{'fraction_non_alphanumeric': 0.03920061491160646, 'fraction_numerical': 0.027671022290545733, 'mean_word_length': 4.674418604651163, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Methyl Perillate as a Highly Functionalized Natural Starting Material for Terephthalic Acid.

Renewable commodity chemicals can be generated from plant materials. Often abundant materials such as sugars are used for this purpose. However, these lack appropriate functionalities and, therefore, they require extensive chemical modifications before they can be used as commodity chemicals. The plant kingdom is capable of producing an almost endless variety of compounds, including compounds with highly appropriate functionalities, but these are often not available in high quantities. It has been demonstrated that it is possible to produce functionalized plant compounds on a large scale by fermentation in microorganisms. This opens up the potential to exploit plant compounds that are less abundant, but functionally resemble commodity chemicals more closely. To elaborate this concept, we demonstrate the suitability of a highly functionalized plant compound, methyl perillate, as a precursor for the commodity chemical terephthalic acid.


Leaf extraction
Fresh leaves ≤ 3 cm were snap frozen in liquid nitrogen and ground with pestle and mortar.
139.8 mg of powder was extracted with 6 mL pentane containing 4.66 µg/mL cis-nerolidol as internal standard for analysis by GC-MS.

Essential oil distillation
Hydrodistillation was performed on lab-scale according to Stahl (Stahl, 1962). Hundred grams of fresh Salvia dorisiana leaves ≤ 3 cm were cut. The leaves were cooked in 1 L demi water in a 2 L round bottom flask for 1 h without organic solvent, and afterwards the pure essential oil layer was removed from the 4°C cooling bulb with a long Pasteur pipette. The essential oil was dried over a MgSO4 column, and the oil yield in w/w% of fresh weight (FW) of the leaves determined, average yield from one distillation 0.13 g (0.13 w/w%).
Steam distillation was performed for larger-scale oil harvesting, in a home-made kettle and cooling system [http://indekoperenketel.nl/]. Tap water (30 L) was heated to 100°C and the steam lead through 16.34 kg of Salvia dorisiana prunings during 1 h. Steam with extracted volatiles was then cooled-down gradually to 10-15°C. The water layer of the condensate was continuously removed by a separation funnel during distillation. The water layer was extracted one time with diethyl ether, and this was combined with the oil layer. The solvent was evaporated and the essential oil was dried over MgSO4, yield 10.7 g (0.065 w/w%).

Quantification of monoterpenes
The oil was diluted to 53.2 μg/mL in pentane for analysis by GC-MS. A standard series of limonene, methylperillate, perillyl alcohol, perillyl aldehyde and perillyl acetate was prepared ranging from 0.1-50 μg/mL in pentane. Oil and leaf compounds were quantified using a linear and 2 nd order polynomal fitted equation from the standard series.

GC-MS analysis
GC-MS analysis of essential oil was performed on a 7890A gas chromatograph (Agilent) equipped with a mass selective detector (Model 5975C, Agilent) with settings as reported previously (Jongedijk et al., 2015).  Perillic acid was esterified with excess methanol, using toluenesulfonic acid as catalyst (Dayal et al., 1981). Perillic acid (3.00 mmol, 0.50 g) was dissolved in methanol (0.32 mol, 13 mL) and p-toluenesulfonic acid (0.15 mmol, 0.029 g), stirred (350 rpm) and heated to reflux (65 °C) for 22 h under N2. The solution was cooled to room temperature and diluted with 12 mL chloroform, washed twice with saturated sodium bicarbonate (15 mL) and once with brine (15 mL). The organic layer (bottom) was diluted with chloroform to 20 mL, dried with magnesium sulphate and filtered. The solvent was removed using a rotary evaporator at 40 ˚C.
The slightly-yellow oil was identified by GC-MS. A by-product was detected, that was identified as 8-methoxy-methylperillate by NMR and GC-MS. The product mixture was separated on column (