Guava is rich in tannins, phenols, triterpenes, flavonoids,
essential oils, saponins, carotenoids, lectins, vitamins, fiber and
fatty acids. Guava fruit is higher in vitamin C than citrus (80 mg
of vitamin C in 100 g of fruit) and contains appreciable amounts of
vitamin A as well. Guava fruits are also a good source of pectin -
a dietary fiber. The leaves of guava are rich in flavonoids, in
particular, quercetin. Much of guava's therapeutic activity is
attributed to these flavonoids. The flavonoids have demonstrated
antibacterial activity. Quercetin is thought to contribute to the
anti-diarrhea effect of guava; it is able to relax intestinal
smooth muscle and inhibit bowel contractions. In addition, other
flavonoids and triterpenes in guava leaves show antispasmodic
activity. Guava also has antioxidant properties which is attributed
to the polyphenols found in the leaves.
Guava's main plant chemicals include: alanine, alpha-humulene,
alpha-hydroxyursolic acid, alpha-linolenic acid, alpha-selinene,
amritoside, araban, arabinose, arabopyranosides, arjunolic acid,
aromadendrene, ascorbic acid, ascorbigen, asiatic acid, aspartic
acid, avicularin, benzaldehyde, butanal, carotenoids,
caryophyllene, catechol-tannins, crataegolic acid, D-galactose,
D-galacturonic acid, ellagic acid, ethyl octanoate, essential oils,
flavonoids, gallic acid, glutamic acid, goreishic acid, guafine,
guavacoumaric acid, guaijavarin, guajiverine, guajivolic acid,
guajavolide, guavenoic acid, guajavanoic acid, histidine, hyperin,
ilelatifol D, isoneriucoumaric acid, isoquercetin, jacoumaric acid,
lectins, leucocyanidins, limonene, linoleic acid, linolenic acid,
lysine, mecocyanin, myricetin, myristic acid, nerolidiol,
obtusinin, octanol, oleanolic acid, oleic acid, oxalic acid,
palmitic acid, palmitoleic acid, pectin, polyphenols, psidiolic
acid, quercetin, quercitrin, serine, sesquiguavene, tannins,
terpenes, and ursolic acid
