Lichenes/lichens

D. are condensation products of aromatic hydroxy-carboxylic acids in which the carboxy group of the acidic molecule (S) is esterified by the phenolic hydroxy group of the 2nd acidic molecule (A, alcohol). Depending on the number of hydroxycarboxylic acids in the molecule distinction is made between di- and tridep-sides and on the linkage between para- and meta-de-psides. D. occur mainly in lichens ( lichen substances) where the substituents in the above formula can be r, R =CHj, n-CjH, n-CsH, R, R =H, CHj, CHO,... 

Section 7.2 deals with issues related to secondary metabolites (phytochemicals) from lichen. Lichen compounds and extractives because they possess some biological effects will form also the focus of this section. How they influence biological host and agents would be described briefly in the latter part of this section with proper X-ray of various reported agents of lichen otigm that display antiviral activities. The exact sources of these compounds and extractives would be fully elucidated. Here, we will lightly also mention yet-to-be-validated lichen-derived compounds with speculated or rumored antiviral property. This perhaps may inspire further comprehensive screening of such to fully validate their claims. 

Henningsson, B., and Lundstrom, H. (1970). The influence of lichens, lichen extracts, and usnic acid on wood destroying fungi. Mater. Organismen 5, 19-31. 

They are called didepsides, tridepsides, poly-depsides, etc., depending on the number of phenol residues they contain. Obtained from lichens, present in tea. 

It is found in lichens and in some algae. It has m.p. 120 C, is very soluble in water and is about twice as sweet as sucrose. It is a reference compound upon which the erythro nomenclature is based. 

H02C(CH2)2C02H. Colourless prisms m.p. 182 C, b.p. 235°C. Occurs in amber, algae, lichens, sugar cane, beets and other plants, and is formed during the fermentation of sugar, tartrates, malates and other substances by a variety of yeasts, moulds and bacteria. Manufactured by the catalytic reduction of maleic acid or by heating 1,2-dicyanoethane with acids or alkalis. Forms an anhydride when heated at 235°C. Forms both acid and neutral salts and esters. Used in the manufacture of succinic anhydride and of polyesters with polyols. 

Chemical Designations - Synonyms Allomaleic acid Boletic acid trans-Butenedioic acid trans-1,2-Ethylenedicarboxylic acid Lichenic acid Chemical Formula H02CCH=CHC02H. 

Flechte, /. lichen plait, twist skin eruption, flechten, v.t. plait, twist, braid, interweave, Flechten-far toffi m. lichen coloring matter, -rot, n, orcein, -saure, /. fumaric acid (old name). -stSrkemehl, n. lichenin, moss starch, -stoffe, m.pl. lichen substances. 

Lackmus, m., -farbstoff, m. litmus, -fiechte,/. litmus lichen, archil, -losung, /. litmus solution. -papier, n. litmus paper. 

Mooa-pflanzen, f.pl. Boi.) Bryophyta. -pul-ver, n, lycopodium powder. -Starke, /. lichen starch, lichenin. -tierchen, n. Zobl.) bryo-zoan, polyzoan. -torf, m. peat, peat turf, surface peat, -wuchs, m. mossy growth, moralisch, a. moral ethical. 

Finne, K., Goransson, K. and Winckler, L. Oral Lichen Planus and Contact Allergy to Mercury , International Journal of Oral Surgery, 11, 236-39 (1982)... 

Frykholm, K. O., Frithiof, L. Fernstrom, A. I. B., Moberger, G., Blohm, S. G. and Bjorn, E. Allergy to Copper Derived from Dental Alloys as a Possible Cause of Oral Lesions of Lichen Planus Acta Dermatovenerol, 49, 268-81 (1969)... 

Constant dripping of rain water contaminated by atmospheric pollution (e.g. from near-by chimney stacks) or by organic acids from lichens, etc. 

Lead in building can be corroded by organic acids from new wood, decaying wood and lichens see Sections 9.3 and 18.10). This is a common phenomenon with run-off from lichens which grow on tiles and slates. Where this occurs, a sacrificial strip of lead has been advocated... 

To date, 152 species of flowering plants belonging to 46 different families, as well as a few species of mushrooms, mosses, ferns, and lichens, have been screened. Extracts from 20 seed plants have shown enough inhibitory activity to warrant further study. Leaf extracts of members of three families, Liliaceae, Pinaceae, and Labiateae, show a high incidence of antiviral agents. Several members of the Capri-foliaceae, on the other hand, contain virus-stimulating agents. 

Ei addition, clinical observations in EFN-a-treated hqiatitis C or melanoma patients have suggested a promoting effect of type I EFN in autoreactive skin disorders such as Lichen planus. This inflammatory skin disease was, however, not restricted to EFN-a treated patients but was found to be associated with expression by so far unknown mechanisms of the EFN-induced MxA... 

Acitretine ch3o x x Oral 0.25-1.0 mg/kg/d Psoriasis (erythrodermic, pustular, and severe recalcitrant) Palmoplantar keratoderma pustulosis palmoplantaris, icthyosis, Darier s disease, pityriasis rubra pilaris, lichen ruber planus... 

Pemphigus, bullous dermatitis herpetiformis, severe erythema multiforme (Stevens-Johnson syndrome), exfoliative dermatitis, mycosis fungoides, severe psoriasis, severe seborrheic dermatitis, angioedema, urticaria, various skin disorders, such as lichen planus or keloids... 

Allomaleic acid 2-butenedioic acid trans-butenedioic acid boletic acid lichenic acid trans-l,2-ethenedicarboxylic acid... 

Auch Aluminiumhydrid reduziert Carbonsaure-amide ohne Nebenreaktionen zu Aminen. Es kann vorteilhaft zur selektiven Reduktion ungesattigter Verbindungen an-gewendet werden, da es im Gegensatz zu Diboran C,C-Mehrfachbindungen unter den iib-lichen Reaktionsbedingungen nicht angreift. 

Pustulan (a glucan from the lichen Umbilicaria pustulata)... 

Recently, there has been much interest in developing water-soluble tributyltin biocides to lessen the costs of application, and to prevent fire hazards when treating material in confined spaces. Bis(tributyltin) oxide itself has a very low aqueous solubility ( 0.001%), but it may be made water-dispersible by the addition of certain (534, 535) quaternary ammonium salts. Formulations of this type, although currently under development as wood preservatives (534), have been used extensively in the United Kingdom for the treatment of stonework to eradicate fungal growths, algae, mosses, and lichens (535). 

Using FmA catalysis and protected 4-hydroxybutanal, compound (97) has been stereoselectively prepared as a synthetic equivalent to the C-3-C-9 fragment of (-F)-aspicillin, a lichen macrolactone (Figure 10.35) [160]. Similarly, FruA mediated stereoselective addition of (25) to a suitably crafted aldehyde precursor (98) served as the key step in the synthesis of the noncarbohydrate , skipped polyol C-9-C-16 chain fragment (99) of the macrolide antibiotic pentamycin [161,162]. 

Figure 10.35 Stereoselective generation of chiral precursors for the synthesis of the lichen macrolactone (+)-aspicillin and the macrolide antibiotic pentamycin using FruA catalysis.

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