Ethylene antagonists

Purple waxflower
Photo of protective effect of ZSAP2 and 1-MCP on Purple waxflower after 1 day exposure to ethylene.

Summary of technology

Up to 44% of fresh horticultural produce is estimated to be spoiled before it reaches the consumers. Large distances between production and domestic or export markets worsens the quantitative and qualitative post-harvest losses in horticultural commodities.
In nature, the hormone ethylene triggers physiological processes in plants including flower abscission, fruit ripening and senescence. The ability to control the production and action of ethylene allows for the shortening or extension of the storage life of horticultural produce such as fruits, vegetables and cut flowers. Currently the only commercially available inhibitor of ethylene action and fruit ripening is 1-MCP (SmartFresh). It is limited in its use, as it is a gas, which restricts its application to fumigation.
Researchers at Curtin University have discovered a new class of ethylene antagonist which delays ripening and reduces flower drop, dramatically reducing post-harvest losses of horticultural produce. These compounds are used in formulations that extend storage, transport and shelf life of fruits, vegetables and cut flowers.
These compounds can be used as pre-harvest control agents, because they are available in liquid form. By applying to crops the rate of flower, seed or fruit development can be controlled to allow for increasing yields, protecting from plant stresses and enhancing profits to the growers.


These novel compounds have the following advantages:

  • They are solids and liquids, not gases.
  • Improved handling and storage.
  • Can be applied using a range of methods (e.g. fumigation, spray, dip and waxing).
  • Can be used either pre- or post-harvest.

Potential Applications

Post harvest fruits such as apple, nectarines, plums, tomatoes, apples, bananas, pears, papaya, mangoes, peaches, apricots, oranges, lemons, limes, grapefruit, tangerines, kiwifruit, pineapple, persimmon, avocados, melons, berries, cherries; leafy green vegetables such as lettuce, spinach and cabbage, roots such as potatoes and carrots, bulbs such as onions and garlic, herbs such as basil, oregano, dill; legumes such as soybean, lima beans and peas as well as corn, broccoli, cauliflower and asparagus.

Cut flowers such as wax flowers, azalea, hydrangea, hybiscus, snapdragons, poinsettia, cactus, begonias, roses, tulips, daffodils, petunias, carnation, lily, gladiolus, alstroemeria, anemone, columbine, aralia, aster, bougainvillea, camellia, bellflower, cockscomb, falsecypress, chrysanthemum, clematis, cyclamen, freesia, and orchids of the family Orchidaceae and other commercial cultivars, hybrids and newly developed cultivars.

Crops for pre-harvest such as apples, pears, mangos, cherries, pecans, grapes, olives, coffee, snapbeans, oranges, lemons, limes, grapefruit, tangerines and other commercial cultivars; and fibre and oil crops such as cotton, rapeseed, mustard and canola crops.


This innovation is a collaboration between Prof Zora Singh (Department of Environment and Agriculture) and Dr Alan Payne (Department of Chemistry) at Curtin University. Prof Singh has more than 20 years of experience in developing post-harvest solutions which have been adopted into commercial practise for the fruit growing industry in Western Australia. He is a Fellow of Horticultural Society of India. Dr Payne is a synthetic organic chemist who has worked in industry and academia.

Stage of development

A series of compounds have been synthesized and screened in several proof-of-concept studies on stone and pome fruits and waxflowers and are shown to be potent ethylene antagonists.

Experimental results show blocking of ethylene action and production, delayed fruit ripening, and extended storage life of horticultural produce in industry accepted models and also reduce post-harvest drop of buds/flowers in waxflowers. Data for the lead compounds (referred to as ZSAP2) are presented in Figure 1 below.

Intellectual Property

An Australian provisional patent application has been filed which covers the lead compounds.


Curtin is seeking potential partners and licensees to develop and market products incorporating these compounds.

Graphical representation of the protective effect
Graphical representation of the protective effect of ZSAP2 on WX73 and WX107 waxflowers (control, ethylene only, ZSAP2 only and ZSAP2 followed by ethylene).

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