N-glycyl-L-tyrosine

Vapour pressure

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09 Dec 2021 - 03 Feb 2022

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Version / remarks:

July 23, 2009

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Version / remarks:

March 23, 2006

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

effusion method: isothermal thermogravimetry

Key result

Temp.:

20 °C

Vapour pressure:

< 0.002 Pa

Temp.:

25 °C

Vapour pressure:

< 0.012 Pa

Conclusions:

The vapour pressure of the test item N-Glycidyl-L-tyrosine dihydrate was determined to be < 0.0015 Pa at 20 °C and < 0.012 at 25 °C

Reference 2

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with limited documentation / justification

Justification for type of information:

1. SOFTWARE
EPISuite 4.1
2. MODEL (incl. version number)
MPBPWIN v1.40

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
NCC(=O)NC(C(=O)O)Cc1ccc(O)cc1
CAS: 658-79-7
Name : Glycyl-L-Tyrosin

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint:
vapour pressure
- Unambiguous algorithm:
Modified Grain Method:   Chapter 2 of Lyman (1985) describes the modified Grain method used by MPBPWIN.  This method is a modification and significant improvement of the modified Watson method.  It is applicable to solids, liquids and gases. The KF structural factors are available in chapter 14 of Lyman et al (1990); the variation of this parameter is related to chemical class and is small (roughly 0.99 to 1.2), so large errors in its selection are unlikely (Lyman, 1985).  The modified Grain method may be the best all-around VP estimation method currently available.

- Defined domain of applicability:
Currently there is no universally accepted definition of model domain.  However, users may wish to consider the possibility that property estimates are less accurate for compounds outside the Molecular Weight range of the training set compounds, and/or that have more instances of a given fragment than the maximum for all training set compounds.  It is also possible that a compound may have a functional group(s) or other structural features not represented in the training set, and for which no fragment coefficient was developed.  These points should be taken into consideration when interpreting model results. The complete training sets for MPBPWIN's estimation methodology are not available.  Therefore, describing a precise estimation domain for this methodology is not possible. The current applicability of the MPBPWIN methodology is best described by its accuracy in predicting vapor pressure as described above in the Accuracy section.

- Appropriate measures of goodness-of-fit and robustness and predictivity:
The accuracy of MPBPWIN's "suggested" VP estimate was tested on a dataset of 3037 compounds with known, experimental VP values between 15 and 30 deg C (the vast majority at 25 or 20 deg C).  The experimental values were taken from the PHYSPROP Database that is part of the EPI Suite.  For this test, the CAS numbers were run through MPBPWIN as a standard batch-mode run (using the default VP estimation temperature of 25 deg C) and the batch estimates were compared to PHYSPROP's experimental VP. The plot clearly indicates that the estimation error increases as the vapor pressure (both experimental and estimated) decreases, especially when the vapor pressure decreases below 1x10-6 mm Hg (0.0001333 Pascals).The estimation methodology uses the normal boil point to estimate the liquid-phase vapor pressure.  For solids, the melting point is required to convert the liquid-phase vapor pressure to the solid-phase vapor pressure. VP estimation error can be introduced by:
(1) poor Boiling Point estimates or values
(2) poor Melting Point estimates or values (for solids)
The 3037 compound test set contains 1642 compounds with available experimental Boiling points and Melting points ... For this subset of compounds, the estimation accuracy statistics are (based on log VP):
number = 1642
r2 = 0.949
std deviation = 0.59
avg deviation = 0.32
These statistics clearly indicate that VP estimates are more accurate with experimental BP and MP data.

5. APPLICABILITY DOMAIN
- Descriptor domain:
molecular weight, similarity in structure(i.e. common functinal groups or fragments), boiling point, melting point
- Similarity with analogues in the training set:
The complete training sets for MPBPWIN's estimation methodology are not available. Therefore, describing a precise estimation domain for this methodology is not possible.
The current applicability of the MPBPWIN methodology is best described by its accuracy in predicting vapor pressure as described above in the "Appropriate measures of goodness-of-fit and robustness and predictivity" section.


6. ADEQUACY OF THE RESULT
Since the substance contains common functional groups like the amino or carboxy-group its falls within the applicability domain of the method. Hence, the results obtained here are considered to be reliable.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Method: other (calculated): MPBPWIN (LOGKOW(c)) Program, Version 1.40, Syracuse Research Corporation, Merrill Lane, Syracuse, New York, 13210, U.S.A., 2000

GLP compliance:

no

Type of method:

other: estimation

Key result

Temp.:

25 °C

Vapour pressure:

< 0 hPa

Calculation result (modified Grain method): 1.55E-10 hPa

Conclusions:

According to MPBPVP v1.40 the vapour pressure of N-glycyl-L-tyrosine is < 1.55E-10 hPa at 25°C.

Description of key information

Vapour pressure: < 0.0015 Pa at 20 °C (OECD 104, GLP)

Key value for chemical safety assessment

Vapour pressure:

0.002 Pa

at the temperature of:

20 °C

Additional information

According to OECD Test Guideline 104 (2006) and Regulation (EC) No 440/2008 Method A.4., the Vapour pressure of the test item N-Glycyl-L-tyrosine / (Gly-Tyr) at 20 °C is:
< 0.0015 Pa.