Surface comparisons of some odour molecules: Conformational calculations on sandalwood odour V

Abstract

Molecular surface comparison seems to be a very suitable tool for the investigation of small differences between biologically active and inactive compounds of the same structural type. A fast method for such comparisons, based on volume matching followed by the estimation of comparable surface dots, is presented and applied on a few selected sandalwood odour molecules.

Structure−Odor Relationships

“…The discovery of the above new synthetic sandalwood odorant assisted Buchbauer and his co-workers in the conformational analysis of several sandalwood compounds. − 8- tert -Butylbicyclo[4.4.0]decanol (BBD) is an extremely rigid molecule: only the tert -butyl group and the hydroxyl group are free to rotate. Both of these rotations can be neglected because rotation of the symmetrical tert -butyl group leads to identical conformations and rotation of the hydroxyl group does not significantly change the shape of the molecule.…”

“…(2) The molecular surface of structurally similar but inactive compounds deviate considerably from the calculated mean surface of sandalwood odorants. , …”

“…248 (2) The molecular surface of structurally similar but inactive compounds deviate considerably from the calculated mean surface of sandalwood odorants. 249,250 (3) The surface region around the hydroxyl group and a part of the hydrophobic bulky group seem to be very important in determining the sandalwood odor of a molecule. Other parts of the molecular surface can tolerate greater surface variations.…”

Some Aspects of the Molecular Surface of Sandalwood Odour Molecules. Conformational Calculations on Sandalwood Odour VII

“…The examination o f molecular surfaces seems to be a very promising tool for the investigation of sandalwood odour molecules [1][2][3][4]. These com pounds usually contain terpenoid structures with a polar group, often a hydroxyl group, and a rather hydrophobic voluminous residue at the other side of the molecule.…”

Conformational Parameters of the Sandalwood‐Odor Activity: Conformational calculations on sandalwood odor

“…From earlier studies 1161, it was postulated that in these mixtures only the isomers with largest similarity to the rigid standard molecule A possess strongest sandalwood odor, whereas the other isomers show a much weaker odor impression or even no sandalwood scent. The comparison of these isomers with A was performed on the base of comparable molecular surfaces [9], and the similarity postulate was found to be valid, e.g., for the explanation of the odor difference of the optical isomers ofp-santalol [14]. The most rigid compound 6a -(tert-butyl)-trans-perhydronaphthalen-2a -01 (A) [ neighborhood of the OH group, and a part of the bulky aliphatic group (P3).…”