Which of the following are classified as natural penicillins?

Natural penicillins are derived directly from the Penicillium fungi and have been used since the discovery of antibiotics. Penicillin G and Penicillin V fall under this classification.

Penicillin G is a narrow-spectrum antibiotic effective against many gram-positive bacteria and some gram-negative cocci. It is typically administered via injection because it is not stable in the acidic environment of the stomach. Penicillin V is similar to Penicillin G but can be taken orally due to its stability in acidic conditions, making it more convenient for outpatient treatment.

The other options include semi-synthetic penicillins or penicillins that have been developed to have different properties or spectra of activity. For example, Ampicillin and Amoxicillin, which are included in the first option, are aminopenicillins, designed to expand the spectrum of penicillin to include some gram-negative bacteria. Cloxacillin and Dicloxacillin fall under the category of penicillinase-resistant penicillins developed to combat bacteria that produce the enzyme penicillinase, making them resistant to degradation by certain bacterial enzymes. Lastly, Carbenicillin and Ticarcillin are extended-spectrum penicillins that target a broader range of gram-negative organisms, especially P