Graduate Thesis Or Dissertation
 

Polyphenols from the bark of Douglas-fir and red alder

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/cv43p193k

Descriptions

Attribute NameValues
Creator
Abstract
  • The objectives of this research were to isolate and determine the molecular structures of certain polyphenols in Douglas-fir and red alder barks. The compounds of interest in Douglas-fir were the lignans which are eventually incorporated into the outer bark phlobaphenes. Phlobaphenes are the red colored, alcohol soluble, water insoluble phenolic polymers in conifer outer bark. They are commonly believed to be formed by oxidative coupling reactions of polyphenols in the bark. Four neolignan glycosides were isolated and identified from the methanol extract of Douglas-fir inner and outer bark. In addition several other non-lignan type polyphenols were isolated and identified which likely play a role in phlobaphene formation. The compounds of interest in red alder bark were the diarylheptanoid glycosides which have potential medicinal and adhesive value. The methanol extract yielded five new diarylheptanoids glycosides compounds. The isolations were carried out by column chromatography and the molecular structures determined by use of ¹H and ¹³C Nuclear Magnetic Resonance Spectroscopy, Fast Atom Bombardment Mass Spectroscopy, and enzymic hydrolysis of the parent glycosides. These results showed that a variety of polyphenol types, including neolignans which may be phlobaphene precursors, are present in Douglas-fir bark. This information suggests that most of the polyphenols in Douglas-fir bark can be used to make water-proof, formaldehyde free, wood adhesive polymers once we understand the molecular structures and reactions of these natural renewable substances. The diarylheptanoid compounds isolated from red alder bark belong to a class of compounds which have a history of biological activity. These compounds now provide a basis for further systematic testing for pharmaceutical value in future research. The structures of the polyphenols in red alder also give insight into how these polyphenols, and red alder bark, can be used to make new types of wood adhesives copolymers.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using ScandAll PRO 1.8.1 on a Fi-6670 in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details GonzalezLaredoRubenFrancisco1994.pdf 2017-10-20 Public Download