Re: thresholds and weights of toxicity risk [message #1990 is a reply to message #1986] |
Thu, 24 August 2023 14:58 |
thomas
Messages: 715 Registered: June 2014
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Senior Member |
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Dear Norwid,
I admit that fitness criteria are not covered by the manual, because originally they were very simple.
The calculated combined toxicity risk of a compound is simply the sum of risk contributions from the 4 toxicity classes (mutagenic, tumorigenic, irritant, and reproductive effective. A low risk contributes 1, a higjh risk contributes 2 to the combined score. Thus, a non-existing combined risk would be 0 and the very unlikely theoretical maximum is 8.
Threshold may be fractional numbers, because they describe the sigmoid curve that translate the risk (0...8) into a fitness (1...0)
The determination, whether a compound is assigned a no, low or high risk is based on a statistical approach based on whether and which fragments are present from a predefined fragment list, which are frequently found in toxic compound of the particular toxicity class.
Hope, this explains it somewhat...
[Updated on: Thu, 24 August 2023 14:58] Report message to a moderator
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