**3. Materials and Methods**

NMR spectra were recorded on a Bruker Avance-400 (400.13 MHz) and on a Bruker DRX-600 equipped with a TXI CryoProbe in CDCl3 and in CDCl3:CD3OD 1:1 (δ values referred to CHCl3 and CH3OH at 7.26 and 3.34 ppm respectively). HR-MS spectra were acquired by a Q-Exactive Hybrid Quadrupole-Orbitrap mass spectrometer (Thermo Scientific, Waltham, MA, USA). TLC plates (Kieselgel 60 F254) and silica gel powder (Kieselgel 60, 0.063–0.200 mm) were from Merck.

All the reagents were purchased from Sigma-Aldrich and used without any further purification. DLS measurements were performed with a homemade instrument composed with a Photocor compact goniometer, a SMD 6000 Laser Quantum 50 mW light source operating at 5325 Å, a photomultiplier (PMT-120-OP/B) and a correlator (Flex02-01D, Correlator.com).

### *3.1. Dynamic Light Scattering (DLS)*

Measurements were performed at (25.00 ± 0.05) ◦C with temperature controlled through the use of a thermostat bath. In DLS, the intensity autocorrelation function, g(2)(t), was measured for the instrument configuration corresponding to the scattering angle of 90◦. The intensity autocorrelation function is related to the electric field autocorrelation function through the Siegert relation. The electric field autocorrelation function, g(1)(t), is defined as

$$g^{(1)}(t) = \int\_{-\infty}^{+\infty} \tau A(\tau) \exp\left(-\frac{t}{\tau}\right) \mathbf{d} \, \ln \tau \tag{1}$$

where τ = 1/Γ and *q* is the modulus of the scattering vector *q* = 4λ*<sup>n</sup>*0/λ *sin* (θ/2)*, n*0 = 1.33 is the refractive index of the solvent, λ is the incident wavelength and θ represents the scattering angle. Evaluation of the relaxation rate Γ distribution allows calculating the translational diffusion coefficient: *D* = <sup>Γ</sup>/*q*2: (J. B. a. R. Pecora, Dynamic Light Scattering: With Applications to Chemistry, Biology, and Physics, Couvire Dover Publications, 2003.)

Inverse Laplace transforms were performed using a variation of the CONTIN algorithm incorporated in Precision Deconvolve software. For spheres diffusing in a continuum medium at infinite dilution, in the approximation of spherical objects, the diffusion coefficient is related to the hydrodynamic radius, *Rh*, through the Stokes–Einstein equation:

$$R\_h = \frac{kT}{6\pi\eta\_0 D} \tag{2}$$

where *k* is the Boltzmann constant, *T* is the absolute temperature and η0 = *0.89cP* is the solvent viscosity. For not spherical particles, *Rh* represents the radius of a spherical aggregate with the same diffusion coefficient measured. In the present system, due to the high dilution, it is possible to consider the approximation that η η0, where η represents the solution viscosity. In this hypothesis, Equation (2) can be reasonably used to estimate the averaged hydrodynamic radius of the particles.

### *3.2. Synthetic Procedures and Characterization of Intermediates 4–7, (S)-1,2-O-Distearoyl Glycerol and Pure Sulfavant S (3)*

Compound **4:** Sodium hydride (0.235 g, 0.01 mol) was portion-wise added to (*S*)-(+)-1,2- isopropylideneglycerol (0.6 g, 0.00457 mol) dissolved in THF (7.5 mL), and after 30 min of stirring benzyl bromide (0.85 g, 0.005 mol) was added; after 20 h at 60 ◦C the mixture was evaporated and purified by silica gel chromatography using a light petroleum ether/diethyl ether gradient to give **4** (1.0 g, 0.0045 mol, 94%); 1H-NMR (400 MHz, CDCl3): δ 7.19–7.08 (5H, overlapped), 4.38 (2H, bs), 4.12 (1H, m), 3.86 (1H, m), 3.58 (1H, m), 3.38 (1H, m), 3.30 (1H, m), 1.27 (3H, s), 1.20 (3H, s); HRESIMS *m*/*z* 245.1140 [M + Na]+ (calcd for C13H18O3Na<sup>+</sup>, 245.1148).

Compound **5:** Compound **4** (1.0 g, 0.0045 mol) was dissolved in methanol/water 95/5 (7 mL) and Dowex H<sup>+</sup> (7.3 g) was added; after stirring for 1.5 h the mixture was filtered and evaporated giving compound **5** (0.762 g, 0.0042 mol, 93%); 1H-NMR (400 MHz, CDCl3): δ 7.29–7.17 (5H, overlapped, Ph), 4.58 (2H, bs), 3.86 (1H, m), 3.60 (1H, m), 3.52 (1H, m), 3.44 (2H, m); HRESIMS *m*/*z* 205.0829 [M + Na]+ (calcd for C10H14O3Na<sup>+</sup>, 205.0835).

Compound **6:** Compound **5** (0.762 g, 0.0042 mol) was dissolved in anhydrous dichloromethane (7 mL) before addition of 1.1 equiv. of stearic acid, *N,N'*-dicyclohexylcarbodiimide (1.0 g, 0.008 mol) and 4-dimethylaminopyridine (0.51 g, 0.0042 mol) under argon. The reaction mixture was stirred for 16 h at 25 ◦C; after evaporation under reduced pressure, the mixture was purified by silica gel chromatography using a gradient of petroleum ether/diethyl ether to give compound **6** (2.76 g, 0.0039 mol, 92%) as pale-yellow oil. 1H-NMR (400 MHz, CDCl3): δ 7.29–7.17 (5H, overlapped, Ph), 5.28, (1H, m, H-2), 4.57 (2H, CH2Bn), 4.39 (1H, dd, = 3.76 and 11.8 Hz, H-1a), 4.23 (1H, dd, *J* = 6.4 and 11.8 Hz, H-1b), 3.63 (2H, bd, *J* = 5.2 Hz, H-3), 2.33 (4H, m, α-methylene), 1.63 (4H, m, β-methylene), 1.28–1,32 (56H, m, acyl chains CH2), 0.83 (6H, overlapped, acyl chains CH3); HRESIMS *m*/*z* 737.6062 [M + Na]+ (calcd for C46H82O5Na<sup>+</sup>, 737.6054).

(*S*)-1,2-*O*-distearoyl glycerol**:** Compound **6** (2.76 g, 0.0039 mol) was dissolved in THF/MeOH 1/1 (25 mL) and Pd-C (10%) (0.350 g) was added; after stirring for 16 h at 25 ◦C the mixture was filtered, evaporated and purified by silica gel chromatography using a light petroleum ether/ethyl acetate gradient to give (*S*)-1,2-*O*-distearoyl glycerol (0.875 g, 0.0014 mol, 35%); 1H-NMR (400 MHz, CDCl3): δ 5.1 (1H, m, H-2), 4.32 (1H, dd, *J* = 4.4 and 11.9 Hz, H-1a), 4.23 (1H, dd, *J* = 5.8 and 11.9 Hz, H-1b), 3.72 (2H, bd, *J* = 4.8 Hz, H-3), 2.33 (4H, m, α-methylene), 1.63 (4H, m, β-methylene), 1.21–1.35 (56H, m, acyl chains CH2), 0.85 (6H, overlapped, acyl chains CH3); HRESIMS *m*/*z* 647.5591 [M + Na]+ (calcd for C39H76O5Na<sup>+</sup>, 647.5585).

Compound **7:** Peracetylated glucosyl-trichloroacetimidate (0.491 g, 0.001 mol) and (*S*)-1,2-*O*- distearoyl glycerol (0.625 g, 0.001 mol) were dissolved in anhydrous dichloromethane (15 mL), and the solution was kept at 0 ◦C; then, trimethylsilyl trifluoromethanesulfonate (TMSOTf) (35 μL in 1.5 mL of CH2Cl2) was added dropwise. The reaction mixture was stirred on activated 3 Å molecular sieves under argon for 5 h at 0 ◦C and quenched adding triethylamine (150 μL); after evaporation under reduced pressure the crude product was purified by silica gel chromatography using a gradient of petroleum ether/diethyl ether to give compound **7** (0.430 g, 0.00045 mol, 45%). 1H-NMR (300 MHz, CDCl3): δ 5.19 (1H, m), 5.06 (1H, overlapped), 4.99 (1H, t, *J* = 9.5 Hz), 4.88 (1H, dd, *J* = 9.5 and 7.9 Hz), 4.52 (1H, d), 4.02–4.32 (4H, overlapped), 3.93 (1H, dd, *J* = 11.0 and 4.9 Hz), 3.68 (2H, m), 2.3 (4H, m, α-methylenes) 1.98–2.02 (12H, bt), 1.60 (4H, m, β-methylenes), 1.32–1.22 (56H, acyl chains CH2), 0.89 (6H, overlapped, acyl chains CH3); HRESIMS *m*/*z* 977.6545 [M + Na]+ (calcd for C53H94O14Na, 977.6541).

Sulfavant S **(3**): white solid; 1H-NMR (400 MHz, CD3OD/CDCl3 1/1): δ values are referred to CHD2OD (3.34 ppm and 49.0 ppm): δ 5.28 (1H, m, H-2), 4.40 (1H, dd, *J* = 2.7, 12.0 Hz, H-1a), 4.31 (1H, d, *J* = 7.6 H-1), 4.24 (1H, dd, *J* = 6.9, 12.0 Hz, H-1b), 4.05 (1H, dd, *J* = 5.4, 11.0 Hz, H-3a), 3.79–3.71 (3H, H-3b, H-3, H-4), 3.41 (1H, bt, *J* = 8.9 Hz, H-2), 3.26 (1H, overlapped, H-6a), 3.25 (1H, overlapped, H-5), 3.09 (1H, dd, *J* = 7.2, 15.7 Hz, H-6b), 2.36–2.27 (4H, α-methylenes of stearoyl portions), 1.65–1.56 (4H, β-methylenes of stearoyl portions), 1.36–1.20 (60H, aliphatic methylenes), 0.89 (6H, bt, *J* = 6.0 Hz, 2CH3); 13C-NMR (100MHz, CD3OD:CDCl3 1:1): δ 174.1, 173.7 (C, acyl esters of stearoyl part), 103.2 (CH, C1), 76.1 (CH, C2), 73.8 (CH, C5), 72.4 (CH, C3), 72.3 (CH, C4), 70.2 (CH, C2), 68.2 (CH2, C3), 63.2 (CH2, C1), 53.6 (CH2, C6), 34.2 (CH2, α-methylene of stearoyl portion), 32.2–29.0 (CH2, methylenes of stearoyl portion), 24.9 (CH2, β-methylene of stearoyl portion), 13.8 (CH3, methyls of stearoyl portion); HRESIMS *m*/*z* 849.5772 [M-K]- (calcd for C45H85O12S-, 849.5767).
