Carotenoids from Guava (Psidium guajava L.):  Isolation and Structure Elucidation

Abstract

Sixteen carotenoids were isolated from the flesh of Brazilian red guavas (Psidium guajava L.). Their structures were established by means of UV-visible, 400 and 500 MHz (1)H NMR, 120 and 125 MHz (13)C NMR, mass, and circular dichroism spectra. The carotenoids were identified as phytofluene, (all-E)-, (9Z)-, (13Z)-, and (15Z)-beta-carotene, (all-E)-gamma-carotene, (all-E)-, (9Z)-, (13Z)-, and (15Z)-lycopene, (all-E,3R)-beta-cryptoxanthin, (all-E, 3R)-rubixanthin, (all-E,3S,5R,8S)-cryptoflavin, (all-E,3R,3'R, 6'R)-lutein, (all-E,3S,5R,6R,3'S,5'R,8'R)-, and (all-E,3S,5R,6R,3'S, 5'R,8'S)-neochrome. Thirteen of the carotenoids identified are reported as guava carotenoids for the first time.

Determination of Antioxidant Capacity, Total Phenolics and Antimicrobial Properties of Spray-Dried Guava Extract for Value-Added Processing

“…The spray dried guava powder showed 264.3 mg/100 g of polyphenolic content, previous study on comparative analysis of antioxidant activity and composition of red and yellow strawberry guava fruits also reported (501.33 mg/100g and 292 mg/100 g) of polyphenolic content, this values are in close agreement, and processed guava fruit powder in our study is beneficial to be used as function food product. The reason of better retention of total phenol content during spray drying process at high temperature is encapsulation with carrier agent maltodextrin, since long duration of cooking at high temperatures had been observed as the main causes of loss of nutrients which causes disruption of cell wall and breakdown of biochemical compounds, also the 1 step processing of spray drying reduces the time of contact of high temperature with sample and reduces losses of essential components [25]. Other reports also show total phenol content of 100 to 320 mg/100 g on a fresh weight basis for blackberry, blueberry, and strawberry before and after processing [26].…”

Metabolic profile of lettuce leaves by high-field NMR spectra

“…Lutein and lactucaxanthin were identified on the basis of three 1 H signals correlated in TOCSY and assigned to the terminal group (on the right of the chemical structure scheme): 2.44 (CH-6 0 ), 5.46 and 6.16 (CH CH, 7 0 and 8 0 ). The possible presence of neoxanthin is supported by the presence of a singlet at 6.04 ppm, related to a 13 C resonance at 103.3 ppm; 26 this is quite unusual for a single double bond carbon and more suitable for allenes C C CH. 27 Several weak signals in 6.7-6.0 ppm range might belong to carotenoids; they show additional TOCSY correlations, but remain unassigned to single specific compounds, see Table 2.…”

Composition of the essential oil from the leaves of tree domestic varieties and one wild variety of the guava plant (Psidium guajava L., Myrtaceae)

“…The leaves were observed to contain amino acids, triterpenes and steroids, acids, phenols, saponins and carotenes. Volatile acids [(E)-cinnamic acid and (Z)-3-hexenoic acid], fatty acids, and the essential oil were also encountered (Opute, 1978;Cuellar et al, 1984;Idstein et al, 1985;Mercadante et al, 1999).…”