Листя троянди

Two leaf absolutes carry the name rose leaf absolute: one from Rosa centifolia and one from Rosa damascena, the Damask rose. Absolutes are similar to essential oils but have a higher concentration, up to 80-90% of aromatic substances, and a lower volatility.

The plants

Rosa × centifolia, the cabbage rose, has a shrubby appearance, with greyish green pinnate leaves bearing 5-7 leaflets. The Damask rose, Rosa × damascena, has pinnate leaves with five (rarely seven) leaflets.

Green leaf chemistry

Green leaf volatiles are organic compounds released by plants. They include C6 aldehydes such as (Z)-3-hexenal and n-hexanal, and derivatives such as (Z)-3-hexenol and (Z)-3-hexen-1-yl acetate. In plants, lipoxygenase adds dioxygen at position 13 of linolenic acid to give linolenic acid 13-hydroperoxide. Hydroperoxide lyase cleaves this compound at the C12-C13 bond, and one of its primary products, (Z)-3-hexenal, can be reduced to (Z)-3-hexenol. A portion of the (Z)-3-hexenol is further converted to (Z)-3-hexenyl acetate.

cis-3-Hexenol, also called leaf alcohol, has the CAS number 928-96-1. It is a colorless oily liquid with an intense grassy-green odor of freshly cut green grass and leaves. Most plants produce it in small amounts.

Toxicity

In rats, the oral LD50 of the Rosa centifolia leaf absolute is above 5000 mg/kg.

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