chemaxon.calculations.pka

class RequiredPkaType(enum.IntEnum):

Pka types to be calculated. This is the input option for the pka function.

ACIDIC = <RequiredPkaType.ACIDIC: 0>

Calculate only acidic pKa values

BASIC = <RequiredPkaType.BASIC: 1>

Calculate only basic pKa values

PKA = <RequiredPkaType.PKA: 2>

Calculate both acidic and basic pKa values

class PkaType(enum.IntEnum):

pKa types of the calculated pKa values. This is the type of the pKa function's result.

ACIDIC = <PkaType.ACIDIC: 0>

Acidic pKa value

BASIC = <PkaType.BASIC: 1>

Basic pKa value

class PkaValue:

PkaValue

PkaValue( atom_index: int, pka_type: PkaType, value: float)
atom_index: int

Index of the atom

pka_type: PkaType

Pka type

value: float

Pka value

class PkaResult:

PkaResult

PkaResult(result: chemaxon.calculations.pka._CPkaResult)
pka_values: list[PkaValue]

List of all pka values

structure: chemaxon.molecule.Molecule

The input structure extended by pka values as atomic properties

def acidic_values(self):

Returns acidic pka values sorted by their value in ascending order

def basic_values(self):

Returns basic pka values sorted by their value in descending order

def min_acidic(self):

Returns the acidic pka value with the lowest value

def max_basic(self):

Returns the basic pka value with the highest value

def pka( mol: chemaxon.molecule.Molecule, consider_tautomerization: bool = False, is_micro: bool = False, is_large_model: bool = False, basic_min: float = -10.0, acidic_max: float = 20.0, number_of_acidic_values: int = 2, number_of_basic_values: int = 2, temperature: float = 298, required_pka_type: RequiredPkaType = <RequiredPkaType.PKA: 2>) -> PkaResult:

pKa calculation.

Most molecules contain some specific functional groups likely to lose or gain proton(s) under specific circumstances. Each equilibrium between the protonated and deprotonated forms of the molecule can be described with a constant value called p K a. The pka function calculates the pKa values of the molecule based on its partial charge distribution.

Link: https://docs.chemaxon.com/display/docs/calculators_pka-plugin.md

Parameters
  • mol: Molecule - Input molecule
  • consider_tautomerization: bool - Whether to consider tautomerization and resonance during pKa calculation
  • is_micro: bool - Whether to calculate micro-pKa values. In case of false, macro-pKa values will be calculated.
  • is_large_model: bool - Whether to use large pKa model.
    • small: optimized for at most 8 ionizable atoms
    • large: optimized for a large number of ionizable atoms
  • basic_min: float - Minimum basic pKa value to be considered
  • acidic_max: float - Maximum acidic pKa value to be considered
  • number_of_acidic_values: int - Number of acidic pKa values to be displayed
  • number_of_basic_values: int - Number of basic pKa values to be displayed
  • temperature: float - Temperature in Kelvin
Returns

PkaResult