Molecules in Cosmetics, Day 5

Welcome to the last day of this blog post series! I hope you've enjoyed it so far, and have found it enlightening. Today we will cover our last set of molecules--sterols, sulfonic acids, sulfosuccinates, sulfuric acid esters/organosulfates, triglycerides and thio compounds

molecules in cosmetics day 5

1. STEROLS

A polycyclic structures with four rings and an OH group. These molecules have specialty skin and hair care functions. For example, cholesterol is used to soften the skin and improve its texture with its emollient properties.

 Figure 1. General structure of sterol

Figure 1. General structure of sterol

 Figure 2. Cholesterol

Figure 2. Cholesterol

2. SULFONIC ACIDS

An S atom single-bonded to an OH group and double-bonded to two O's. Sulfonic acids are defined by the identity of the R-group attached to the S atom. The most commonly known sulfonic acid may be Ensulizole, or phenylbenzimidazole sulfonic acid, a sunscreen agent. Other sulfonic acids are used as surfactants for cleansing.

 Figure 3. Sulfonic acid

Figure 3. Sulfonic acid

 Figure 4. Phenylbenzimidazole sulfonic acid (Ensulizole)

Figure 4. Phenylbenzimidazole sulfonic acid (Ensulizole)

3. SULFOSUCCINATES

Sodium salts of alkyl esters of sulfosuccinic acid, these molecules have diverse use from emulsifiers to wetting agents to skin and hair conditioners. Disodium laureth sulfosuccinate is an example of a surfactant you can find in shampoos.

 Figure 5. Sulfosuccinate

Figure 5. Sulfosuccinate

 Figure 6. Disodium laureth sulfosuccinate

Figure 6. Disodium laureth sulfosuccinate

4. SULFURIC ACID ESTERS/ORGANOSULFATES

Similar to a sulfate structure, except that one of the O's is also bonded to an R-group which defines the overall structure and function of the molecule. Sulfuric acid esters are used as surfactants in cosmetics, like sodium laureth sulfate.

 Figure 7. Sulfuric acid esters (organosulfates)

Figure 7. Sulfuric acid esters (organosulfates)

 Figure 8. Sodium laureth sulfate

Figure 8. Sodium laureth sulfate

5. TRIGLYCERIDES

An ester made up of a glycerol backbone and three attached fatty acids. Triglycerides like caprylic/capric triglyceride offer emollient properties to a product.

 Figure 9. General structure of a triglcyeride

Figure 9. General structure of a triglcyeride

 Figure 10. Caprylic/capric triglyceride

Figure 10. Caprylic/capric triglyceride

6. THIO COMPOUNDS

Thio compounds are simply compounds containing sulfur. These compounds are not often used in cosmetics due to their malodor.  Thio compounds like ammnoium thioglycolate are used for hair waving and straightening (Legally Bonde, anyone?) They can also have anti-bacterial and anti-fungal applications.

 Figure 11. Thio compound

Figure 11. Thio compound

 Figure 12. Ammonium thioglycolate

Figure 12. Ammonium thioglycolate

We're finally at the end of the week! Now again, I know that a lot of this information is a bit overwhelming. I wouldn't recommend that you make flashcards of these structures. Rather, be familiar with the names and structures as you come across them. Even though I offered you examples, if the structure is completely new to you, let you learn it naturally as you come across it in your careers.

Next week we're going to continue to prep you for my spring e-course by talking about the structure of skin! Also if you're not already subscribed to my newsletter, you may want to sign up this weekend. I'll be sharing a tip of mine on how I went from a B/C chemistry student to an A student in my undergraduate coursework.