4-hydroxyindole

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

2018-04-03

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data based on calculations using EPI Suite v4.11.

Principles of method if other than guideline:

EPISuite/WATERNT (v 1.01).estimation program, implemented in EPISuite, estimates the water solubility.
The WATERNT v1.01 is validated for a molecular weight range between 30 and 628 using >4600 compounds. The validation set contains many chemicals that are similar in structure to chemicals in the training set, but also many chemicals that are different from and structurally more complex than chemicals in the training set. The training set includes > 1000 compounds.
Justification for use of the WATERNT model:
The substance of interest, CAS 2380-94-1, falls into the applicability range of the MW domain of the model with MW 133.15. Additionally, this substance does not contain complex functional groups, thus the model is also applicable in view of suitable fragments.

EPISuite/WSKOWWIN (v.1.42): WSKOWWIN estimation program, implemented in EPISuite, estimates the water solubility of an organic compound using the compounds logKow. Water solubility (as logS) is estimated based on one of two possible equations: 1) linear regression based on logKow, melting point (MP) and molecular weight (MW) (plus correction factors); 2) linear regression based on logKow and molecular weight only (plus correction factors). When an experimental melting point is available, WSKOWWIN applies the equation containing both MP and MW parameters. In the absence of a MP, the equation containing just the MW is used to make the estimate. The regression equations were trained with a dataset of 1450 compounds (r2eq1=0.97; r2eq2=0.93) and validated on two datasets of 85 and 817 compounds (r2 equal to 0.86 and 0.90, respectively). Predictions provided by WSKOWWIN are not supported by a specific parameter however it is generally assumed that water solubility estimates for compounds outside the MW and LogKow range of the training set compounds (min MW = 18.02; max MW = 719.9; min LogKow = -3.89; max LogKow = 8.27) are less accurate.

Type of method:

other: calculated

Water solubility:

18 142 mg/L

Conc. based on:

other: calculated

Remarks on result:

other: WATERNT v1.01

Water solubility:

153 500 mg/L

Conc. based on:

other: calculated

Temp.:

25 °C

Remarks on result:

other: WSKOW v1.42

Conclusions:

The water solubility of 4-hydroxyindole was calculated to be 15350-18142 mg/L.

Key value for chemical safety assessment

Water solubility:

18 142 mg/L

at the temperature of:

25 °C

Additional information

The water solubility of 4-hydroxyindole was calculated to be 15350-18142 mg/L.