A Study of the Chemical Constituents of Gymnosparm pollens

Abstract

An attempt was made to reassess the nucleic acid contents of pollen materials in this paper, dealing with 6 species of gymnosperm, including 5 species of Pinus and one Gingko species, and one Alnus species of angiosperm as comparison. The starch, water soluble sugar and free amino acid patterns in pollens were examined as well as their lipid compositions and fatty acid patterns of saponified lipids. Results obtained are summarized as follows: 1. The DNA content was around 0.05% on dry weight basis of pollen in 5 species of Pinus. Gingko pollen, however, contained about 3 times as much DNA as in Pinus and Alnus [aponica O. 3%. The discussion was made in relation to the higher DNA content in Gingko pollen. The RNA content comprised ranging from 0.8% to 1. 02% in 5 species of Pinus, while 3.73% in gingko and 0.72% in A. [aponica, indicating exceptionally high RNA content in Gingko pollen. 2. The soluble carbohydrate content in pollen ranged from 11.4% to 16.2%. The pollen starch content varied with a narrow range of 2. 53.5% in 3 species of Pinaceae, but as much as 7.0% in P. koraiensis and as low as low as 0.6 % in P. aurescens. It is noticeable that no starch was detectable in Gingko pollen. 3. The nitrogen content of frce amino acids of pollens comprised 0.38% to 0.51% in 5 species of Pinaceae, while 0.97% and 0.64% in Gingko and A. [aponica, respectively. 4. The total lipid content was in the range of 3.87% to 6.28% in Pinus pollens and 2.39 % in Gingko and A. [aponica., The free fatly acid content was variable from 0.13% to 2.0% in Pinus and 0.26% in Gingko and as low as 0.06% in A. [aponica. The bound and free sterol content of pollens varied considerably O. 3~1. 66% and 0.09-0.2%, respectively and the ratio of bound sterol to free one ranged from 1. 5% to 12.7%, indicating more bound form than free one. 5. The gas chromatograms detected 8 fatty acids in both genera Pinus and Alnus and 11 ones in Gingko, though 7 to 10 fatty acids were identified. The major fatty acids are palmitic acid(25. 0-28.1%), oleic acid(29. 8-41, 5%) and linoleic acid (24.9-33.5%) in Pinus species, while palmitic acid 19.3%, linoleic acid 42.6%, linolenic acid 11%, behenic acid 14% in Gingko, and palmitic acid 11. 6%, oleic acid 16.5%, linoleic acid 43.4%, linolenic acid 26.8% in Alnus [aponica. It is noteworthy that much higher linolenic acid was contained in Gingko pollen with lower oleic acid, as compared with those of Pinaceae, and behenic acid occurred only in Gingko.