Which of the following is not steroid -

Ans. is 'c' i.e., Leukotrians o Steroids are complex molecules consisting of four fused carbon rings.o There is a phenanthrene nucleus made of three six-membered rings (A,B,C, rings), and a cyclopentane which forms Dring.o The fully saturated parent compound (steroid) is known as cyclopentanoperhydrophenathrene.o The alcohol derivatives of steroids, in which one or more OH groups are present in the steroids nucleus, are termed sterols, i.e. sterols are a class of steroids containing hydroxy (OH) groupQ,o Cholesterolergosterol, coprosterol and sitosterol are some important sterols.o In animal tissues, Cholesterol is the major sterolQ. Functionally, cholesterol is a very important molecule being precursor of a variety of steroids -Steroid hormones Progesterone, estrogen, androgens (TestosteroneQ, glucocorticoids, mineralocorticoids.Bile acids:- Cholic acid0,Chenodeoxycholic acidQVitamin Do So, all above mentioned compounds have cyclopentanoperhydrophenanthrene nucleus.