Extraction of Martinella
obovata bark
Naomi 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
FCC
 Column
 Round 1
 Length – 30 cm
 HE/EtOAc (1:1)
 Diameter – 6 cm
 CH2Cl2/MeOH (95:5)
 Silica gel – 18 cm
 Round 2
 Sand – 1 cm
 HE/EtOAc (2:1)
 Gradient (Hex/EtOAc)
 HE/EtOAc (4:1)
 Tubes 1-20 (8:1)
 Round 3
 HE/EtOAc (8:1)
 Tubes 21-138 (4:1)
 Tubes 139-156 (1:1)
 Tubes 157-160 EtOAc
TLC Analysis – Hex/EtOAc (4:1)
F1
F2
F3
F4
F5
F6
Solvated fractions
111 to 160 turned
from pale green
to pale then dark
yellow.
The transition
occurred at F6,
making F6 visually
difficult to classify
as either color.
F5
Treated with
vanillin stain
Fraction summary
 F1: Fractions 3-12
 F4: Fractions 111-125
 Blue/black on TLC plate
Rf = 0.69
 Discard – same Rf as F5 & F6
Much fainter on TLC plate
 Oily yellow, 0.9508 g
 Solvated fraction pale in color
 F2: Fractions 35-49
 F6: Fractions 126-130
 Pink on TLC plate
Rf = 0.33
 Pink/red on TLC plate
Rf = 0.10
 Pale green powder, 1.0286 g
 Dark green powder, 0.2404 g
 F3: Fractions 73-84
 F5: Fractions 131-160
 Pink/red on TLC plate
Rf = 0.13
 Pink/red on TLC plate
Rf = 0.08
 Thin yellow film, 0.0471 g
 Yellow/tan powder, 0.9731 g
Fraction 1 – NB1-6-2
Fraction 2 – NB1-6-3
Fraction 3 – NB1-6-4
Fraction 5 – NB1-6-6
Fraction 6 – NB1-6-7
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

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
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
(3) Gentry, A.H.; Cook, K. Martinella (Bignoniaceae): A widely used eye medicine of South America.
Journal of Ethnopharmacology, 1984, 11, 337-343.

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