Q1 · June 2019 · 2 marks
Reaction of deoxymonosaccharide A with 2 equivalents of \mathbf{H I O}_{4} affords propanedial, formic acid and formaldehyde. The structure of A is
- (a)
- (b)
- (c)
- (d)
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Answer: (a)
CSIR NET Chemical Science — Natural Products previous year questions
29 questions · 2011–2019 · all with verified answer · last checked 2026-11-10
Q2 · Dec 2019 · 2 marks
The natural product that gives signal at \delta 218 \mathrm{ppm} in its { }^{13} \mathrm{C} \mathrm{NMR} spectrum
- (a) \alpha-pinene
- (b) camphor
- (c) geraniol
- (d) carvone
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Answer: (b)
Q3 · Dec 2018 · 2 marks
The keto-hexose among the following is
- (a) Xylose
- (b) Galactose
- (c) Fructose
- (d) Mannose
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Answer: (c)
Q4 · June 2017 · 2 marks
The correct match of natural products in Column-I with their biosynthetic precursors in Column-II is Columnn-I Column-II
- (a)
I. I-Lysine II. L-Ornithine A-IV, B-I - (b)
III. Farnesyl IV. Geranyl pyrophosphate A-IV, B-II - (c) A-III, B-I
- (d) A-III, B-II
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Answer: (a)
Q5 · June 2017 · 2 marks
Among the following, the natural product that is a steroid and contains an \alpha,\beta-unsaturated ketone is
- (a) estrone
- (b) prostaglandin
- (c) cortisone
- (d) morphine
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Answer: (c)
Q6 · June 2017 · 2 marks
The major product formed in the reaction of D-glucose with 2 ZnCl in MeOH is a methyl glucopyranoside (A or B). The structure of this product and the molecular orbital interaction present between ring-oxygen and the anomeric C-O bond responsible for its stability, respectively, are 
A B
A B - (a) A and \mathbf{n} \rightarrow \sigma *
- (b) A and \mathbf{n} \rightarrow \sigma
- (c) B and n → σ *
- (d) B and n \rightarrow \sigma
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Answer: (c)
Q7 · Dec 2017 · 2 marks
The following natural product Enterodiol is a
- (a) terpene
- (b) steroid
- (c) lignan
- (d) alkaloid
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Answer: (c)
Q8 · Dec 2017 · 2 marks
The structure of ribonucleoside uridine is
- (a)
- (b)
- (c)
- (d)
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Answer: (b)
Q9 · Dec 2016 · 2 marks
Correct characteristics of the functional groups of adenine in DNA base pair are
- (a) \mathrm{N}(3) is a hydrogen bond acceptor and \mathrm{C}(6) \mathrm{NH}_{2} is a hydrogen bond donor.
- (b) \mathrm{N}(1) is a hydrogen bond acceptor and \mathrm{C}(6) \mathrm{NH}_{2} is a hydrogen bond donor
- (c) Both \mathrm{N}(3) and \mathrm{C}(6) \mathrm{NH}_{2} are hydrogen bond acceptors
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Answer: (b)
Q10 · Dec 2016 · 2 marks
The correct match for the following is
| Column-A | Column-B | |
| (i) | Camphor | (A)Structural protein |
| (ii) | Insulin | (B) Hormone |
| (iii) | keratin | (C) Enzyme |
| (D) Steroid | ||
| (E) Terpene |
- (a) (i)-(A); (ii)-(C); (iii)-(E)
- (b) (i)-(E); (ii)-(B); (iii)-(A)
- (c) (i)-(D); (ii)-(C); (iii)-(A)
- (d) (i)-(E); (ii)-(B); (iii)-(D)
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Answer: (b)
Q11 · June 2015 · 2 marks
Antitubercular drug(s) among the following is (are)
- (a) Salbutamol A and B
- (b) Ethambutanol B and C
- (c) Isoniazid C and D
- (d) Diazepam D alone
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Answer: (c)
Q12 · Dec 2015 · 2 marks
The correct match for the compounds in column A with the description in column B is Column A Column B (P) 
(X) Oil of Wintergreen (Q) 
(Y) Aspirin (R) 
(Z) Ibuprofen
(X) Oil of Wintergreen (Q) (Y) Aspirin (R) (Z) Ibuprofen - (a) P-Y, Q-Z, R-X
- (b) P-Z, Q-X, R-Y
- (c) P-Z, Q-Y, R-X
- (d) P-X, Q-Z, R-Y
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Answer: (b)
Q13 · June 2014 · 2 marks
Atorvastatin (structure given below) is a 
- (a) cholesterol lowering drug
- (b) blood sugar lowering drug
- (c) anti-plasmodial drug
- (d) anti-HIV drug
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Answer: (a)
Q14 · Dec 2014 · 2 marks
The biosynthetic precursor of abietic acid is
- (a) Shikimic acid
- (b) Mevalonic acid
- (c) Chorismic acid
- (d) Cinnamic acid
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Answer: (b)
Q15 · Dec 2014 · 2 marks
The amino acid constituents of artificial sweetener given below are 
- (a) D-Glutamic acid and L-phenylglycine
- (b) L-Glutamic acid and L-phenylalanine
- (c) L-Aspartic acid and L-phenylalanine
- (d) L-Aspartic acid and L-tyrosine
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Answer: (c)
Q16 · June 2013 · 2 marks
Match the following drugs with their medicinal activity
- (a) 5-fluorouracil (i) Anti-bacterial A-i, B-ii
- (b) Amoxicillin lowering (ii) Cholesterol (iii) Anticancer (iv) Anti-inflammatory A-iv, B-iii
- (c) A-iii, B-iv
- (d) A-iii, B-i
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Answer: (d)
Q17 · June 2013 · 2 marks
The biosynthetic precursor for the steroids is
- (a) secologanin
- (b) shikimic acid
- (c) mevalonic acid
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Answer: (c)
Q18 · June 2013 · 2 marks
Number of isoprene units present in lupeol is 
- (a) two
- (b) four
- (c) six
- (d) eight
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Answer: (c)
Q19 · June 2013 · 2 marks
\boldsymbol{\alpha}-Pinene on reaction with dilute alkaline \mathbf{K M n O}_{4} produces a diol, which on further oxidation with chromium trioxide gives product A, which undergoes a positive haloform test. The compound A is
- (a)
- (b)
- (c)
- (d)
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Answer: (c)
Q20 · June 2013 · 2 marks
The major product formed in the reaction of guanosine with one equivalent of methyl iodide is
- (a)
\mathrm{I}^{\ominus} - (b)
- (c)
- (d)
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Answer: (a)
Q21 · June 2013 · 2 marks
Reaction of the dipeptide, given below, with hydrogen in the presence of \mathbf{1 0} \boldsymbol{\%} palladium over carbon, produces a mixture of 
- (a) Gly-Leu + toluene + carbon dioxide
- (b) Phe-Leu + toluene + carbon dioxide
- (c) Phe-Leu + benzyl alcohol + carbon dioxide
- (d) Gly-Leu + benzyl alcohol + carbon dioxide
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Answer: (b)
Q22 · Dec 2013 · 2 marks
For estrone, among the statements A-C, the correct ones are
- (a) It is a steroidal hormone A, B and C
- (b) It has two hydroxyl groups A and B
- (c) It has one ketone and one hydroxyl groups A and C
- (d) B and C
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Answer: (c)
Q23 · Dec 2013 · 2 marks
The peptide A on reaction with 1-fluoro-2, 4-dinitrobenzene followed by exhaustive hydrolysis gave phenylalanine, alanine, serine and N -(2, 4-dinitrophenyl) glycine. On the other hand, pepetide A after two cycles of Edman degradation gave Phe-Ser as the product. The structure of the peptide A is
- (a) Phe-Ser-Ala-Gly
- (b) Phe-Ser-Gly-Ala
- (c) Gly-Ala-Phe-Ser
- (d) Ala-Gly-Phe-Ser
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Answer: (c)
Q24 · June 2012 · 2 marks
Among the following, the amino acid which is basic in nature is:
- (a) Tyrosine
- (b) Asparagine
- (c) Leucine
- (d) Arginine
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Answer: (d)
Q25 · Dec 2012 · 2 marks
Degradation of penicillin G gives penicillamine that can utilize nitrogen, oxygen or sulfur atoms as donors to bind with lead (II), mercury (II) or copper(II). The structure of penicillamine is
- (a)
- (b)
- (c)
- (d)
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Answer: (a)
Q26 · Dec 2012 · 2 marks
The biosynthetic precursor of cadinene is: 
Cadinene
Cadinene - (a) shikimic acid
- (b) mevalonic acid
- (c) arachidonic acid
- (d) prephenic acid.
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Answer: (b)
Q27 · Dec 2012 · 2 marks
A tripeptide gives the following products on Edman degradation. 
The tripeptide is
The tripeptide is - (a) Phe-Ala-Gly
- (b) Phe-Gly-Ala
- (c) Ala-Gly-Phe
- (d) Glv-Ala-Phe
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Answer: (a)
Q28 · Dec 2012 · 2 marks
Match the following (i) \boldsymbol{\beta}-amyrin
- (a) alkaloid; secondary alcohol (ii) squalene (i)-(C), (ii)-(D), (iii)-(B), (iv)-(A)
- (b) alkaloid, phenol (iii) morphine (i)-(B), (ii)-(A), (iii)-(C), (iv)-(D)
- (c) triterpene, secondary alcohol (iv) ephedrine (i)-(C), (ii)-(B), (iii)-(D), (iv)-(A)
- (d) acyclic triterpene, polyene (i)-(A), (ii)-(D), (iii)-(B), (iv)-(C)
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Answer: (a)
Q29 · June 2011 · 2 marks
The major product formed on nitration \left(\mathbf{H N O}_{\mathbf{3}} / \mathbf{H}_{\mathbf{2}} \mathbf{S O}_{\mathbf{4}}\right) of uridine followed by reduction with tin and \mathbf{H C l} is:
- (a)
- (b)
- (c)
- (d)
Show answer
Answer: (c)
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