Mechanism of 2-acetyl-1-pyrroline biosynthesis in Bassia latifolia Roxb. flowers
- 369 Downloads
The flowers of Bassia latifolia are known to contain 2-acetyl-1-pyrroline (2AP), the compound responsible for pleasant aroma in basmati and other scented rice. Four growth stages of Bassia flowers were identified and 2AP contents were analysed in each stage. It was found that 2AP (3.30 ppm) gets synthesized only in fleshy corolla of mature flowers (fourth stage). The activity of γ-aminobutyraldehyde dehydrogenase (AADH); an enzyme responsible for synthesis of γ-aminobutyricacid (GABA) from γ-aminobutyraldehyde (GABald) was assessed in these four stages. The AADH activity was absent in the fourth stage. It was concluded that ceased activity of AADH in fourth stage flowers leads to the accumulation of γ-aminobutyraldehyde which is cyclised spontaneously to Δ1-pyrroline, the key precursor of 2AP. Δ1-pyrroline further reacts unenzymatically with methylglyoxal to form 2AP.
Keywordsγ-aminobutyraldehyde dehydrogenase Bassia latifolia 2 acetyl-1-pyrroline Biosynthesis SPME
Authors are thankful to Dr. P. Srinivas (Central Food and Technology Research Institute, Mysore, India) for generous gift of authentic 2AP.
- Buttery RG, Juliano BO, Ling LC (1983a) Identification of rice aroma compound 2-acetyl-1-pyrroline in Pandan leaves. Chemistry and Industry (London), p 478Google Scholar
- Fogel WA, Bieganski T, Maslinski C (1979) Effects of inhibitors of aldehyde metabolizing enzymes on putrescine metabolism in guinea pig liver homogenates. Inflamm Res 9(1):42–44Google Scholar
- Ishitani M, Arakawa K, Mizuno K, Kishitani S, Takabe T (1993) Betaine aldehyde dehydrogenase in the gramineae: levels in leaves both betaine-accumulating and nonaccumulating cereal plants. Plant Cell Physiol 34:493–495Google Scholar
- Midya S, Brahmachary R (1996) The aroma of Bassia flower. Curr Sci 71:430Google Scholar
- Schieberle P (1989) Formation of 2-acetyl-1-pyrroline and other important flavor compounds in wheat bread crust. In Thermal generation of aromas pp. 268–275, ACS Symposium series 409. American Chemical Society, WashingtonGoogle Scholar
- Srivong P, Wangsomnuk P, Pongdontri P (2007) Characterization of a fragrant gene and enzymatic activity of betaine aldehyde dehydrogenase in aromatic and nonaromatic Thai rice cultivars. KKU Sci J 36(4):290–301Google Scholar