extraction of martinella obovata bark naomi bryner
TRANSCRIPT
Extraction of Martinella obovata barkNaomi Bryner
Overview - Genus
Bignoniaceae family 120 genera, 800 species
Found in Central and South America Tropical rainforests
Versatile plant Horticulture, food, crafts,
timber, dyes, rituals, and medicine
Overview - Species
Eye medication 13 ethnolinguistic
groups
8 S. American countries
Amazon Indian tribes
‘yuquilla’
From fleshy root bark Stripped, pounded, and
strained
Applications for curing conjunctivitis Martinelline
Martinellic acid
Research goals
Investigate processes for pre-extraction treatment of root bark
Develop a protocol for extraction
Perform FCC and identify useful fractions via TLC
Isolate martinelline and martinellic acid
Characterize the compounds via spectroscopic methods
Pre-extraction treatment
Dr. Halligan’s provisions John Beck @ SBC
Stripping bark from twigs and branches Tedious & timely
37.3 g bark material obtained
Milling the plant material Blender & solvent
Extraction
Merck Research Labs 1995
CH2Cl2/MeOH (1:1)
Bark & solvent Sat @ rt overnight
Filtered out solids
Evaporated to drier conditions 6.09 g slimy residue
Fractionation
Solvent search
Round 1 HE/EtOAc (1:1)
CH2Cl2/MeOH (95:5)
Round 2 HE/EtOAc (2:1)
HE/EtOAc (4:1)
Round 3 HE/EtOAc (8:1)
FCC
Column Length – 30 cm
Diameter – 6 cm
Silica gel – 18 cm
Sand – 1 cm
Gradient (Hex/EtOAc) Tubes 1-20 (8:1)
Tubes 21-138 (4:1)
Tubes 139-156 (1:1)
Tubes 157-160 EtOAc
TLC Analysis – Hex/EtOAc (4:1)
Treated with vanillin stain
F1
F2
F4
F3
F6 F5
F5
Solvated fractions111 to 160 turnedfrom pale greento pale then darkyellow. The transitionoccurred at F6,making F6 visually difficult to classifyas either color.
Fraction summary
F1: Fractions 3-12 Blue/black on TLC plate
Rf = 0.69
Oily yellow, 0.9508 g
F2: Fractions 35-49 Pink on TLC plate
Rf = 0.33
Pale green powder, 1.0286 g
F3: Fractions 73-84 Pink/red on TLC plate
Rf = 0.13
Thin yellow film, 0.0471 g
F4: Fractions 111-125 Discard – same Rf as F5 & F6
Much fainter on TLC plate
Solvated fraction pale in color
F6: Fractions 126-130 Pink/red on TLC plate
Rf = 0.10
Dark green powder, 0.2404 g
F5: Fractions 131-160 Pink/red on TLC plate
Rf = 0.08
Yellow/tan powder, 0.9731 g
Fraction 1 – NB1-6-2
NH
N
HO
O
NH
NH
HN
HN
NH
Martinellic acid
NH
N
O
O
NH
NH
HN
HN
NH
HN
HN
NH
Martinelline
Fraction 2 – NB1-6-3
NH
N
HO
O
NH
NH
HN
HN
NH
Martinellic acid
NH
N
O
O
NH
NH
HN
HN
NH
HN
HN
NH
Martinelline
Fraction 3 – NB1-6-4
NH
N
HO
O
NH
NH
HN
HN
NH
Martinellic acid
NH
N
O
O
NH
NH
HN
HN
NH
HN
HN
NH
Martinelline
Fraction 5 – NB1-6-6
NH
N
HO
O
NH
NH
HN
HN
NH
Martinellic acid
NH
N
O
O
NH
NH
HN
HN
NH
HN
HN
NH
Martinelline
Fraction 6 – NB1-6-7
NH
N
HO
O
NH
NH
HN
HN
NH
Martinellic acid
NH
N
O
O
NH
NH
HN
HN
NH
HN
HN
NH
Martinelline
Final thoughts
Conclusions IR analysis was
inconclusive
NMR study was cut short
F5 & F6 comparison May be multiple
compounds present
May apply to more fractions
Future Work
HPLC to complete isolation UV-vis
Identify! LC-MS
Complete NMR
Antibacterial properties Potency
Killing mechanism
References
(1) Arevalo, C.; Ruiz, I.; Piccinelli, A.; Campone, L.; Rastrelli, L. Phenolic derivatives from the leaves of Martinella obovata (Bignoniaceae). Natural Product Communications, 2011, 6:7, 957-960.
(2) Gentry, A. H. A synopsis of Bignoniaceae ethnobotany and economic botany. Annals of the Missouri Botanical Garden, 1992, 79, 53-64.
(3) Gentry, A.H.; Cook, K. Martinella (Bignoniaceae): A widely used eye medicine of South America. Journal of Ethnopharmacology, 1984, 11, 337-343.
(4) Witherup, K.; Ransom, R.; Graham, A.; Bernard, A.; Salvatore, M.; Lumma, W.; Anderson, P.; Pitzenberger, S.; Varga, S. Martinelline and martinellic acid, novel G-protein linked receptor antagonists from the tropical plant Martinella iquitosensis (Bignoniaceae). Journal of the American Chemical Society, 1995, 117, 6682-6685.
(5) Ma, D.; Xia, C.; Jiang, J.; Zhang, J. First Total Synthesis of Martinellic Acid, a Naturally Occurring Bradykinin Receptor Antagonist. Organic Letters, 2001, 3:14, 2189-2191.
(6) Zhang, Z.; Zhang, Q.; Yan, Z.; Liu, Q. One-Step Synthesis of the Tricyclic Core of Martinellic Acid from 2-(Cyanomethyl)-3-oxo-N-arylbutanamides. Journal of Organic Chemistry, 2007, 72, 9808-9810.
(7) Ma, D.; Xia, C.; Jiang, J.; Zhang, J.; Tang, W. Aromatic Nucleophilic Substitution or CuI-Catalyzed Coupling Route to Martinellic Acid. Journal of Organic Chemistry, 2003, 68, 442-451.
(8) Davies, S.; Fletcher, Ai.; Lee, J.; Lorkin, T.; Roberts, P.; Thomson, J. Asymmetric Synthesis of (-)-Martinellic Acid. Organic Letters, 2013, 15:8, 2050-2053.
(9) Powell, D.; Batey, R. Total Synthesis of the Alkaloids Martinelline and Martinellic Acid via a Hetero Diels-Alder Multicomponent Coupling Reaction. Organic Letters, 2002, 4:17, 2913-2916.
(10) Yee Ng, Pui.; Masse, C.; Shaw, J. Cycloaddition Reactions of Imines with 3-Thiosuccinic Anhydrides: Synthesis of the Tricyclic Core of Martinellic Acid. Organic Letters, 2006, 8:18, 3999-4002.
(11) Shirai, A.; Miyata, O.; Tohnai, N.; Miyata, M.; Procter, D.; Sucunza, D.; Naito, T. Total Synthesis of (-)-Martinellic Acid via Radical Addition-Cyclization-Elimination Reaction. Journal of Organic Chemistry, 2008, 73, 4464-4475.
(12) Lovely, C.; Mahmud, H. An approach to the pyrroloquinoline core of martinelline and martinellic acid. Tetrahedron Letters, 1999, 40, 2079-2082.