HSP Application note #17
Hansen Solubility Parameter (HSP) and Mosquitos
HSPiP Team Senior Developer, Dr. Hiroshi Yamamoto
Hansen Solubility Parameters (HSP)
Hansen Solubility Parameters(HSP) were developed by Charles M. Hansen as a way of predicting if one material will dissolve in another and form a solution. They are based on the idea that "like dissolves like" where one molecule is defined as being 'like' another if it bonds to itself in a similar way.
What can perhaps be surprising is that one can assign HSP to so many different things. Gases like carbon dioxide, solids like carbon-60, sugar, and biological materials like human skin, depot fat, DNA, and even some proteins all have HSP. The list can be continued with drugs, polymers, plasticizers, and in fact any organic material and even many inorganic materials like salts. The only requirement for an experimental confirmation is that the material must behave differently in a sufficient number of test solvents upon contact.
I really dislike mosquitos.
I have a really small garden, and I and my boys love to glow vegetables and flowers. But in summer time, so a lot of mosquitos attack us and we never go to garden. The other day, I wrote one article about HSP and natural herbs. At there, one of the compound(matatabi-lactone) is used as mosquitos repellant.So, I start to research before summer season.
As I wrote in the article, matatabi-lactone is used as avoidance compounds for cockroach and mosquito. So, I compile the molecule that show same effect to mosquitos.
There is very good site in Wikipedia to search about it.
The most popular compound is DEET.
This compounds was developed my US army.
it is very effective, but someone get an allergy with this compounds.
|2: N,N-Diethyl-m-toluamide or N,N-Diethyl-3-methylbenzamide|
And there are many natural herbs that are used for mosquitos repellant.
like for Cat, Catnip is also used for this purpose.
|4: Citral||5: Citronellal|
These compounds have very similar HSP.
This result means mosquitos hate where Cat love, but I do not know the reason.
The soldier might suffer with cat or lion when they use DEET. For the beginner, "Smilar HSP" or "not Similar" is very hard to determin.
Drag=Rotate, Drag+Shift=Larger/Smaller, Drag+Alt or Command(Window key)=Translate.
If you are using HTML5 enable browser such as Chrome, Safari or FireFox (IE9 is out of support), you will see the Canvas. If you pick solvent, solvent name will appear.
The solvent(Blue small sphers) are most widely selected popular slvents. Please check the position of your molecules in this space.
So, similar HSP means similar solubility (to mosquito's organ) and shows similar effect.
To determine if the parameters of two molecules (usually a solvent and a polymer) are within range a value called interaction radius (R0) is given to the substance being dissolved. This value determines the radius of the sphere in Hansen space and its center is the three Hansen parameters.
From version 3.1.X, Double Spheres function is available.
Then what mosquito like?
In WikiPedia, Mosquito likes,
Floral or Fruity Fragrances
Lactic Acid, (CAS# 50-21-5)
This compound HSP is [16.3, 10.7, 25.9] Volume 75.5 (Calc.)
dH is very high and it is so far from mosquito repellant compounds' HSP.
You release more lactic acid when you have been exercising or after eating certain foods (e.g., salty foods, high-potassium foods). (wikiPedia)
Yes, I love such foods.
So, problems is vapor pressure of these compounds.
In HSPiP, there is function to estimate Antoine constants.
If you enter lactic acid SMILES into Y-MB text field, and push calculator button,
Y-MB break molecule into functional groups and calculate vapor pressure.
It is estimation value but 0.016mmHg@25C
Smiles(Simplified Molecular Input Line Entry Syntax)
SMILES is a string obtained by printing the symbol nodes encountered in a depth-first tree traversal of a chemical graph.
Y-MB Properties Estimation
Y-MB break Smiles into correspponding Functional Groups and Estimate various Properties. These estimation schemes are come from Pirika technologies.
The boiling point of DEET is much higher, so vapor pressure of DEET is 0.002mmHg@50C.
So, we need to put much amount of chemical on our skin.
So, I search other chemicals that HSP is similar to DEET in HSPiP database.
HSPiP(Hansen Solubility Parameters in Practice)
The first edition of HSPiP that appeared in November, 2008, greatly enhanced the usefulness of the Hansen solubility parameters (HSP).
The HSP values of over 1200++ chemicals and 500 polymers are provided in convenient electronic format and have been revised and updated using the latest data sources in the second edition (March, 2009).
A third edition of the HSPiP appeared in March, 2010. There are now 10,000 compounds in the HSP file which also includes data on density, melting point, boiling point, critical parameters, Antoine constants and much more. The user is able to carry out many different sorts of optimisations of solubility, evaporation, diffusion, adhesion, create their own datasets (automatically if required) and explore the huge range of applications for HSP in coatings, paints, nanoparticles, cosmetics, pharma, organic photovoltaics and much more.
The 3rd Edition v3.1 was released on 12 December 2010. Current users can upgrade free (now v3.1.09) by downloading the latest .msi installer from http://hansen-solubility.com
The 4th Edition v4.0.x was released on 2 Jan. 2013. The Current users can upgrade with free charge.
2013.1.28 The Visual How to manual of HSPiP. You can understand what HSPiP can do.
There are 95 candidates.
I show you several.
Actually, a lot of surfer containing compounds are listed.
But I do not hope mercaptan like smell in my garden even though it is mosquito repellant.
|raspberry ketone methyl ether
|3-phenyl propyl formate
There exist other type of mosquito repellant.
These have more large dH compared to previous group.
Please try to calculate if you are interested in.
Japanese Health Care company announced that they developed Oral medicine avoidance for mosquito.
It contains citral.
Citral evaporate from skin slowly and prevent mosquito attack.
I checked their patent.
Citral CAS#5392-40-5 HCode 16642 HSP[16.3, 2.3, 6.2] MVol 171.3
Citronelle acetaldehyde ??
Limonene CAS# 5989-27-5 HCode 1253 HSP[17.2, 1.8, 4.3] MVol 162.9
Citronellal CAS# 5949-05-3 HCode [16.2, 5.9, 5.2]
Linalool CAS#78-70-6 HCode 17042 HSP[16.5, 2, 9,1] MVol 179.8
Geraniol CAS# 106-24-1 HCode 9093 HSP[16, 4.7, 11] MVol 173.4
（HSP calculation is done with new developing version）
Concentration of Geraniol in urine is very low and effect of Geraniol is not strong.
Maybe, Geraniol will be metabolism.
Mechanism of metabolism is very hard to understand, but logP(logKow), logS(solubility to water) ,logBCF (bio concentration factor) can be predicted with HSPiP.
Citral logP=3.45 logS=-1.06
limonene logP=4.57 logS=-2.86
Citronellal logP=3.48 logS=-1.8
Linalool logP=2.97 logS=-0.99
Geraniol logP=3.56 logS=-2.0
And this patent said that these compounds change one's body smell.
In that case vapor pressure is also very important. HSPiP will calculate Antoine Constant for vapor presuure.
Citral AntA=6.9305, AntB=1668.7 AntC=184.1
Limonene AntA=7.0443, AntB=1597.4, AntC 208.6
Citronellal AntA=7.2031, AntB=1680.1, AntC180.7
Linalool AntA=7.2517, AntB=1628.1, AntC=178.5
Geraniol AntA=7.475, AntB=1829.7, AntC=168.3
If body temperature is 36C,
If the vapor pressure is very high, rapidly evaporate and effect will disappear.
And like Geraniol, VP is so small, it will not effect.
So, Citral has relatively high solubility to water and moderate VP, and the result become max.
So, if you want to search other compounds, HSP[16.5, 2, 5] ,0.25mmHg(36C）logS=-1, logP=3.5
Try with HSPiP
I checked my natural herbs database.
The Lemon grass contain a lot of Citral.
And Lemon Grass is used for very famous soup "Tom Yum Goong".
That means when eat Tom Yum Goong, Citral will released from our body, and it prevent from mosquito.
So, Japanese patent means nothing.
I took my boys to the firm.
They enjoyed sucking milk. After that, they were completely absorbed in killing mosquitos that biting cow.
I am thinking what happen if they feed the Lemon Grass to cows.
It is known that Pig contracted both Bird flu and Human flu.
And New flu may incubate inside pig body.
If the Lemon Grass prevent mosquito from animal, it is very interesting.
Now one of the Japanese veterinary college become HSPiP user. So such study may proceed.
Today's newspaper, Japanese university researcher found that the mosquito's mouthpart have a lot of TRPA1 protein.
And that organ is paralyzed by some chemicals, the mosquito can not chase animals they said.
What kind of chemicals (HSP) does they use?
If I found, I will report again.