploring the new synthesized derivatives of resveratrol.
Critique
Resveratrol is indeed has a lot of benefits to our health. With further studies and researches like this, we could discover more of its advantages. The goal of the study is to synthesize new derivatives of resveratrol, which may be useful in the future. The researchers used locally available grapes, but it still yield good results compared to the standard resveratrol. Also, one of the good points of this study is that no heavy metal was used in making the derivatives and the researchers cautiously did the experiment in dark areas so that the sunlight won’t affect the resveratrol that they will collect. On the other side, the title of the article was quite confusing because, the researchers only synthesized resveratrol derivatives, but did not explore its potential health benefits. The potential health benefits were not presented in the study maybe because the researchers of the study were leaving it to the other researches that have interest in expounding the study and search for the benefits of the newly found derivatives. The tests for the resveratrol derivatives were also limited, the researches should have used verities of testing methods, not just by getting the functional groups of each through the IR spectra. In other research articles, resveratrol was tested in terms of its health benefits. A study that was done by Bertelli AA., et al in the year 1995, focused on the resveratrol’s absorption and concentration of resveratrol in different organs and its possibility to fight against coronary heart disease when there is a prolonged administration of red wine to the diet. The researchers of this study used rats for this experiment. The downside of this article is that they had to sacrifice lives of animals just to know the results. The second related study of Lu and Serrero in 1996 is about the effect of resveratrol on the growth of human breast cancer cells. The antiestrogenic effect of resveratrol could be observed at a concentration of 10−6 M and above. The results obtained were that resveratrol, a partial estrogen receptor agonist itself, and acts as an estrogen receptor antagonist in the presence of estrogen leading to inhibition of human breast cancer cells. The last study was conducted also by Bertelli AA., et al, in 1996 and it is concerned on the antiplatelet activity of synthetic and natural resveratrol in red wine. The effect of the phytoalexin resveratrol alone or associated with red wine, and polyphenol have been assessed at different concentrations on platelet-rich plasma from healthy volunteers. By adding resveratrol to the plasma, the platelets in it were decreased. The three different studies were more focused on the effects resveratrol could give to our body. In contrast, the article only focused on synthesizing new derivatives of resveratrol without actually exploring its health benefits or how could it affect our body. The three studies used different methodologies and conducted different experiments to obtain the necessary results for the study. The article also used variety of methods, experiments and tests to acquire data.

The study was done carefully and yields a number of derivatives, but I suggest that the researchers should also have tested other species of grapes, to see if the different kinds of grapes produce different derivatives. The title of the study also was quite confusing, because in the article, the researchers did not explore the benefits of the new found derivatives. The researchers should have kept the title short to avoid the confusion of the readers. The result of the different tests on the derivatives was clearly shown in tables, but the researchers did not explain the meaning of the functional groups that are present in each derivative, so that it would be understandable to the readers what the derivatives have or lacks. Also, it would be better if the researchers compared the benefits of the new derivatives of resveratrol, but unfortunately, they did not do further experiments on exploring the derivatives.

Having a good health is one of the best things a man could have in his life. Advancements in medical technology nowadays provide us improvements in curing diseases and preventing further illnesses. That is why researches like this have a big impact in our society because we are currently experiencing a lot of health problems. Resveratrol has a lot of benefits that could fight one of the leading causes of death around the world, cancer. This study opens us to the new possibilities that could be explored in the near future. With the new synthesized derivatives there will be chances of having the cure for some diseases. Resveratrol is also a natural substance which means that it is a lot safer than those medicines which contains chemicals that are bad for the body and contains a lot of side effects.

References:
Adams, M. (2011). Amazing food fact: Miracle nutrient resveratrol is synthesized by grapes in response to fungal attacks. Retrieved February 18, 2013, from Natural News: http://www.naturalnews.com/033905_resveratrol_grapes.html
Bertelli AA, et al. (1995). Plasma, urine and tissue levels of trans- and cis-resveratrol (3,4',5-trihydroxystilbene) after short-term or prolonged administration of red wine to rats. Retrieved February 27, 2013, from Europe PubMed Central: http://www.europepmc.org/abstract/MED/9063768
Bertelli AA, et al. (1996). Antiplatelet activity of synthetic and natural resveratrol in red wine. Retrieved February 27, 2013, from Europe PubMed Central: http://www.europepmc.org/abstract/MED/7499059
Ferrières, J. (2004). The French paradox: lessons for other countries. Retrieved February 18, 2013, from NCBI: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1768013/
Lu, R. & Serrero, G. (1999). Resveratrol, a natural product derived from grape, exhibits antiestrogenic activity and inhibits the growth of human breast cancer cells. Retrieved February 27, 2013, from Wiley Online Library: http://www.onlinelibrary.wiley.com/doi/10.1002/(SICI)1097-4652(199906)179:3%3C297::AID-JCP7%3E3.0.CO;2-P/abstract
Maddox, T. (2012). Resveratrol Supplements. Retrieved February 18, 2013, from WebMD: http://www.webmd.com/heart-disease/resveratrol-supplements