Life on Earth is dependent on sunlight. In the process known as photosynthesis, plants,
algae and certain bacterias are capable of using this source of energy to drive the synthesis
of organic compounds. The oxygenic photosynthesis results in the release of molecular
oxygen and the removal of carbon dioxide from the atmosphere that is used to synthesize
Pesticides are divided to insecticides, fungicides, herbicides, rodenticides, acaricides
and nematocides according to the organisms that they affect. There are various forms
of insecticides; most are repellants or insect growth regulators used in agriculture,
public health, horticulture or food storage. It is evident that insecticides have been
used to boost food production to a considerable extent and to control disease vectors.
Mistletoe extracts have immunomodulatory activity. We
show that nontoxic concentrations ofViscumalbumextracts
increase natural killer (NK) cell-mediated killing of tumor
cells but spare nontarget cells from NK lysis. The com-pounds responsible for this bioactivity were isolated from
mistletoe and characterized. They have low molecular mass
and are thermostable and protease-resistant.
B-Sitosterol, stigmasterol and a minor compound 5,6-dehydrokawain were isolated from the ethanol extract of the rhizomes of Alpinia globosa, a medicinal plant of Vietnam. The paper provides characteristic spectra and HPLC profile of the natural -pyrone 5,6- dehydrokawain that would be useful for the purpose of fast determination of this bioactive compound in plant extracts.