deterrents from fungi and plants Flashcards
fungal antibiotics
penicillin
insecticides
tobacco pyrthrum neem rotenone mint oils
penicillin
- fungal mold
- history in treatment of infected wounds
- ebers papyrus -used for wounds and skin problems 4700years ago
- staphylococcus aureus
- alexander fleming discovered it accidentally
- pill or needle
cloxacillin
resistant to the b-lactamase enzyme produce by some penicillin resistance bacteria
ampicillin
has a greater range of activity and was the first penicillin derivative to be effective against gram negative bacteria
ticarcillin
developed to treat difficult gram-negative bacterial infections
after the discovery of penicillin
- new antibiotics were obtained from various species of soil bacteria
- streptogramin antibacterials such as streptomycin from genus streptomyces
- vancomycin from actinomycetales
in situ
culturing of soil bacteria has led to the discovery of a number of potential anti-bacterial drugs - teixobactin
- highly toxic to gram positive
- harmless to mammalian tissue
- a potentially important source of new drugs is the higher plants ,but few have been investigated in detail
tobacco
-solanaceous annual herb (tomato or solanaceae fam)
-stimulant drug
-tobacco wash (leavens soaked in water) sprayed onto fruit trees
-mixing powered tobacco leaves with stored cereal grains to protect them from pest attack
-alkaloid nicotine
-seen as highly poisonous
-black leaf 40-40% concentration of nicotine sulfate-marketed as relatively safe
-harmful to human so the production decreased and a synthetic alternative used instead (neonicotine sulfate)
malathion and dichlorodiphenyltrichloroethan (DDT)
nicotine
- absorbed through direct contact or by ingestion
- acetylcholine receptor agonist (mimic) that results in acetylcholine accumulation
- leading to paralysis and death
neonicotinoids
safer, semi-synthetic nicotine
- first major insecticide to be introduced since 1950’s
- in 2003-clothianidin and thiamethoxam-used on corn and soybean crops in the USA
- imidacloprid-worlds must widely used insecticide- less toxic to mammals than insects
Pyrethrum
- herbaceous composite
- native in asia
- widely cultivated in africa and South America
- german women noticed dead insects near her tanacetum flowers
- concentrated in the flowering heads and hand harvested
- most popular natural insecticide in the early 20Th century
- these contact insecticides are neurosensor blockers-axonic poisons; they keep the sodium channels open wich results in repeated firing of the nerve cells and eventual insect paralysis
- biodegradable -low toxicity to birds and mammals
- high doses can be dangerous to humans
- toxic to fish
semi synthetic pyrethrin
allethring and permethring and transfluthrin
- ten times more effective than natural pyrethrin
- control animal ectopasasites: flea collars for pets, insecticidal dips for domestic animals and mosquito coils
neem
- fast growing tree native to indian subcontinent
- 25-30 m
- frost intolerant, prefers hot, arid environments and sandy soils
- very tolerant species, but grows best in humid tropical regions
- according to hindu mythology-the neem tree is of divine origin
- recovered from archeological excavations dating 4000 years ago
- many parts of the plant used in traditional ayurvedic med
- neem oil and leaves used to deter insencts in granaries
- also used in cosmetics
- proven less successful than hoped (refined material is expensive to make and neem based are slow actin)
biopiracy of neem
american patent law does not recognize oral tradition, meaning that companies in india would be completely excluded from the american market (kadidal 1998)
-would lipohilic solvent extraction be considered and innovation
