Hydrangenol

China Hydrangea macrophylla (Thunb.) Seringe Febrifugin, hydrangeic acid, hydrangenol, rutin.50 Antimalarial, antitussive, diuretic. 

When 10 /J. of hydrangenol and 10 /J. of gibberellin, in appropriate concentrations, were placed separately at the base of the first sheath of d-1 maize, elongation of the second leaf sheath increased with increased concentrations of... 

Figure 4. Mean length of fully expanded second leaf sheath of d-1 mutant maize treated with gibberellin tmd hydrangenol...

Hydrangenol is not the only chemical that acts in this manner. p-Coumaric acid, cinnamic acid, and / -hydroxyethylhydrazine (Figure 5) increased the activity of gibberellin applied to Meteor pea. 

Dormancy in yam bulbs (Dioscorea batatas) was found to be induced by three inhibitors, batatasins I, II, and III (72, 73). The structures for batatasins I and III were assigned recently. Batatasin I is 6-hydroxy-2,4,7-trimethoxyphenanthrene and batatasin III is 3,3-dihydroxy-5-methoxy-bibenzyl. Biogeneti-cally, hydrangenol, lunalaric acid and batatasin III appear to... 

H, Kakegawa, H. Matsumoto, and T. Satoh. Inhibitoty effects of hydrangenol derivative on the activation of hyalumnidaae and thrir antiallergic actlvitiei. Plante Med. 54 385 (1988). 

Those that have been identified in recent times include flavonoids,212-214 aurothiomalate,215 hydrangenol,216 occurring in the leaves of Hydrangea, tannins,217 derivatives of tranilast,218 curcumin,219 an extract of the spice turmeric, glycyrrhizin,220 found in the roots and rhizomes of licorice (Glycyrrhiza glabra), used as an effective antiinflamatory agent in Chinese medicine. 

Kakegawa, H., Matsumoto, H., and Satoh, T., Inhibitory effects of hydrangenol derivatives on the activation of hyaluronidase and their antiallergic activities, Plant. Med., 54, 385, 1988. 

Bisbenzyl (Phe-CH2-CH2-Phe) compounds include dihydroresveratrol (4,3, 5 -trihydroxybisbenzyl) and the allergenic benzopyranone hydrangenol from Hydrangea... 

Substituted 3,4-dihydroisocoumarins are produced by the radical-promoted reaction between ethyl 2-bromomethylbenzoates and aldehydes. A total synthesis of naturally-occurring hydrangenol has been achieved in this way <07TL4131 >. 

The directed metalation of aromatic systems that was discussed in Section 2.1.3.3 has one ramification that was not mentioned there the directed lithiation of an o-methyl group. Although the resultant species is formally a resonance-stabilized anion, and therefore covered in Volume 2 of this series, we mention it here for consistency with the other topics covered. In particular, the examples that have appeared in recent years involve substrates having a methyl ortho to a tertiary amide. Intentional use of such a directed lithiation has been used in the synthesis of the isocoumarin natural products hydrangenol and pyllodul-cin.137,138 Interestingly, the directed metalation of 5-methyl-oxazoles and -thiazoles occurs in preference to deprotonation at a 2-methyl group (azaenolate) (Scheme 33). ... 

Cyanide toxicity due to accidental exposure is unexpected. Patients ingesting hydrangea may develop vomiting and epigastric soon after exposure. Allergic contact dermatitis due to the sensitizer, hydrangenol, has been reported. 

Knoevenagel condensation. DBU was used as the base for the condensation of dimethyl 3-hydroxyhomophthalate (1) with p-benzyloxybenzaldehyde (2). Note that this reaction is not successful with p-hydroxybenzaldehyde. The condensation was the first step in a synthesis of hydrangenol (4), a component of a variety of Hydrangea Hortensia D.C. ... 

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