Geranium species

Figure 10. Structure of Geraniin, an Insect Growth Inhibitor Isolated from Geranium Species...

Geraniin (26) (Fig. 12.10), a hydrolyzable tannin from the leaves of Geranium species, releases ellagic acid on hydrolysis. Ellagic acid (10) is an antinutritional factor because of its ability to bind essential metals (Harbome, 1989). 

Bate-Smith EC 1981 Astringent tannins of the leaves of Geranium species. Phytochemistry 20 211-216... 

Extracts from 152 plant species, representing 46 different families, were screened for effects on tobacco mosaic virus (TMV) replication in cucumber cotyledons. Twenty species have shown enough activity to warrant further study. Several members of the Caprifoliaceae family increased virus replication. An extract of Lonicera involucrata enlarged the virus lesions in local lesion hosts and produced a thirty fold increase in virus titer, but had no effect on virus replication in systemic hosts. The active material appears to affect the virus defense mechanism of local lesion hosts. An extract of common geranium is an active virus inhibitor. It inactivates TMV and TMV-RNA (ribonucleic acid) in vitro by forming non-infectious complexes. In vivo, it also inhibited starch lesion formation in cucumber cotyledons incited by TMV infection. 

Target species Geraniums, tomatoes, eggplant, peppers, and potatoes. 

One advantage that secondary metabolites should have is that, when biosynthetic pathways are known, it is possible to identify events that have evolutionary implications. It has always been attractive, therefore, fo consider the use of numerical mefhods in assessing the implications of chemical profiles. An early example of fhis was an analysis of the flavonoids of Geranium by Bate-Smith (1973), in which flavonoid scores were produced for each species based on the presence or absence of individual flavonoids. These scores were used to identify the relative advancement of individual species. 

Confirmatory evidence has been provided for the revised structure of a guaiadiene (428) present in geranium oil/ Another component of costus oil has been identified as the triene acid (429) and an isomer (430) of guaioxide (cf. Vol. 1, p. Ill) has been isolated from the roots of a Ligularia species/ ... 

In absence of flower, A. naviculare is often confused with associated species of Geranium and Delphinium. Shepherds are the main collectors of this plant for use in individual households. They bring the plant material down to the village and share with relatives and privileged people in the society. Sometimes, they send dry material of A. naviculare to their relatives in Kathmandu, the capital city of Nepal. 

The worker in the essential oils soon learns that commercial geranium oils are extracted from several species, varieties, and strains of Pelargonium and not from Geranium... 

We have shown that genetically controlled biochemical compounds in geraniums confer resistance to the two-spotted spider mite. Initial discovery of mite susceptibility among breeding materials led to an assessment of variation both at the genus and species levels. This... 

Issues relating to the properties and conditions for use of sorbic acid as a preservative in wine have been described elsewhere (Volume 1, Section 9.2.3). This adjuvant to SO2 protects wine from fermentation in the presence of yeast, but has no effect on bacterial activity. Furthermore, it is broken down by lactic bacteria, developing a very unpleasant smell reminiscent of geranium leaves. All species of lactic bacteria occurring in wine seem capable of causing this reaction. The use of sorbic acid must therefore be restricted to sweet wines, in conjunction with a sufficiently high dose of SO2 to prevent any bacterial activity. 

Well-known eudesmane derivatives in flavors and fragrances include a- and p-selinene from the oils of Cannabis saliva var. indica (Moraceae), celery (Apium graeveolens, Umbelliferae) and hops (Humulus lupulus, Moraceae), (+)-a- and (+)-P-eudesmol from some oils of eucalyptus (Eucalyplus macarlhuri), (-)-epi-y-eudesmol with its woody odor from the north African oil of geranium (Pelargonium odoralissimum and allied species), and the almost odorless diastereomeric (+)-y-eudesmol from various ethereal oils (+)-p-Costus acid and (+)-p-costol belong to the constituents of the essential oil obtained from the roots of Saussurea... 

Enantioselective GC has found a wide variety of applications, for instance, studies of citronellol (Ravid et al., 1992) and a-terpineol (Ravid et al., 1995) in a variety of species and verbenone in rosemary oils (Ravid et al., 1997). Chiral phases were applied to the separation of linalool and linalyl acetate in a variety of plant species (Konig et al., 1992 Cassabianca et al., 1998), extracts of Angelica seeds and roots (Holm et al., 1997) and other monoterpenoids in geranium oils (Kreis Mosandl, 1993). Separation of monoterpenes in Scots pine and juniper oils (Hiltunen Laakso, 1995), Abies (Holm et al., 1994) and Picea (Persson et al., 1996) oils and limonene, linalool, citronellal and P-citronellol Cymbopogon winterianus)... 

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