Guaiac, Backout tree – Guajacnm officinale L., G. sanctum L.
Distribution – Antilles, Lesser Antilles and Bahamas, Florida, Venezuela, Colombia. Cultivated within the range and in India.
Trees 6 to 10 m tall. Leaves opposite, 2-3-paired (in G. sanctum 3-7-paired); flowers are blue, 5-petal, collected in apical umbrellas. The fruit is characteristic, obverse heart-shaped, two-celled, with two swollen ridges-ribs along the edges, decomposing into 2 or 4-5 (G. sanctum) parts.
The raw material is wood (Lignum Guajaci) – very heavy (sinks in water), unable to split. Comes in the form of shavings of a greenish-yellow color; the taste is scratchy, the smell is characteristic.
The wood contains within 25% resins, saponins and an essential oil rich in azulene. Resin is extracted from crushed wood, traditionally by boiling in water. Comes in the form of small pieces of dark green color, relative density 1.20-1.24, taste bittersweet, turning into scratchy; when heated, an aromatic smell appears.
Resina Guajaci contains up to 70% guaiac resin acid, which is a lingan resinol derived from diphenylbutene:
Upon receipt of the resin, azulenes also partially pass into it. Among the minor components – gum up to 4-5%.
Wood is a source of guaiazulene. A decoction of wood and a tincture of resin are prescribed for rheumatism and gout. The alcohol solution of the resin in the presence of oxidizing agents changes color from brown to bright blue. This property is used in analytical practice.
The plant contains balsams (oil-resins).
PLANTS CONTAINING RESINS AND BALMS
Like essential oils, resins are complex mixtures of various organic compounds. In plants, they are often present simultaneously with essential oils, but may be accompanied by substances from other groups of natural compounds – gums, tannins, sterols, sometimes rubber.
According to the primary composition, there are three main groups of natural resins:
– resins (actually) – Rsina;
– oil-resin, or balms, – Olea-resina, or Balsama. These are liquid resins, which are natural solutions of resins in their own essential oil;
– gum resins – Gummi-resina. These are liquid (in living plants) mixtures of gums and resins dissolved in essential oil (more precisely, Cummi-olea-resina).
The resins themselves, freed from accompanying substances, like the components of essential oils, are also terpenoids, but more complex, belonging mainly to the class of diterpenes (C 20 H 32 ).
Resin hydrocarbons (for example, pimaradiene), their oxygen derivatives, resinol or resin acids (for example, abietic and pimaric acids) and resinol or resin alcohols (for example, cafestol) are distinguished among resin diterpenes.
Among the resinols, rezitannols or tannols, which have the properties of tannins, are distinguished into a special group. Resinols can form esters.
The constituent substances of resins can be triterpene acids and alcohols – derivatives of a- and b-amirin (for example, mastic tree), lignans (for example, guaiac resin), etc.