4 hydroxy 3 5 dimethoxyacetophenone

The 4′-hydroxy-3′,5′-dimethoxyacetophenone (97%), 2-hydroxy-4-diethylamino-benz- aldehyde (98%), citric acid (>99.5%), boric acid (H₃BO₃, >99.5%), trisodium phosphate (Na₃PO₄, 96%), ammonia aqueous solution (25%), polyvinyl alcohol (PVA, Mw 89,000–98,000; 98% + hydrolyzed), chitosan (high molecular weight), starch from potatoes (soluble), and glycerol (99.5%) were purchased from Sigma Aldrich (Steinheim am Albuch, Germany). Sulfuric acid (H₂SO₄, 95–97%), acetic acid (CH₃COOH, 98%), and microcrystalline cellulose were acquired from Merck KGaA (Darmstadt, Germany). Methanol (MeOH, >99%) and diethyl ether (>99%) were purchased from CHIMREACTIV SRL (Bucuresti, Romania).
All chemicals, reagents, and solvents were used as purchased, without further purification, for the synthesis and preparation of samples.

4′-hydroxy-3′,5′-dimethoxyacetophenone (97%), 2,3-dihydroxybenzaldehyde (97%), 2,4-dihydroxybenzaldehyde (98%), 2,5-dihydroxybenzaldehyde (98%), 2,3,4-trihydroxybenzaldehyde (98%), 2-hydroxy-3-methoxybenzaldehyde (98%), 2-hydroxy-4-methoxybenzaldehyde (98%), citric acid (>99.5%), boric acid (H₃BO₃, >99.5%), trisodium phosphate (Na₃PO₄, 96%) iodine (I₂, 99.8%) and potassium iodide (KI, (>99%) were purchased from Sigma–Aldrich (Steinheim am Albuch, Germany). Sulfuric acid (H₂SO₄, 95–97%) and acetic acid (CH₃COOH, 98%) were acquired from Merck KGaA (Darmstadt, Germany). methanol (MeOH, >99%) and ethylene glycol (>99%) were purchased from CHIMREACTIV SRL (Bucuresti, Romania). HPLC grade solvents (methanol, acetonitrile) were used for the LC–MS measurements, and formic acid was of LC–MS grade; all were Sigma–Aldrich (Steinheim am Albuch, Germany).
All chemicals, reagents, and solvents were used without further purification.
The dye-sensitized solar cells were purchased from Solaronix (Aubonne, Switzerland) (Test Cell Kit 74991). The anode was made of FTO glass on which TiO₂ was deposited; their active area was 0.36 cm². The cathode was made of FTO glass with Pt deposited onto it.

Agro‐infiltration experiments were performed as described in van Herpen et al. (2010). In brief, Agrobacterium strains were grown at 28°C at 220 rpm for 48 h in LB media with spectinomycin/rifampicin (100 mg/L). Cells were collected by centrifugation for 20 min at 2000 g (15°C) then resuspended (10 mm MES, 10 mm MgCl₂ and 100 μm 4′‐hydroxy‐3′,5′‐dimethoxyacetophenone; Sigma) to a final OD₆₀₀ of 0.5, followed by incubation for 2 h (50 rpm, RT). For co‐infiltration, equal volumes of the Agrobacterium strains were mixed. In all experiments, an Agrobacterium strain harbouring a gene encoding the TBSV P19 protein was added to suppress gene silencing (Qu and Morris, 2002). N. benthamiana plants were grown from seeds on soil in a greenhouse with 16‐h light at 28°C (16 h)/25°C (8 h). Strain mixtures were infiltrated into leaves of 4‐week‐old N. benthamiana plants using a 1‐mL syringe. The plants were grown under greenhouse conditions until further analysis.
Arabidopsis (Columbia‐0) stable transformants were obtained by floral dipping using Agrobacterium containing the 35S:AtTPS21 plasmid (Liu, 2011). Primary transformants were screed in vitro on (½ MS 1% agar) plates containing 50 μg/mL kanamycin, and selected transformed lines were made homozygous. The production of (E)‐β‐caryophyllene was confirmed in Arabidopsis as described latter for N. benthamiana.