Suppressive Effect of Constituents Isolated from Kernel of Prunus armeniaca on 5 .ALPHA.-Androst-16-en-3-one Generated by Microbial Metabolism

Abstract

It is well known that body odors are a complex mixture of many kinds of volatile compounds and body odor is also related to the metabolism of microorganisms living on the skin (1-4). Iida et al. (5) reported that the vinyl ketones 1-octen-3-one and cis-1,5-octadien-3-one, which were scented with a strong metallic odor, Abstract: It has recently been reported that 5a-androst-16-en-3-one (androstenone) is a key compound in body malodors, and that female subjects were more sensitive than male subjects to androstenone. Androstenone is generated by the metabolism of a skin-resident microorganism, Corynebacterium xerosis, and apricot kernel extract (AKE) effectively suppressed this metabolism. In this study, AKE was fractionated according to its suppressive activity on androstenone generation in C. xerosis, in order to confirm its active constituents. (R)-Prunasin and (S)-prunasin, which were nitrile compounds, were isolated and identified as the active constituents in AKE and they strongly suppressed the bacterial metabolism. Amygdaline was also isolated as an (R)-and (S)-mixture. This compound is a typical bioactive ingredient in apricot kernel and the structure has one more glucose molecule with b-1,6 bond in contrast to prunasin. However, amygdalin was not included in the active fraction and it did not have any effect on suppressing androstenone generation. Furthermore, neither prunasin nor amygdalin had any bactericidal effect. In addition, the generation of hydrogen cyanide was not detected from either of them during incubation with C. xerosis in the reaction to generate androstenone. Based on these results, we confirmed that prunasin was the active constituent in AKE suppressing the generation of androstenone. The mechanism did not depend on the inhibition of metalloprotein through the generation of hydrogen cyanide from prunasin. This suppressive effect is possibly based on the tertiary structure of prunasin and the structure may influence the metabolic components that are related to the generation of volatile steroids in skin-resident microorganisms. 353 JOS

Polyprenylated Benzoylphloroglucinol-Type Derivatives Including Novel Cage Compounds from <i>Hypericum erectum</i>

“…The IR spectrum of 2 showed absorption bands at 3438, 2); and so on, the same as those of 1. These HMBC results and the molecular formula of 2 indicated that it was a cage compound having a tricyclo[4,3,1,1 3,8 ]undecane carbon skeleton and an endo-peroxide moiety as shown in Fig. 1.…”

“…We isolated interesting polyprenylated benzoylphloroglucinol derivatives and some of them had novel cage structures. Compound 1 has tricycle[3,3,1, 1 3,7 ]decane carbon skeleton (adamantane) and 2, 3 and 8 had a tricycle[4,3,1,1 3,8 ]undecane carbon skeleton (homoadamantane).…”

“…6,7) The suppression effect of cyanogenic compounds from the kernel of Prunus ardelmeniaca, generating the key compound 5a-androst-16-en-3-one (androstenone) by microbial metabolism was reported. 8) Isovaleric acid is a typical malodor component that is also generated from L-leucine by a skin-resident microorganism, Corynebacterium xerosis. Takenaka et al, reported that C. xerosis demonstrated strong ability to generate isovarelic acid and that the natural antimicrobial compounds from Sophora flavescens effectively suppressed the generation of isovaleric acid from L-leucine.…”