Plant Hormones Abscisic Acid Auxins Cytokinins Ethylene Gibberellins

Gibberellin nomenclature

GA1 GA2 GA3 GA4 GA5 GA6 GA7 GA8 GA9 GA10 GA11 GA12 GA13 GA14 GA15 GA16 GA17 GA18 GA19 GA20 GA21 GA22 GA23 GA24 GA25 GA26 GA27 GA28 GA29 GA30 GA31 GA32 GA33 GA34 GA35 GA36 GA37 GA38 GA39 GA40 GA41 GA42 GA43 GA44 GA45 GA46 GA47 GA48 GA49 GA50 GA51 GA52 GA53 GA54 GA55 GA56 GA57 GA58 GA59 GA60 GA61 GA62 GA63 GA64 GA65 GA66 GA67 GA68 GA69 GA70 GA71 GA72 GA73 GA74 GA75 GA76 GA77 GA78 GA79 GA80 GA81 GA82 GA83 GA84 GA85 GA86 GA87 GA88 GA89 GA90 GA91 GA92 GA93 GA94 GA95 GA96 GA97 GA98 GA99 GA100 GA101 GA102 GA103 GA104 GA105 GA106 GA107 GA108 GA109 GA110 GA111 GA112 GA113 GA114 GA115 GA116 GA117 GA118 GA119 GA120 GA121 GA122 GA123 GA124 GA125 GA126 GA127 GA128 GA129 GA130 GA131 GA132 GA133 GA134 GA135 GA136


Gibberellins are assigned A-numbers in order of discovery according to the system proposed by MacMillan and Takahashi (Nature 217, 170-171, 1968).

Numbers will be assigned to novel GAs for which evidence is presented for their natural occurrence and an unequivocal assignment of structure. Identification can be established by:

Retention Indices

Retention indices can be obtained from capillary GC-MS to provide additional criteria for identification. To overcome variations in column temperature and flow-rate, the retention index procedure of Kovats(1958) is recommended.

A solution of each n-alkane from C16 to C36 is co-injected with the sample and the retention times of the n-alkanes peaks are recorded. The retention time of the peak of interest is also recorded.

The retention index is calculated with the following formulae.

Cx = (Rt(peak of interest) - Rt(preceding n-alkane) + Cn(preceding n-alkane)x ) / ( Rt(following n-alkane) - RT(preceding n-alkane) )

Cx × 100 = Retention index.

Reference: Kovats E (1958) Gas chromatographische Charakteriserung organischer Verbindungen.I.Retentions indices aliphatischer halogenide, alkohole, aldehyde und ketone Helv Chim Acta 41: 1915-1932